LABORATORY NOTES 
IN 
QUALITATIVE ANALYSIS 
AND 
MEDICAL CHEMISTRY. 
BY 
CHARLES PLATT, Ph. D., F. C. S. (Lond.) 
PROFESSOR OF CHEMISTRY AND TOXICOLOGY, HAHNEMANN MEDICAL COLLEGE AND HOSPITAL, 
PHILADELPHIA. 
JOHN JOS. McVEY. 
1895. Copyright, 1895, 
By JOHN JOS. McVEY. PREFACE. 
The writer, in designing this manual, aims to provide the 
student with an outline sketch of chemical tests which shall be 
of permanent and practical utility. AV ith this in view all ex- 
periments requiring expensive apparatus have been omitted, and 
those, only, given which would come naturally within the field 
of the average home or office laboratory. It is intended that the 
tests shall be criticised, compared, and elaborated, and that ad- 
ditions shall be made under the instructor's advice. By this 
means it is believed that each student, at the end of his laboratory 
course, will find himself provided with a handy book of reference, 
the more valuable because of his own part in its making. 
C. P. CONTENTS. 
PAGE 
PART I.-Qualitative Analysis. 
Table of Principal Elements 8 
Classification of the Metals 9 
Preliminary Tests for Metals 9 
Analytical Scheme for Metals 17 
Characteristic Tests for Acids 20 
Analytical Scheme for Metals and Acids ... 23 
Examination of Solids . 24 
Special Tests-Arsenic 25 
Antimony 26 
Mercury . . 27 
Phenol 27 
Chloroform 27 
Alcohol 28 
Glycerol 28 
Ether 28 
Special Tests for the Alkaloids 28 
Separation of Metals and Alkaloids from Organic 
Mixtures 34 
PART II.-The Carbohydrates 39 
The Proteids 45 
PART III.-Clinical. 
Milk, Composition 55 
Recognition of Constituents 55 
Clinical Analysis 56 
Urine, Composition 60 
Clinical Analysis 60 
Urinary Sediments 77 
Urinary Calculi 80 
Gastric Fluid, Composition 83 
Clinical Analysis 84 
Volumetric Analysis • 86 
APPENDIX. 
Weights and Measures 98 
List of Reagents . 100 
Index . io5 
V PART I. 
QUALITATIVE ANALYSIS. TABLE OF PRINCIPAL ELEMENTS. 
F. W. Clarke, 1895 (Cal. to 0 - 16). 
Atomic 
Atomic 
Symbols. 
Weights. 
Symbols. 
Weights. 
Aluminum, . 
. . Al, . . 
. 27 
Magnesium, . 
• • Mg, . . 
. 24.3 
Antimony, . 
. . Sb, . . 
. 120 
Manganese, . . 
. . Mn, . 
. 55 
Arsenic, . . 
. . As, . . 
. 75 
Mercury, . . . 
• • Hg, . . 
. 200 
Barium, . . 
• 
. . Ba, . . 
. 137.43 
Molybdenum, 
. . Mo, . . 
. 96 
Bismuth, . . 
. . Bi, . . 
. 208 
Nickel, .... 
. . Ni, . . 
. 58.7 
Boron, . . . 
. . B, . • 
. 11 
Nitrogen, . ■ . 
. . N, . . 
. 14.03 
Bromine, . . 
. . Br, . . 
. 79.95 
Oxygen, . . . 
. . o, . . 
. 16 
Cadmium, . 
. . Cd, . . 
. 112 
Phosphorus, . 
. . p, . . 
. 31 
Calcium, . . 
. 40 
Platinum, . . 
. . Pt,. . 
. 195 
Carbon, . . . 
. . C,.. . 
. 12 
Potassium, . . 
. . K, . . 
. 39.11 
Chlorine, . . 
. . Cl, . . 
. 35.45 
Silicon, .... 
. . Si, . . 
. 28.4 
Chromium, . 
. . Cr, . . 
. 52.1 
Silver, .... 
• ■ Ag, . . 
. 107.92 
Cobalt, . . . 
. 59.5 
Sodium, . . . 
. . Na, . . 
. 23.05 
Copper, . . . 
. 63.6 
Strontium, . . 
. Sr, . . 
. 87.66 
Fluorine, . . 
. . F, . . 
. 19 
Sulphur, . . . 
. . S, . . . 
. 32.06 
Gold, .... 
197.3 
Tin, . . . 
. . Sn, . . 
. 119 
Hydrogen, . 
. . H, . . 
. 1.008 
Titanium, . . 
. . Ti, . . 
. 48 
Iodine, . . . 
. . I, . . . 
. 126.85 
Tungsten, . . 
. . W, . . 
. 184.9 
Iron,.... 
Fe, . . 
. 56 
Uranium, . . . 
• • u, . . 
. 239.6 
Lead, .... 
. . Pb, . . 
. 206.95 
Vanadium, . . 
. .V, . . 
. 51.4 
Lithium, . . 
. . Li, . . 
. 7.02 
Zinc, 
. . Zn, . . 
. 65.3 THE METALS. 
CLASSIFICATION FOR PURPOSES OF ANALYSIS. 
The metals are commonly divided into five groups, according 
to their behavior with certain general, or group reagents; as follows: 
Group I.-Metals forming chlorides insoluble in water, and con- 
sequently precipitated from solutions of their salts by Hydro- 
chloric Acid. Lead, Silver, Mercury (Mercurous). 
Group II.-Metals forming sulphides insoluble in water and in 
dilute acids, precipitated from solutions of their salts by Sulphu- 
retted Hydrogen. 
(a) The sulphides are soluble in Ammonium Sulphide and in 
Sodium or Potassium Hydroxides. Arsenic, Antimony, Tin. 
(&) The sulphides are insoluble in Ammonium Sulphide and in 
Sodium or Potassium Hydroxides. Mercury (Mercuric), Lead, 
Bismuth, Copper, Cadmium. 
Group III.-Metals forming sulphides and hydroxides, which are 
decomposed by acids, but which are insoluble in water, precipi- 
tated from neutral solutions by Ammonium Sulphide. Tron, 
Manganese, Aluminum, Chromium, Cobalt, Nickel, Zinc. 
Group IV.-Metals forming sulphides soluble in water or de- 
composed by dilute acids, but whose carbonates are insoluble, pre- 
cipitated from solutions of their salts by Ammonium Carbonate. 
Barium, Strontium, Calcium, Magnesium. 
Group V.-Metals forming chlorides, sulphides, and carbonates 
soluble in water, and not precipitated by the preceding group 
reagents. Potassium, Sodium, Lithium. (Ammonium, NH4, is also, 
commonly included in this group.) 
PRELIMINARY TESTS. 
Group V. The ' 'Alkali Metals. ' ' 
Potassium, K., Sodium, Na., Lithium, Li., Ammonium, NH4. 
Potassium. 
(Use KC1, Solution or Solid.) 
1.-Test on clean platinum wire, in Bunsen flame, observe the 
9 10 
QUALITATIVE ANALYSIS. 
violet color developed. In presence of sodium compounds the 
yellow rays produced thereby may be excluded by use of blue 
glass. 
2. -PtCl4 precipitates from solutions of potassium salts, yellow 
crystalline, potassium platinic chloride, K2PtClG. 
3. -H2C4H4O6 precipitates from concentrated alkaline solutions 
of potassium salts, white, crystalline, acid potassium tartrate, 
KHC4H4O6. 
Sodium. 
(Use NaCl, Solution or Solid.) 
1. -Test on platinum wire, in Bunsen flame, observe the bright 
yellow color developed. 
2. -Potassium pyroantimoniate, H2K2Sb2O7, precipitates from 
concentrated solutions of sodium salts, a white, crystalline, sodium 
pyroantimoniate, H2Na2Sb2O7. 
Lithium. 
(Use LiCl, Solution.) 
1. -Na2HPO4 precipitates from hot solutions of lithium salts, 
lithium phosphate, Li3PO4. 
2. -Lithium compounds color the non-luminous flame crimson, 
or carmine red. 
Ammonium. 
(Use NH4OH and (NH4)2SO4.) 
1. -Note the odor of NH40H. 
2. -Note the action of the fumes on red litmus paper. 
3. -Upon one watch glass place a drop of NH4OH, upon another 
a drop of HC1. Observe the white fumes of NH4C1 produced 
when the glasses are brought together. 
4. -Test a solution of (NH4)2SO4. Note that no odor is given 
off. Add a few drops of NaOH (SoL) and heat. Note the char- 
acteristic odor of ammonia. 
5. -PtCl4, and H2C4H4O6 produce precipitates with ammonium 
salts resembling those produced from solutions of potassium com- 
pounds. 
For the separation of the members of this group, see p. 19. PRELIMINARY TESTS. 
11 
Group IV. Metals of the "Alkaline Earths." 
Barium, Ba., Strontium, Sr., Calcium, Ca., Magnesium, Mg. 
Barium. 
(Use BaCl2, Solution.) 
1. -(NH4)2CO3 precipitates white barium carbonate, BaCO3: 
BaCl2 + (NH4)2CO3 = BaCO3 + 2 NH4C1. 
2. -H2SO4 (dil.) precipitates white barium sulphate, BaSO4: 
BaCl2 + H2SO4 = BaSO4 + 2 HC1. 
3. -Na2HPO4 precipitates white barium phosphate, BaHPO4. 
4. -K2CrO4 precipitates yellow barium chromate, BaCrO4. 
5. -Barium compounds impart a green color to the flame. 
Strontium. 
(Use Sr(NOs)2, Solution.) 
1. -(NH4)2CO3 precipitates white strontium carbonate, SrCO3. 
2. -H2SO4 (dil.) precipitates white strontium sulphate, SrSO4. 
3. -K2CrO4 precipitates from alkaline solutions yellow stron- 
tium chromate, SrCrO4, soluble in HC2H3O2. 
4. -Strontium compounds impart an intense red or crimson 
color to the flame. 
Calcium. 
(Use CaCl2, Solution.) 
1. -(NH4)2CO3 precipitates white calcium carbonate, CaCO3. 
2. -H2SO4 precipitates white calcium sulphate, CaSO4, soluble 
in an excess of water. 
3. -Na2HPO4 precipitates white calcium phosphate, CaHPO4, 
soluble in HC2H3O2. 
4. -(NH4)2C2O4 precipitates white calcium oxalate, CaC2O4, 
soluble in HC1, insoluble in HC2H3O2. 
5. -Calcium compounds impart a yellowish red color to the 
flame. 
Magnesium. 
(Use MgCl2 Solution.) 
1.-(NH4)2CO3 precipitates white magnesium carbonate, 
MgCO3. 12 
Q UA LI TA T1VE A AA L YSIS. 
2. -Add NH4C1, then (NH4)2CO3. Note that now no precip- 
itate is formed. MgCO3 is soluble in NH4C1. 
3. -To the solution from the last test, add Na2HPO4. Note 
that a white precipitate of MgNH4PO4 is formed. This precipi- 
tate is aided by the addition of NH4OH and by agitation. 
For the separation of members of this group, see p. 19. 
Group III. 
Aluminum, AL, Chromium, Cr., Iron, Fe., Nickel, Ni., Cobalt, Co., Manganese, 
Mn., Zinc, Zn. 
Aluminum. 
(Use Solution of Potash Alum, or of A12C16.) 
1. -NH4OH precipitates white aluminum hydroxide, Al 2 (OH) 6. 
2. -NaOH precipitates white aluminum hydroxide, A12(OH)6. 
Soluble in excess of the reagent. 
3. -(NH4)2S precipitates white aluminum hydroxide, Al2- 
(OH)6: 
A12C16 -p3(NH4)2S + 6 H2O = A12(OH)6 + 6 NH4C1 + 3 H2S. 
4. -(NH4)2CO3 precipitates white aluminum hydroxide, 
A12(OH)6: 
A12C16 + 3(NH4)2CO3 + 3H2O = A12OH6 + 6NH4C1-|-3CO2. 
Chromium. 
(Use Cr2Cl6 Solution.) 
1. -NH4OH precipitates light green chromium hydroxide, 
Cr2(OH)6. 
2. -NaOH precipitates light green chromium hydroxide, 
Cr2(OH)6. Soluble in excess but precipitated again on boiling. 
3. -(NH4)2S precipitates light green chromium hydroxide, 
Cr2(OH)6. ' 
4. -Fused with a mixture of KNO3 and Na2CO3 on platinum 
foil, yellow sodium and potassium chromates are formed, soluble 
in water. 
5. -Acidify the solution obtained in the last test, with HC2- 
H3O2 and then add Pb(C2H3O2)2 (Sol.)-a yellow precipitate of 
lead chromate, PbCrO4 is formed. PRELIMINARY TESTS. 
13 
Iron. 
Ferrous Compounds. (Use FeSO4 Solution..) 
1. -NaOH or NH4OH precipitates white, or greenish white, 
Fe(OH)2, turning brown on exposure to the air. 
2. -(NH4)2S precipitates black ferrous sulphide, FeS. 
3. -K4Fe(CN)6 precipitates bluish white potassium ferrous 
ferrocyanide, K2Fe2(CN)6. 
4. -K3Fe(CN)6 precipitates dark blue ferrous ferricyanide, 
Fe5(CN)12, known as Turnbull's blue. 
5. -K(CN)S gives no reaction. 
Ferric Compounds. (Use Fe2Cl6 Solution.) 
1. -NaOH or NH4OH precipitates reddish brown ferric hydrox- 
ide, Fe2(OH)6. 
2. -(NH4)2S precipitates black ferrous sulphide, FeS. 
3. -K4Fe(CN)6 precipitates ferric ferrocyanide, Fe7(CN)18, 
known as Prussian Blue. 
4. -K3Fe(CN)6 produces no precipitate but imparts a green or 
brown color to the solution. 
5. -K(CN)S produces a blood red color due to the formation of 
ferric sulphocyanate, Fe2(CNS)6. The color is destroyed by ad- 
dition of HgCl2. 
Manganese. 
(Use MnSO4 Solution.) 
1. -NaOH or NH4OH precipitates whitish manganous hydrox- 
ide Mn(OH)2, turning brown and oxidizing, on exposure to the 
air, to Mn2(OH)6. 
2. -(NH4)2S precipitates flesh colored manganous sulphide, 
MnS. 
3. -Fused with a mixture of KNO3 and Na2CO3 on platinum 
foil, green potassium and sodium manganates are formed. 
Zinc. 
(Use ZnSO4, or ZnCl2, Solution.) 
1.-NaOH added carefully precipitates white zinc hydroxide, 
Zn(OH)2 easily soluble in excess: 
ZnCl2 4-2 NaOH = Zn(OH)2 + 2 NaCl. ' 
Zn(OH)2 +2 NaOH = Na2ZnO2 + 2 H2O. 14 
QUALITATIVE ANALYSIS. 
2. -NH4OH precipitates white Zn(OH)2 soluble in excess. 
3. -(NH4)2S precipitates white zinc sulphide, ZnS. 
Nickel and Cobalt. 
(Omitted because of relative medicinal unimportance.) 
For the separation of members of this group, see p. 18. 
Group II. 
Arsenic, As., Antimony, Sb., Tin, Sn., Mercury (Mercuric) Hg., Bismuth, Bi., 
Lead, Pb., Copper, Cu., Cadmium, Cd. 
Arsenic. 
Arsenous Compounds. (Use As2O3, Solution in water.) 
1. -H2S gas precipitates yellow arsenous sulphide, As2S3. In- 
soluble in boiling HC1, soluble in alkalies, and in alkaline sul- 
phides and carbonates. 
2. -Ammonio silver nitrate precipitates yellow silver arsenite, 
Ag3AsO3. Soluble in excess of NH4OH. 
3. -Ammonio cupric sulphate precipates green copper arsenite, 
CuHAsO3. Soluble in excess of NH4OH. 
Arsenic Compounds. (Use NaII2AsO4 in Solution.) 
1. -H2S gas precipitates, slowly, arsenous sulphide, As2S3, 
mixed with sulphur. 
2. -Ammonio silver nitrate precipitates brown silver arsenate, 
Ag3AsO4. Soluble in excess of NH4OH. 
3. -Ammonio cupric sulphate precipitates bluish green copper 
arsenate, CuHAsO4. 
For Special Tests for Arsenic, see p. 25. 
Antimony. 
(Use Tartar Emetic in Solution.) 
1. -Acidify with HC1 and pass H2S gas, an orange precipitate 
of Sb2S3 is formed. Soluble in alkaline sulphides but insoluble 
in alkaline carbonates. 
2. -NaOH and NH4OH precipitate antimonous hydroxide, 
Sb(OH)3. Soluble in excess of the reagent. 
3. -In the absence of tartaric or citric acids, e. g., in solutions 
of the chloride, SbCl3, an excess of water produces a precipitate 
of a basic salt, the oxychloride, SbOCl, or "Powder of Algaroth." 
For Special Tests for Antimony, see p. 26. PRELIMINARY TESTS. 
15 
Mercury (ic). 
(Use HgCl2 Solution.) 
1. -H2S gas precipitates black mercuric sulphide, HgS, in- 
soluble in HNO3, HC1, or (NH4)2S. 
2. -NaOH precipitates yellow mercuric oxide, HgO. 
3. -SnCl2 precipitates white mercurous chloride, Hg2Cl2. 
2 HgCl2 + SnCl2 =Hg2Cl2 + SnCl4. 
An excess of the reagent precipitates gray metallic mercury. 
HgCl2 + SnCl2 = Hg + SnCl4. 
4. -KI precipitates yellow to scarlet mercuric iodide, Hgl2. 
For Special Tests for Mercury, see p. 27. 
Bismuth. 
(Use Bi(NO3)3 Solution.) 
1. -H2S gas precipitates black bismuth sulphide, Bi2S3. 
Soluble in boiling HNO3, but insoluble in alkalies and alkaline 
sulphides. 
2. -NaOH and NH4OH precipitate white bismuth hydroxide, 
Bi(OH)3. 
3. -KI precipitates brown bismuth iodide, Bil3, soluble in ex- 
cess of the reagent. 
4. -H2O in excess precipitates basic salts of bismuth, bismuth 
subnitrate, BiONO3. 
Copper. 
(Use CuSO4 Solution.) 
1. -H2S gas precipitates black cupric sulphide, CuS, soluble in 
hot HNO3, practically insoluble in alkalies and in alkaline sul- 
phides. 
2. -NH4OH precipitates bluish cupric hydroxide, Cu(OH)2, 
soluble in excess, forming a dark blue solution. 
3. -NaOH precipitates blue cupric hydroxide, Cu(OH)2, in- 
soluble in excess, turning black on boiling. 
4. -K4Fe(CN)6 precipitates reddish brown cupric ferrocyanide, 
Cu2Fe(CN)6. 
Lead, (see Group I.) 
Tin and Cadmium. 
(Omitted because of relative medicinal unimportance.) 
For the separation of the members of this group, see p. 17. 16 
QUALITATIVE ANALYSIS. 
Group I. 
Lead, Pb., Silver, Ag., Mercury (Mercurous), Hg2. 
Lead. 
(Use Pb(NO3)2 Solution.) 
1. -HC1 precipitates white crystalline lead chloride, PbCl2 
soluble in hot water. 
2. -NaCl precipitates white crystalline lead chloride, PbCl2, 
soluble in hot water. 
3. -H2SO4 (dil.) precipitates white lead sulphate, PbSO4. 
4. -K2CrO4 precipitates yellow lead chromate, PbCrO4, soluble 
in fixed alkalies. 
5. -NH4OH precipitates white basic lead hydroxide. 
6. -H2S precipitates black lead sulphide, PbS, insoluble in 
alkalies and alkaline sulphides, but soluble in hot HNO3. 
7. -KI precipitates yellow lead iodide, Pbl2, soluble in hot 
water. 
Silver. 
(Use AgNO3, Solution.) 
1. -HC1 precipitates white silver chloride, AgCl, soluble in 
NH40H, insoluble in HNO3. 
2. -NaCl produces the same precipitate as does HC1. 
3. -H2SO4 produces no precipitate. 
4. -K2CrO4 precipitates reddish yellow silver chromate, Ag2- 
CrO4. 
5. -H2S precipitates black silver sulphide, Ag2S. 
Mercury(ous). 
(Use Hg2(NO3)2 Solution.) 
1. -HC1 precipitates white mercurous chloride, Hg2Cl2 which 
turns black on the addition of NH40H, mercurous ammonium 
chloride, NH2Hg2Cl being formed. 
2. -H2SO4 produces no precipitate. 
3. -K2CrO4 precipitates orange mercurous chromate, Hg2CrO4. 
4. -KI precipitates green mercurous iodide, Hg2I2. 
5. -H2S precipitates black mercuric sulphide, HgS, mixed with 
Hg. 
For the separation of the members of this group, see p. 17. ANALYTICAL SCHEME FOR METALS. 
17 
ANALYTICAL SCHEME FOR METALS. 
Group I. 
To the solution, add HC1, drop by drop, until there is no further 
precipitate. Filter, and wash the precipitate with cold water. 
(Reserve the filtrate for Group II.). Perforate the filter paper, 
wash the precipitate into a test tube and heat to boiling with water. 
Filter rapidly while the liquid is still hot. 
The Filtrate contains PbCl2. 
Test for lead with H2SO4 and 
with K2CrO4. Pb. 
The Residue contains AgCl and Hg2Cl2 
Perforate the filter paper, wash the residue intc 
a test tube, add NH4OH, warm and filter. 
A Black Resi- 
due = NH2Hg2Cl. 
Hg. 
The Filtrate contains 
(NHs)s(AgCl)2. Boil off the 
excess of NH4OH, add a lit- 
tle HNO3 to acidify the so- 
lution. 
A white precipitate = 
AgCl. Ag, 
Group II. 
Pass H2S gas through the slightly acid filtrate from Group I., 
as long as a precipitate is formed. Filter and wash the precipi- 
tate. (Reserve the filtrate for Group III.). Perforate the filter 
paper, wash the precipitate into a test tube, add (NH4)2S, warm 
gently, filter, and wash. 
A. The precipitate contains Hg, Pb, Bi, Cu. 
B. The filtrate contains As, Sb. 
A. Perforate the filter paper, wash the precipitate into a beaker, 
add strong HNO3, boil for several minutes, and filter. 
The Filtrate contains Pb, Bi, Cu. Boil 
off the excess of acid, add a little water, 
and then a few drops of dilute II2SO4. 
A precipitate = PbSO4. Pb. 
Filter, and add NH4OH to the filtrate. 
If there be a precipitate, filter and apply 
tests for bismuth, Bi. If the NH4OH does not give a precipitate, but forms a 
dark blue solution, then copper is present. Cu. 
A Black Residue = HgS. Ilg. 
Transfer the residue to a porce- 
lain dish, dissolve in HC14-HNO3. 
Boil off the excess of acid, dilute 
with a little water and test for 
Mercury with SnCl2 or KI. 18 
QUALITATIVE ANALYSIS. 
B. The Filtrate containing As and Sb. 
To this solution add HNO3. The sulphides, if present, are re- 
precipitated. Filter, and wash the precipitate. Perforate the 
filter paper and wash the precipitate into a large test tube. Add 
some fragments of solid (NH4-)2CO3 and warm for several min- 
utes. Filter and wash. 
The Residue contains Sb2S3. Dissolve 
in hot HC1, dilute with water, warm, 
and pass H2S gas. An orange red pre- 
cipitate = Sb2S3. Sb. 
Apply Special Tests to the original 
solution. 
Acidify the Filtrate with HNO3. 
A bright yellow precipitate = As2S3. 
As. 
Apply Special Tests to the original 
solution. 
Group III. (Phosphates, Oxalates, etc., being absent.) 
Boil the filtrate from Group II., until all the H2S is expelled, 
add a few drops of HNO3, and boil again. Then add NH4C1, 
and NH4OH (excess). If there be a precipitate, filter, and wash. 
(Reserve the filtrate.) Perforate the filter paper, wash the pre- 
cipitate into a test tube, add NaOH and boil for several minutes. 
Filter and wash. 
The Precipitate contains, Fe2(OH)6 
and Cr2(OH)6. Test a portion for 
Chromium, Cr., by Tests 4 and 5 
(p. 12). Dissolve the remainder of the 
precipitate in dilute HC1 and test for 
iron, Fe with KCNS. 
Fe. 
The Filtrate contains K2A12O4. Acid- 
ify slightly with HC1, then add (NH4)2- 
COS. A precipitate = A12(OH)6 or- 
Add an excess of NH4C1 to the alka- 
line filtrate, and heat slowly to boiling. 
A precipitate = Al2( OH )6. 
Al. 
To the filtrate (reserved above) from the ammonia precipitation, 
add (NH4)2S. Warm and filter. (Reserve the filtrate for Group 
IV.) Treat the precipitate with cold dilute HC1, filter and boil 
the filtrate. Cool, and add a large excess of NaOH. Filter. 
The Residue = Mn(OH)2. Dissolve 
in HC1, and test according to p. 13. 
Mn. 
To the Filtrate add (NH4)2S. A white 
precipitate = ZnS. 
Zn. 
Group III. (Phosphates, etc., present.) 
To the filtrate from Group II., add NH4C1, NH4OH, and 
(NH4)2S. Filter and reserve the filtrate for Group IV. Wash ANALYTICAL SCHEME FOR METALS. 
19 
the precipitate and dissolve it in cold dilute HC1. Boil, to expel 
the H2S, and filter if necessary. Add a few drops of HN03 and 
boil again. Test a small portion of the solution with KCNS for 
iron, Fe. To the remainder of the solution add Fe2Cl6 drop by 
drop, until all is precipitated, concentrate, neutralize with K2CO3, 
and add an excess of BaCO3. Filter. 
Boil the Precipitate with NaOH for 
several minutes. 
To the Filtrate add HC1, and boil to 
expel CO2. Add (NH4)2S and NH4OH. 
Filter, dissolve the precipitate in HC1, 
add excess of NaOH. Test the precip- 
itate for Manganese, Mil., and the fil- 
trate for Zinc, Zn. 
Test the Solution 
for aluminum. 
Al. 
Test the Precipi- 
tate for Chromium. 
Cr. 
To the filtrate from Group III., add HC1, boil, and filter. To 
the filtrate add NH40H and (NH4)2CO8. Filter. Test the fil- 
trate for magnesium Mg., with Na2HPO4, see p. 12). Dissolve 
the precipitate in a small amount of HC1, evaporate the solution 
to dryness, and treat the residue with absolute alcohol. 
Group IV. 
Residue = BaCl2, 
dissolve in water, 
and test for barium, 
Ba. 
Evaporate the Solution, to expel the alcohol, and con- 
vert the chlorides to nitrates by repeated evaporations with 
HNO3. Evaporate finally to dryness, and treat the resi- 
due with absolute alcohol. 
Residue = Sr(NO3)2. Dis- 
solve in water and test for 
strontium. Sr. 
Solution contains Ca- 
(NO3)2. Test for Calcium, 
Ca. See p. 11. 
Test the original solution for Ammonium, NH4. (See p. 10.) 
For Potassium, Sodium, and Lithium, use the flame tests with 
the original solution, or, evaporate the solution containing only 
members of this group, and heat strongly. Dissolve the residue 
in a little water, add a few drops of HC1, filter if necessary, and 
add an excess of PtCl4. A precipitate = K2PtCl6, K. Add a 
little water, filter and test the filtrate for sodium by the flame test, 
and with potassium pyroantimoniate. A precipitate = H2Na2- 
Sb2O7, Na. Test another portion of the filtrate for lithium by 
the flame test, and with sodium phosphate. A precipitate = Li 3- 
PO4, Li. 
Group V. 20 
QUALITATIVE ANALYSIS. 
CHARACTERISTIC TESTS FOR COMMON ACIDS. 
Hydrochloric Acid, HC1, and Chlorides. 
1. -AgNO3 precipitates curdy white silver chloride, AgCl, solu- 
ble in NH4OH, insoluble in HNO3. 
2. -Hg2(NO3)2 precipitates white mercurous chloride, Hg2Cl2. 
3. -Pb(C2H3O2)2 precipitates white crystalline lead chloride, 
PbCl2. 
4. -H2SO4 and MnO2 warmed with the solution, liberate 
chlorine gas. 
5. -Apply Test 3 under Ammonium (Metals, Group V.). 
Sulphuric Acid, H2SO4, and Sulphates. 
1. -BaCl2 precipitates white barium sulphate, BaSO4, insoluble 
in HC1. 
2. -Pb(C2H3O2)2 precipitates white lead sulphate, PbSO4, 
soluble only in hot concentrated acids. 
Nitric Acid, HNO3, and Nitrates. 
1. -Boiled with copper filings red fumes are produced, the 
liquid turning green. If the nitric acid be present in combination, 
add H2SO4 to decompose the nitrates. 
2. -Add to the solution in a test tube an equal bulk of H2SO4. 
Cool the mixture and float over it a solution of FeSO4. At the 
contact of the two liquids a brown ring will develop. 
3. -A small quantity of the fluid added to a solution of brucia 
in concentrated H2SO4, develops a fine red color. (Chloric acid 
gives the same reaction.) 
4. -Nitrates and nitric acid are reduced by a mixture of zinc 
and H2SO4, NH3 being formed. 
Acetic Acid, HC2H3O2, and Acetates. 
1. -Note the characteristic odor of the acid. 
2. -Add Fe2Cl6 then NH4OH to neutralization, the liquid 
acquires a dark red color. The same is given in solutions of the 
neutral acetates without the addition of NH4OH. 
3. -Warm the solution with a few drops of H2SO4 and the 
same of C2H5OH. The characteristic odor of ethyl acetate, 
C2H.5(C2H3O2) is developed. CHARACTERISTIC TESTS FOR ACIDS. 
21 
Oxalic Acid, H2C2O4, and Oxalates. 
1. -CaCl2 with NH4OH precipitates white calcium oxalate, 
CaC2O4, soluble in HC1, insoluble in HC2H3O2. 
2. -AgNO3 precipitates white silver oxalate, Ag2C2O4, soluble 
in hot concentrated HNO3, and in NH4OH. 
Tartaric Acid, H2C4H4O6, and Tartrates. 
1. -CaCl2 precipitates white calcium tartrate, CaC4H4O6.4H2O, 
soluble in HC2H3O2. Soluble also in NaOH, from which solu- 
tion it is reprecipitated on boiling. 
2. -From solutions of normal tartrates, AgNO3 precipitates 
white silver tartrate, Ag2C4H4O6, which blackens on boiling. 
3. -Heated on platinum foil, tartaric acid, or tartrates, fuse, 
carbonize, and give off the characteristic odor of burnt sugar. 
Citric Acid, H3(C6H5O7), and Citrates. 
1. -CaCl2 precipitates white calcium citrate, Ca3(C6H5O7)2, 
insoluble in NaOH. The precipitate is most easily obtained from 
the hot solution. Calcium citrate is soluble in HC2H3O2. (Dis- 
tinction from oxalates.) 
2. -Ca(OH)2 in excess precipitates, from the boiling solution 
only, white calcium citrate, Ca3(C6H5O7)2. 
3. -Heated on platinum foil, citric acid fuses, carbonizes, and 
gives off pungent acid fumes. 
Phosphoric Acid, H3PO4, and Orthophosphates. 
1. -Fe2Cl6 with NaC2H3O2 precipitates yellowish-white ferric 
phosphate, Fe2(PO4)2. 
2. -CaCl2 with NH4OH precipitates white calcium hydrogen 
phosphate, CaHPO4, soluble in HC2H3O2. 
3. -AgNO, precipitates yellow silver phosphate, Ag,P04, sol- 
uble in HNO3 and in NH4OH. 
4. -Ammonium molybdate (NH4)2MoO4 precipitates yellow 
ammonium phosphomolybdate, (NH4)3PO4(MoO3)402H2O. 
5. -"Magnesia Mixture" precipitates white magnesium am- 
monium phosphate, Mg(NH4)PO4. 
Hypophosphites: 1.-On ignition inflammable PH3 is given off. 2.-AgNO3 
precipitates white silver hypophosphite, turning black on exposure. 
Pyrophosphates: 1.-AgNOs precipitates white silver pyrophosphate. 2.- 22 
Q UALITA T1VE ANAL YS1S. 
MgSO4 precipitates magnesium pyrophosphate, soluble in excess of the reagent. 
3.-(NH4)2MoO4 reacts very slowly, or not at all. 
Metaphosphates: 1.-AgNO3 precipitates white silver metaphosphate. 2.- 
(NH4)2MoO4 causes no precipitate. 3.-Albumen forms a white precipitate. 
Chromic Acid, H2CrO4, and Chromates. 
See p. 12. Chromium. 
Permanganic Acid, H2Mn2O8, and Permanganates. 
See p. 13. Manganese. 
Hydrocyanic Acid, HCN, and Cyanides. 
1. -Note the characteristic odor. 
2. -AgNO3 precipites white silver cyanide, AgCN, soluble in 
KCN, slightly soluble in NH4OH, and in boiling HNO3, but in- 
soluble in cold dilute HNO3. To obtain the reaction with 
cyanides, such as KCN, add first a little HNO3 to decompose the 
cyanide and then add the AgNO3. The precipitate is distin- 
guished from AgCl by its sparing solubility in NH4OH, and by 
the odor of HCN developed on warming with HC1. 
3. -Evaporate to dryness at a low temperature with NH4HS. 
Dissolve the residue in water and add Fe2Cl6. The solution turns 
blood red in color. 
Hydroiodic Acid, HI, and Iodides. 
1. -AgNO3 precipitates yellow silver iodide, Agl, insoluble in 
HNO3 or in NH4OH. 
2. -Hg2(NO3)2 precipitates green mercurous iodide, Hg2I2. 
3. -HgCl2 precipitates red mercuric iodide, Hgl2. 
4. -Add a few' drops of "Chlorine water," and then a little 
starch paste. A blue color is developed which disappears when 
the solution is heated, but reappears when the solution is cooled. 
For free iodine the same test is used w'ithout the addition of 
4 ' Chlorine w'ater. ' ' 
Hydrobromic Acid, HBr, and Bromides. 
1. -AgNO3 precipitates yellowish-white silver bromide, AgBr, 
insoluble in HNO3, slightly soluble in NH4OH. 
2. -Hg2(NO3)2 precipitates yellowish mercurous bromide, 
Hg2Br2. CHARACTERISTIC TESTS FOR ACIDS. 
23 
3. -Add a little carbon disulphide, CS2, and then a few drops 
of chlorine water. Mix well by shaking. The CS2 acquires a 
reddish-yellow tint. (With iodides by the same test, the CS2 is 
colored violet-red.) 
4. -With starch paste and chlorine water a yellow color is 
developed. 
Carbonic Acid, H2CO3, and Carbonates. 
1. -Acids, such as HC1, produce an effervescence of CO2 gas. 
2. -Ca(OH)2 and Ba(OH)2 precipitate white CaCO3, and 
BaCO3, soluble in acids with effervescence. 
ANALYTICAL SCHEME FOR METALS AND ACIDS. 
1. -Evaporate some of the solution to dryness. Note the char- 
acter of the residue. (Presence or absence of organic compounds, 
etc.). Cool, add a few drops of H2SO4, and warm again. Note 
any effervescence (carbonates), peculiar odors, or fumes (sul- 
phides, sulphites, iodides, bromides), or characteristic acid fumes, 
(HC1, HNO3, etc.). See Preliminary Examination of Solids. 
2. -Examine the solution for metals, according to the Analy- 
tical Scheme, p. 17. 
3. -Test the original solution for HC1, HNO3 and H2CO3. 
4. -If arsenic or antimony be present, precipitate with II2S gas. 
In absence of arsenic and antimony, or after their removal, (boil 
off the H2S gas), add concentrated Na2CO3 solution and boil. 
Filter off the precipitate, if any, add a little HNO3 and boil again 
to drive off the CO2. Test the solution for H2SO4, H2C2O4, 
H3PO4, HI, HBr, HCN, etc. 
If H2SO4 or sulphates are present, these must be removed be- 
fore testing for oxalic or phosphoric acids. The following scheme 
of separation may be used: To the neutral solution add BaCl2 
and CaCl2. Filter and digest the precipitate with dilute HC1 
(a residue = BaSO4), filter, add NH4OH to an alkaline reaction, 
then add HC2H3O2 to an acid reaction. (A residue = CaC2O4, 
shows presence of oxalic acid). Filter and add NH40H to an 
alkaline reaction. (A precipitate = CaHPO4, shows presence of 
phosphoric acid). 
The tests obtained in this solution are to be confirmed by tests 
with the original solution. 24 
QUALITATIVE ANALYSIS. 
To complete the examination of an unknown liquid, preceding 
tests being negative, apply the special tests given on pages 25-28. 
Finally, test for the common alkaloids, p. 28. 
EXAMINATION OF SOLIDS. 
Preliminary Examination. 
1. -Heat some of the substance on a loop of platinum wire, in 
a flame. The flame is colored yellow, by sodium compounds; 
crimson, by strontium; violet, by potassium; yellowish-red, by cal- 
cium; green, by barium and copper; blue, by arsenic and anti- 
mony; carmine-red, by lithium. 
2. -Heat some of the substance on a piece of platinum foil, or 
in a small tube. If combustible, we have, probably, organic com- 
pounds, or C, S, P; if volatile, ammonia (note odor), Hg, As, etc., 
or volatile salts; if fusible, salts of alkalies, certain metallic salts, 
etc.; if water vapor be evolved, a crystalline salt containing water of 
crystallization, hydroxides, etc. 
3. -Add a little powdered charcoal to the substance, and heat on 
platinum foil. If the substance deflagrates, we have probably, 
nitrates, chlorates, iodates, etc. 
Preparation of the Solution for Analysis. 
Reduce the substance to a fine powder and dissolve in boiling 
water, if possible. If all does not go into solution, add a little 
HC1, and boil again. If some still remains undissolved, try a 
fresh portion of the powder with HNO3, and, finally, dissolve any 
remaining residue in a mixture of HNO3 (1 pt.) and HC1 (3 pts.) 
If strong acids be required for the solution, it is best to evaporate 
to dryness and to redissolve in water before proceeding with the 
analysis. 
In treating with the acids, note any peculiar appearances. For 
example, a sudden effervescence on adding HC1, would indicate 
the probable presence of carbonic acid, and therefore the salt is 
probably a carbonate. An odor of HNO3 would indicate, nitrates, 
or the odor of H2S, sulphides, etc. 
A residue insoluble in acids may be due to the presence of one 
of the following substances: Silica (sand), silicates (glass, etc.), 
BaSO4, SrSO4, PbSO4, AgCl, AgBr, Agl, etc. In such a case try 
the action of an alkali on a small portion of the powder, and then SPECIAL TESTS. 
25 
fuse the dry powder with Na2CO3, or with a mixture of Na2CO3 
and KNO3. The fused mass will now be soluble in acidified 
water. Carbon, sulphur, etc., insoluble in acids, will be recog- 
nized by their characteristic appearances in the preliminary tests. 
CS2 is the most convenient solvent for sulphur, and may be used 
to separate it from other substances insoluble in that reagent. 
Treat the solution obtained according to the general scheme for 
analysis. 
SPECIAL TESTS. 
Arsenic. 
1. -Marsh's Test.-The apparatus consists of a flask provided 
with a safety tube, for the introduction of the solution, and a de- 
livery tube for the exit of the gases evolved. The latter pass into 
a wide tube containing calcium chloride, and thence into a long 
tube of smaller bore, contracted at intervals and drawn to a fine 
point at the end. Zinc, water, and sulphuric acid are brought 
together in the flask, and the solution under analysis added. 
Hydrogen gas, and, in presence of arsenical compounds, arsenetted 
hydrogen gas are produced. The inflammable gas issuing at the 
end of the tube, in presence of arsenetted hydrogen burns with a 
bluish-white flame, and gives off white fumes which may be col- 
lected and examined microscopically for crystals of As2O3. If a 
cold surface, such as a piece of porcelain, be held in the flame, 
metallic arsenic is deposited in a brilliant steel gray to brown 
mirror. By heating the long tube near one of its contractions a 
fine mirror of arsenic is deposited on the glass just in advance of 
the flame. If the gas be passed into a solution of silver nitrate, 
metallic silver is deposited in black flakes. After filtering, the 
clear solution may be examined for As2O3. Antimony gives 
somewhat similar tests, but may easily be distinguished. (See 
under Antimony.) Organic matter must be absent and the 
reagents used must be absolutely pure. 
2. -Fleitmann's Test.-This is similar to the Marsh's Test, de- 
pending upon the production of arsenetted hydrogen by the action 
of nascent hydrogen on a reducible arsenical compound. Potas- 
sium hydroxide is used in place of the sulphuric acid, and the test 
is commonly made in a test tube. A paper moistened with silver 
nitrate is held at the mouth of the tube; the mixture is boiled, 26 
QUALITATIVE ANALYSIS. 
and in the presence of arsenic the paper is blackened by the re- 
duction of the silver nitrate to metallic silver. 
3. -Reinsch s Test.-The solution to be tested is acidulated with 
hydrochloric acid, a strip of pure bright copper foil is introduced 
and the mixture boiled. ' In the presence of arsenical com- 
pounds, a steel-gray deposit of arsenic forms upon the copper. 
Antimony, mercury, and even organic matter, may produce a 
similar appearance, but the arsenic may be identified as follows: 
The copper slip is removed, washed carefully, and dried between 
folds of filter paper. A strip is then cut, rolled into a small coil, 
introduced into a clean reduction-tube and heated. The arsenic 
volatilizes, and collects in the cooler portions of the tube in white 
octahedral crystals of As2O3. Organic matter is burned away 
without the formation of a sublimate. (For Antimony and Mer- 
cury, see below.) 
4. -Heated with charcoal, arsenous and arsenic oxides are vola- 
tilized, giving off the characteristic odor of garlic. (Other tests 
for arsenic, see p. 14.) 
Antimony. 
1. -Marsh's Test.-This test is performed as described under 
arsenic, similar mirrors of metallic nature being formed. Anti- 
mony is distinguished from arsenic as follows: The deposit ob- 
tained by holding a cold surface in the flame is insoluble in solu- 
tions of sodium or calcium hypochlorite, (arsenic spots-soluble.) 
If the spot be dissolved in a drop of nitric acid, the solution 
evaporated to dryness, and the residue moistened with a drop 
of silver nitrate, no color is developed, (arsenic-a brick red 
color). The spot dissolved in ammonium sulphide and evap- 
orated to dryness, yields an orange red residue, (arsenic-bright 
yellow). The antimony mirror obtained by heating the tube is 
formed immediately above the flame, (with arsenic, in advance of 
the flame), is darker than the arsenical mirror and less volatile. 
Antimonettcd hydrogen does not precipitate metallic silver from 
solutions of silver nitrate, but does precipitate black silver anti- 
monide. 
2. -Reinsch s Test.-Performed as indicated under arsenic. The 
antimony coating is distinguished from arsenic by the fact that 
when heated in the reduction-tube, the sublimate produced is 
either amorphous or composed of fine acicular crystals. (Other 
tests for antimony, see p. 14). SPECIAL TESTS. 
27 
Mercury. 
1.-The solution to be tested is acidulated with hydrochloric 
acid, and a strip of pure bright copper is introduced. A deposit 
of metallic mercury (silvery white by gentle friction) is formed 
in the cold. (Compare with Reinsch's Test for Arsenic.) If the 
copper be dried and heated as in Reinsch's Test, a sublimate of 
metallic globules of mercury is formed. 
To test for corrosive sublimate in calomel, treat a few grains of 
the calomel with boiling water, filter, and test the filtrate for mer- 
cury. Calomel is insoluble in water, corrosive sublimate is solu- 
ble. (Other tests for mercury, see pages 15 and 16). 
Phenol; (Carbolic Acid,) C6H5OH. 
1. -Note the characteristic odor, and the greasy stain upon 
paper. 
2. -Heated with a little nitric acid the solution turns yellow, 
trinitro-phenol (picric acid), C6H2(NO2)3OH, being formed. 
3. -A few drops of ferric chloride impart a violet-blue color to 
the solution. 
4. -Add a few drops of the solution to a little hydrochloric 
acid in a test tube, then add ohe drop of nitric acid and warm 
gently. A purple-red color is developed. 
5. -Mix the solution with one-quarter volume of ammonia, add 
a few drops of sodium hypochlorite solution, and warm. A bluish 
green color is developed, turning to a red on addition of hydro- 
chloric acid. 
6. -The addition of bromine water produces a yellowish-white 
precipitate of tribrom-phenol, C6H2Br3OH. 
Chloroform, CHC13. 
1. -To some alcoholic potassium hydroxide in a test tube add a 
few drops of aniline, and one or two drops of chloroform, or of 
the solution to be tested. Warm gently; the disagreeable odor of 
benzo-isonitril, C6H5NC, is produced. 
2. -A strip of paper moistened with chloroform, when ignited, 
burns with a greenish flame, and gives off fumes of hydrochloric 
acid. 
3. -Heat some of the solution to be tested with Fehling's solu- 
tion. Red cuprous oxide is precipitated as in the test for glucose 
(q. v.). 28 
QUALITATIVE ANALYSIS. 
Alcohol, C2H5OH. 
1. -To a dilute solution of potassium dichromate add a few 
drops of sulphuric acid, and then a little alcohol, or the solution to 
be tested. Warm the mixture gently: it turns green, and the 
characteristic odor of aldehyde is produced. 
2. -To the liquid to be tested add a few drops of dilute potassium 
hydroxide, and a small crystal of iodine, or, add to the alkaline so- 
lution, a solution of iodine in potassium iodide until the liquid is 
faintly colored. A precipitate of iodoform will be produced. 
Note the characteristic odor. 
C2H5OH + 6K0H +18 = CHI3 + CHO2K + 5KI + 5H2O. 
An excess of alcohol holds the iodoform in solution. 
3. -Add a little sulphuric acid and some strong solution of 
sodium acetate. The characteristic odor of acetic ether, (ethyl 
acetate) C2H5(C2H3O2), is developed on warming. 
Glycerol, (Glycerin,) C3H5(OH)3. 
1. -Add sodium hydroxide to a slightly alkaline reaction, and 
heat, in a non-luminox® flame, a borax bead moistened with this 
solution. Boric acid is produced and the flame is colored green. 
2. -Warm the solution with sulphuric acid. The character- 
istic odor of acrolein, C3H4O, is produced. 
For medicinal use, the aqueous solution of glycerol should be 
neutral to litmus paper, no brown color should develop when 
treated with sulphuric acid, and no red precipitate should be ob- 
tained on heating with Fehling's solution. 
Ethyl Ether, (C2H5)2O. 
Ether is best recognized by its odor, volatility and inflam- 
mability. It burns with a luminous flame. With sulphuric acid 
and potassium dichromate a green color is developed, as in the 
alcohol test (q. v.). 
For medicinal use, it should be neutral in reaction, should leave 
no residue on evaporation, and when shaken with sodium hydrox- 
ide, no color should be developed. 
SPECIAL TESTS FOR THE ALKALOIDS. 
The alkaloids may be defined as organic, nitrogenous substances, 
basic in character, and capable of combining directly with acids ALKALOIDS. 
29 
to form salts. They are commonly divided into two groups: (1) 
Liquid or Volatile Alkaloids, consisting of Carbon, Hydrogen and 
Nitrogen. Nicotine, Sparteine, and Coniine. (2) Solid or Non- 
Volatile Alkaloids, consisting of Carbon, Hydrogen, Nitrogen and 
Oxygen. Morphine, Quinine, Atropine, Strychnine, etc. 
General Properties.-Most alkaloids are insoluble, or very slightly 
soluble in water; more soluble in alcohol, chloroform and benzene. 
The salts of the alkaloids, on the other hand, are generally solu- 
ble in water and in alcohol, but insoluble, or slightly soluble, in 
chloroform, benzene, and ether. In appearance, they are generally 
white, with strong taste, and characteristic physiological action. 
The hydroxides of the alkalies and alkaline earths precipitate alka- 
loids from aqueous solutions of their salts. Alkali carbonates 
precipitate most of the alkaloids. Among other precipitants ap- 
plicable in general to the whole class, we have tannic acid, picric 
acid, phospho-molybdic acid, mercuric potassium iodide (Mayer's 
solution), and the chlorides of platinum and gold. 
Volatile Alkaloids. 
These are volatile liquids, colorless when pure and first separated, 
but turning brown on exposure tQ the air. They are characterized 
by disagreeable penetrating odors. 
Nicotine, C10H14N2. 1.-Acrid odor and taste (a rapidly fatal 
poison), soluble in ether, chloroform, turpentine, water and 
alcohol. 
2. -Picric acid, gold chloride, mercuric chloride, and platinic 
chloride, produce precipitates generally amorphous at first, 
changing to crystalline. 
3. -Hydrochloric acid develops a violet color; nitric acid, an 
orange color. 
4. -If one drop be placed upon a watch glass and covered with 
a second watch glass carrying a drop of nitric or hydrochloric 
acid, white fumes are produced. 
5. -An ethereal solution of iodine added to a solution of the 
alkaloid in ether, separates a brownish oil, which gradually be- 
comes crystalline. 
Coniine, C8H17N. 1.-Resembles nicotine in physical proper- 
ties, and in its precipitation by the general alkaloidal reagents. 
2.-Evaporated with hydrochloric acid, a greenish-blue crystal- 
line residue is obtained. 30 
Q UAL1TA TIVE ANAL YSIS. 
3. -Evaporated with sulphuric acid, a red color is developed 
changing to green. 
4. -If a drop be placed upon a watch glass and covered with a 
second watch glass carrying a drop of hydrochloric acid, dense 
white fumes are developed,, and the drop of coniine assumes a 
crystalline form. 
Sparteine, C15H26N2. 1.-General characters same as above. 
2.-An etherial solution of iodine added to a slightly ammonia- 
cal etherial solution of sparteine, separates minute dark greenish- 
brown crystals. 
Non-Volatile or Fixed Alkaloids. 
By far the greater number of alkaloids are included here. They 
are mostly white, odorless solids, fusing at a temperature above 
100° C. without change, but decomposed when heated above their 
fusing points. 
Morphine, Cx 7H19NO3.H2O. 1.-A white crystalline solid, 
insoluble in ether and chloroform, soluble in boiling alcohol, used 
generally in form of its salts. 
2. -Nitric acid dissolves morphine and its salts with efferves- 
cence, producing a red solution gradually changing to yellow. 
3. -Sulphuric acid dissolves it, forming a colorless solution, 
which is turned green on addition of a crystal of potassium di- 
chromate, or pink on addition of a trace of nitric acid. 
4. -Neutral ferric chloride develops a blue color changing to 
green on addition of an excess of the reagent. 
5. -Neutral solutions of morphine are precipitated with gold 
chloride, platinic chloride, potassium dichromate, and with picric 
acid, but not with mercuric chloride. 
Codeine, C\ 8H2 1.-Sparingly soluble in water, 
easily soluble in alcohol and chloroform. 
2. -Cold concentrated sulphuric acid dissolves codeine, forming 
a colorless solution which turns blue after several days, or when 
warmed, best after the addition of a trace of ferric chloride. 
3. -Nitric acid dissolves codeine, producing a yellow solution. 
4. -With chlorine water a colorless solution is obtained, which 
turns red with ammonia. 
Meconic Acid, C7H4O7.3H2O. 1.-Soluble in water, more 
soluble in alcohol. 
2.-To a drop of the solution on a watch glass add a drop of ALKALOIDS. 
31 
ferric chloride. A red color appears which is not destroyed by 
mercuric chloride (difference from ferric sulphocyanate). 
3. -Silver nitrate produces a white precipitate which turns red 
on addition of ferric chloride. 
4. -Barium chloride produces a white precipitate. 
Quinine, C20H24N2O2.3H2O. Quinine sulphate, (C20H24- 
N2O2)2H2SO47H2O. Quinine bisulphate, C20H24N2O2 . H2- 
SO4.7H2O. 1.-A flaky white powder nearly insoluble in water, 
soluble in dilute acids, in alcohol, chloroform, ether, etc. The 
sulphate is more soluble in water, and the bisulphate is easily 
soluble. 
2. -Dissolve a few grains of the substance in a little dilute sul- 
phuric acid, and add water. A blue fluorescence indicates quinine. 
3. -Test the solution obtained above as follows: a.-Add tannic 
acid, =a white precipitate, b.-Add picric acid, =a yellow pre- 
cipitate. c. -Add sodium hydroxide, = a white precipitate. 
4. -Add to the solution a few c.c. of bromine water, or of 
chlorine water, and then add an excess of ammonia. A green 
color is developed. 
5. -Treat the solution with chlorine water and then with a few 
grains of solid potassium ferrocyanide. The solution turns pink, 
changing to red, best after the addition of a little ammonia. 
Cinchonine, C19H22N2O. 1.-Forms in white crystalline 
needles almost insoluble in water, slightly soluble in alcohol and 
chloroform, easily soluble in dilute acids. 
2.-Chlorine water forms a yellowish-white precipitate, in- 
soluble in ammonia. 
2. -Potassium ferrocyanide forms a white precipitate soluble in 
excess of the reagent. 
3. -Ammonia forms a white precipitate, insoluble in excess. 
4. -Solutions of the sulphate are not fluorescent. (Unlike 
Quinine.) 
Caffeine, (Thein'), C8H10N4O2.H2O. 1.-Long silky needles, 
soluble in water, more soluble in alcohol-. The solutions are neu- 
tral in reaction. 
2. -Concentrated nitric acid dissolves it, forming a yellow solu- 
tion, which, on evaporation and warming with ammonia, turns 
purple. 
3. -Sulphuric acid forms a colorless solution. 
Strychnine, C21H22N2O2. 1.-White crystalline powder, with 32 
QUALITATIVE ANALYSIS. 
intensely bitter taste (very fatal action). Sparingly soluble in 
alcohol, ether, or in water, soluble in chloroform and in dilute 
acids. The official salt is the sulphate, (C21H22N2O2)2H2SO4.- 
5H2O. 
2. -Dissolve a minute crystal of strychnine in one or two drops 
of strong sulphuric acid, and draw through the solution, which 
should be colorless, a small fragment of potassium dichromate. 
A blue color is developed, rapidly changing to violet, cherry-red, 
and finally to yellow. Black oxide of manganese, potassium 
ferricyanide, or potassium permanganate may be used in place of 
the dichromate. The permanganate, however, colors the solution, 
and thus interferes with the delicacy of the test. 
3. -Test a solution of strychnine with the following reagents: 
(a) Picric acid produces a yellow crystalline precipitate. (6) 
Tannic acid produces a white precipitate, (c) A solution of 
iodine in potassium iodide produces a brownish precipitate, (d) 
A solution of potassium dichromate gives a yellow crystalline pre- 
cipitate. (e) Mercuric chloride gives a white precipitate. 
4. -Dissolved in strong nitric acid, the solution should be color- 
less or yellow. A red or pink color denotes presence of brucine. 
Brucine, C23H26N2O4.4H2O. 1.-Soluble in alcohol and 
chloroform, sparingly soluble in water and in ether. The physi- 
ological action is similar to that of strychnine, though not quite so 
energetic. 
2. -Treated with strong nitric acid, brucine is colored red, turn- 
ing to a yellow on standing or when heated. Stannous chloride 
changes the red to a violet. (With morphine, there is no change 
on addition of stannous chloride.) 
3. -Chlorine water added slowly to a strong solution of brucine, 
develops a red color, changed to yellowish-brown by ammonia. 
4. -Test the solution with the following: (a) Tannic acid gives 
a white precipitate. (6) Picric acid gives a yellow precipitate. 
Atropine, C17H23NO3. 1.-White crystalline powder, spar- 
ingly soluble in cold water, more soluble in hot water, and easily 
soluble in alcohol and chloroform. The solutions are alkaline in 
reaction. 
2. -Solutions of atropine are not colored by nitric acid, and are 
only very slowly colored by potassium dichromate. 
3. -Dissolve a fragment of potassium dichromate in sulphuric 
acid, add a grain of atropine and a few drops of water, and warm ALKALOIDS. 
33 
the mixture. A pleasant odor resembling that of orange blossoms 
is developed. 
4. -Moisten the alkaloid with strong nitric acid, dry on the 
water bath, cool and add a few drops of alcoholic potassium 
hydroxide. A violet color is developed, changing slowly to red. 
5. -Test a solution of atropine as follows: (a) Sodium hy- 
droxide forms a white precipitate. (6) Gold chloride forms a 
yellow precipitate, (e) Picric acid forms a yellow precipitate, 
(d) Bromine in hydrobromic acid forms a yellow amorphous 
precipitate which afterwards becomes crystalline. 
6. -The physiological test, dilatation of the pupil, is characteristic. 
Veratrine, C32H50NO9(?). 1.-White amorphous, occasionally 
crystalline, powder, bitter taste, insoluble in water, soluble in 
alcohol, chloroform, ether, etc. When heated it melts and gives 
off acrid fumes. 
2. -Sulphuric acid dissolves it, giving a solution yellow at first, 
turning to an orange and finally to carmine-red. The solution 
shows a partial green fluorescence. 
3. -Hydrochloric acid dissolves the alkaloid, forming a colorless 
solution which turns dark red on warming. 
4. -Bromine water produces g violet coloration. 
5. -Test the solution with the following reagents: (a) Gold 
chloride gives a yellow precipitate. (6) Iodine in potassium 
iodide gives a brownish precipitate, (c) Bromine in hydrobromic 
acid gives a brownish precipitate. 
Aconitine, CgJbjNOj 2 (crystalline variety). 1.-A white 
powder slightly soluble in cold water, more soluble in hot, soluble 
in alcohol, ether and chloroform. A rapidly fatal poison. 
2. -Concentrated sulphuric acid dissolves aconitine, forming a 
yellowish-brown solution. 
3. -Dissolved in aqueous phosphoric acid and the solution 
evaporated, a violet color is produced. 
4. -Test the solution of aconitine with the following reagents: 
(a) Sodium hydroxide forms a white precipitate. (6) Tannic 
acid forms a precipitate, (c) Iodine in potassium iodide forms a 
precipitate, (d) Picric acid gives no precipitate. («) Mercuric 
chloride gives no precipitate. 
5. The taste is characteristically acrid, causing a tingling, be- 
numbing sensation in the mouth. This test must be performed 
with the greatest precaution. 34 
QUALITATIVE ANALYSIS. 
Physostigmine, C15H21N3O2. 1.-White amorphous, tasteless 
powder, sparingly soluble in water, soluble in alcohol, ether and 
chloroform. The solutions are alkaline. 
2. -Sulphuric acid dissolves the alkaloid, forming a yellow solu- 
tion turning to olive-green. 
3. -The sulphuric acid solution, neutralized carefully with am- 
monia and warmed, is colored first red, then reddish-yellow, green 
and blue. 
4. -Bromine in potassium bromide produces a red color. 
Cocaine, C17H21NO4. 1.-A white crystalline powder, fusing 
at 98° C., sparingly soluble in water, soluble in alcohol, ether and 
chloroform. The solutions are strongly alkaline. The hydro- 
chlorate, C\ 7H2 jNO4HC1, is easily soluble in water, the solutions 
having a slightly bitter taste and producing a tingling sensation, 
followed by numbness, on the tongue. 
2. -The alkaloid should give colorless solutions with sulphuric 
acid and with nitric acid. 
3. -Test a solution of cocaine with the following reagents: (a) 
Gold chloride gives a yellow crystalline precipitate. (6) Platinic 
chloride, a yellowish-white precipitate, (c) Picric acid, a yellow- 
ish crystalline precipitate, (d) Mercuric chloride, a white floc- 
culent precipitate, (e) Iodine in potassium iodide gives a rose- 
colored precipitate in dilute solutions, a brown precipitate in 
strong solutions. 
SEPARATION OF METALS, ALKALOIDS, ETC., FROM 
ORGANIC MATTER. 
The special tests given for the metals and alkaloids are, as a 
rule, applicable only in absence of organic matter. When, as is 
often the case, an organ, a tissue or an organic fluid is presented 
for examination, it becomes necessary to either remove or destroy 
the organic matter before proceeding with the analysis. Many 
processes have been proposed, but all, though simple in theory, 
require expert chemical knowledge for their successful application. 
The methods given below for metals are particularly adapted for 
the separation of arsenic, but apply with slight modifications to 
all of the metallic poisons. 
Separation of Metals. Method of Fresenius and Bobo.-The 
solid matter is finely divided and treated with an equal weight of 
pure hydrochloric acid and water. The mixture is then digested EXAMINATION OF ORGANIC MIXTURES. 
35 
on a water-bath and small quantities of potassium chlorate added 
from time to time. When the solid matter has been entirely de- 
composed the clear yellow liquid is evaporated, until the odor of 
chlorine has disappeared, and then filtered. The solution obtained 
can be examined by the usual tests for the metals ; in the case of 
arsenic, best after the addition of sodium sulphite and subsequent 
heating to drive off the sulphur dioxide gas. 
By Distillation.-In the case of arsenic, and of certain other vol- 
atile compounds of metallic poisons, the following method may be 
used : The finely divided organic matter is dried on the water 
bath, mixed with its own weight of pure hydrochloric acid and 
distilled from a glass retort provided with a condenser. The dis- 
tillate is received in cold water, and may be examined at once for 
poisons. 
By Dialysis.-The finely cut material is digested in cold water- 
or in dilute acid-for 24 hours, and then placed in a dialyzer. 
The latter is suspended in a larger vessel containing distilled water, 
and at the end of 24 hours again, the water is evaporated and the 
residue examined for poisons. This method is applicable also to 
the separation of the alkaloids. 
Separation of Alkaloids, Ptomaines, etc. The separation of 
the alkaloids from organic matter is one of the most difficult and, 
on the whole, one of the most unsatisfactory problems of chem- 
ical toxicology. The following outlines will indicate the general 
nature of the processes used : 
Stas-Otto Method.-Treat the finely comminuted mass with twice 
its weight of pure 90 per cent, alcohol, and with 10 to 30 grains 
of oxalic acid. Digest at 70° C., and filter. Evaporate the fil- 
trate in vacuo, over sulphuric acid, dissolve the residue in absolute 
alcohol, filter, and again evaporate at a low temperature. Dissolve 
in water, add sodium hydrogen carbonate to alkaline reaction, agi- 
tate with ether, and separate the etherial layer. Allow the ether 
to evaporate spontaneously and examine the residue for alkaloids, 
or, redissolve in water and again extract with ether to further pur- 
ify the residue before testing. 
Dragendorff"1 s Method.-This method is convenient, as affording 
a partial separation of the alkaloids during their extraction. The 
finely divided substance is digested for several hours with water 
acidulated with sulphuric acid. The extract is removed and the 
process repeated, the temperature being maintained at from 40° C. 36 
QUALITATIVE ANALYSIS. 
to 50° C. The extracts are united, evaporated to a syrup, and di- 
gested with 4 volumes of alcohol for 24 hours at 30° C. The 
alcoholic extract is filtered, the residue washed with 70 per cent, 
alcohol, and the united extracts freed from alcohol by evaporation. 
The aqueous residue, diluted if necessary, is filtered, and the acid 
liquid, containing the sulphates of the alkaloids, treated with the 
following reagents : 
1. -Agitate with petroleum ether, remove etherial layer, repeat 
•extraction, evaporate extracts. Residue consists chiefly of coloring 
matters. 
2. -Extract with benzene. Evaporate extract. Residue, if 
•crystalline, may be cantharidine, santonine, or digitaline; if amorph- 
ous, elaterine, or colchicine. 
3. -Extract with chloroform. Evaporate extract. Residue 
may be cinchonine, digitaline, or picrotoxine. 
4. -Treat again with petroleum ether, remove etherial layer, 
render alkaline with ammonia. Treat the alkaline solution with 
petroleum ether at 40° C., and remove extract while warm. 
Evaporate extract. Residue may be strychnine, quinine, brucine, or 
veratrine. Extract again with cold petroleum ether. Residue may 
be coniine or nicotine. 
5. -Extract the alkaline solution with benzene. Evaporate ex- 
tract. Residue may be strychnine, brucine, quinine, cinchonine, 
atropine, hyoscyamine, physostigmine, aconitine, codeine, thebaine, or 
narceine. 
6. -Extract with chloroform. Evaporate extract. Residue may 
be morphine. 
7. -Extract with amyl alcohol. Evaporate extract. Residue 
may be morphine, solanine, or salicine. 
8. -Evaporate remainder of the solution with powdered glass. 
Extract with chloroform. Evaporate extract. Residue may be 
curarine. PART II. 
THE CARBOHYDRATES. 
THE PROTEIDS. THE CARBOHYDRATES. 
The carbohydrates form an important group of compounds, 
chiefly of vegetable origin, but occurring also in smaller quantities 
in the animal tissues and fluids. They may be classified as fol- 
lows : 
Amyloses. 
(C6H10O5)n 
Cellulose, 
Starch, 
Dextrin, 
Granulose, 
Glycogen. 
Glucoses. 
(C6H12O6)n 
Dextrose, (Glucose) 
Levulose, (Fruit Sugar) 
Galactose, 
Inosite, 
Sorbose. 
Saccharoses. 
(Ci 2H2 2Oi i )n 
Sucrose, (Cane Sugar). 
Lactose, (Milk Sugar). 
Maltose, 
Melitose, 
Mycose. 
The carbohydrates are nearly all neutral in reaction; some are 
crystalloids, others colloids. Of the three series, the first, the 
amyloses, are the most complex in nature, and most easily broken 
down into simpler forms. The glucoses are the most permanent, 
and resist efforts to transform them. They may, of course, be 
decomposed, but the products of decomposition are not carbohy- 
drates. 
Cellulose. 
Prepared by reducing vegetable tissue to a pulp and washing 
out the starches, gums, salts, etc., present. 
Chemical filter paper, which is nearly pure cellulose, is suitable 
for most of the tests. 
1. -To some shreds of filter paper in a test-tube add a little 
sodium hydroxide. Warm the mixture and let it stand. Note 
that the paper fibres swell slightly and become more or less gelat- 
inous. 
2. -To a second sample add strong sulphuric acid and warm 
gently. Note that the paper turns brown or black, and goes par- 
tially or entirely into solution. 
3. -Dissolve some pure cellulose in a solution of ammonio- 
cupric hydroxide. Then add hydrochloric acid carefully until 
39 40 
THE CARBOHYDRATES. 
the blue color of the solution is destroyed, and note that the cel- 
lulose is precipitated in a stringy mass. 
4.-Cellulose is insoluble in water, alcohol, or in ether. 
Starch. 
1. -Add a few grains of starch to a little sodium hydroxide in 
a test-tube. Note that the starch swells and forms a thick paste 
in the cold. 
2. -Prepare some starch paste as follows: Add sufficient ground 
starch to water in a test-tube to form a milky fluid. Pour 
this milky fluid into a beaker of boiling water. Note that the 
milky appearance disappears. Dilute some of the "paste" so 
formed, in another beaker with water. When cool, add a few 
drops of iodine solution. A blue color is produced. Divide this 
blue solution into three parts, (a) Heat one part carefully until 
the color disappears. Upon cooling, the color will again develop. 
If carefully performed this may be repeated several times. (6) 
To the second part, add a few drops of sodium hydroxide. The 
blue color is destroyed, but may be reproduced by the addition of 
dilute hydrochloric acid, (c) To the third part, add mercuric 
chloride. The blue color is destroyed. 
3. -Starch is insoluble in cold water, or in alcohol. When 
heated with water it is partially dissolved, the soluble portion 
being known as granulose, the insoluble portion, as starch-cellulose. 
To some of the clear starch solution obtained in (2) add alcohol. 
The granulose is precipitated. 
4. -To some of the solution obtained in (2) add dilute sul- 
phuric acid and heat to boiling. Test a small portion of the solu- 
tion in another test-tube, with iodine. If the boiling has been 
sufficient no blue color will appear, showing the conversion of the 
starch into dextrin and dextrose. 
2(C6H10O5) + H2O = C6H12O6 + C6H10O5. 
The dextrin first produced gives a red or brown coloration with 
the iodine. 
5. -By the action of diastase, starch is converted into maltose 
and dextrin. 
3(C6H10O5) + H2O = C12H22O11+C6H10O5. 
By continued action the maltose is converted into dextrose. THE CARBOHYDRATES. 
41 
6.-Add a few grains of starch to nitric acid in a test-tube, and 
warm, if necessary, to start the reaction. Note the violent ebulli- 
tion, red fumes, etc. 
Dextrin. 
An amorphous substance, readily soluble in water, insoluble in 
alcohol and in ether. 
1. -Drop some of the aqueous solution into alcohol; a white 
precipitate is formed. 
2. -Add ammonia and basic lead acetate ; a white precipitate is 
formed. 
3. -With iodine solution a red or brown coloration is obtained, 
which disappears when the solution is heated. 
4. -Boiling with hydrochloric acid converts dextrin into dex- 
trose. 
Glycogen. 
A white or yellowish-white tasteless amorphous powder, insolu- 
ble in alcohol or ether, imperfectly soluble in boiling water. 
1. -With iodine in potassium iodide, glycogen gives a deep red 
color when in solution, a brown color when in form of powder. 
On heating the solution the color disappears, but reappears on 
cooling. (Unlike dextrin.) 
2. -With sodium hydroxide and one or two drops of copper 
sulphate a blue coloration is obtained, but there is no precipitate 
on boiling. (See Trommel's Test, under Dextrose.) 
3. -Basic lead acetate, alone, precipitates glycogen from its 
aqueous solution. (Unlike dextrin.) 
4. -Boiling with dilute hydrochloric acid converts glycogen into 
dextrose. 
Dextrose. (Glucose, Grape Sugar, etc.) 
A white powder, more or less crystalline, soluble in water, less 
soluble in alcohol, insoluble in ether. It is sweet to the taste, but 
less so than cane sugar. 
1. - Moore's Test.-Add to a dilute solution of glucose, one-half 
volume of sodium hydroxide, and heat to boiling. A brown col- 
oration is obtained. Add a little nitric acid, the color disappears 
in part and the characteristic odor of caramel is given off. 
2. -Picric Acid Test.-Add to the solution a few drops of picric 42 
THE CA RB OHYDRA EES. 
acid and a little sodium hydroxide. Heat the mixture and a 
mahogany-brown color is developed. 
3. -Silver Test.-To some ammoniacal silver nitrate add a few 
grains of glucose. When dissolved, heat to boiling. The solution 
turns dark and a metallic mirror of silver is formed at the bottom 
of the tube. Tartaric acid and aldehyde each give the same test. 
4. -Fermentation Test.-To the solution in a test-tube add a small 
piece of dry yeast and invert the tube over mercury. After stand- 
ing for 24 hours in a warm place, carbonic anhydride gas will be 
found to have accumulated at the top of the tube. The liquid 
may be tested for alcohol. It is well to make a control test with 
yeast and pure water in a second test-tube. 
5. -BottgeFs Test.-To the solution of glucose in a test-tube add 
sodium hydroxide and then a few grains of bismuth subnitrate. 
Mix the solution well and heat to boiling. A black precipitate of 
metallic bismuth is formed. Sodium carbonate may be used in 
place of sodium hydroxide. 
6. - Trammer1 s Test.-To the solution add an excess of sodium 
hydroxide, and then a solution of copper sulphate drop by drop, 
until a slight permanent precipitate is formed. In the presence of 
glucose the bluish white precipitate of cupric hydroxide first 
formed dissolves on agitation, producing a dark blue solution. 
Heat the liquid and, in presence of glucose, yellow cuprous hy- 
droxide and red cuprous oxide are precipitated just as the liquid 
begins to boil. The same precipitation occurs, but much more 
slowly, in the cold. 
7. -Fehling1 s Test.-Heat some diluted Fehling's solution (See 
Appendix) to boiling in a test-tube, and add, drop by drop, the 
solution to be tested. A yellowish-red precipitate indicates glucose. 
Various modifications of Fehling's Test have been proposed, 
chief among which are, Pavy1s Ammoniated Cupric Test, depending 
upon the decolorization of the solution instead of the production 
of the red precipitate, Haines' Test, Loewe's Test, Schmiedeberg1 s 
Test, etc. Formulae for Pavy's Solution and for Haines' Solution 
are given in the Appendix. Haines' Solution is less subject to 
decomposition than Fehling's completed solution, and thus possesses 
a certain advantage. It is best, however, to preserve Fehling's 
Solution in two parts and to mix a sufficient amount for each test, 
at the time of execution. 
8. -Indigo-Carmine Test.-Add sqdium carbonate to the solution, THE CA RBOIIYDRA TES. 
43 
to render it alkaline, and then add sufficient indigo-carmine solu- 
tion to impart a blue color. Boil, and the solution turns first vio- 
let, then yellow, but the blue color may be restored by agitation 
with air. 
9. -Phenylhydrazine Test.-Add to the solution two grammes of 
phenylhydrazine hydrochloride, and four grammes of sodium 
acetate. Dissolve the salts by agitation and warm on the water- 
bath for 45 minutes. If glucose be present, on cooling, if not 
before, a yellow crystalline precipitate of phenyl glucosazone will 
separate out. 
10. -Alpha-naphthol Test.-Add to the liquid a saturated solution 
of alpha-naphthol and an excess of sulphuric acid. In presence of 
glucose (and of other sugars) a violet color is developed. The 
addition of water causes a blue precipitate to form, soluble in 
alcohol, ether, and sodium hydroxide, with the production of a 
yellow solution. 
For the detection of glucose in the urine, see p. 68, and for the quanti- 
tative estimation of glucose, see p. 69. 
Sucrose. (Cane Sugar.) 
A white crystalline solid, easily soluble in water, insoluble in 
absolute alcohol and in ether. 
1. -To a little sugar in a test-tube add sulphuric acid and warm 
gently. The sugar is charred. 
2. -Heat some sugar on a piece of platinum foil. It melts, 
darkens, chars, and burns, giving off inflammable gases and the 
characteristic odor of caramel. 
3. -To a solution of sugar add a little sodium hydroxide and 
warm. If the sugar be pure there is no change of color as there 
is with glucose. 
4. -Warmed with nitric acid, sugar is converted into saccharic, 
tartaric, and, finally, oxalic acid, red fumes of nitrogen oxides 
being evolved. 
5. -Cane sugar does not reduce Fehling's Solution ; with Trom- 
mer's Test a blue solution is obtained, but this is not reduced on 
boiling. 
6. -By the action of yeast and, also, by boiling with dilute acids, 
cane sugar is converted into glucose. To a dilute solution of sugar, 
add a little sulphuric acid and boil for several minutes. Cool the 
solution and apply Trommer's Test. 44 
THE CARBOHYDRATES. 
4-H2O = C6H12O6+C6H12O6. 
(Cane Sugar.) (Dextrose.) (Levulose.) 
Lactose. (Milk Sugar.) 
A white crystalline solid, less soluble in water than cane sugar 
or dextrose, insoluble in alcohol or ether. It possesses only a 
faint sweet taste. 
Lactose responds to the sarpe tests as glucose ; it reduces Fehl- 
ing's Solution, though less strongly. By boiling with acids and 
under the influence of ferments it is converted into galactose. It 
differs from glucose in undergoing lactic fermentation, but after 
conversion to galactose the latter is subject to ordinary alcoholic 
fermentation. Lactose may be prepared from milk by acidulating 
with acetic acid, boiling, and filtering off the casein, fat, albumen, 
etc. On evaporation of the filtrate, crystals of lactose will sepa- 
rate out. 
Maltose. 
A white, crystalline substance, needle-shaped crystals, soluble 
in both water and alcohol. Like lactose, it responds to nearly all 
of the glucose tests. Its reducing power with Fehling's Solution 
is one-third less than glucose. It readily undergoes alcoholic fer- 
mentation, and by prolonged boiling with water, or, more readily, 
by boiling with dilute acids, it is converted into dextrose. THE PROTEIDS. 
The proteids occur in both the vegetable and animal kingdoms, 
most abundantly in the latter. They all contain carbon, hydro- 
gen, oxygen and nitrogen ; most of them contain sulphur, and 
phosphorus is present in a few. Various formulae have been cal- 
culated for the simpler proteids, but little, however, is known re- 
garding their true constitution. They vary in composition as fol- 
lows : 
C H N SO 
From 51.5 6.9 15.2 0.3 20.9 
To 54.5 7.3 17.0 2.0 23.5 
Classification: 
A. Animal Proteids. 
I. Albumins. 1. Serum-Albumin. 2. Egg-Albumin. 3. 
Cell-Albumin. 4. Muscle-Albumin. 5. Lact-Albumin. 
II. Globulins. 1. Vitellin. 2. Crystallin. 3. Myosinogen. 
4. Fibrinogen. 5. Fibrinoplastin or Paraglobulin. 
6. Globin. 
III. Albuminates (Derived Albumins.) 
1. Acid Albumins, (a) Acid Albumin. (6) Syntonin. 
2. Alkali Albumins, (a) Alkali Albumin. (6) Case- 
inogen. 
IV. Proteoses. 1. Albumoses. 2. Globuloses, etc. 
V. Peptones. 1. Hemipeptone. 2. Antipeptone. 
VI. Coagulated Proteids. 
VII. VIII., IX. Fibrin, Lardacein, Meta- and Para-Albu- 
mins. See p. -, under Albuminoids. 
B. Vegetable Proteids. 
These resemble the animal proteids in their properties and clas- 
sification. The Vegetable Globulins are the most important and 
abundant, though under the action of reagents they are often sep- 
arated from the plant in other, derived, forms. 
C. Albuminoids.-(Seep. 51.) 
45 THE PROTEJDS. 
46 
Tests for the Proteids. 
All proteids are insoluble in alcohol. Some are soluble in 
water, others are not. Many not soluble in water are soluble in 
dilute saline solutions. Some are soluble in concentrated saline 
solutions, others are insoluble. All are soluble when heated with 
strong acids, and all are soluble, after change, in the gastric and 
pancreatic juices. The classification and subdivision of the pro- 
teids depend upon their behavior with the above reagents. 
"The Protein Reactions." (Applying to all proteids.) 
1. -Xantho-proteic Reaction.-To a little of the solution in a test- 
tube, add a few drops of cone, nitric acid and heat to boiling. A 
yellow color is produced. Cool, and divide the solution into two 
parts ; to one add ammonia, to the other add sodium hydroxide. 
An orange-yellow color appears in each instance. 
2. -Millon''s Reaction.-To the solution add a few drops of Mil- 
lon's Reagent (See Appendix) and boil. The white precipitate 
first formed turns red on heating. The presence of sodium chlo- 
ride interferes with this reaction. 
3. -Piotrowski's Reaction.-To the solution add a drop of copper 
sulphate and then an excess of sodium hydroxide ; a violet color- 
ation is obtained which becomes darker on boiling. The same 
result is obtained with Fehling's Solution. 
Removal of Proteids from Solutions. 
It is frequently necessary to remove the proteids from a solution 
preparatory to tests for other substances. In urine analysis, for 
instance, the albumin must be removed before testing for sugar, 
or for urea. This removal may be accomplished, in most cases, by 
boiling the slightly acid solution. Albumins and Globulins are 
coagulated and may be filtered off. If the solution is not already 
acid, render so by addition of acetic acid. The same result may 
be obtained by the addition of an excess of absolute alcohol to the 
slightly acid solution, all proteids being thereby precipitated. A 
third method, of wide application, is the following: Add to the 
solution a few drops of acetic acid, (sufficient to acidulate it) 
then add an equal volume of a strong solution of ammonium 
sulphate. Boil for several minutes and filter. Saturation with 
ammonium sulphate precipitates all proteids except peptones. THE PROTEIDS. 
47 
Albumins. 
1. -Mercuric chloride precipitates white albuminate of mercury. 
2. -Copper sulphate precipitates blue albuminate of copper. 
3. -Lead acetate precipitates white albuminate of lead. 
4. -Add to the solution a few drops of acetic acid, and then a 
drop or so of potassium ferrocyanide. A white precipitate is 
formed. 
5. -Picric Acid Test.-Add to the solution a few drops of picric 
acid ; a precipitate is formed. This is best performed as a "con- 
tact test," floating the solution of picric acid over the solution to 
be tested. A white zone of precipitated albumin will form between 
the two liquids. 
6. -Tannic Acid Test.-Add to the solution a fewr drops of a 
solution of tannin. A precipitate is formed. 
7. -Nitric Acid forms a white precipitate if not added in excess. 
8. -Nitric Acid Contact Test.-Place about one inch of strong 
nitric acid in a'test-tube, and float over it carefully, so as to avoid 
admixture, some of the solution to be tested. In the presence of 
albumin, a white cloudy ring, or zone, will fond at the contact of 
the two liquids. 
9. -Acidulated Brine Test.-Heat the acidulated brine (See Ap- 
pendix) in a test-tube to boiling, and float over this the solution 
to be tested. A white precipitate is formed at the juncture of the 
two liquids. 
10. -Tanret's Test.--Heat the Tanret's Solution (See Appendix) 
in a test-tube, and float over this the solution to be tested. A 
white precipitate is formed at the juncture of the two liquids. 
11. -Trichloracetic Acid Test.-Add some of the crystals to the 
solution to be tested, and allow them to dissolve without agitation 
at the bottom of the tube. A white precipitate is formed. 
12. -Heat Test.-Heat some of the aqueous solution of albumin 
just to boiling. The albumin is coagulated, forming a white pre- 
cipitate. The solution should be slightly acid. The temperature 
at which the coagulation takes place averages between 60° C. and 
75° C. 
13. -Burn a small fragment of solid albumin on a piece of plat- 
inum foil. Note the characteristic odor of burnt horn. 
Egg- and Serum-Albumin may be readily distinguished by the 
follmying tests: 48 
THE TROT EID 8. 
Egg-Albumin. 
1. -Rapidly precipitated by 
alcohol. 
2. -Precipitated by ether. 
3. -Readily precipitated by 
HC1, the precipitate not dissolv- 
ing in excess. 
4. -Readily precipitated .by 
HN03, the precipitate not dis- 
solving easily in excess. 
Serum-Albumin. 
1. -Slowly precipitated by al- 
cohol. 
2. -Not precipitated by ether. 
3. -Not readily precipitated 
by HC1, the precipitate dissolv- 
ing easily in excess. 
4. -Precipitated by HN03, 
the precipitate dissolving easily 
in excess. 
For the detection of Albumin in the Urine, see p. 65. 
Albuminates. 
1. -To the solution of an albumin add nitric acid carefully until 
a precipitate is formed. Then add a slight excess of acid and the 
precipitate will redissolve. (An acid-albuminate has been formed.) 
2. -Boil the solution obtained in the first test and note that the 
albuminate does not coagulate. 
3. -Apply the Xantho-Proteic Reaction to some of the same 
solution. 
4. -Then add to the same solution dilute sodium hydroxide 
until a precipitate is formed. Add an excess of sodium hydroxide 
and the precipitate redissolves. 
5. -To the solution of an albumin, add a few drops of strong 
sodium hydroxide, and warm the mixture. (An alkali-albuminate 
is formed.) 
6. -Boil the solution obtained in the last test and note that the 
albuminate does not coagulate. 
7. -Apply Piotrowski's Reaction to the same solution. 
8. -Then add to the same solution (5) dilute hydrochloric acid ; 
a precipitate will form, soluble in excess of the acid. 
9. -Try solubility of casein in water. (Insoluble.) 
10. -Make a solution of casein in water, to which a little sodium 
hydroxide has been added, and test this solution as follows : (a) 
By heat (No coagulation). (6) Neutralize with acid and note the 
precipitate formed, soluble in excess of acid. (c) Apply Pio- 
trowski's Reaction. 
Peptones. 
The peptones are formed by the action of the gastric and pan- THE PR0TE1DS. 
49 
creatic juices on albuminous bodies, and also, possibly, by the 
action of dilute acids. They differ from true albumins in con- 
taining less carbon, and less nitrogen, also in their power of diffu- 
sion. Test a solution of peptone as follows : 
1. -Apply the Xantho-Proteic Reaction. 
2. -Apply Millon's Reaction. 
3. -Add an excess of sodium hydroxide, and a trace of copper 
sulphate, as in Piotrowski's Reaction. The solution turns rose- 
red in color. (With ammonia the solution acquires a violet-red 
tint.) This is known as the Biuret Reaction, because of the sim- 
ilar result obtained with a urea product, biuret, C2O2N3H5. 
4. -Mercuric chloride precipitates a white peptonate. 
5. -Picric acid forms a yellowish-white precipitate. 
6. -Nitric acid, acetic acid and potassium ferrocyanide, and 
copper sulphate, form no precipitates with peptones. 
7. -Boil the solution and note that the peptone does not coagu- 
late. 
Coagulated Proteids. 
Coagulate some egg-albumin by heat and test the coagulum as 
follows : 
1. -Try the solubility in water. (Insoluble.) 
2. -Apply the Xantho-proteic Reaction. 
3. -Apply Millon's Reaction. 
4. -Apply Piotrowski's Reaction. 
5. -Heat in a test-tube with sodium hydroxide. Alkali-albu- 
minate is formed and goes into solution. 
Gluten. 
Gluten is a vegetable proteid derived from the vegetable myosin 
and albumose (proteose) of flour. It may be prepared for testing 
by kneading dough in a stream of water until free from starch. 
1. -Apply the Xantho-proteic Reaction. 
2. -Apply Millon's Reaction. 
3. -Boil with water and note that it does not dissolve. 
4. -Add sodium hydroxide to the mixture obtained in the last 
test, and boil again. Note that the gluten gradually decomposes 
and goes partially into solution with the formation of an alkali- 
albuminate. 50 
THE PROTEIDS. 
Tests for Sulphur in Albumin 
1. -Heat a solution of lead acetate in a test-tube and add sodium 
hydroxide until the white precipitate of lead hydroxide, first 
formed, is just redissolved. Boil the clear liquid, and while boil- 
ing add a little albumin solution. The mixture turns black from 
the formation of lead sulphide. 
2. -Heat a little of the solid albumin in a tube, and hold in the 
mouth of the tube a piece of paper moistened with lead acetate. 
The paper is blackened by the fumes evolved. 
3. -Boil some albumin solution with a few grains of bismuth 
subnitrate and an excess of sodium hydroxide. A black precipi- 
tate of sulphide of bismuth is formed. 
Separation and Identification of the Chief Protein Classes. 
* \ 
1. If the proteid be solid, test its solubility. 1.-Soluble in pure 
water. 
(а) Coagulated by heat, Albumins. 
(б) Not coagulated by heat, Peptones. 
2. -Insoluble in pure water, but soluble in one per cent, solu- 
tions of sodium chloride, Globulins. 
(а) Precipitated by saturation with sodium chloride, Fibrinogen, 
Paraglobulin, Myosin. 
(б) Not precipitated by saturation with sodium chloride, Vitellin, 
Crystallin. 
3. -Insoluble in pure water or dilute sodium chloride, but solu- 
ble in acids and in the gastric juice. 
(a) Soluble in dilute hydrochloric acid or in dilute alkalies, 
Albuminates. 
(&) Insoluble in dilute acids and alkalies, but easily soluble 
when digested with gastric and pancreatic juice, Coagidated Pro- 
teids. 
(c) Insoluble in water, sodium chloride, dilute acids, or gastric 
juice, soluble in the stronger alkalies ar.d in strong hydrochloric 
acid. Lardacein (Amyloid Substance.) 
II. If the proteid be in solution, (1) Test a portion of the solution 
for proteids by the Xantho-proteic, Millon's and Piotrowski's 
Tests. 
2.-Test the reaction of the solution. 
(a) If acid, apply tests for the acid-albiiminates. THE PROTEIDS. 
51 
(6) If alkaline, test for the alkali-albuminates. 
3. -Acidify, if necessary, and boil the solution. If there be a 
coagulation the proteid is either an afZmmm, or a globulin. Add 
magnesium sulphate (saturated solution) to the original sample. 
A precipitate indicates Globulin, if no precipitate be formed, Al- 
bumin is present. 
4. -If the proteid is not coagulated by heat, it is then probably 
either an albuminate, an albumose, or a peptone. 
(а) Albuminates were tested for under 2, a. b. 
(б) An Albumose would be recognized by the biuret reaction (sim- 
ilar to that given for peptones) and by the characteristic reaction 
with nitric acid. Albumose is precipitated by nitric acid in the 
cold, the precipitate dissolves on heating, and reappears when the 
liquid cools. 
(c) Peptones may be recognized by the biuret reaction, by giv- 
ing no precipitate with nitric acid, and no precipitate on satura- 
tion with ammonium sulphate. 
THE ALBUMINOIDS. 
The term albuminoid is best restricted to a group of substances 
which, while similar to the proteids in many particulars, differs 
from them in certain others. 
Among the albuminoids we have the following: 
I. Collagen, from the white connective tissue. 
II. Ossein, a collagen from the bones. 
III. Gelatin, derived from collagen by boiling with water. 
IV. Chondrin, similar to the above, derived from the cartilages. 
V. Mucin, from the cement substance or ground mass of 
epithelium and connective tissue. 
VI.-XIV. Elastin, Nuclein, Plastin; Nucleo-Albumins, Spermatin, 
Keratin, Metalbumin, Paralbumin, Lardacein, etc. The last three 
are also often classed as proteids. 
Gelatin. 
When dried and pulverized bones are digested with dilute 
hydrochloric acid, the mineral salts are dissolved and ossein left 
behind. This last boiled with water is rapidly converted into the 
substance gelatin. Test the properties of gelatin as follows: THE PROTEIDS. 
52 
1. -Try the action of cold water. The gelatin swells without 
dissolving. 
2. -Warm the mixture and it will be found that the gelatin 
dissolves. Divide this solution into two parts: 
(а) Allow one part to cool in a test-tube, and note that on 
cooling the gelatin separates out, or 11 gelatinizes. ' ' 
(б) Boil the remainder of the solution for several minutes, and 
then let it cool. Note that now it does not gelatinize. 
3. -To the solution obtained in 2, b., or to a fresh solution of 
gelatin, apply the following tests: 
(a) Xantho-proteic = lemon-yellow color. 
(&) Piotrowski's. 
(c) Mercuric chloride = precipitate. 
(d) Picric acid = precipitate. 
(e) Nitric acid = no precipitate. 
(/) Acetic acid and potassium ferrocyanide = no precipitate. 
In these reactions, with the exception of 2, a., gelatin resembles 
peptone. The following tests serve to distinguish between the two: 
Peptones. 
1. Feeble osmotic power. 
2. Alcohol precipitates with 
difficulty. 
3. Treatment with hydro- 
chloric acid produces syntonin. 
4. Solutions do not gelatinize. 
Gelatin. 
1. No osmotic power. 
2. Alcohol precipitates easily. 
3. Treatment with hydro- 
chlorine acid does not produce 
syntonin. 
4. Solutions gelatinize. PART III. 
CLINICAL. MILK. 
AVERAGE COMPOSITION OF MILK. 
Human Colos- 
trum (Tidy). 
Woman's Milk 
(Leeds). 
Cow's Milk 
(Konig). 
Cow's Milk 
(Hoppe-Seyler)- 
Water, 
84.077 p. c. 
86.732 p. c. 
87.17 p. C. 
85 to 86 p. c. 
Solids, 
15.923 11 
13.268 " 
12.83 11 
14 to 15 " 
Casein, 
1.995 " 
( 3.02 " 
3 to 4 " 
Albumin, 
| 3.228 " 
t 0.53 " 
0.3to0.5 " 
Fat, 
5.781 " 
4.131 " 
3.69 " 
- 4.0 " 
Lactose, 
6.513 " 
6.936 " 
4.88 " 
4.5 to 5.0 " 
Salts, 
0.335 " 
0.201 " 
0.71 " 
- 
The salts consist of chlorides, phosphates and sulphates, of cal- 
cium, magnesium, sodium, and potassium, with a small amount 
of iron and a trace of silica. There are, also, certain gases in so- 
lution : According to Pfliiger, 100 volumes of milk contain 7.60 
of carbonic anhydride, 0.10 of oxygen and 0.70 of nitrogen. 
Pathological alterations may occur after the administration of cer- 
tain drugs and in morbid conditions. Albumin may increase, 
pus and blood may make their appearance. In osteomalacia the 
salts are increased ; in acute fevers the amount secreted diminishes 
while there is a relative increase in the percentage of casein. In 
chronic diseases the fat and salts increase while the casein is di- 
minished. In syphilis the salts increase while casein and fat are 
both diminished. The germs of infectious diseases are best recog- 
nized by physiological and microscopical tests. Again, cow's milk 
occasionally exhibits an abnormal appearance due to the presence 
of chromogenic bacilli, not necessarily, however, pathogenic in 
character. " Red" and " Blue" milks are examples of this phe- 
nomenon. 
To Recognize the Constituents of Milk. 
1. Dilute some milk in a beaker, with an equal volume of 
water, then add dilute acetic acid, and note the coagulation of the 
55 56 
MILK ANALYSIS. 
casein. This casein coagulum (formed also by rennet) contains 
considerable butter-fat, which may be extracted with ether, after 
first treating the coagulum with absolute alcohol. Filter off the 
coagulum and reserve the filtrate, the Whey, for tests 2 and 3. 
Test the Casein as follows: (a) Apply the Xantho-proteic Re- 
action. (6) Apply Millon's Reaction. (c) Warm with water 
and add a few drops of sodium hydroxide. The casein goes into 
solution and may be reprecipitated by addition, to neutralization, 
of dilute acetic acid. 
2. -Test the whey for Lactose as follows: (a) By Moore's Test. 
(6) By Trommer's Test. 
3. -Test the whey for Inorganic Constituents. Place the whey in 
an evaporating dish, add a few grains of sodium or potassium 
nitrate, and evaporate to dryness with occasional stirring. When 
the mixture is near dryness heat cautiously until it ignites. Then 
heat strongly until only a white ash remains. Let it cool, add a 
little water and a few drops of dilute nitric acid, warm gently, 
and filter. Divide the filtrate into three parts and test: (a) For 
Phosphates, with ammonia and magnesia mixture. (6) For 
Chlorides, with nitric acid and silver nitrate, (c) For Sulphates, 
with hydrochloric acid and barium chloride. 
4. -To some cream in a test-tube, add a little sodium hydroxide 
and a few drops of alcohol. Warm gently and note the character- 
istic odor of butyric ether, indicating the presence of Butter-Fat. 
5. -To separate the Butter-Fat, add to the milk one-half its vol- 
ume of sodium hydroxide, and one-half of ether. Shake well and 
let it stand in a warm place. The fat dissolves in the ether and 
floats on the top. The ethereal layer may be removed and the 
ether evaporated, leaving the fat in a pure state. 
Clinical Analysis of Milk. 
Quantity. The normal amount secreted by a healthy woman 
may be placed at from 700 to 1000 c.c. daily. A cow in good 
condition secretes 6000 to 7000 c.c. daily, or about four times its 
body weight in the year. 
Reaction. Tested with litmus paper, human milk is normally 
alkaline. The milk of the cow and other herbivora is alkaline or 
amphoteric in reaction, while that of the carnivora is acid. 
Specific Gravity. The specific gravity of milk varies normally MILK ANALYSIS. 
57 
from 1028 to 1034. It is raised by the removal of the cream and 
lowered by the addition of water. When the milk has suffered 
both of these operations, therefore, the specific gravity may be 
normal. Method. The specific gravity is usually taken with a 
hydrometer after a thorough shaking of the sample. When the 
temperature of the milk departs considerably from the tempera- 
ture of registration of the hydrometer (usually 60° F.) a correc- 
tion must be made. Sufficiently accurate results may be obtained 
by subtracting one from the hydrometer reading for each 10° 
below 60° F., or by adding one to the reading for each 10° above 
60° F. 
A hydrometer with specially constructed scale, known as the 
lactometer, is frequently used in the municipal control of milk. 
Upon this instrument the 0° mark corresponds to a specific gravity 
of 1000, that of pure water, while 100° corresponds to a specific 
gravity of 1029, the minimum acceptable specific gravity for pure 
milk. The scale is commonly extended to 130°, 120° correspond- 
ing to a specific gravity of 1034, the maximum for pure milk. 
Fat. (Cream).-(a) By the Creamometer.-A 100 c.c. glass 
cylinder graduated from above downward, is filled to the zero 
mark with the well shaken sample. After standing for 24 hours 
in a cool place the percentage of separated cream may be read 
directly from the graduations. This should be between 10 and 20 
volumes. Comparing with the specific gravity, less than 10 vol- 
umes in a milk of specific gravity above 1033 indicates skimming. 
Less than 20 volumes in a milk of specific gravity below 1029, 
indicates the addition of water. There are, however, several pos- 
sible sources of error in this method. Cream varies in consistency 
and consequently in bulk, and moreover, the addition of water 
causes a rapid separation of the cream with an apparent increase 
in quantity. 
(6) By Feser*s Lactoscope.-This method depends upon the fact 
that the relative opacity of milk varies with the number of sus- 
pended fat globules. Four c.c. of milk are introduced into the 
instrument and water added until the black lines upon the inner 
cylinder are plainly visible. The volume of the mixture indi- 
cates, by graduations on the outer tube, the percentage of fat in 
the sample. Whole milk should show three per cent, or over, by 
this method. 
(c) By Extraction with Ether.-The milk is rendered alkaline with 58 
MILK ANALYSIS. 
potassium hydroxide, and shaken with ether. The etherial solu- 
tion of fat is separated and the process repeated until all of the 
fat is removed. The etherial extracts are united and evaporated 
in a carefully weighed platinum dish. After drying at 110° C., 
the weight is again taken, the increase representing the fat in the 
measured volume of milk under analysis. 
Pkoteids. The milk is diluted and treated with acetic acid and 
carbonic anhydride gas. The precipitated casein is freed from fat 
by washing with ether, dried, and weighed. The filtrate from the 
casein is evaporated on the water bath and the albumin precipi- 
tated with acetic acid tannin solution. The tannin is removed by 
washing with dilute alcohol, and the albumin remaining is dried 
and weighed. 
The determination of the proteids in milk offers many difficul- 
ties, and is generally omitted in the ordinary clinical examination, 
as is also the test for sugar which follows. 
Lactose. The milk is acidified with hydrochloric acid, boiled 
and filtered. The filtrate is boiled to convert the lactose into glu- 
cose, and the latter is determined by means of Fehling's solution 
(see p. -) or, the lactose may be directly titrated, 10 c.c. of 
Fehling's being decomposed by 0.0676 grammes of that carbo- 
hydrate. 
Total Solids, (a) By Calculation.-An approximation, suf- 
ficiently accurate for clinical purposes, particularly in the exami- 
nation of mother's milk, may be made by means of Hehner and 
Richmond's formula. 
T_F + (0.2186 x G) 
0.859 
T = Total Solids. F = Fat percentage, as determined by Feser's 
lactoscope, or by extraction with ether. G = Last two figures of 
the specific gravity; e. g., if the specific gravity is 1030, then 
G = 30. 
If the specific gravity and total solids be known, the fat can be 
calculated by the same formula transposed as follows: 
F =0.859 T -0.2186 G, * 
or, if the milk is poor and has been skimmed, 
F = 0.859 T - 0.2186 G - 0.05 (JjL_ 2.5). MILK ANALYSIS. 
59 
(6) By weight.-Five grammes of milk are accurately weighed 
in a platinum dish with about 10 grammes of dry sand or pow- 
dered gypsum. The milk is then evaporated and the whole care- 
fully dried at 100° C., until a constant weight is obtained. The 
loss in weight gives the water of the milk, and, by difference, the 
total solids. 
Ash. By incinerating the solids obtained in the last test, the 
percentage of ash may be determined. 
Detection of Adulterants in Milk. 
Certain substances are occasionally added to milk for the pur- 
pose of preservation, and while not strictly adulterants, in inten- 
tion, may be injurious to health and should be mentioned here. 
Probably the most common of these are sodium carbonate, benzoic 
acid, salicylic acid, borax, boric acid, etc. These will be detected 
in the course of the clinical analysis by the increase in the ash, 
and may then be identified by special tests. 
Of adulterants proper, ivater is by far the most common and will 
be detected by variation in the specific gravity, total solids, etc. 
Though fraudulent, however, the addition of water, provided the 
latter be pure, has not the same injurious effect as the skimming of 
the milk, an adulteration by subtraction of food value. Annatto, 
added to increase the rich appearance of the milk, is not of itself 
harmful. Its presence may be detected by rendering the milk 
alkaline and soaking in it strips of filter paper. These latter will 
gradually acquire a yellow tint. Starch may be tested for by the 
addition of iodine solution, a blue color being developed. Cane 
Sugar will reveal itself in the taste and in the proportion of total 
solids, as well as in the percentage of sugar found. Chalk will be 
deposited on standing, and may be tested for in the ash. Other 
substances, but rarely met with, are glycerine, magnesium car- 
bonate, tragacanth, dextrin, and arrow-root. These will increase 
the total solids, and may be identified by special tests. THE URINE. 
Constituents of Normal Urine.-Urea and related substances; uric 
acid, xanthine, creatinine, etc. Fatty and other non-nitrogenous 
substances; fatty acids, oxalic, lactic acids, minute quantities of 
carbohydrates. Aromatic substances; etherial sulphates of phenol, 
cresol, pyrocatechin, indoxyl and skatoxyl, hippuric acid, etc. 
Pigments and ferments. Inorganic substances; chlorides, sul- 
phates and phosphates of sodium, potassium, calcium and mag- 
nesium, ammonium compounds and carbonates. Gases; nitrogen 
and carbonic anhydride. 
Abnormal Constituents.-Serum albumin and other proteids; blood 
and bile pigments, bile acids, abnormal urinary pigments; glu- 
cose, lactose, and glycuronic acid; leucin and tyrosin; fats, lecithin, 
chloresterin, cystin; blood corpuscles, pus, casts, renal epi- 
thelium, etc. 
In the urine of the 24 hours, averaging 1500 c.c., with a total 
of 60 grammes dissolved solids, the proportions are as follows:- 
( Hammarsten.) 
Urea, . . 30.0 grammes. Sodium Chloride, 15.0 grammes. 
Uric Acid, . 0.7 " Sulphuric Acid, 2.5 " 
Creatinine, . 1.0 " Phosphorus Pen- 
Hippuric Acid, 0.7 " toxide, . 2.5 " 
Other Organic Potassium Oxide, 3.3 11 
Constituents, 2.6 " Ammonia, . 0.7 " 
Magnesium Oxide, 0.5 " 
Total Organic, 35.0 grammes. Calcium Oxide, 0.3 
Other Inorganic 
Constituents, 0.2 " 
Total Inorganic, 25.0 grammes. 
General Plan of Clinical Urinary Analysis. 
I. Ascertain Quantity passed in 24 hours, and obtain an 
average Sample. 
60 URINE ANALYSIS. 
61 
II. Note Color, Appearance, and Odor. 
III. If turbid, test Character of Sediment. 
IV. Test Reaction with litmus paper. 
V. Determine the Specific Gravity. 
VI. Calculate the Total Solids. 
VII. Set aside a sample for Microscopic Examination; filter 
the remainder of the urine and use filtered urine for 
the following tests: 
VIII. Test for Mucin. 
IX. Test for Albumin, and, if present, determine amount. 
X. Test for Sugar in a sample from which the albumin, if 
originally present, has been removed by boiling and 
filtering. If sugar be found, determine amount. 
XI. Determine the amount of Urea. (In albumin free 
Urine.) 
XII. Determine the approximate amount of Chlorides. 
XIII. Determine the approximate amount of Sulphates. 
XIV. Determine the approximate amount of Phosphates. 
XV. Test for Blood. 
XVI. Test for Bile. 
XVII. Make Microscopic Examination of the Sediment. 
Notes on the Clinical Analysis. 
Quantity. 
An adult man passes on an average, 1400 to 1600 c.c. of urine 
in 24 hours. Women secrete less than men; children absolutely 
less but relatively more, about 60 c.c. for each kilogramme of 
body weight, (man, about 23 c.c. for each kilo). The urine is 
increased after the ingestion of much liquid, reaching 2000 to 3000 
c.c. It is increased, also, in nervous excitement, hysteria, chorea, 
in forms of diabetes, and in the albuminuria of contracted kidney. 
It is diminished by profuse perspiration, hence in summer, by ab- 
stinence from liquid food, by sleep, often in valvular disease, 
acute inflammations, fever, diarrhoea, enteritis, etc.; often in 
chronic Bright's disease, and in uraemia. 
The sample selected for analysis, owing to variation in the com- 
position of the urine during the day, should be an average of that 
passed. If the average sample is not obtainable, note the time of 
passing; night, morning, before or after a meal, etc. 62 
URINE ANALYSIS. 
Color, Appearance and Odor. 
Normal urine is described as clear, straw-yellow, sherry colored, 
or amber. It varies normally in shade from nearly colorless to 
dark amber. In disease there is a similar variation in shade and 
also frequently a variation in color. It is light colored after inges- 
tion of a large amount of water, and often nearly colorless in 
diabetes. It is dark after profuse perspiration, muscular activity, 
etc., and in acute febrile conditions. It may be red from presence 
of blood pigments, or greenish-yellow, brown, to black from presence 
of bile. "Blue" urine is sometimes observed in cholera and in 
typhus. Again, the color may be due to drugs ingested; phenol 
and gallic acid, producing a black urine; santonin, chrysophanic 
acid, rhubarb, senna, etc., a yellow urine. 
In case the color be so pronounced as to interfere with the chem- 
ical tests, the urine should be decolorized by shaking with pow- 
dered animal charcoal and filtering. 
The urine is usually clear when passed, though a faint cloudi- 
ness is not uncommon. All urines become turbid on standing. 
A turbidity may be due to an excess of mucus, to pus, chyle, 
semen, phosphates, urates, etc. By heating, the turbidity due 
to phosphates is slightly increased, but it disappears at once on the 
addition of a few drops of nitric acid or of acetic acid. By heat- 
ing, the turbidity due to urates disappears. If due to pus or to 
mucus, the turbidity is increased by heat and also by acetic acid. 
The odor of normal urine is described as aromatic. After stand- 
ing, however, it may become ammoniacal. Asparagus, turpentine, 
cubebs, valerian, and garlic, all impart characteristic odors. The 
urine of diabetes has a sweetish odor, that of albuminuria, after 
standing, often a fetid odor. 
Reaction. 
The reaction of an average sample of normal urine is always 
acid; the total acidity in terms of oxalic acid being about 2 
grammes for the 24 hours. The acidity is reduced, or the urine 
may become alkaline, after hearty meals, hot baths, administration 
of alkaline salts, etc., in starvation, with a strictly vegetable diet, 
in general debility, chlorosis, or anaemia. The acidity is increased 
with a meat diet, by muscular activity, in fevers, typhus, and 
often in pneumonia. URINE ANALYSIS. 
63 
Upon standing the urine may at first become more acid, from 
decomposition of urates, but later an alkaline fermentation sets 
in, the urea is decomposed and ammonium carbonate formed. 
At this stage the turbidity is increased by precipitation of phos- 
phates, and an ammoniacal odor is noticeable. 
For the quantitative determination of the acidity, see under Volu- 
metric Analysis. 
Specific Gravity. 
The specific gravity of normal adult urine varies generally be- 
tween 1010 and 1030, with an average of 1020 for 1500 c.c. passed. 
In children from two to thirteen years of age the average is about 
1012. 
In order that the determination of the specific gravity shall be 
of any value, it is necessary to know the amount passed and to 
use an average sample. When the amount passed varies from the 
normal (1500 c.c.) the specific gravity of the average sample may 
be reduced to the normal by the formula:- 
A.x G- + 1000 = D 
1500 
In which A equals the amount passed, G equals the last two 
figures of the observed specific gravity, and D equals the specific 
gravity of the urine reduced to the normal quantity. Thus, sup- 
pose 3000 c.c. were passed, and the specific gravity of the average 
sample to be 1015. 
3000 x 15 1000 _ 1030 
1500 
Reduced to the normal, then, of 1500 c.c., the specific gravity is 
1030, showing that though the specific gravity of the original 
sample was low, the total solids are in reality high. 
Considered with the amount passed in 24 hours, the specific 
gravity gives the following indications: A decreased amount with 
increased specific gravity indicates diminished secretion, loss of 
water by other excretions, or the presence of some morbid process, 
fever, etc. An increased amount with decreased specific gravity in- 
dicates abundant ingestion of water, absorption of exudations, or 
some form of diseased kidney. A decreased amount with decreased 
specific gravity indicates, possibly, uraemia, or some forms of Bright's 64 
URINE ANALYSIS. 
disease. An increased amount with increased specific gravity may in- 
dicate diabetes mellitus. 
The specific gravity is usually determined by means of the 
urinometer, a small hydrometer with special scale. This scale is 
adjusted to give accurate readings at a certain temperature (usually 
60° F.) marked upon the instrument, and as the temperature of 
the urine tested is nearly always above this, it is necessary, in ac- 
curate determinations, to make a corresponding correction. The 
temperature of the urine is determined and for each 6° above 
60° F., one is added to the observed specific gravity. Thus the 
corrected specific gravity for a urine reading 1020 at 72° F. is 
1022. For more accurate determinations it is necessary to use the 
pycnometer, for which, see works on physics. 
Total Solids. 
The total solids average in normal urine from 55 to 65 grammes 
(840 to 1000 grains) in the 24 hours. They may be calculated 
with sufficient accuracy for clinical purposes by multiplying the 
last twTo figures of the specific gravity by Haser's coefficient, 2.33. 
The product expresses the number of grammes in 1000 c.c. of 
urine, and from this the number of grammes in the urine passed 
may be easily calculated. By using 0.233 instead of 2.33, the 
percentage of total solids may be obtained at once. Other factors 
or coefficients, which have been proposed, are Trapp's = 2, and 
that of Loebisch = 2.2; Haser's, however, is generally accepted as 
the most accurate. For the urine of young children, the coefficient 
1.80 should be used. In English measure the number of grains 
of total solids in 24 hours may be roughly calculated by multi- 
plying the last two figures of the specific gravity by the number 
of fluid ounces passed. 
Mucin. 
Mucin may be present in normal urines, but it is greatly in- 
creased by irritation of the urinary tract. It is precipitated by 
acetic acid in the cold (unlike albumin) and may best be tested 
for by floating the clear filtered urine over acetic acid in a test 
tube. A cloudy coagulum is formed above the surface of contact. 
Mucin is not precipitated by boiling, but is precipitated by dilute 
mineral acids, as well as by acetic, citric, and other organic acids. 
See, also, under Urinary Sediments. URINE ANALYSIS. 
65 
Albumin. 
Normal urine is free from proteids, but, on the other hand, the 
presence of a trace of albumin is not necessarily always patho- 
logical. Temporary albuminuria may occur after severe bodily 
exertion, after the shock of a cold bath, from excess of albuminous 
foods, from the presence of semen, etc. When more than a trace 
is present, or when this trace persists for a considerable time, the 
existence of a serious abnormal condition is indicated. Serum 
albumin and serum globulin are the forms most frequently met 
with, while haemoglobin, fibrinogen, peptones and proteoses, may 
also appear. In general, the immediate cause of albumin in the 
urine may be stated as impaired circulation through the glomeruli 
of the kidney, a result of either venous or arterial disorder, of 
changes in the blood itself, or of diseased condition of the kidney. 
The albuminuria of pregnancy, like that due to ovarian or uterine 
tumors, is a result of disordered venous reflux, and the same may 
be said of the albuminuria of heart disease. Albumin may occur 
in gout, from faulty renal metabolism, in scarlet fever, diphtheria, 
pneumonia, and in poisoning by phosphorus or morphine. It is 
typical in Bright's disease. In acute Bright's disease there is 
much albumin and often blood. In large white kidney there is 
also much albumin, while in granular contracted kidney and in 
albuminoid kidney, there is an increase in the amount of urine 
and a decrease in the albumin. 
Typical albuminous urine is pale greenish-yellow, of low specific 
gravity, forms a persistent froth on shaking, and usually deposits a 
sediment soon after being passed. 
Heat Test. A long test tube is three-quarters filled with clear 
acid urine and the upper half of this is carefully heated to 
boiling. A cloudiness appearing in the heated portion may be due 
to albumin or to phosphates. Add a few drops of nitric acid, 
phosphates will be dissolved and any cloudiness remaining will be 
due to albumin. 
Precautions.-If the urine is not already acid, acidify, before 
heating, by addition of a few drops of nitric acid. Acetic acid 
may be used, but has the double disadvantage of being more 
likely to cause the solution of a trace of albumin than nitric, and 
also of precipitating mucin. A cloudiness appearing only after 
some minutes may be due to albumoses. Urates, if abundant, 66 
URINE ANALYSIS. 
sometimes separate on cooling, but are not likely to be mistaken 
for albumin. When adding the nitric acid, after heating, should 
the first few drops cause no precipitate, continue the addition of 
acid until one drop has been added for each c.c. of urine. 
Nitric Acid Contact Test. Warm some pure nitric acid in a 
test tube, and then float over it carefully by means of a pipette, 
an equal volume of the urine to be tested. A white zone or ring 
at the contact of the two liquids indicates albumin. 
Precautions.-A pink, red, or brown color may appear at the 
contact, due to action of the acid on the coloring matters of the 
urine. When cold acid is used in the test, crystalline nitrate of 
urea may separate at the contact, or acid urates may cause a 
cloudiness just above. Resinous matters, if present, as after in- 
gestion of turpentine, balsams, etc., may cause a yellowish-white 
zone, soluble, however, in alcohol. (Unlike albumin.) 
Ferrocyanide Test. Add a little dilute acetic acid to the urine, 
filter if mucin be precipitated, and then float the clear acidified urine 
over a solution of potassium ferrocyanide in a test tube. A white 
zone forming at the contact of the two liquids indicates albumin. 
This is a delicate and accurate test, albumoses and nucleo-albu- 
mins being the only other substances precipitated. 
Picric Acid Test. Warm some picric acid solution in a test 
tube and add the urine to it, drop by drop. A slight opalescence 
as each drop of urine enters the acid indicates albumin. This 
test may also be performed by the contact method, floating the 
acid over the urine. 
Precaution.-If cold acid be used, peptones, mucin, and alka- 
loids, may also be precipitated. With the warm acid the test is 
exceedingly delicate. 
For other tests, see Albumin, Part II. 
Quantitative Estimation. The quantitative estimation of al- 
bumin is difficult, and an accurate determination is rarely possible 
in the ordinary clinical analysis. A rough comparison of the 
amount of albumin in the urine from day to day may be made 
from the bulk of coagulum obtained by the heat test, using always 
the same size tube and the same amount of urine. A more accu- 
rate estimation may be made with EsbacE s Albuminometer. The 
urine, diluted with a known volume of water, if there be much 
albumin, is introduced into the tube to the mark U, and Esbach's 
reagent (see Appendix) added to the mark R. The mixture is URINE ANALYSIS. 
67 
shaken, the tube stoppered and allowed to stand 24 hours. The 
volume of the precipitate measured by the graduations, gives the 
percentage of albumin. Each main division equals 0.1 per cent. 
There is rarely more than 1.0 per cent, of albumin present. 
A still more accurate method, is the following: The urine is di- 
luted with 9 volumes of water, and from this diluted urine (one- 
tenth urine) test solutions are prepared, each containing 10 c.c. 
of water and a measured volume of the one-tenth urine; e. g., 
(1) Contains 10 c.c. of water plus 1 c.c. of the one-tenth urine; 
(2) Contains 10 c.c. of water plus 2 c.c. of the one-tenth urine, 
etc. Nitric acid contact tests are now made with each test solution 
until one is found which responds only after standing for 2-3 
minutes. The percentage of albumin in the original urine may 
be calculated from the formula: 
30 V 
In which V equals the volume of one-tenth urine added to the 10 
c.c. of water, and P equals the percentage sought. For instance, 
if to the test solution, which produces a zone of coagulum only 
after standing 2-3 minutes, 5 c.c. of the one-tenth urine had been 
added, then the percentage of albumin originally present is 
10 + = 0.10 per cent. 
30 X 5 1 
Sugar in Urine. 
Transitory glycosuria, may occur in cerebro-spinal meningitis, in 
epilepsy, from brain injuries, under the influence of strong emo- 
tion, in pneumonia, ague, cholera, gout, in chloroform narcosis, 
and after excessive use of saccharin or starchy food. Lactose is 
frequently present in the urine of mothers during the weaning 
period. Permanent glycosuria is indicative of diabetes. In general, 
diabetic urine is pale straw-colored with sometimes a greenish tint, 
it is often turbid and has a characteristic sweetish odor. The 
specific gravity is high (1030-1050) and the quantity passed is 
seldom less than 1600 c.c. in 24 hours. It may vary, however, 
between the extreme limits of 500 c.c. and 8000 c.c. Diabetes 
mellitus with polyuria, is far more serious than without, and, in- 
deed, glycosuria without polyuria does not seem to be necessarily 68 
URINE ANALYSIS. 
fatal. The percentage of sugar varies from 2-3 per cent, to 12 
per cent. 
Trommer's Test. Add to the urine in a test tube about one- 
fourth its volume of sodium hydroxide, and then dilute copper 
sulphate, drop by drop, until a slight permanent precipitate is 
formed. In the presence of glucose the bluish white precipitate 
of cupric hydroxide first formed, dissolves on agitation, producing 
a dark blue solution. Heat the liquid and, in presence of glucose, 
yellow cuprous hydroxide and red cuprous oxide are precipitated 
just as the liquid begins to boil. The same precipitation takes 
place without heating, but much more slowly. 
Precautions.-A normal urine will often decolorize the solution, 
but no red precipitate is formed. The sodium hydroxide causes a 
precipitation of flocculent phosphates, which, however, bear no 
resemblance to the granular cuprous precipitate. A precipitate of 
yellow cuprous hydroxide, which separates on the cooling of the 
test, is probably not due to sugar. Uric acid, hypoxanthin, mticus, 
albumin, peptones, pepsin, creatinine, and excessive urinary pig- 
ments, all interfere with the delicacy of the test. Glycuronic acid, 
(see p. 77), is also a frequent cause of error. When there is but 
a slight reduction, greater delicacy may be attained by clarifying 
the urine with animal charcoal or lead acetate, filtering, and test- 
ing the filtrate. 
Fehling's Test, Haines' Test, etc. (See Appendix for the 
solutions.) 
Heat the diluted test solution in a tube to boiling, and add the 
urine drop by drop until nearly an equal volume has been intro- 
duced. A yellowish-red precipitate, as in Trommer's Test, indi- 
cates glucose. 
Precautions.-The test solution should remain clear when boiled 
before addition of the urine. The precautions given under Trom- 
mer's Test apply here, and should be carefully observed. 
Bottger's Bismuth Test. To a few c.c. of the urine in a test 
tube, add an equal volume of sodium hydroxide and a few grains 
of bismuth subnitrate. Mix well and boil for several minutes. 
In presence of glucose, black metallic bismuth will be precipitated. 
A slightly more delicate reaction is obtained by using the Almen- 
Bottger Test, (Nylander's). Ten c.c. of urine are boiled with 
1 c.c. of Almen's reagent, (see Appendix); black metallic bismuth 
is separated. URINE ANALYSIS. 
69 
Precautions.-Albumin, if present, will cause the precipitation 
of black bismuth sulphide. Many normal urines will cause a 
slight darkening of the bismuth subnitrate, such as might be pro- 
duced by a trace of sugar. 
Phenyl Hydrazine Test. To 50 c.c. of urine add 2 grammes 
of phenyl hydrazine hydrochloride, and about 4 grammes of sodium 
acetate. Dissolve the reagents in the urine and heat on the water 
bath for 45 minutes. In presence of glucose fine yellow crystalline 
needles of phenyl glucosazone separate out on cooling. 
Precautions.-A similar precipitate is given by other carbohy- 
drates. It may be necessary to examine the precipitate micro- 
scopically for the characteristic crystals, or even to determine their 
melting point (204°-205° C.) in order to positively identify them. 
Fermentation Test. (See p. 42). This test is useful in identi- 
fying glucose in presence of other reducing substances.' 
Indigo-Carmine Test. (See p. 42). This is an exceedingly 
delicate test, but gives a faint reaction with nearly all urines. 
Alpha-Naphthol Test. (See,p. 43). Delicate, and often 
recommended. 
Quantitative Determination. By Fehling's Solution.-Ten c.c. 
of Fehling's solution (see Appendix) are measured into a porce- 
lain dish with 30 to 40 c.c. of water. The diluted solution is 
heated to boiling and the urine added from a burette until the blue 
color of the Fehling's solution has entirely disappeared. Note the 
number of c.c. of urine required to produce this result, and calcu- 
late the amount of glucose present, by the formula = P, in 
which U represents the number of c.c. of urine added to produce 
complete decomposition, and P equals the percentage of glucose 
in the sample. From this the amount passed in the 24 hours 
urine can be calculated. When considerable sugar is present, it is 
well to dilute the urine with a known volume of water, to deter- 
mine the glucose in the diluted sample, and then to calculate back 
to the original. 
This method is by far the most satisfactory of any possible to 
the clinical observer. The fermentation processes, which follow, 
are not to be recommended unless reducing substances other than 
glucose are known to be present. Approximate results only are 
obtained. 
Roberts' Fermentation Method.-After a careful determination of 70 
URINE ANALYSIS. 
its specific gravity, the urine, together with a small piece of com- 
pressed yeast, is placed in a loosely stoppered flask and left for 24 
hours. The alcohol and carbonic anhydride produced by the fer- 
mentation, reduce the specific gravity of the solution one degree 
for each grain of sugar per fluid ounce. At the end of the opera- 
tion the specific gravity is again determined, the loss representing 
the number of grains of sugar per fluid ounce. This number 
multiplied by 0.23 gives the percentage of glucose in the sample. 
It is well to make a parallel test on a sample without sugar, ob- 
serving any variation that may occur in its specific gravity. 
Einhorn's Method.-Ten c.c. of the urine are shaken with about 
1 gramme of compressed yeast, and the mixture introduced into 
Einhorn's apparatus, a small graduated tube of special form. 
The carbonic anhydride gas evolved is measured at the end 
of 24 hours, its volume expressing directly, by the graduations on 
the tube, the percentage of glucose present. 
Urea. 
The urea varies in normal urine from 20 to 40 grammes (309 to 
617 grains) in the 24 hours, with an average of about 33 grammes 
(500 grains). Women secrete less than men, children absolutely 
less, but relatively, i. e., in proportion to body weight, more. 
The urea is increased by a nitrogenous diet, by mental and, possi- 
bly, physical activity, at the beginning of the crisis in fevers, in 
ague, in diabetes, in pleurisy, and in acute tuberculosis. The 
urea is decreased by profuse perspiration, by diarrhoea, in cholera, 
in the later stages of chronic Bright's disease, in diabetic coma, in 
anaemia, and generally, in most chronic debilitating disorders. 
Expressing, as it does, the progress of nitrogenous metabolism in 
the body, the determination of the urea passed is important. 
Approximate Estimation.-When the chlorides are normal and 
when sugar and albumin are absent, the urea may be taken as 
one-half the total solids. 
Hypobromite Method.-There are several applications of this 
method, depending on differences in the form of apparatus used; 
the principle is the same, however, in all. A solution of sodium 
hypobromite containing an excess of sodium hydroxide, (see Ap- 
pendix), is added to the urine; the urea is decomposed, nitrogen 
gas is set free, and sodium bromide and carbonate are formed. URINE ANALYSIS. 
71 
CON2H4 + 3NaBrO + 2NaOH = 3NaBr + Na2CO3 + N2 + 3 H20. 
The nitrogen evolved is measured and, from its volume, the per- 
centage of urea calculated. 
A solution of chlorinated soda with potassium bromide may be 
used in place of the alkaline hypobromite. It has the advantage 
of keeping better and of being more easily obtainable. (See Ap- 
pendix. ) 
Twenty c.c. of fresh hypobromite solution (40 c.c. of the chlori- 
nated soda) are placed in a bottle, and the measured urine, con- 
tained in a small test tube, is introduced in such a manner that 
the tube will stand in the bottle without spilling. The bottle is 
then connected by means of a perforated stopper and rubber tube 
with the top of an inverted burette standing in a jar of water. 
All connections are carefully made, and the volume of air in the 
burette read from the graduations. The urine is now slowly mixed 
with the hypobromite, nitrogen gas is evolved, and a correspond- 
ing volume of air is driven from the bottle, displacing the water 
in the burette. When the evolution of gas has ceased, let the ap- 
paratus stand for a few minutes, and then measure again the air 
in the burette. The increase in volume represents the volume of 
nitrogen given off. The observed increase, in c. c., multiplied by 
the factor 0.0028 gives the weight in grammes of urea in the 
sample taken; e. g., if 4 c.c. of urine were used for the test, and 
20 c.c. of nitrogen were evolved, then we have, 0.056 gramme 
(0.0028 X 20) of urea in 4 c.c. of urine, or, 1.40 per cent. 
(0.056 -4 x 100). 
Theoretically the factor employed should be 0.00268, but as the 
theoretical volume of nitrogen is not given off, 0.0028 gives more 
accurate results. In reading the volume of gas in the burette it is 
of course necessary that the latter shah be raised or lowered so as 
to bring the water on the same level inside and out. 
The ureameter devised by Prof. Doremus, of N. Y., is con- 
venient and with practice yields excellent results. The small 
quantity of urine (1 c.c.), however, which is used increases the 
liability of error. With this apparatus, the percentage of urea is 
read directly from the graduations on the tube. 
Uric Acid and Urates. 
Uric acid is normally present in the urine in combination, as a 72 
URINE ANALYSIS. 
urate. It is increased in pneumonia, indigestion, acute rheuma- 
tism, and in disorders of the circulation and respiration. It is 
decreased in most chronic diseases, in the later stages of Bright's 
disease, in diabetes, in gouty affections, and in chronic rheuma- 
tism. It is to be remembered that the appearance of a deposit of 
uric acid, or of urates, does not necessarily point to an excess of 
these ingredients. High acidity of the urine, and a decrease in 
mineral salts, tend to produce a separation of uric acid equally 
with the presence of an increase of that substance. The deposits 
are easily recognized. (See under Urinary Sediments.) 
Uric acid may be separated from the urine as follows : To 200 
c.c. of urine add 20 c.c. of strong hydrochloric acid and let the 
mixture stand 48 hours. Collect the sediment on a previously 
weighed filter paper, wash with cold water, dry and weigh. The 
increase in weight represents uric acid. 
To detect uric acid or urates apply the Murexid Test. Evaporate 
the sediment with a drop of strong nitric acid. A yellow residue 
is obtained, which, when moistened with a drop of ammonium 
hydroxide, turns purple. 
Chlorides. 
The chlorine of the 24 hours urine varies from 6 to 10 grammes, 
equivalent to 10 to 16 grammes of sodium chloride. The average 
for an adult man may be placed at 7 grammes chlorine (11.5 
grammes sodium chloride), for women, at 6 grammes chlorine, 
and for children, about 5 grammes chlorine. The amount varies 
during the day, being increased several hours after a full meal, and 
by mental or physical labor. It is diminished, in most fevers (in- 
creasing again after the crisis), in pneumonia, pleurisy, typhoid, 
cholera, and in many chronic diseases. 
Approximate Estimation.-To the urine in a test tube add a few 
drops of nitric acid and one drop of a concentrated solution of 
silver nitrate. If the chlorides be normal, a curdy white precipi- 
tate is formed ; if low, only a milky cloudiness ; if absent, there 
is no precipitate. For the accurate determination of the chlorides, 
see under Volumetric Analysis. 
Sulphates. 
Sulphuric acid is found in the urine conibined with both organic 
and inorganic bases, the latter combination being normally in ex- URINE ANALYSIS. 
73 
cess of the former. The sulphates are increased by animal food, 
by physical activity, by ingestion of sulphur compounds, in acute 
inflammatory diseases, pneumonia, acute rheumatism, delirium, 
and often in diabetes insipidus. They are decreased, with dimin- 
ished metabolism in chronic affections, in leukaemia, and in dia- 
betes mellitus. 
Approximate Estimation.-Add to the urine a few drops of hydro- 
chloric acid and one-fourth volume of barium chloride. An 
opaque milky cloudiness indicates normal sulphates ; an opaque 
creamy precipitate, increased sulphates ; a faint semi-transparent 
cloudiness, diminished sulphates. 
Sulphates of Organic Bases. Sulphates of phenol, cresol, 
pyrocatechin, indol, skatol, etc. These compounds are derived 
partially from the food, but are interesting chiefly as putrefaction 
products absorbed from the intestine. In normal urine they are 
present in small amount, probably about 10 per cent, of the total 
sulphates, but in certain stomach troubles, in disordered absorp- 
tion, and from abnormal fermentative and putrefactive changes, 
they may be considerably increased.* 
Determination of Organic Sulphates.-100 c.c. of the urine are 
mixed with 100 c.c. of Barium Mixture, (2 volumes of saturated 
solution of barium hydroxide with 1 volume of saturated barium 
chloride) and the precipitate formed, filtered off. An aliquot 
part of the filtrate is acidified with hydrochloric acid and boiled. 
It is then heated to 100° C. for an hour, allowed to stand until 
completely settled, and finally filtered through an ashless paper. 
The precipitate is dried, ignited and weighed. The weight of 
barium sulphate found multiplied by 0.34335 gives its equivalent 
in terms of sulphuric anhydride. 
The Total Sulphates may be determined by acidifying the urine 
with hydrochloric acid, boiling, and adding barium chloride until 
all is precipitated. The precipitate is then treated as described 
above. 
Phosphates. 
The phosphates of the urine may be divided into two classes, 
the alkaline phosphates, phosphates of sodium and potassium ($); 
the earthy phosphates, phosphates of calcium and magnesium (|). 
The latter are subject to but little variation in disease. The total 
phosphates are increased, in acute inflammatory diseases, in the 74 
URINE ANALYSIS. 
early stages of acute fevers, in phthisis, leukaemia, osteomalacia, 
and sometimes in diabetes. They are decreased, in many chronic 
brain troubles, in epilepsy, general paralysis, melancholia, etc., 
in some forms of Bright's disease and of heart affections, in chlo- 
rosis, rickets, gout and chronic rheumatism. 
Total Phosphates.-Add to the urine magnesia mixture (see 
Appendix) and ammonia. The total phosphates are precipitated, 
and can be compared with a corresponding precipitate from a 
normal urine. 
Earthy Phosphates.-Approximate Estimation.-Place 2 inches of 
urine in a 6-inch test-tube, add a few drops of sodium hydroxide 
and heat to boiling. Set aside for 15 minutes to allow the pre- 
cipitate to settle. If the phosphates be normal the precipitate 
will occupy about inch at the bottom of the tube; if high, 1 
inch or more; if low, less than | inch. 
Alkaline Phosphates.-Approximate Estimation.-Add ammonia to 
the urine, filter from the precipitated earthy phosphates, and to 
the filtrate add volume of magnesia mixture. A milky appear- 
ance on shaking indicates normal phosphates; a creamy appear- 
ance, increased phosphates; a slight cloudiness, decreased phos- 
phates. 
For the accurate determination of Phosphates see under Volu- 
metric Analysis. 
Blood. 
Blood in the urine may be derived from the kidneys, in cancer, 
acute nephritis, after powerful diuretics, etc.; from the bladder, 
in diphtheritic and acute cystitis, calculi, carcinoma, congestion, 
etc.; from structural disease of the prostate, and from mechanical 
injury. When uniformly mixed with the urine the blood is prob- 
ably from the kidneys; when stringy, or in clots, it is more likely 
to be from the bladder, prostate, or urethra. Unless in consider- 
able quantity, its recognition is best effected by microscopic ex- 
amination of the sediment, or by spectrum analysis. When pres- 
ent in any considerable amount, the urine will be dark red or 
brown, often ' ' smoky ' ' in appearance, and the precipitate of 
earthy phosphates with sodium hydroxide (Heller's Test for blood) 
will be reddish instead of white. Should the urine be alkaline 
and the phosphates already precipitated, add an equal volume of 
normal acid urine and a few drops of barium chloride before boil- URINE ANALYSIS. 
75 
ing with sodium hydroxide. Hemoglobin may be detected by 
the Guaiacum Test. A mixture of freshly prepared tincture of 
guaiacum with 11 ozonized ether, ' ' or old oil of turpentine, is added 
to the urine. A blue color indicates the possible presence of 
haemoglobin. Lecanau's Test may be used for the detection of 
haematin. The urine is acidulated with acetic acid and boiled. 
The brownish coagulum of albumin and haematin is separated by 
decantation, washed with water, and shaken with alcohol which 
has been acidified with sulphuric acid. The reddish-brown solu- 
tion is filtered and the filtrate examined spectroscopically, or, it 
may be evaporated to dryness and the residue tested for iron. 
Bile. 
Bile constituents may occasionally appear in the urine of healthy 
persons, particularly during the heat of summer, but as a rule 
their presence is characteristic of the condition known as jaundice. 
Bile pigments and bile acids may both be present, but the clinical 
examination is practically limited to the former. The urine is 
generally yellowish-brown to green, sometimes almost black, and 
yields a characteristic yellow froth on shaking. It must be re- 
membered, however, that certain drugs may produce a similar 
appearance. 
Tests for Bile Pigments. Ultzmanris Test.-To lOc.c. of urine 
add 3 to 4 c.c. of sodium hydroxide and an excess of pure hydro- 
chloric acid. An emerald green color indicates bile pigments. 
Gmelin's Test.-The urine is floated over yellow nitric acid in a 
test tube. A succession of colors, green, blue, violet and red, will 
appear at the contact of the two liquids. 
FleischVs Test.-The urine mixed with nitric acid, or with sodium 
nitrate, is floated over strong sulphuric acid in a test tube. The 
same succession of colors appears, as in the last test. 
Test for Bile Acids. Pettenkofer's Test.-Evaporate about 200 
c.c. of urine to dryness, extract the residue with absolute alcohol, 
filter, evaporate the alcoholic filtrate, and dissolve the second res- 
idue in a little water. Add a few drops of a concentrated solution 
of cane sugar, and a drop of sulphuric acid, then warm the mix- 
ture in a capsule. A purple or cherry-red color indicates the 
presence of bile acids. 
Instead of evaporating the alcoholic filtrate, the bile acids may 
be precipitated from that solution by an excess of ether, the pre- 76 
URINE ANALYSIS. 
cipitate separated, and dissolved in water. The water solution in 
either case will probably need to be decolorized by animal char- 
coal, before applying the color test. 
Other Pathological Ingredients. 
Serum Globulin.-This resembles serum albumin and generally 
accompanies it in the urine. It is insoluble in water and may be 
detected by dropping the urine slowly into a beaker of clear water, 
each drop as it falls producing a slight cloudy appearance. Serum 
globulin responds to the regular albumin tests. 
Albumose.-Tested for, in presence of other proteids, as follows: 
Saturate the urine with sodium chloride, acidify with acetic acid, 
boil, and filter while hot. The albumose separates from the fil- 
trate on cooling, dissolve in water and apply the Ferrocyanide 
Test. (See p. 66.) 
Peptones.-Peptones may appear in the urine, in suppurative 
diseases, croupous pneumonia, typhoid, small-pox, scarlet fever, 
and in tuberculosis, though it is probable that deutero-albumose 
is often mistaken for the peptone. In presence of other proteids, 
acidify with acetic acid, add ammonium sulphate to saturation, 
filter and examine the filtrate for peptones by the xantho-proteic 
and biuret tests. Show the absence of other proteids from the 
filtrate by the nitric acid and ferrocyanide tests. (See p. 48.) 
Acetone.-Found in the urine in febrile conditions and in the 
later stages of diabetes mellitus. Half a litre of urine is distilled 
with phosphoric acid and the first 100 c.c. of distillate collected 
and tested. Le Nobel's or Legal's Test.-To 25 c.c. of the distillate 
add a little fresh solution of sodium nitroprusside and a few drops 
of strong sodium hydroxide. A ruby red color appears, slowly 
changing to yellow. Add acetic acid and boil; the color is changed 
to a greenish blue or violet. Chautard's Test.-A drop of aqueous 
solution of magenta, previously decolorized by sulphurous acid, 
added to the distillate, develops a rich violet color. 
Ethyldiacetic Acid.-This is related to acetone in its occurrence 
and is often confused with it. Diacetic Acid may be detected by 
boiling a sample of urine and adding thereto a few drops of ferric 
chloride. A deep red color is developed. If ferric phosphate 
should be precipitated, add the ferric chloride carefully until the 
precipitation ceases, filter, and then add a few drops more of the URINARY SEDIMENTS. 
77 
reagent. Other substances sojnetimes present give a red color with 
ferric chloride, but not after boiling. 
Glycuronic Acid.-Occurs in normal urine in traces, but is much 
increased after ingestion of chloral, chloroform, nitrobenzole, 
camphor, morphine, etc. It is of importance because of its re- 
semblance to glucose, responding to the principal glucose tests. 
The identification of glycuronic acid is difficult, but it maybe dis- 
tinguished from glucose by the fact that it does not undergo alco- 
holic fermentation with yeast. 
Pws.-May be due to renal abscess, inflammation or cancer of 
the bladder, suppuration of the prostate or uretha, to leucorrhcea, 
etc., etc. When the pus originates in the bladder the urine is 
often alkaline. It is best recognized microscopically/but if in 
considerable amount, the following tests may be applied. The 
whitish sediment always present in a urine carrying pus, is not 
dissolved by heat. It is insoluble in dilute acids, but soluble in 
sodium hydroxide, forming a gelatinous, ropy mass. Hydrogen 
peroxide added to pus causes a rapid effervescence. 
Fat.-May be due to an excess of fatty food, or it may occur in 
fatty degeneration of the liver, in phosphorus poisoning, etc., oc- 
casionally in diabetes mellitus and in Bright's disease. When the 
fat is present in considerable amount the urine will be more or less 
milky in appearance and, on standing, the fat globules will rise to 
the surface. The fat may be extracted from such a sample by 
agitation with ether. When present in small amount the fat 
globules, or fatty casts, will be recognized in the microscopic 
examination. 
URINARY SEDIMENTS. 
Urinary sediments may be divided into two groups, organized 
and unorganized, according to structure and composition. Organ- 
ized sediment includes mucus and pus cells, blood corpuscles, 
epithelium, casts, spermatozoa, fungi, etc. The unorganized sed- 
iment varies with the reaction of the urine, acid urine containing 
amorphous urates of sodium and potassium, crystalline uric acid, 
oxalate of lime, cystin, leucin and tyrosin ; while alkaline urine 
may contain amorphous phosphate and carbonate of lime, crys- 
talline urate of ammonium, triple phosphates, and phosphates of 
calcium and magnesium. 
The sediment for examination is separated from the urine by 78 
URINE ANALYSIS. 
deposition or by use of the centrifugal machine. When the ex- 
amination is to be delayed, it is necessary to guard against fer- 
mentative changes, and for this purpose camphor, salicylic acid, 
or better, chloroform, may be added. 
Organized Sediments. 
Mucus Cells.-Often present in normal urine. Round or oval 
globules with faintly marked margins, averaging about 0.01 mm. 
in diameter, but sometimes swelling to twice that size, generally 
with but a single nucleus. (See also, p. 64.) 
Pus Cells.-From suppuration in the urinary tract. Similar to 
mucus cells in appearance, but distinguished by being generally 
multi-nucfear. The indistinct nuclei are rendered more promi- 
nent by addition of acetic acid. The pus cells are distinguished 
from white blood corpuscles by their somewhat larger size, their 
granular appearance and their more , irregular outlines. The 
addition of alkalies converts pus into a gelatinous mass. Urine 
carrying pus yields albumin by chemical tests. (See also, p. 77.) 
Blood Corpuscles.-Recognized as more or less yellow biconcave 
discs with smooth or crenated margins, generally without nuclei. In 
dilute urine the corpuscle is often swollen, and occasionally is 
biconvex in form. In concentrated urine shrunken and crenated 
corpuscles are common. (See also, p. 74.) 
Epithelium.-Occurs in rounded, cylindrical, polygonal, or 
granular cells, often nucleated. These may originate in the 
bladder, ureters, pelvis of the kidney, kidney, vagina or urethra. 
The large, Hat "squamous" cells from the vagina and bladder 
are common in the urine of women. Renal epithelial cells are 
rounded or polygonal, small, and often with a large nucleus. 
Certain of the smaller round cells may resemble pus, but their 
single nucleus and greater size will easily distinguish them. 
Epithelium is much increased by catarrh in the urinary organs. 
Casts.-Moulds of the uriniferous tubules of the kidney, pointing 
to a diseased condition of that organ, inflammation, congestion, 
etc. Classed, according to appearance, as hyaline and waxy casts, 
epithelial casts, blood, fatty and granular casts. They are, in 
general, cylindrical in shape, with rounded ends, often nearly 
transparent and difficult to identify. They are best detected after 
staining with iodine or with magenta, and by use of concentrated 
light. They are quickly destroyed by the fermentation of the URINARY SEDIMENTS. 
79 
urine. Casts are found in acute and chronic nephritis, in chronic 
Bright's disease, in jaundice, etc., or they may be due to irrita- 
tion by renal calculi. Hyaline casts occur in albuminuria, in 
fever urine, and in many chronic disorders. As the disease or 
inflammation progresses, granular, epithelial and blood casts 
become more numerous. Fatty casts indicate a fatty degenera- 
tion. The presence of casts together with pus and blood, estab- 
lishes the renal origin of the latter. 
Fungi, Bacteria, etc.-Absent from normal urine when passed, 
but often developing rapidly on exposure to the air. The identi- 
fication of bacteria is difficult, requiring preparation of cultures 
and examination under high powers with appropriate staining 
agents. Yeast fungi are often abundant in diabetic urine. The 
micrococcus urese, derived from the atmosphere, multiplies rapidly 
in urine, and is the chief factor in the ammoniacal fermentation. 
Spermatozoa are often present, and may occasionally prove to 
be of medico-legal interest. Their characteristic form is easily 
recognizable under a high power. 
Unorganized Sediments. 
Uric Acid.-Common in acute fevers, uric acid diathesis, gravel, 
etc. Found in acid urine in red or brownish-yellow crystals. 
The crystals, which are described as whetstone, envelope, spear and 
fan shaped, are often gathered together in bunches or in rosettes. 
They are insoluble in acids, but are dissolved by alkalies and by 
heat. The murexid test (p. 72) may be applied. 
Urates.-Associated with uric acid in acid urines and found also 
as crystalline, or semi-crystalline, ammonium urate in alkaline 
urine. The amorphous urates are granular, often provided with 
spicules, and like the prismatic crystalline forms are reddish or 
yellow in color. The murexid test (p. 72) may be applied. 
Oxalates.-Oxalate of lime occurs in acid urine, in small octa- 
hedra or in envelope and dumb-bell forms. Its presence is not 
significant, though it may point to mal-assimilation, particularly 
from irregularity of diet. 
Phosphates.-In alkaline urine we may have amorphous and 
crystalline phosphates of lime, crystalline phosphates of mag- 
nesium, and crystalline triple phosphate. The latter, triple phos- 
phate, or ammonium magnesium phosphate, occurs in large 80 
URINARY CALCULI. 
crystals of various forms, often as triangular prisms with beveled 
edges, occasionally in stellate feathery forms. When present in 
freshly voided urine the triple phosphate indicates decomposition 
of the urine in the bladder. The presence of other crystalline 
phosphates and of amorphous phosphates is not particularly 
significant. 
Carbonates.-Rare as a sediment. Amorphous carbonate of lime 
may occur in alkaline urines, occasionally in imperfect dumb-bell 
forms, but generally as rounded or oval granules with dark 
contours. 
Leucin.-A rare sediment, occasionally appearing in white shiny 
lamellae, generally, however, in groups of yellowish striated 
spherules, somewhat like those of sodium urate, but distinguished 
from the latter by not dissolving on application of heat. They 
are distinguished from oil-drops by their insolubility in ether. 
Tyrosin.-A rare sediment, occurring with leucin in acute 
atrophy of the liver, in small-pox and in typhus. It is usually 
found in the form of yellowish-green globules, but when pure 
occurs in fine needle-like crystals radiating from a center. 
Cystin.-A rare sediment, found in colorless six-sided transpar- 
ent plates, often in overlapping masses. The crystals are soluble 
in hydrochloric acid and in ammonia, but are insoluble in water. 
The chief interest of cystin lies in its tendency to formation of 
calculi. 
URINARY CALCULI. 
Calculi may consist of uric acid and urates, of calcium oxalate, 
ammonium oxalate, and more rarely of phosphates, carbonates, 
cystin, xanthin, etc. As a rule, each calculus is built up of two 
or more of the above substances arranged in concentric layers 
around a central nucleus. These layers may often be separated, 
and in the analysis should be examined separately. 
Uric Acid and Urates form hard calculi, generally Smooth, often 
reddish or yellowish-brown in color, and of variable size. Pure 
Pho&phatie Calculi are of rare occurrence, though we frequently find 
phosphates deposited around a uric acid nucleus. The Fusible 
Calculus consists of a mixture of calcium, magnesium, and am- 
monium phosphates. It is readily fusible when heated, giving 
off vapor of water and ammonia. It resembles chalk in appear- 
ance and consistency. Calcium Oxalate is frequently met with, UR J NA RY CAL CULL 
81 
forming calculi often of considerable size, brown or olive in color, 
and with a rugged surface (mulberry calculi). When small and 
hard, the term hemp-seed calculus is applied. The rare Cystin 
Calculi are more or less transparent and waxy in appearance, 
though crystalline in structure. They are commonly tinted yel- 
low, changing to green on exposure. Xanthin Calculi are very 
rare. They are described as yellowish-brown in color, often with 
scattered white spots. Occasionally altered blood clots will form 
concretionary masses known as Fibrinous Calculi. 
The following scheme will serve as an aid in the recognition of 
the chief varieties of calculi: 
Pow'der the calculus and heat a small portion of the powder on 
platinum foil in the Bunsen flame. 
A. If it chars, burns, and leaves but little residue, it probably 
consists of either uric acid, urates, cystin, xanthin, or fibrin. 
Test a portion of the powder with boiling water; if soluble, we 
have urates; if insoluble, uric acid. Confirm in either case by the 
murexid test. 
Treat another portion of the powder with hydrochloric acid, and 
warm ; a residue may be uric acid; cystin and xanthine go into 
solution. Cystin gives a brown color with the murexid test and 
yields a residue soluble in ammonia. Xanthine gives a yellow 
color. Fibrinous calculi will be completely burned when heated, 
giving off the characteristic odor of burning feathers, and respond- 
ing to the proteid tests. 
B. Should the powder, when heated, char but slightly and leave 
a considerable residue, or possibly undergo no change at all, we 
may have phosphates, oxalates and carbonates of calcium and 
magnesium. 
A fresh portion of the powder is treated with dilute hydrochloric 
acid ; if soluble with effervescence, carbonates are present; if sol- 
uble without effervescence, we have phosphates or oxalates. A 
residue will probably consist of uric acid. Filter, render alkaline 
with ammonia, boil, acidify with acetic acid, and again filter. A 
white residue is calcium oxalate, which, if dried and heated on 
platinum, is converted into calcium carbonate, soluble in hydro- 
chloric acid with effervescence. 
To a portion of the filtrate, add a drop of ferric chloride; a pre- 
cipitate indicates phosphates. Add to the remainder of the fil- 
trate, oxalate of ammonium and ammonia; a precipitate indicates 82 
URINARY CALCULI. 
calcium. Filter and test the filtrate for magnesium with sodium 
phosphate. 
C. Should the powder when heated melt and give off water 
vapor with fumes of ammonia, the calculus consists of a mixture 
of calcium, magnesium, and ammonium phosphates. (The Fusi- 
ble Calculus). THE GASTRIC FLUID. 
The gastric fluid is a thin, almost colorless liquid, with an acid 
reaction, and a specific gravity of 1001 to 1010. The following 
analysis is given hy Schmidt: 
Water 994.404 
Organic Substances, chiefly pepsin . . 3.195 
Hydrochloric Acid 0.200 
Sodium Chloride 1.465 
Potassium Chloride 0.550 
Other Inorganic Salts .... 0.186 
The composition varies, however, during the digestive process 
and in disease. The average 1 ' total acidity ' ' is probably between 
0.10 and 0.36 per cent. The "free acid " is commonly stated as 
from 0.20 to 0.30 per cent., but these figures are undoubtedly high 
and only to be reached on a carbohydrate diet. With ordinary 
nitrogenous foods the free acid will rarely exceed 0.10 per cent. 
The hydrochloric acid formed in the early stages of digestion com- 
bines rapidly with the proteids, and is not likely to be detected in 
the fluid until about one hour after the meal. Lactic acid is com- 
monly present in small amount and, under certain conditions, 
butyric and other organic acids may appear. In fevers, in 
anaemia, in catarrh of the stomach, etc., pepsin and hydrochloric 
acid may both be considerably reduced. Hydrochloric acid may 
be absent in serious disease of the gastric mucous membrane, in 
atrophy, gastric cancer and chronic catarrh. On the other hand, 
it is often largely increased in nervous dyspepsia and in gastric 
ulcers. As a result of excessive fermentative changes, lactic and 
butyric acids may appear in large amount. In such a case there 
is always a corresponding increase in gaseous products, the 
stomach is distended and gaseous eructations occur. Among the 
abnormal constituents of the vomit, we may find excessive mucus, 
albumin, blood and bile, while in uraemia, urea and ammonium 
carbonate are also often present. 
83 84 
THE GASTRIC FLUID. 
The clinical examination of the gastric fluid (obtained best by 
use of the stomach tube about one hour after the administration 
of a test breakfast of bread and water) is practically limited to 
the determination of the total acidity, hydrochloric acid, or- 
ganic acids, and pepsin strength. The fluid is filtered and the 
clear filtrate tested, first qualitatively, for the acids. 
Free Hydrochloric Acid, Qualitative. Gunzberg's Test.- 
To a few drops of the filtered gastric fluid add an equal quantity 
of Gunzberg's reagent (see Appendix) and evaporate to dryness at 
a gentle heat. A bright red ring will form at the margin. It will 
be found convenient to use a flat porcelain dish for this test, 
rotating the same over a small flame and avoiding a high tem- 
perature. Organic acids do not give the reaction, but the test is 
said to respond to one part of hydrochloric acid in 10,000 parts of 
water. 
The materials for Gunzberg's reagent being expensive and some- 
times difficult to obtain, Boas' Test is often substituted. The 
procedure is the same as with Gunzberg's test, and the results are 
practically as accurate. For Boas' reagent, see Appendix. 
Congo-red Test.-In presence of considerable free hydrochloric 
acid, a dark blue spot is obtained by touching a piece of Congo- 
red paper with a drop of the gastric fluid. A light blue or violet 
spot may be due to organic acids. 
Methyl-Violet Test.-To 10 c.c. of water add a few drops of a 
solution of methyl-violet. Divide the test solution into 2 parts, 
and to one add an equal volume of filtered gastric fluid. Com- 
pare with the remainder of the test solution. A change in color, 
from violet to blue, indicates hydrochloric acid, but the delicacy 
of the test is destroyed by pepsin. 
Organic Acids, Qualitative. Uffelmann's Test.-Treat the 
gastric fluid filtrate with ether and evaporate the ether extract to 
dryness. Dissolve the residue in a small quantity of water and 
add a few drops of Uffelmann's reagent (see Appendix). The 
amethyst-blue of the reagent is changed to a canary-yellow by 
lactic acid (1-10,000). Hydrochloric acid in considerable amount 
decolorizes the reagent, and butyric acid turns it reddish-brown. 
Total Acidity, Quantitative.-Dilute 10 c.c. of the filtered 
gastric fluid with about 40 c.c. of water, add a few drops of al- 
coholic phenolphthalein solution, and titrate with decinormal 
sodium hydroxide until the liquid acquires a faint pink color. THE GASTRIC FLUID. 
85 
The number of c.c. of the decinormal alkali used, multiplied by 
0.00364 will give the weight in grammes of hydrochloric acid in 
the 10 c.c. of gastric fluid. From this the percentage may be 
calculated. For convenience the total acids are reported, as in- 
dicated above, in terms of hydrochloric acid. 
The relative amounts of free acid, organic acids, and acid pro- 
teids, may be determined by titrating a second, undiluted, sample 
of the gastric fluid. The decinormal alkali is added until a drop 
of the fluid under examination gives no reaction with Gunzberg's 
reagent. The number of c.c. of alkali used serves for the calcu- 
lation of the free acid. The addition of the decinorma] solution 
is continued until no reaction is obtained with Congo-red paper, 
and from the number of c.c. used the organic acids are estimated, 
being calculated in terms of hydrochloric acid. Phenolphthalein 
may now be added to the fluid, and the titration continued until 
the pink color is developed. From this last titration the acid 
proteids are calculated. The total deeinormal alkali used indi- 
cates the total acidity. 
For the principles involved in the above test, and for the pre- 
paration of the deeinormal alkali solution, see under Volumetric 
Analysis. 
Pepsin.-Tlje determination of the pepsin is of little practical 
value, it is rarely absent, and the digestion tests used are subject 
to other factors than the pepsin strength. Coagulated egg albumin 
is cut in discs 1 mm. thick and 10 mm. in diameter. Two discs 
are placed in each of 2 test tubes, together with 10 c.c. of the fil- 
tered gastric Huid. To one of the tubes add 2 drops of concen- 
trated hydrochloric acid, and then warm both for 1 to 2 hours at 
40° C. Complete solution should take place in both samples. VOLUMETRIC ANALYSIS. 
Quantitative analyses may be conducted by either gravimetric 
or volumetric processes. In the former, the constituents are pre- 
cipitated from solutions by reagents, the precipitates are dried and 
weighed, and from their weights the composition of the substance 
is calculated. Volumetric analyses are, as a rule, more quickly 
performed and require less extensive laboratory appliances. The 
process, depending on the principle of Definite and Fixed Propor- 
tions in chemical combinations, consists in the determination of 
the amount of a substance in solution by the addition thereto of a 
reagent of known strength, the standard solution. The reagent is 
added from an accurately graduated glass vessel, known as a 
burette, and the end of the reaction is revealed either by a change 
in the liquid itself, or by a change in color of a substance added 
as an indicator. 
The reaction between sulphuric acid and potassium hydroxide 
is expressed by the equation: 
2 KOH + H2SO4 = K2SO4 + 2 H2O 
Molecular Weights, 
111.98 
97.82 
If sulphuric acid be added to a solution of potassium hydrox- 
ide, the solution will remain alkaline until sufficient acid has been 
added to complete the above reaction. In other words, to 111.98 
parts of potassium hydroxide we must add 97.82 parts of sul- 
phuric acid, in order that complete neutralization shall take place. 
If more acid be added, the solution will become acid in reaction. 
If 97.82 grammes of sulphuric acid exactly neutralize 111.98 
grammes of potassium hydroxide, then if we make a solution 
containing 97.82 grammes of sulphuric acid in 1000 c.c., each c.c. 
of this solution will neutralize 0.11198 grammes of potassium hy- 
droxide. So, also, in a solution containing 48.91 grammes of the 
acid to 1000 c.c., each c.c. will neutralize 0.05599 grammes of the 
alkali. If now to a solution of potassium hydroxide of unknown 
86 VOLUMETRIC ANALYSIS. 
87 
strength we add a standard solution of sulphuric acid (one con- 
taining a known weight of the acid in each c.c.) until neutraliza- 
tion is effected, we can calculate the amount of alkali from the 
number of c.c. of acid used. 
Again, were we to add a standard solution of sodium chloride to 
a solution of silver nitrate, the reaction would be expressed by the 
equation: 
AgNO3 4- NaCl = AgCl -|- NaNO3 
Molecular Weights, 
169.55 
58.37 
The number of c.c. of standard sodium chloride necessary to 
complete the above reaction (to precipitate all of the silver as 
silver chloride) affords us the means of calculating the amount of 
silver nitrate in the solution. The same principle may be applied 
in other ways, as, for instance, in the determination of the amount 
of iron in a solution. We may first reduce the iron to the ferrous 
state by appropriate reducing agents, and then by the addition of 
a solution of known oxidizing power, we may reconvert the iron 
to the ferric condition. The number of c.c. of oxidizing solution 
used, multiplied by the oxidizing power of each c.c., affords the 
data necessary for the calculation of the iron present. 
Solutions Used. 
In order, then, to make a quantitative determination of any sub- 
stance by volumetric processes, we must have an appropriate 
reagent, of known strength, a standard solution. The strength of 
this reagent will be determined by the nature of the analysis, but 
it is convenient that the weight in grammes, dissolved in each litre, 
shall bear an intimate relation to the molecular weight, thus sim- 
plifying subsequent calculations. The solutions most commonly 
used are designated as Normal, ( y ), Deci-Normal, ( and 
Centi-Normal, ( 
A Normal Solution of a univalent substance contains, in each 
litre, its molecular weight expressed in grammes. 
A Normal Solution of a bivalent substance contains, in each 
litre, its molecular weight expressed in grammes. 
A Normal Solution of a trivalent substance contains, in each 
litre, J its molecular weight expressed in grammes. 88 
VOL UMETRIC J AllL YSIS. 
A Deci-Normal Solution is the strength of the correspond- 
ing normal solution. 
A Centi-Normal Solution is the strength of the cor- 
responding normal solution. 
For example, 1 litre of y KOH (normal potassium hydroxide) 
contains 55.99 grammes of KOH. One litre of Ty KOH contains 
5.599 grammes of KOH. One litre of Tyy KOH contains 0.5599 
grammes of KOH. One litre of y H2SO4 contains 48.91 grammes 
of H2SO4 (Molecular weight of bivalent H2SO4 = 97.82). One 
litre of Ty H2S04 contains 4.891 grammes of H2SO4, etc. 
Indicators.-The success of the volumetric process depends upon 
the accuracy of our means of recognizing the completion of the 
chemical reaction which takes place between the reagent and the 
substance under titration. This is generally accomplished by 
adding to the solution a substance which will reveal by change of 
color the slightest excess of the reagent. The substance so used 
is known as an indicator, and must answer to the following con- 
ditions: The completion of the test, the end reaction, must be 
marked by an indisputable change in color, but little of the indi- 
cator should be used, and the color change must not be interfered 
with by any impurities present, nor by the products of the re- 
action itself. The following are some of the indicators in common 
use. For their preparation, see Appendix. 
Litmus.-Red with acids, blue with alkalies. Litmus is used 
chiefly in the titration of the mineral acids and alkalies; it is not 
reliable as an indicator in presence of carbonates, phosphates or 
arsenates. 
Phenolphthalein.-Colorless with acids, red with alkalies. This 
indicator is much used and is extremely delicate, but its value is 
lessened by presence of ammonium salts or of borax. 
When it is necessary to use phenolphthalein or litmus in pres- 
ence of carbonic aciid (carbonates), the solution under titration 
should be boiled. 
Methyl Orange.-Red with acids, yellow with alkalies. It is not 
affected by carbonic anhydride, and hence may be used in pres- 
ence of carbonates, but it is not satisfactory with organic acids. 
Cochineal.-Yellow with acids, violet with alkalies. Used 
chiefly with ammonia and ammonium compounds. 
Other special indicators will be referred to in describing certain 
of the processes which follow. VOL UMETR1C A NA L YSIS. 
89 
Acidimetry. 
The estimation of acids by means of standard alkali solutions. 
Sodium or potassium hydroxides are the alkalies generally used, 
the standard solutions being prepared as follows: 
Normal Potassium Hydroxide.-If pure potassium hydroxide were 
obtainable it would be only necessary to dissolve 55.99 grammes 
of that substance in 1 litre of water. (55.99 being the molecular 
weight of univalent potassium hydroxide.) It can not be ob- 
tained pure, however, owing to its tendency to absorb carbonic 
anhydride and moisture from the air, and the following U. S. P. 
method is advised: Dissolve 75 grammes of potassium hydroxide 
in 1050 c.c. of water at 15° C., and fill a burette with this solu- 
tion. Dissolve 0.63 grammes of pure crystallized oxalic acid in 
about 10 c.c. of water and add a few drops of phenolphthalein. 
Now add the potassium hydroxide, from the burette, until the 
oxalic acid is just neutralized, a faint pink tint being developed in 
the solution. Note the number of c.c. of alkali used, and then 
dilute the remainder of the solutidn until 10 c.c. will exactly 
neutralize the 0.63 grammes of oxalic acid. The reaction between 
1 the alkali and acid is expressed by the equation: 
2 KOH + H2C2O4.2 H2O = K2C2O4 + 4 H2O 
Molecular weights, 
112 
126 
From this it can be seen that 126 parts of oxalic acid are 
neutralized by 112 parts of potassium hydroxide, or 63 parts by 
56 of potassium hydroxide. Normal potassium hydroxide con- 
tains 56 grammes to the litre, and 10 c.c. of the normal solution 
contain 0.56 grammes. Hence, in the preparation of the normal 
alkali as described, when 10 c.c. exactly neutralize 0.63 grammes 
of oxalic acid, then that 10 c.c. must contain 0.56 grammes of 
potassium hydroxide, and the solution must be normal. 
Deci-Normal Potassium Hydroxide.-Dilute 100 c.c. of the normal 
solution to 1000 c.c., with pure water. 
Normal Sodium Hydroxide.-This contains 39.96 (40) grammes 
of sodium hydroxide to the litre. The solution is prepared by 
dissolving 54 grammes of sodium hydroxide in 1050 c.c. of water, 
proceeding then exactly as described under potassium hydroxide. 
The reaction in this case is expressed by the equation: 90 
VOLUMETRIC ANALYSIS. 
2 NaOH + H2C2O4.2H2O = Na2C2O4 + 4 H2O 
2)H 
2)V/ 
Each Cubic Centimeter of a Normal Alkali Solution is equivalent to: 
Grammes. 
Acid, Acetic, HC2H3O2 .... 0.05986 
Citric, H3C6H5O7.H2O . . . 0.06983 
Hydrobromic, HBr .... 0.08076 
Hydrochloric, HC1 . . . . 0.03637 
Hydriodic, HI 0.12753 
Lactic, HC3H5O3 . 0.08979 
Nitric, HN03 0.06289 
Oxalic, H2C2O4.2 H2O . . . 0.06285 
Sulphuric, H2SO4 .... 0.04891 
Tartaric, H2C4H4O6 . . . 0.07482 
Method of Analysis.-A weighed quantity of the acid is diluted 
with a little water, a few drops of phenolphthalein added, and 
then the standard alkali, from a burette, until a faint pink tint is 
developed. The number of c.c. of standard solution used, mul- 
tiplied by the equivalent of each c.c., gives the weight of pure 
acid in the solution. From this, and the weight of the sample, 
the percentage may be calculated. 
If 5 grammes of hydrochloric acid solution were taken for anal- 
ysis, and 20 c.c. of normal alkali were required to develop the 
pink color, then the 5 grammes of acid solution contain, 20 x 
0.03637=0.7274 grammes of pure acid, or, 0.7274-5-5 x 100 = 
14.55 per cent. 
Remarks. -It is often inconvenient to weigh the sample taken for 
analysis, and in such a case, a definite volume must be used. The 
titration with the normal solution will give the number of grammes 
of pure substance in the sample, and for many solutions we can 
assume the weight of the sample to be equal to as many grammes 
as there were c.c. taken. (1 c.c. of water weighs 1 gramme). Or, 
we can determine the specific gravity of the solution by means of 
a hydrometer, and calculate the weight of the sample by multi- 
plying its volume by its specific gravity. 
The pharmacopceial practice is to weigh off such a quantity of 
the substance, for analysis, that the number of c.c. of standard VOL UMETR1C A NA L YSIS. 
91 
solution used will directly express the percentage sought. Thus, 
3.64 grammes of U. S. P. acidum hydrochloricum, containing 
31.9 per cent, of pure hydrochloric acid, will be exactly neutral- 
ized by 31.9 c.c. of normal alkali. 3.64 grammes of the dilute 
acid of the pharmacopoeia, containing 10 per cent, of pure acid, 
will be exactly neutralized by 10 c.c. of normal alkali. 
The method is, in general, the same for any acid, merely sub- 
stituting in the calculation the proper equivalent for each c.c. of 
the standard alkali used. 
TbtaZ Acidity of the Urine.-To 50 c.c. of urine add several drops 
of phenolphthalein, and titrate with decinormal potassium hy- 
droxide until the pink color appears. Each c.c. of the decinormal 
alkali is equivalent to 0.006285 grammes of oxalic acid. Assum- 
ing that the 50 c.c. of urine weigh 50 grammes, the percentage 
may be easily calculated. In case the urine is highly colored, it 
is best to first remove the color by shaking with animal charcoal 
and filtering. The total acidity of the 24 hours' urine averages 
about 2 grammes of oxalic acid. ' It is to be remembered that the 
acid reaction of the urine is in reality due to the presence of acid 
salts and not at all to oxalic acid, this last substance being gen- 
erally adopted, however, because of the greater ease in calculation 
and as affording a simple means of comparison. 
Total Acidity of the Gastric Fluid.-(See p. 84.) 
Alkalimetry. 
The estimation of alkalies by means of a standard acid solution. 
Several of the acids are used for this purpose, the more common 
being oxalic, sulphuric and hydrochloric. Oxalic acid has the 
distinct advantage over the others of easy preparation, but, as a 
rule, sulphuric acid will be found to have the widest application 
and to give the most satisfactory results. 
Normal Oxalic Acid.-Dissolve 62.85 grammes of the pure 
crystalline acid in water and dilute to 1 litre. (62.85 being £ the 
molecular weight of the bivalent, crystalline oxalic acid.) 
Deci-Normal Oxalic Acid.-Dilute 100 c.c. of the normal acid to 
1000 c.c. with water; or, dissolve 6.285 grammes of the acid in 
water and dilute to 1 litre. 
Centi-Normal Oxalic Acid.-Dilute 10 c.c. of the normal acid to 
1000 c.c. with water; or, dissolve 0.6285 grammes of the acid in 
water and dilute to 1 litre. 92 
VOLUMETRIC ANALYSIS. 
Normal Sulphuric Acid.-The normal solution of sulphuric acid 
contains 48.91 grammes in 1 litre. (48.91 being 4 the molecular 
weight of the bivalent acid.) It is prepared by mixing 30 c.c. of 
pure concentrated acid, specific gravity 1.835, with enough water 
to make 1050 c.c. The mixture is cooled and its strength de- 
termined by titration with normal potassium hydroxide. It is 
then diluted with water until 10 c.c. will exactly neutralize 10 c.c. 
of the normal alkali; in other words, until each c.c. contains 
0.04891 grammes of pure sulphuric acid. 
Each Cubic Centimeter of a Normal Acid Solution is equivalent to: 
Grammes. 
Ammonia gas, NH3 0.01701 
Ammonium hydroxide, NH4OH . . 0.03497 
Lithium carbonate, Li2CO3 . . . 0.03693 
Potassium bicarbonate, KHCO3 . . . 0.09988 
Potassium carbonate, K2CO3 . . . 0.06895 
Potassium hydroxide, KOH . . . 0.05599 
Sodium bicarbonate, NaHCO3 . . . 0.08385 
Sodium carbonate, Na2CO3 . . . 0.05292 
Sodium hydroxide, NaOH .... 0.03996 
Method of Analysis.-A weighed quantity of the sample is diluted 
with water, or, if solid, is dissolved in water, a few drops of phenol- 
phthalein added, and the standard acid run in from a burette until 
the pink color of the solution is just destroyed. The number of 
c.c. of standard acid used, multiplied by the equivalent of each 
c.c., gives the weight of pure alkali in the solution. From this, 
and the weight of the sample, the percentage can be calculated. 
If 5 grammes of sodium hydroxide solution were taken for 
analysis, and 25 c.c. of normal sulphuric acid were required to 
effect neutralization, then the 5 grammes of alkali solution con- 
tain 25 x 0.03996 = 0.999 grammes of pure sodium hydroxide, 
or, 0.999 5 x 100 = 19.98 per cent. 
Remarks.-In the titration of carbonates, methyl orange is to be 
used as the indicator, the standard acid being added until the so- 
lution acquires a faint orange-red tint. Otherwise the process is 
as described. The remarks on p. 90 are also applicable here. VOLUMETRIC ANAL YSIS. 
93 
Estimation of Haloid Salts. 
Salts of chlorine, bromine and iodine, may be conveniently es- 
timated by precipitation with a standard solution of silver nitrate. 
The reagent is added until all of the halogen has been precipitated 
as silver salt, and from the number of c.c. used the original 
halogen compound may be calculated. The completion of the 
reaction may be determined by testing small portions of the solu- 
tion from time to time, filtering off the precipitate and adding a 
drop of silver nitrate, until no further precipitation occurs. Much 
more satisfactorily, however, we can add to the solution a few drops 
of potassium chromate, which, by formation of red silver chromate 
when all of the halogen has been precipitated, will reveal the 
slightest excess of the silver nitrate. 
Deci-Normal Silver Nitrate.-Dissolve 16.955 grammes of pure 
silver nitrate in water and dilute to 1 litre, at 15° C. (The 
molecular weight of silver nitrate being 169.55, the deci-normal 
solution will contain T\yth of the molecular weight, expressed in 
grammes.) The solution should be kept in the dark. 
Should pure silver nitrate not be available, a trial solution 
stronger than the deci-normal is first prepared, and then 0.1167 
grammes of pure sodium chloride is dissolved in water and 
titrated. Were the silver nitrate deci-normal, 20 c.c. would ex- 
actly precipitate all of the chlorine of the salt as silver chloride; 
but as the solution is stronger than deci-normal, less than 20 c.c. 
will complete the reaction. Determine the exact strength of the 
strong silver nitrate and dilute with such a quantity of water as 
will reduce it to the strength required, i. e., to the deci-normal. 
Each Cubic Centimeter of Deci-Normal Silver Nitrate Solution is 
equivalent to: 
Grammes. 
Ammonium Bromide, NH4Br . . . 0.009777 
Lithium Bromide, LiBr .... 0.008677 
Potassium Bromide, KBr .... 0.011879 
Potassium Chloride, KC1 .... 0.007440 
Potassium Cyanide, KCN .... 0.013002 
Potassium Iodide, KI ... . 0.016556 
Sodium Bromide, NaBr .... 0.010276 
Sodium Chloride, NaCl .... 0.005837 
Zinc Chloride, ZnCL .... 0.006792 94 
V OL UMETRIC A NA L YSIS. 
Method of Analysis.-To a measured volume of the salt solution, 
or to a weighed quantity of the salt dissolved in water, add a few 
drops of neutral potassium chromate, and then the deci-normal 
silver nitrate, from a burette, until the solution acquires a slight 
but permanent red tinge. The number of c.c. of the deci-normal 
solution used multiplied by the equivalent of each c.c., gives the 
weight of the halogen salt in solution. From this and the weight 
of the sample, the percentage strength can be calculated. 
In titrating potassium cyanide, no indicator is used, but the 
silver nitrate is added until the appearance of the first, slight, per- 
manent precipitate. 
Total Chlorides of the Urine.-Dilute 10 c.c. of the urine (pre- 
viously decolorized with animal charcoal if necessary) to about 
50 c.c. with water. Add a few drops of neutral potassium chro- 
mate, as an indicator, and titrate with deci-normal silver nitrate 
until the solution acquires the red tint indicative of the complete 
precipitation of the chlorides. The number of c.c. used, multi- 
plied by 0.005837, will give the weight of sodium chloride in the 
10 c.c. of urine. From this, the percentage, and also the amount 
passed in the 24 hours, may be calculated. 
It is to be remembered that by this method all of the chlorides 
of the urine are calculated as the sodium salt, though potassium 
chloride is also present. This error may be avoided by re- 
porting in terms of chlorine, using the factor 0.003537 instead 
of 0.005837. The average daily amount passed by adult males is 
from 6 to 10 grammes of chlorine, equivalent to 10 to 16 grammes 
of sodium chloride. 
Total Phosphates in Urine. 
Standard Uranium Nitrate Solution.-Dissolve 35.5 grammes of 
pure uranium nitrate in 1 litre of water. Each c.c. of this solu- 
tion is equivalent to 0.005 gramme of phosphoric anhvdride, 
p2o5. 
Acid Solution of Sodium Acetate.-Dissolve 10 grammes of sodium 
acetate in 90 c.c. of water and add 10 c.c. of glacial acetic acid. 
Method of Analysis.-To 50 c.c. of the urine add 5 c.c. of the 
acid solution of sodium acetate, and heat the mixture to about 
80° C. Run in the uranium nitrate while the solution is still 
hot, and test from time to time until a drop of the mixture de- VOLUMETRIC ANALYSIS. 
95 
velops a brown color when touched with a drop of potassium 
ferrocyanide. The number of c.c. of uranium nitrate used, mul- 
tiplied by 0.005 gives the weight in grammes of phosphoric anhy- 
dride in the 50 c.c. of urine. 
The amount of phosphoric anhydride (commonly known as 
phosphoric acid) passed in the 24 hours, varies from 2.5 to 3.5 
grammes. APPENDIX. WEIGHTS AND MEASURES. 
MEASURES OF WEIGHT. 
1 milligramme = 0.001 gramme = 0.01543 grains, Troy. 
1 centigramme = 0.010 " 
1 decigramme = 0.100 " 
1 gramme = 1.000 " = 15.43235 grains, Troy. 
1 decagramme = 10.000 grammes. 
1 hectogramme = 100.000 " 
1 kilogramme =1000.000 " = 2.6790 pounds, Troy. 
1 kilogramme = 2.2046 pounds, Av. 
1 tonneau = 1000.000 kilogrammes. 
Troy Weight. 
Pound. 
Ounces. 
Pennyweights. 
Grains. 
Grammes. 
1 
12 
240 
5760 
= 373.2419 
1 
20 
480 
=- 31.1035 
1 
24 
-= 1.5552 
Apothecaries' Weight. 
Pound. 
Ounces. 
Drachms. 
Scruples. 
Grains. 
Grammes. 
1 
12 
96 
288 
5760 = 
373.2419 
1 
8 
24 
480 = 
31.1035 
1 
3 
60 = 
3.8879 
1 
20 = 
1.2959 
1 = 
0.0648 
Avoirdupois Weight. 
Pound. 
Ounces. 
Drachms. 
Grains. 
Grammes. 
1 
16 
256 
7000 = 
453.5926 
1 
16 
437.5 = 
28.3495 
1 
27.343 = 
1.7718 
99 100 
APPENDIX. 
MEASURES OF CAPACITY. 
1 millilitre = 1 cubic centimetre = 0.061027 cubic inch. 
= 0.033816 U. S. fluid ounce. 
= 16.2310 U. S. minims. 
1 litre = 1000 cubic centimetres = 33.816 U. S. fluid ounces. 
= 35.219 Imperial " 
= 1.0567 U. S. quart. 
1 kilolitre = 1000 litres =264.18 U. S. gallons. 
1 U. S. minim = 0.06 c.c. 
1 U. S. fluid ounce = 29.57 c.c. 
1 Imperial fluid ounce = 28.39 c.c. 
1 U. S. gallon = 3785.43 c.c. 
1 Imperial gallon = 4543.46 c.c. 
' MEASURES OF LENGTH. 
1 millimetre = 0.001 metre = 0.03937 inch. 
1 centimetre = 0.010 " 
1 decimetre => 0.100 " 
1 metre = 1.000 " =- 3.28089 feet. 
1 decametre = 10.000 metres. 
1 hectometre = 100.000 " 
1 kilometre = 1000.000 " = 0.62138 mile. 
1 inch = 2.53995 centimetres. 
1 foot = 0.30479 metre. 
1 yard = 0.91438 metre. 
1 mile = 1.60931 kilometres. 
Water boils. 
Water freezes. 
Centigrade 
100° 
0° 
Fahrenheit 
212° 
32° 
Reaumur 
80° 
0° 
MEASURES OF TEMPERATURE. 
To convert °C to °F, multiply by 9, divide by 5, then add 32. 
To convert °F to °C, subtract 32, then multiply by 5, and di- 
vide by 9. APPENDIX. 
101 
LIST OF REAGENTS. 
Acid, Acetic, HC2H3O2. Sp. gr. 1.04. 30 per cent. 
" Hydrochloric, HC1. Sp. gr. 1.16. 32 per cent. 
" Nitric, HN03. Sp. gr. 1.24. 32 per cent. 
" Nitro-hydrochloric, NOCI q Cl2. About 1 part cone. 
HN03 to 3 parts HC1. 
" Oxalic, H2C2O4. 1 part crystals in 10 parts water (1-10). 
" Phosphoric, H3PO4. Sp. gr. about 1.7. 85 percent. 
" Picric, CfiH2(NO2)3OH. Aqueous solution. 
" Salicylic, HC7H5O3. Solid, or in aqueous solution. 
" Sulphuric, H2SO4. Concentrated, sp. gr. 1.84. 
" Tannic, HC14H9O9. Aqueous solution. 
" Tartaric, H2C4H4O6. (1-3.) 
" Trichloracetic, HC2C13O2. Solid. 
Acidulated Brine. 500 c. c. of saturated NaCl solution, 30 c.c. 
HC1. 
Alcohol, C2H5OH. Absolute. Not less than 99 per cent, by 
weight. 
Alcohol, C2H5OH. Ordinary. About 91 per cent, by weight. 
Almen's Reagent. BiONO3, 2 grammes ; NaKC4H4O6, 4 
grammes; NaOH, 8 grammes; water, 100 c.c. 
Ammonium Carbonate, (NH4)2CO3. (1-4.) 
" Chloride, NH4C1. (1-8.) 
" Hydroxide, NH40H. 10 per cent. NH3. 
' ' Molybdate, (NH4 ) 2MoO4. Solution in nitric acid. 
" Oxalate, (NH4)2C204. (1-24.) 
" Sulphate, (NH4)2SO4. Saturated aqueous solu- 
tion. 
" Sulphide, (NH4)2S. By passing H2S through 
nh4oh. 
Barium Carbonate, BaCO3. Solid, or sat. solution. 
" Chloride, BaCl2. (1-10.) 
" Hydroxide, Ba(OH)2. Sat. aqueous solution. 
" Nitrate, Ba(NO3)2. (1-10.) 
Bismuth Subnitrate, BiONO3 (?). Solid. 
Bleaching Powder, CaOCl2. 
Boas' Reagent. Pure resorcin, 5 grammes ; White sugar, 3 
grammes; dilute alcohol, 100 c.c. 
Bromine Water, Br. Aqueous solution of bromine. 102 
APPENDIX. 
Calcium Chloride, CaCl2. (1-8.) 
" Hydroxide, Ca(OH)2. Saturated aqueous solution. 
Carbon Disulphide, CS2. Pure. 
Carbonic Anhydride, CO2. By action of HC1 on CaCO3. 
Chlorine Water, CL Aqueous solution of chlorine. 
Chlorinated Soda, for Urea Test. 25 c.c. solution of chlorinated 
soda; 5 c.c. KBr (20 per cent.); 5 c.c. NaOH. 
Chloroform, CHC13. Sp. gr. about 1.49 at 15° C. Boils at 
60° C. 
Cochineal, Indicator. Macerate 1 gramme for several days with 
20 c.c. alcohol and 60 c.c. water. Filter. 
Congo-red Paper. Prepared by soaking unsized paper in 1 per 
cent, aqueous solution of Congo-red. 
Copper Sulphate, CuSO4. (1-8.) 
Cupric Ammonium Hydroxide. Solution of Cu(0H)2 in am- 
monia. 
Cupric Ammonium Sulphate. To a solution of CuSO4 add 
ammonia until the precipitate first formed just redissolves. 
Esbach's Reagent. Picric Acid, 10 grammes; Citric Acid, 20 
grammes; Water to 1000 c.c. 
Ether, (C2H5)2O. Sp. gr. about 0.727 at 15° C. Boils at 
37° C. 
Fehling's Solution. Prepared in 2 parts. I. 34.639 grammes 
of pure crystallized CuSO4, dissolved in water and diluted to 500 
c.c. II. 173 grammes Rochelle salts and 60 grammes NaOH, dis- 
solved in water and diluted to 500 c.c. For use mix equal vol- 
umes of I. and II. Ten c.c. of the mixed solution = 0.05 gramme 
glucose. 
Ferric Chloride, Fe2ClG. (1-15.) 
Ferrous Sulphate, FeSO4. (1-10.) 
Gold Chloride, AuC13. (1-30.) 
Gunzberg's Reagent. Phloroglucin, 2 pts.; Vanillin, 1 pt.; Ab- 
solute Alcohol, 30 pts., by weight. 
Haines' Solution. Dissolve 2 grammes pure CuSO4 (crys.) in 
15 c.c. of water, add 15 c.c. of pure glycerin and then 150 c.c. of 
5 per cent. KOH solution. A clear dark blue liquid should 
result. 
Indigo-Carmine Solution. 1 gramme commercial indigo-car- 
mine in 150 c.c. of water. 
Iodine Test Solution. 1 gramme iodine, 3 grammes potassium 
iodide, in 50 c.c. water. APPENDIX. 
103 
Lead Acetate, Pb(C2H3O2)2. (1-10.) 
Litmus Test Solution. Exhaust powdered litmus with boiling 
alcohol. Digest residue in cold water, filter, and extract residue 
with boiling water. Filter and preserve the filtrate as a test solu- 
tion. Litmus paper is prepared by impregnating unsized paper 
with the above solution. 
Magnesium Chloride, MgCl2. (1-10.) 
Mixture, 1 pt. cryst. MgCl2; 2.5 pts. NH4C1; 5 
pts. NH40H; and 10 pts. water. Let stand, then 
filter. 
Sulphate, MgSO4. Saturated aqueous solution. 
Mayer's Solution. 13.546 grammes HgCl2 dissolved in 600 c.c. 
of water. 49.8 grammes KI dissolved in 100 c.c. of water. 
Mix and dilute to 1000 c.c. 
Mercuric Chloride, HgCl 2. (1-20.) 
Mercurous Nitrate, Hg2(NO3)2. (1-20.) Acidulate with 
nitric acid. 
Methyl Orange. (Tropaeolin D.) 1 gramme in 1000 c.c. of 
water. Add dilute H2SO4 drop by drop, until liquid just turns 
red. Filter. 
Millon's Reagent. 1 pt. mercury treated with 2 pts. HN03 in 
the cold. Then heat on water bath, dilute with 2 pts. water, and 
after several hours, decant the clear liquid. 
Pavy's Ammoniated Test Solution. CuSO4, 4.158 grammes; 
Rochelle salts, 20.4 grammes; KOH, 20.4 grammes; Strong am- 
monia, 300 c.c.; Water to 1000 c.c. 
Phenolphthalein. (Indicator.) 1 gramme in 100 c.c. dil. 
alcohol. 
Platinic Chloride, PtCl4. (1-10.) 
Potassium Carbonate, K2CO3. (1-20.) 
" Chlorate, KC1O3. Solid. 
" Chromate, K 2 CrO4. (1-10.) 
" Dichromate, K2Cr2O7. (1-10.) 
" Ferricyanide, K3Fe(CN)6. (1-12.) 
" Ferrocyanide, K4Fe(CN)6. (1-12.) 
" Hydroxide, KOH. (1-9.) 
" Iodide, KI. (1-20.) 
" Nitrate, KN03. Solid. 
" Sulphate, K2SO4. (1-12.) 
" Sulphocyanide, KCNS. (1-12.) 104 
J PPENDIX. 
Silver Nitrate, AgNO 3. (1-20.) 
" Ammonium Nitrate. To solution of AgNO3 add NH40H 
until the precipitate first formed is just redissolved. 
Sodium Acetate, NaC2H3O2. (1-5.) 
li Carbonate, Na2CO3. (1-5.) 
" Chloride, NaCl. Solid, or saturated solution. 
" Hydroxide, NaOH. (1-9.) 
" Alcoholic. Sol. of NaOH in alcohol. 
Hypobromite, NaBrO, for Urea Test. 100 grammes of 
NaOH in 250 c.c. water. 25 c.c. Bromine added. 
" Phosphate, Na2HPO4. (1-10.) 
" Sulphate, Na2SO4. Saturated solution. 
u Sulphite, Na2SO3. (1-5.) 
Stannous Chloride, SnCl 2. (1-6.) Acidified with HC1. 
Strontium Nitrate, Sr(NO3)2. Aqueous solution. 
" - Sulphate, SrSO4. Saturated solution. 
Sulphuretted Hydrogen, H2S. Prepared by action of FeS on 
HC1. 
Tanret's Solution, HgCl2, 1.35 grammes; KI, 3.32 grammes; 
Acetic acid, 20 c.c. Distilled water to 100 c.c. 
Uffelmann's Reagent. 10 c.c. of 4 per cent. Phenol; 1 drop of 
dil. Fe2Cl6; 20 c.c. water. INDEX. 
Acetates, 20 
Acetic acid, 20 
Acetone in urine, 76 
Acid albumin, 45, 48, 50 
Acidimetry, 89 
Acidity of gastric fluid, Determ, of, 84 
urine, Determ, of, 91 
Acids and Metals, Separation of, 23 
Acids, List of, 100 
Tests for, 20 
Acidulated brine solution, 100 
test, 47 
Aconitine, 33, 36 
Adulterants in milk, 59 
Albumin, 45, 47, 50, 51 
Estimation of, 66 
in milk, 55 
in urine, 66 
Sulphur in, 50 
Albuminates, 45, 48, 50 
Albuminoids, 45, 51 
Albumose, 45, 51 
in urine, 76 
Alcohol, 28, 100 
Alkali albumin, 45, 48, 50 
Alkali metals, 9 
Alkalimetry, 91 
Alkaline earth metals, 11 
Alkaline phosphates in urine, 74 
Alkaloids, Non-volatile, 30 
Properties of, 29 
Separation from organic 
matter, 34, 35 
Tests for, 28 
Volatile, 29 
Almen-Bottger test, 68 
Almen's reagent, 100 
Alpha-naphthol test, 43, 69 
Aluminum, 8, 12, 18, 19 
Ammonium, 10, 19, 24 
salts as reagents, 100 
Amyloid substance, 50 
Amyloses, 39 
Animal proteids, 45 
Antimony, 8, 14, 18, 24, 26 
Antipeptone, 45 
Appendix, 97 
Arsenic, 8, 14, 18, 24, 25 
Ash in milk, 59 
Atomic weights of elements, 8 
Atropine, 32, 36 
Bacteria in urine, 79 
Barium, 8, 11, 19, 24 
salts as reagents, 100 
Bile acids, Tests for, 75 
pigments, Tests for, 75 
in urine, 75 
Bismuth, 8, 15, 17 
subnitrate, 100 
Bisulphate of quinine, 31 
Biuret reaction, 49 
Bleaching powder, 100 
Blood in urine, 74, 78 
Boas' reagent, 100 
test, 84 
Boron, 8 
Bottger's test, 42, 68 
Bromides, 22, 23 
Bromine, 8 
Brucine, 32, 36 
Cadmium, 8, 15 
Caffeine, 31 
Calcium, 8, 11, 19, 24 
chloride, 101 
hydroxide, 101 
oxalate in calculi, 80 
Calculi, Urinary, 80 
Analysis of, 81 
Varieties of, 80 
Cane sugar, 39, 43 
Cantharidine, 36 
Capacity, Measures of, 99 
Carbohydrates, 39 
Carbolic acid, 27 
Carbon, 8, 24, 25 
Carbonates, 23 
in urine, 80 
Carbon disulphide, 101 
Carbonic acid, 23 
Carbonic anhydride, 101 
Casein in milk, 55, 56 
Caseinogen, 45, 48 
Casts in urine, 78 
Cellulose, 39 
Centi-normal solutions, 88 
Chautard's test, 7 6 
Chlorates, 24 
Chlorides, 20 
105 106 
INDEX. 
Chlorides in urine, 72, 94 
Chlorinated soda, for urea test, 101 
Chlorine, 8 
Chlorine water, 101 
Chloroform, 27, 101 
Chondrin, 51 
Chromates, 22 
Chromic acid, 22 
Chromium, 8, 12, 18, 19 
Cinchonine, 31, 36 
Citrates, 21 
Citric acid, 21 
Cobalt, 8, 14 
Cocaine, 34 
Cochineal, 88, 101 
Codeine, 30. 36 
Colchicine, 36 
Collagen, 51 
Congo-red paper, 101 
test, 84 
Coniine, 29, 36 
Copper, 8, 15, 17, 24 
sulphate, 101 
Cream in milk, 57 
Creamometer, 57 
Creatinine in urine, 60 
Crystallin, 45, 50 
Cupric ammonium sulphate, 101 
Curarine, 36 
Cyanides, 22 
Cystin calculi, 81 
in urine, 80 
Deci-normal solutions, 88 
Dextrin, 39, 41 
Dextrose, 39, 41 
Diabetic urine, 67 
Diacetic acid in urine, 76 
Digitaline, 36 
Dragendorff's method, 35 
Earthy phosphates in urine, 74 
Egg albumin, 45, 48 
Einhorn's method for glucose, 70 
Elastin, 51 
Elaterine, 36 
Elements, Table of, 8 
Epithelium in urine, 78 , 
Esbach's reagent, 101 
Ether, 28, 101 
Ethyldiacetic acid in urine, 76 
Ethyl ether, 28, 101 
Fat in milk, 55, 56, 57 
in urine, 77 
Fehling's solution, 101 
test, 42, 68, 69 
Fermentation test, 42, 69 
Ferric chloride, 101 
compounds, 13 
Ferrocyanide test, 66 
Ferrous compounds, 13 
sulphate, 101 
Fibrin, 45 
Fibrinogen, 45, 50 
Fibrinoplastin, 45 
Fibrinous calculi, 81 
Fleischl's test, 75 
Fleitmann's test, 25 
Fluorine, 8 
Fresenius and Babo's method, 34 
Fruit sugar, 39 
Fungi in urine, 79 
Fusible calculus, 80, 82 
Galactose, 39, 44 
Gastric fluid, 83 
Clinical analysis of, 84 
Composition of, 83 
Mineral acid in, 84 
Organic acid in, 84 
Pepsin in, 85 
Total acidity of, 84 
Gelatin, 51 
Globin, 45 
Globulins, 45 , 50, 51 
Globulose, 45 
Glucose, 39, 41, 43 
Estimation of, 69, 70 
Gluten, 49 
Glycerin, 28 
Glycerol, 28 
Glycogen, 39, 41 
Glycosuria, 67 
Glycuronic acid in urine, 77 
Gmelin's test, 75 
Gold, 8 
chloride, 101 
Granulose, 39, 40 
Grape sugar, 41 
Guaiacum test, 75 
Gunzberg's reagent, 101 
test, 84 
Haines' solution, 101 
test, 42, 68 
Haloid salts. Estimation of, 93 
Haser's co-efficient, 64 
Heat test, 47, 65 
Helmer and Richmond's formula, 58 
Heller's test for blood, 74 
| Hemipeptone, 45 
Hempseed calculi, 81 
Hippuric acid in urine, 60 
Hydriodic acid, 22, 23 
Hydrobromic acid, 22, 23 
Hydrochloric acid, 20, 23, 100 
in gastric fluid,83,84 
Hydrocyanic acid, 22, 23 
Hydrogen, 8 INDEX. 
107 
Hyoscyamine, 36 
Hypobromite method for urea, 70 
Hypophosphites, 21 
Indicators, 88 
Indigo-carmine solution, 101 
test, 42, 69 
Inosite, 39 
Iodates, 24 
Iodides, 22, 23 
Iodine, 8 
test solution, 101 
Iron, 8, 13, 18, 19 
Keratin, 51 
Lactometer, 57 
Lactoscope, 57 
Lactose, 39, 44 
in milk, 55, 56, 57 
Lardacein, 45, 50, 51 
Lead, 8, 16, 17 
acetate, 102 
Lecanau's test, 75 
Legal's test, 7 6 
Length, Measures of, 99 
Le Nobel's test, 76 
Leucin in urine, 80 
Levulose, 39, 44 
Lithium, 8, 10, 19 
Litmus, 88 
paper, 102 
test solution, 102 
Loebisch's coefficient, 64 
Loewe's test, 42 
Magnesia mixture, 102 
Magnesium, 8, 11, 19 
chloride, 102 
sulphate, 102 
Maltose, 39, 44 
Manganese, 8, 13, 18, 19 
Marsh's test for antimony, 26 
arsenic, 25 
Mayer's solution, 102 
Measures, Weights and, 98 
Meconic acid, 30 
Melitose, 39 
Mercuric chloride, 102 
Mercurous nitrate, 102 
Mercury, 8, 15, 16, 17, 24, 27 
Meta-albumin, 45, 51 
Metals, alkali, 9 
Alkaline earth, 11 
Analytical schemes for, 17 
and Acids, Separation of, 23 
Atomic weights of, 8 
Classification of, 9 
Group I., 16, 17 
Group II., 14, 17 
Metals, Group III., 12, 18 
Group IV., 11, 19 
Group V., 9, 19 
Separation from organic mix- 
tures, 34 
Tests for, 9 
Metaphosphates, 22 
Methyl-orange, 88 
Methyl-violet test, 84 
Milk, 55 
Adulterants in, 59 
Albumin in, 55 
Ash in, 59 
Casein in, 55, 56 
Composition of, 55 
Cream in, 57 
Fat in, 55, 56, 57 
Lactose in, 55, 56, 57 _ 
Proteids in, 58 
Quantity of, 56 
Reaction of, 56 
Salts in, 55, 56 
Solids of, 55, 57 
Specific gravity of, 56 
sugar, 39, 44 
, Water in, 55 
Millon's reaction, 46 
reagent, 102 
Molybdenum, 8 
Moore's test, 41 
Morphine, 30, 36 
Mucin, 51 
Mulberry calculi, 81 
Murexid test, 72 
Mycose, 39 
Myosinogen, 45, 50 
Narceine, 36 
Nickel, 8, 14 
Nicotine, 29, 36 
Nitrates, 20, 24 
Nitric acid, 20, 23 
Nitric acid contact test, 47, 66 
Nitrogen, 8 
Nitrohydrochloric acid, 100 
Normal acid. Equivalents of, 92 
Normal alkali, Equivalents of, 90 
Normal solutions, 87 
Nuclein, 51 
Nucleo-albumin, 51 
Nylander's test, 68 
Organic acids in gastric fluid, 84 
Organized sediment in urine, 78 
Ossein, 51 
Oxalates, 21 
in urine, 79 
Oxalic acid, 21, 23, 100 
standard solution, 91 
Oxygen, 8 108 
INDEX. 
Para-albumin, 45, 51 
Paraglobulin. 45, 50 
Pavy's ammoniated test solution, 102 
Pavy's test, 42 
Peptones, 45, 48, 50, 51, 52 
in urine, 76 
Permanganates, 22 
Permanganic acid, 22 
Pettenkofer's test, 75 
Phenol, 27 
Phenolphthalein, 88, 102 
Phenylhydrazine test, 43, 69 
Phosphates, 21 
in urine, 73, 79 
Estimation of, 94 
Phosphatic calculi, 80 
Phosphoric acid, 21, 23, 100 
Phosphorus, 8, 24 
Physostigmine, 34, 36 
Picric acid, 100 
test for albumin, 47, 66 
glucose, 41 
Picrotoxin, 36 
Piotrowski's reaction, 46 
Plastin, 51 
Platinic chloride, 102 
Platinum, 8 
Potassium, 8, 9, 19, 24 
Potassium hydroxide, Standard solu- 
tion of, 89 
salts as reagents, 102 
Proteids, 45 
in milk, 58 
Precipitation of, 46 
Separation of, 50 
Protein reactions, 46 
Proteoses, 45 
Ptomaines, Separation of, 35 
Pus in urine, 77, 78 
Pyrophosphates, 21 
Quinine, 31, 36 
Bisulphate of, 31 
Sulphate of, 31 
Reagents, List of, 100 
Reinsch's test, 26 
Roberts' test for glucose, 69 
Saccharoses, 39 
Salicine, 36 
Salts in milk, 55, 56 
Santonine, 36 
Schmiedeberg's test, 42 
Sediments in urine, 77 
Serum albumin, 45, 48 
Serum globulin in urine, 76 
Silica, 24 
Silicates, 24 
Silicon, 8 
Silver, 8, 16, 17 
ammonium nitrate, 103 
nitrate, 103 
Equivalents of standard 
solution of, 93 
Standard solution of, 93 
test for glucose, 42 
Sodium, 8, 10, 19, 24 
acetate, Acid solution of, 94 
hvdroxide, Standard solution 
of, 89 
hypobromite for urea test, 103 
salts as reagents, 103 
Solanine, 36 
Solids, Examination of, 24 
in milk, 55, 58 
in urine, 64 
Sorbose, 39 
Sparteine, 30 
Spermatin, 51 
Spermatozoa in urine, 79 
Standard solutions, 87 
Stannous chloride, 103 
Starch, 39, 40 
Starch-cellulose, 40 
Stas-Otto method, 35 
Strontium, 8, 11, 19, 24 
nitrate, 103 
sulphate, 103 
Strychnine, 31, 36 
sulphate, 32 
Sucrose, 39, 43 
Sugar, Cane, 39, 43 
Determination of, 69, 70 
Fruit, 39 
Grape, 41 
in urine, 67 
Milk, 39, 44 
Sulphates, 20 
in urine, 72 
of strychnine, 32 
of quinine, 31 
Sulphides, 23, 24 
Sulphites, 23 
Sulphur, 8, 24, 25 
in albumin, 50 
Sulphuretted hydrogen, 103 
Sulphuric acid, 20, 23, 100 
Standard solution of, 92 
Symbols of elements, 8 
Syntonin, 45 
Tannic acid, 100 
test for albumin, 47 
Tanret's solution, 103 
test, 47 
Tartaric acid, 21, 100 
Tartrates, 21 
Temperature, Measures of, 99 
Thebaine, 36 INDEX. 
109 
Thein, 31 
Tin, 8, 15 
Titanium, 8 
Trapp's coefficient, 64 
Trichloracetic acid, 100 
test for albumin, 47 
Triple phosphate in urine, 79 
Trammer's test, 42, 68 
Tungsten, 8 
Tyrosin in urine, 80 
Uflelmann's reagent, 84 
test, 84 
Ultzmann's test, 75 
Unorganized sediment in urine, 79 
Uranium, 8 
nitrate, Standard solution of, 
94 
Urates in calculi, 80 
in urine, 71, 79 
Urea, Approximate estimation <jf, 70 
Hypobromite method for, 70 
in urine, 60, 70 
Ureameter, 71 
Uric acid in calculi, 80 
in urine, 71, 79 
Urinary calculi, 80 
sediments, 77 
Urine, 60 
Acetone in, 76 
Acidity of, 91 
Albumin in, 65 
Albumose in, 76 
Appearance of, 62 
Bacteria in, 79 
Bile in, 75 
Blood in, 74. 78 
Casts in, 78 
Chlorides in, 72 
Estimation of, 94 
Color of, 62 
Composition of, 60 
Creatinine in, 60 
Epithelium in, 78 
Ethyldiacetic acid in, 76 
Urine, Fat in, 77 
Fungi in, 79 
Globulin in, 76 
Glucose in, 67 
Glycuronic acid in, 77 
Hippuric acid in, 60 
Mucin in, 64, 78 
Odor of, 62 
Oxalates in, 79 
Peptones in, 76 
Phosphates in, 73, 79 
Estimation of, 94 
Plan of analysis of, 60 
Pus in, 77, 78 
Quantity of, 61 
Reaction of, 62 
Sediment of, 77 
Serum-globulin in, 76 
Solids in, 64 
Specific gravity of, 63 
Spermatozoa in, 79 
Sugar in, 67 
Sulphates in, 72 
Urates in, 71, 79 
Urea in, 60, 70 
• Uric acid in, 60, 71, 79 
Vanadium, 8 
Vegetable proteids, 45 
Veratrine, 33, 36 
Vitellin, 45, 50 
Volumetric analysis, 86 
Principle of, 86 
Solutions used in, 87 
Water in milk, 55 
Weights and Measures, 98 
Weight, Measures of, 98 
Whey, 56 
Xanthin calculi, 81 
Xantho-proteic reaction, 46 
Zinc, 8, 13, 18