FERMENTATION 
XJXT THE 
HUMAN MOUTH 
ITS RELATION TO CARIES OF THE TEETH. 
THE INFLUENCE OF ANTISEPTICS, FILLING MATERIALS, ETC., 
UPON THE FUNGI OF DENTAL CARIES. 
THE FUNGI OF DENTAL CARIES; THEIR PURE CULTIVATION 
AND EFFECT UPON LOWER ANIMALS. 
By Dr. W. D. MILLER, Berlin, Germany. 
Reprinted from the INDEPENDENT PRACTITIONER, 
Vol. V, Nos. 2, 3, 5, 6 and 7. 
NEW YORK DENTAL JOURNAL ASSOCIATION, 
No. 35 West 46th Street, New York. 
1884. FERMENTATION IN THE HUMAN MOUTH ; ITS RELATION TO 
CARIES OF THE TEETH. 
BY DR. W. D. MILLER, BERLIN, GERMANY. 
(Reprinted from The Independent Practitioner.) 
During the last two years I have stated at different times and 
places, as the result of many experiments, that “ the first stage of 
dental caries consists in a decalcification of the tissue of the teeth 
by acids, which are for the greater part generated in the mouth by 
fermentation.” The object of the investigations described in this 
and the following papers is to determine this ferment, and the con- 
ditions essential to its action. I shall seek in what follows to present 
no views which are not the legitimate and necessary results of rigid 
and exact experiment, and I shall give in detail a description of 
each series of experiments, in order that every one may have an 
opportunity to judge of the accuracy of the work and the justice of 
the conclusions drawn from it. 
It is, nevertheless, with some hesitancy that I venture to present 
before the dental profession the results of my last six months’ labor, 
having learned by experience the almost endless number of agents 
which combine to vitiate such a series of experiments as that which 
I am about to offer, and the exceeding great care which is necessary 
in excluding or eliminating all irrelevant factors. 
If, therefore, I have been guilty of any oversight, or failed to take 
all possible precautions to guard against error, I hope that some one 
will kindly show me where I have gone astray, and put me in the 
right course again. 2 
The larger apparatus necessary for these experiments are : 
1. A large double-walled incubator, with gas regulator for main- 
taining any desired constant temperature. 
2. A Koch sterilizer. 
3. A damp chamber. (See Fig. 1.) 
4. A drying oven for sterilizing instru- 
ments, glass vessels, etc., at a temperature 
of one hundred and fifty degrees Centi- 
grade. 
5. A good microscope, with either water 
or oil immersion. 
It is not necessary to mention the smaller 
instruments, glass vessels, etc., etc., nor 
the apparatus necessary for making a 
chemical analysis of the products of the 
fermentation; these are sufficiently famil. 
iar to every one. 
To avoid repetition, I will say here that 
all vessels and instruments used in the cul- 
ture experiments were purified in the flame 
of a Bunsen burner, when practicable, otherwise by exposing for fif- 
teen minutes in the drying oven to a temperature of one hundred 
and fifty to one hundred and sixty degrees Centigrade, (three hun- 
dred and two to three hundred and twenty degrees Fahrenheit), 
and that all substances used as culture substrata were sterilized 
four times by exposure, at intervals of twelve hours, for half an hour, 
to steam at one hundred degrees Centigrade, in a Koch sterilizer. 
Furthermore, all infections from carious dentine were made as 
follows : The cavity of a freshly extracted carious tooth is cleared 
of food, and carefully brushed over with a pledget of cotton dipped 
in carbolic acid (ninety per cent). The acid is then thoroughly 
absorbed by means of bibulous paper, and layer after layer of the 
soft dentine removed with a repeatedly purified instrument, until 
the deeper parts are reached ; then, a portion of the clean soft den- 
tine, scarcely as large as a pin-head, is removed, and quickly brought 
into or upon the culture medium. 
Fig. 1.—Damp Cham- 
ber. a, shallow glass ves- 
sel partially filled with 
water, b, glass globe lined 
with wet bibulous paper. 
c, metallic stand for cul- 
ture tubes. 3 
Infections from the mouth were made by scratching upon the sur- 
face of the mucous membrane of the cheek, or the margin of the 
gum, with the end of a clean platinum wire, and then dipping it 
into the culture medium. The materials used for culture were : 
No. 1. Sterilized saliva 50,0 
Sugar 1,0 
Starch 0,5 
No. 2. Sterilized milk. 
No. 3. Decoction of malt 50,0 
Sugar 1,0 
The malt decoction is made by boiling, with slight evaporation, 
20,0 dry malt with 120,0 water for ten minutes, and filtering. 
No. 4. Sterilized saliva 50,0 
Water 50,0 
Starch 20,0 
Sugar 2,0 
The starch is added to the cold solution of water and saliva, and 
stirred until it becomes evenly divided throughout the solution ; it is 
then poured into shallow glass vessels with glass covers, and put into 
the sterilizer for complete sterilization ; it there congeals and forms 
a solid mass, upon the surface of which the infections may be made. 
It possesses all the advantages of gelatine, with one great additional 
one, in that it does not liquify at blood temperature. 
No. 5. Decoction of malt 100,0 
Sugar 2,0 
Starch 20,0 
Prepared in the same way as No. 4. 
No. 6. Beef extract 2,0 
Water 100,0 
No. 7. Water 100,0 
Beef extract 2,0 
Sugar 2,0 « 
No. 8. Fresh baked potato, cut into slices one half inch thick, 
with a clean knife. 4 
Other substances were used, but need not be considered here. 
Additional sugar is not absolutely necessary where malt is used, 
though I have, so far, obtained better results by adding a small quan- 
tity. The kind of sugar is immaterial, provided it be fermentable; 
even cane sugar, though not directly fermentable, is converted into a 
fermentable variety in the culture. Where small quantities of any 
culture material were used, the cultures were kept in the damp 
chamber to prevent their drying up or becoming too concentrated 
by evaporation. All cultures were made under a temperature of 
thirty-six to thirty-eight degrees Centigrade. 
We will begin with the fundamental experiments. 
Exp. 1. Fresh saliva is mixed with sugar or starch, one to 
forty, and kept at blood temperature. It invariably becomes acid 
in four to five hours. But some one, no doubt, will say that 
this is a result of no consequence, because the experiment was 
not made within the oral cavity; for his personal benefit we give 
the following : 
Exp. 2. A glass tube two c. m. long and three m. m. wide, is 
filled with starch, sterilized, and fastened to a molar tooth in the 
mouth on going to bed; next morning the contents of the tube 
will have a strong acid reaction. A cavity in a tooth, or a piece of 
linen, which may be saturated with a solution of starch, will answer 
the purpose as well as the glass tube. That the acid is the same in 
each case will be further established below. 
Exp. 3.—The mixture of saliva with starch or sugar, is kept for 
a half-hour in the sterilizer at one hundred degrees Centigrade, and 
then placed in the incubator; it does not become sour in four, nor 
in twenty-four hours; in fact, not at all. We conclude that the 
ferment is rendered inactive by a temperature of one hundred 
degrees Centigrade. 
Exp. 4. The starch is heated to one hundred and fifty degrees 
Centigrade before mixing with the saliva; the solution still 
becomes sour. Conclusion: the ferment exists, not in the starch, 
but in the saliva. 
We have now to determine the question : Is it an organized fer- 
ment (fungi), or is it an unorganized ferment (ptyaline)? This question is determined by the following experiments: 
Exp. 5. From six to eight grams of saliva are agitated in a test- 
tube with as much sulphuric ether as it will take up, starch added, 
and the whole put in the incubator. On examination after a few 
hours, we will find sugar in the solution, but no acid; in other 
words, the acid-forming ferment has been rendered inactive, but 
the unorganized, sugar-forming ferment, not. 
Exp. G. Instead of ether, enough carbolic acid is added to make 
the solution one-half per cent, strong; the result is the same. 
These two experiments show that the ptyaline of the saliva (which 
was not injured by the presence of the ether or the carbolic acid, as 
proved by the fact that it retained its diastatic action) is not the 
cause of the acid reaction. 
Exp. 7. According to Paschutin, ptyaline is devitalized by 
exposure twenty minutes to a temperature of sixty-seven degrees 
Centigrade. Organized ferments could not be killed by the same 
means. We accordingly subject a mixture of saliva and grape- 
sugar to the given temperature for twenty minutes. We thereby 
destroy the ptyaline; the mixture, nevertheless becomes sour if 
allowed to stand in the incubator for twenty hours. 
This experiment confirms the result of experiments five and six, 
and we begin to suspect that we have to deal with an organized fer- 
ment. This supposition is confirmed by the following experi- 
ment. 
Exp. 8. Six to eight drops of a perfectly sterilized solution of 
sugar in saliva (1-40), in a miniature test tube with cotton cork, 
are infected from the mouth, or with carious dentine, as described 
above; in twenty-four hours the solution will be acid; with a frac- 
tion of a drop of this solution a second tube is infected; it will like- 
wise become acid; from this a third, etc., etc.; each becomes acid 
in turn, while the control tube (containing the same solution, not 
infected) remains neutral. 
The conclusion is plain, that we have to do with a ferment which 
is capable of reproducing itself; in other words, an organized fer- 
ment. It therefore becomes evident that not only free in the 
month, but in the deeper parts of carious dentine, we have a 6 
fungus which is capable of producing an acid reaction in charac- 
teristic substrata. 
Exp. 9. Each of thirty small tubes were furnished with eight 
drops of solution No. 1, and each of thirty other tubes with as 
many drops of solution No. 3, and all were sterilized. Twenty-four 
were then infected from the mouth, twenty-four with carious den- 
tine, and twelve were left as controls. 
In twenty-four hours all forty-eight of the infected solutions 
were acid, while the twelve controls remained neutral. 
Exp. 10. Make a solution of 40,0 of saliva and 1,0 of starch; 
put equal portions in two flasks, a and b, and cover the surface of 
the solution in a with a layer of pure oil to prevent the free access 
of air, or: 
Exp. 11. Place flask a in an air-tight bottle containing a fresh 
alkaline solution of pyrogallic acid (which abstracts the oxygen 
from the air), or: 
Exp. 12. Exhaust flask a by means of the air pump, so as to 
produce a tolerably complete vacuum. The quantity of acid pro- 
duced in a will be, on an average, the same as that produced in b. 
We conclude from experiments eight, nine, and ten, that the 
fungus in question is independent of the free access of air or oxygen 
for its development and characteristic action, a conclusion which 
would exclude the fungus of vinegar, (mycoderma aceti) and which 
is of the utmost practical importance, since it signifies that this 
fungus can develop and perform its work deep in the dentinal 
tubules, or under fillings, provided the necessary materials are fur- 
nished it. 
Exp. 13. Place a piece of carious dentine upon the surface of 
the culture material described in number four, five, or six; in 
twelve hours the dentine will be surrounded by a white ring, from 
four to eight m. m. in diameter ; the material within this ring will 
be partially liquified, and have an acid reaction. The same result 
follows when the infection is made from the mouth. 
Exp. 14. Produce 10,0 of saliva by chewing a sterilized quill 
toothpick, add 0,5 starch or sugar, and place in the incubator. 
Then give the oral cavity a most thorough cleansing with pure 7 
water, using toothpick, brush and tloss, the object being to free the 
mouth from micro-organisms as completely as possible. Then 
produce again 10,0 saliva, add 0,5 starch or sugar, and put in the 
incubator. The amount of acid produced in a given time will, in 
the latter case, be often as low as one-fourth of that in the former. 
Conclusion: By thoroughly cleansing the mouth we no doubt 
remove the greater portion of the fungi, hence the small amount 
of acid produced. By using strong antiseptics, or by repeatedly 
filtering the saliva, we may reduce the amount of acid produced 
in twenty-four hours almost to 0. An experiment yet to be made 
is to take the saliva direct from the gland, before it becomes 
infected with the organisms of the mouth; it should not then 
become sour when mixed with starch and allowed to stand at blood 
temperature. In every case a careful microscopic examination 
of the cultures was made, revealing the constant presence of a 
fungus, chiefly in the form of diplococci, either single or in chains, 
less often in form of bacteria, bacilli, or even threads. (See Fig. 2.) 
Sometimes all these forms are 
found on a single thread, thus 
proving what I have already 
demonstrated for Leptothrix buc- 
calis and Leptothrix gigantea 
(Miller), the genetic connection 
of these different forms. The 
particular form in which the 
fungus occurs depends somewhat 
upon the culture medium, as well 
as upon the age of the culture. 
By using a glass tube as culture 
vessel we may demonstrate that 
whether the culture is made in 
the mouth or out of it, under similar conditions the fungus is the 
same. The fungus is not capable of producing an acid reaction of 
all substances in which it may vegetates A luxuriant growth may 
be obtained in beef extract, but no acid is produced, unless sugar 
is present. 
Fig. 2.—Some of the forms in 
which the fungus, treated of in this 
article, occurs. 8 
It is only from carbo-hydrates (especially sugar) that it appears 
to be able to produce acid in any considerable quantity, or at all. 
This question, however, as well as the morphology, physiology, 
development and life-conditions of the fungus, will receive consid- 
eration in a separate number. 
We have, then, a micro-organism which agrees morphologically 
with the Bacterium acidi lactici, and which, without the presence of 
oxygen, produces acid from sugar, so that we would probably not 
be far from right if we were to say that the organism in question 
is simply the fungus of lactic acid; we will, however, reserve our 
decision for the following number, where the analysis of the pro- 
duct of the fermentation will be given, that being the one sure 
method for determining the species of any ferment bacterium. 
In all cultures, it is of course essential that the culture-substratum 
be neutral when the inoculation is made ; should it be acid it must 
be neutralized. This is best accomplished by very carefully adding 
the carbonate of sodium. Without this precaution it would be 
somewhat difficult to determine whether acid had been produced 
by the action of the fungus or not. 
In the light of these experiments the thorough decalcification of 
the tooth substance in caries is easily accounted for. The saliva is, 
no doubt, always, particularly in mouths of uncleanly persons, 
impregnated with sugar, either taken directly into the mouth, or 
formed there by the action of the ptyaline of the saliva upon 
starch. The question of the presumable diastatic action, as well 
as of a presumable inverting power on the part of the organisms 
themselves, will be considered in the chapter on Physiology. 
Wherever this stagnates between the teeth, in fissures, etc., etc., 
especially during sleep, it must become acid. When a portion of 
the dentine has become decalcified, it, as is well known, takes up 
the liquids of the mouth and the fungi with them like a sponge, and 
the fungi, being independent of the free access of air, go on pro- 
ducing acid within the dentinal tubules. As each layer of dentine 
becomes softened in turn, the micro-organisms follow after, contin- 
ually producing new acid. Hereby the zone of softened, non- 
infected dentine is readily understood. The production of acid is entirely independent of the reaction of the saliva as it enters the 
mouth, hence the uselessness of “testing the saliva” for acid. That 
the liquid squeezed out of the tubules of decaying dentine has an 
acid reaction, every dentist in America who has a piece of blue 
litmus paper and is not color blind can easily prove for him- 
self. 
The result of experiment six plainly shows one cause of the good 
effects which the profession has seen from the use of carbolic acid. 
The fact that a pure culture was obtained in most cases by the 
first inoculation seems to indicate that the fungus exists in a state 
of tolerable purity in the deeper parts of the carious dentine. This 
question will, however, receive consideration later. The action of 
the fungus upon substances which contain no carbo-hydrates will 
also be considered under Physiology. 
In addition to these experiments, I add the following: A sound 
bicuspid tooth was sawed into sections, varying from one-third to one 
m. m. in thickness, and an equal number of these sections placed in 
each of two test-tubes. Into one of these test-tubes were then brought 
five c. c. of a perfectly neutralized two per cent, aqueous solution 
of beef extract; into the other the same solution, with the addition 
of 0,2 cane sugar. Both tubes with their contents were then steril- 
ized, and, upon cooling, infected from a pure culture of the fungus 
under consideration. 
The solution in the second tube became acid in a few hours; not so, 
however, with that in the first tube, it being non-fermentable. At 
the end of one week the thinner sections in the second tube were so 
far softened that one of them, removed for examination, could be 
easily bent between the fingers. At the end of the second week 
all but the thicker sections were completely decalcified. One of 
these sections was now placed upon the freezing microtome and 
made into cuts, which were stained in fuchsine and mounted in 
Canada balsam. A microscopic examination showed that the 
fungi had penetrated many of the tubules to a considerable depth, 
the invaded tubules being at the same tirtie slightly extended. At 
the close of the third week the invasion was found to have become 
much more extensive, the tubules much dilated, and in some places 10 
the walls were broken through, leading to the formation of oval 
spaces or caverns in the dentine. 
In short, we had a typical case of caries. 
It is hardly necessary to state that the thinnest sections in the 
first tube, where the development of the fungus was not accompa- 
nied by an acid fermentation, did not show even the traces of 
softening, to say nothing of caries. 
I had then produced caries by inoculating sound dentine from 
a pure culture of a fungus found in carious dentine, in the pres- 
ence of the same fermentable substances that occur in the mouth. 
It seems that a clearer solution of the problem can at present 
scarcely be expected. Of course the thought at once suggests 
itself to every one that this decay is quite independent of putre- 
faction ; all evidence points to the conclusion that putrefaction 
at most does nothing more than dispose of the already devitalized 
and much riddled remains of tissue, and we are in danger of over- 
rating its influence, even at this stage. 
Pieces of dentine in a solution kept constantly pure and sour by 
fermentation, not only become softened and show the microscopic 
changes characteristic of carious dentine, but finally, after some 
months, disappear altogether, as has repeatedly been the case in my 
cultures. From this we must infer that the process commonly 
known as putrefaction is absolutely essential at no stage of caries; 
especially is this the case in caries of enamel. 
It has been intimated that the active agent in this process is 
nearly related to, if not identical with, the fungus of sour milk: 
Bacterium acidi laclici. The analysis of the product of fermen- 
tation will show the truth or falsity of this supposition. 
The method of carrying out such an analysis will now be given. 
Two hundred c, c. fresh saliva are mixed with 2,0 starch and 
allowed to stand forty-eight hours at blood temperature; the mix- 
ture is then filtered and heated to one hundred degrees Centigrade, 
to stop the fermentation. This process is repeated until about a 
litre of the solution has accumulated. It is then placed in a retort 
and reduced to a volume of about seventy-five c. c. It will be very 
strongly acid. A few drops of this liquid are added to a thin 
solution of methyl-violet, and leave it unchanged ; from this we conclude that we have to deal with an organic acid, as an inorganic 
acid would turn it first blue, and then green. Since the acid did 
not distill during the prolonged boiling, we may set it down as 
non-volatile; hence a non-volatile, organic acid. The distillate 
was very slightly acid; we will call it distillate number one, as we 
wish to refer to it again. 
The solution was further reduced in volume to about forty c. c. 
over the water-bath, and then transferred to a large glass vessel, 
briskly shaken with one and one-half to two litres of sulphuric 
ether, and allowed to stand until the ether became perfectly trans- 
parent. This was then filtered into a large retort and distilled, 
proper precautions being observed to prevent accidents. When 
the volume had been reduced to about fifty c. c. the solution was 
filtered into a porcelain vessel, and still further reduced over the 
water-bath. A portion of the solution tested in the short tube of 
a Mitscherlich double-shadow polaristrobometer gave, as a mean of 
nine readings, a rotation of the plane of polarization equal to 
0,015 degrees, or 0° O',9. In other words, the solution was opti- 
cally inactive, the 0° O',9 being far within the range of the error of 
experiment, especially as the solution was not absolutely transparent. 
An excess of freshly prepared oxide of zinc was then added to 
the solution, and the whole slowly and carefully boiled, wTater being 
added as it was found necessary, till the reaction became neutral, 
or nearly so, filtered into a large glass evaporating dish, and put 
away at the temperature of the room for the salt to crystallize. 
A drop of this solution placed upon a glass slide gave, upon crys- 
tallization, the forms seen in figure one, which are at once recog- 
nized as crystals of lactate of zinc. In 
a few days a quantity of a whitish crys- 
talline powder had formed. This was 
placed upon a filter, the mother-liquid 
squeezed out, washed in absolute alcohol, 
dissolved in hot water, re-crystallized and 
dried over sulphuric acid; it then weighed 
0,343. After exposing to a temperature 
of one hundred degrees Centigrade, or a 
little more, till the weight became con- 
Fig. 1 12 
stant, it weighed 0,2816; it lost accordingly 17,9 per cent.* of water 
of crystallization, corresponding to three molecules of water. 
The salt was then dissolved in water, the zinc precipitated as car- 
bonate and burned. The burned mass (zinc oxide) weighed 0,0970. 
We have consequently : 
Substance analyzed (a zinc salt) = 0,343 
Oxide of zinc = 0,097 
The zinc oxide is seen to be equivalent to 28,2 per cent, of the 
substance analyzed. 
The formula for the inactive ethylidene lactate of zinc is— 
C* hs5 °;}Zn + ,H.O, = 248 + 54. 
Dried at ordinary temperature it contains 27,3 per cent, zinc 
oxide. The result obtained from the analysis differs, therefore, from 
that deduced from the formula by less than one per cent., and set- 
tles beyond doubt the fact that the substance analyzed was the 
lactate of zinc, or that the acid generated by the fermentation is 
lactic acid, or, more exactly, inactive ethylidene lactic acid, since, 
as shown above, the acid solution was optically inactive, and the 
zinc salt contained three molecules of water of crystallization. 
The salt was furthermore soluble in sixty-two parts water at four- 
teen degrees Centigrade. 
I repeated the analysis with the following solution: 
Water, 1000 c. c. * 
Saliva, 300 c. c. 
Bouillon, 200 c. c., made by boiling 125,0 beef ten minutes 
in 300 c. c. of water. 
Sugar, 10,0. 
This solution being slightly acid was neutralized with the car- 
bonates of lime and sodium, sterilized, and infected from a pure 
culture of the fungus in question. 
It was treated throughout exactly in the manner above described, 
except that the zinc salt was converted into the sulphide instead 
of the carbonate, and burned with powdered sulphur in a stream 
of hydrogen. The result was as follows : 
* Theoretically 18,2, or 0,3 per cent. more. Substance analyzed, = 1,0540 
Zinc sulphide, = 0,415 
Zinc, = 26,38 per cent. 
instead of 26,74 per cent., as deduced from the 
formula, a difference of only one-third of one per cent. 
In this case the substance was dried at one hundred degrees 
Centigrade before weighing, and the formula becomes 
C, II. 0, ) „ 
* 3 !■ Zn = 243. 
' 
One more analysis was made, using— 
Water, 1000 c. e. 
Liquid beef extract, 20 c. c. 
Sugar, 10,0. 
The result was the same, and need not be given; the two analyses 
above described being abundantly sufficient to show that the acid gen- 
erated by the fungus in question is the common ferment, lactic acid. 
Distillate number one, referred to above, owed its slight acidity, 
we now know, in part at least to lactic acid, since, when an aqueous 
solution of lactic acid is boiled, a small fraction of the acid goes 
over with the water. To ascertain, however, whether any other 
acid, especially volatile, was present, the distillate was boiled with 
carbonate of lime, filtered, evaporated to dryness, a small amount 
of dilute sulphuric acid added, and heated in a retort over the 
water-bath; a few drops of an oily acid came over, which, when 
taken upon the fingers, smelled like butyric acid; the amount, 
however, was so small, that no attempt could be made to analyze it. 
I have been able with some degree of certainty to establish the 
presence of lactic acid in carious dentine, by a method theoretically 
so simple that it seems strange it has never been made use of 
before, but which, however, in practice is only carried out with 
great difficulty. My first and second attempts were only partially 
successful; the third succeeded sufficiently well to justify its 
description here. 
In this experiment I made use of fifteen teeth, all containing 
considerable quantities of carious dentine, and all extracted on the 
day of use. The remains of food were first removed from the 14 
cavities, but none of the softened dentine; then all the softened 
dentine was taken out and placed in a porcelain vessel, cut or 
picked into fine pieces, placed in a test-tube with one c. c. of water, 
and two drops of a ten per cent, solution of hydrochloric acid 
added. Any free lactic acid in the carious dentine would remain 
free, and any existing in combination with lime would be set free 
by the hydrochloric acid. It was then gently shaken with about 
twenty-five c. c. sulphuric ether, and the latter, holding the lactic acid 
in solution was, after some minutes, poured off into a second test- 
tube; here it must be allowed to stand from twenty-four to forty- 
eight hours, till it becomes perfectly clear. It was then filtered into 
a porcelain dish, evaporated, a few drops of distilled water and a 
small quantity of freshly prepared zinc oxide added, gently boiled 
(water being added as necessary) for ten minutes, the three or 
four drops of liquid remaining filtered on to a glass slide, and 
allowed to crystallize. I obtained the forms seen in figure two. 
Their close resemblance to the crystals of the lac- 
tate of zinc (Fig. 1) will be seen at once. There 
can, in fact, scarcely be a doubt that they are lac- 
tate of zinc crystals. The lactic acid concerned 
in their formation must of course have existed in 
the carious dentine. 
I have noticed in the dental journals a tendency 
on the part of some writers on this subject, to derive a large 
amount of satisfaction from the statement that, after all, what 
I have done to clear up the subject of dental caries was done and 
known long ago. 
One writer even states that he might almost have said two years 
ago, something that I said but a few months since. Let me say, 
once for all, that I have too little spare time to devote any of it to 
the discussion of the question who said this or that first, or even 
who might almost have said something two years ago. There is 
perhaps no human disease about which more has been said than 
about caries of the teeth, and when the subject shall have received 
its final settlement there will be hundreds who may say “I told 
you so.” Malassez and Vignal very justly say of Baumgarten, 
Fig. 2 who claims priority over Koch in the discovery of the tubercle 
bacillus: “ II ne sufiit pas de trouver, il faut prouver ”—and I do 
not hesitate to say with reference to some of the discussions which 
for years have been carried on concerning the cause of dental 
caries: II ne sufiitpas de deviner, il faut trouver etprouver. 
It is not enough to guess the cause, or guess at it; we must find 
the cause, and, having found it, prove that it is the cause sought for. 
If we infect a beef-extract-sugar solution with carious dentine, as 
described in the February number of this journal, using every pos- 
sible precaution to obtain perfectly pure material and to prevent the 
access of germs from without, and keep the solution at thirty-seven 
degrees Centigrade, we may observe the following phenomena: In 
from eight to ten hours the solution will show a slight cloudiness, 
which at no time, however, amounts to complete opacity. Tested 
with sensitive litmus paper, it will be seen that the acid reaction has 
already appeared. In fifteen to twenty hours the fermentation will 
generally have reached the most active state, and soon afterwards a 
colorless, flocky precipitate will begin to form on the bottom of the 
vessel, accompanied by a corresponding clarifying of the solution, 
and a diminution of the fermentive activity. After the lapse of forty- 
eight hours the sediment will have completely formed, and the solu- 
tion will be almost as transparent as when the experiment began. 
The time required for the completion of this series of phenomena 
will, however, naturally depend somewhat upon the amountof dentine 
taken for the infection, and the amount of the solution used. 
Impurities in the culture manifest themselves in various ways; it 
may be by an excessive cloudiness of the liquid, or by the formation 
of a skin upon the surface of the solution, or the failure of the latter 
to become clear after the regular lapse of time, etc., etc. 
Dentine is an excellent medium for separating the different fungi 
found in the mouth, the most of them not being able to exist in the 
deeper parts, partly on account of the acidity of the medium, partly 
on account of the lack of free oxygen. We may, therefore, with the 
proper amount of care, obtain material of such purity as to produce 
a pure culture in the first generation. 
If we microscopically examine the sediment which has formed on 16 
the bottom of the vessel, we shall find it to consist of cocci and diplo- 
cocci, either single or in chains; in either case without motion. 
Under a low power they appear round and regular; with fa oil im- 
mersion they are seen to be round or oval, regular or irregular, 
involuted, etc., presenting the most various shapes and sizes. I 
have never been able to 
detect the existence of 
spores, and reproduction 
takes place only after the 
scheme presented in fig- 
ure one, Nos. 1,2, 3, 4, 5, 
6,7. A coccus which may 
be round in the begin- 
ning, by extension in one 
axis becomes oval or 
elongated; soon after it 
shows a contraction in 
the middle, resulting in 
the production of a diplococcus, or two cocci, each of which may 
produce two cocci in the same manner. 
We find, consequently, in a chain taken from a growing culture, 
some of the cocci round, others oval, some of the diplococci but 
slightly contracted, while in others the contraction amounts almost to 
a complete division. (See Fig. 1, d, e, f.) Frequently the cells acquire 
a pronounced bacterium form, so that if they did not occur in the 
same chain with the ordinary forms, one would be in doubt as to 
whether they belonged to the same species. 
The growing cells in a chain sometimes turn upon their shorter 
axis, and then, growing out in the new direction, produce very pecul- 
iar figures. (Fig. 1,/, g.) In stagnant cultures the cells under 
high power are mostly very irregular, having in groups the appear- 
ance of the bones of the wrist. (See Fig. 1, a, b.) 
Very characteristic are the involution forms produced both in stag- 
nant cultures and in media which are not well adapted to the needs of 
the fungus. Here the forms and sizes are so various that it some- 
times becomes exceedingly difficult, if not impossible, to tell if cer- 
Fig. 1 tain ones are normal or abnormal. (See Fig. 1, h, i,j, k.) In ex- 
ceptional cases the threads surround themselves with a thick 
gelatinous sheath. (See Fig. 1, c.) The protoplasm of the involuted 
cells generally presents a granular appearance. (Fig. 1, A, A.) 
If we make a large number of cultures at once we will, in about 
one case out of five to ten (and if the cultures are made in a decoc- 
tion of malt, much more frequently), meet with a second fungus, 
essentially different from the one just described. It occurs chiefly 
in form of bacilli, but also as leptothrix, bacteria, diplococci and 
cocci singly, or, as is mostly the case, in 
long zigzag threads. (Fig. 2.) 
The discovery of this fungus, with 
its different forms of development, af- 
fords a very ready explanation of the 
fact that in a single dentinal tubule 
we sometimes find a transition from 
leptothrix to bacilli, from bacilli to bac- 
teria, and from bacteria to cocci, an 
occurrence which I demonstrated near- 
ly two years ago before the American 
Dental Society of Europe, before the 
Gesellschaft fuer Heilkunde, in Berlin, 
and to various private persons, including some of the most cele- 
brated mycologists in Germany. 
Those who maintain, as was done in the British Dental Association, 
that such cases may n ot be found, are responsible for their own mistake. 
Macro-scopically, cultures of this fungus in beef-extract-sugar so- 
lution are not easily to be distinguished from cultures of that 
described above. The fungus collects as a sediment on the bottom of 
the vessel; it never forms a skin on the surface of the liquid, and pro- 
duces but a moderate cloudiness of the same. In most decoctions, 
however, they present some peculiarities. Sometimes the fungus 
floats about in the solution in semi-transparent balls, or rises up 
from the bottom of the vessel like a miniature cloud of smoke, or 
collects in small patches on the sides of the vessel, while the solu- 
tion itself remains almost perfectly clear. The cells are motionless, 
and do not form spores. 
Fig. 2 18 
In order to discriminate between these 
two fungi I will designate for the present 
the one first described by the prefix A 
(alpha), and the one under consideration 
by the prefix (3 (beta). In all probability 
the /? fungus also produces lactic acid 
from sugar. I say in all probability, be- 
cause, though I have always been able to 
detect lactic acid in cultures of this fun- 
gus, I could not say with absolute certainty 
that cocci and diplococci of the species 
A were not present. 
We have, then, in carious dentine two 
distinct fungi—one always, the other often, 
present; the former surely, the latter prob- 
ably, producing lactic acid from sugar. If 
these fungi are the direct cause of dental 
caries, we should be able to produce caries 
by subjecting sound dentine to their action. 
This I have accomplished, as described in 
the March number of this journal. 
In figure three a are seen in outline two 
tubules of dentine melted together by 
natural caries, and in figure three b two 
tubules melted together by artificial caries. 
In figure four a are likewise two tubules 
from natural caries, and in figure four b 
two from artificial caries. It is a fact of 
considerable interest that, though, the 
fungi themselves are perfectly colorless, 
pieces of dentine subjected to their action 
become yellowish, light brown, or dark 
brown, etc., depending upon the medium 
in which the culture is made, while differ- 
ent pieces of dentine in the same culture do 
not by any means necessarily acquire the 
same color. 
Fig. 3 
Fig. 4 The carrying out of this experiment is attended with diffi- 
culties, and some may try it and fail. I have failed many times. 
The necessity of repeatedly changing the solution very much in- 
creases the danger from impurities; especially must the saccbaromy- 
cetes be guarded against. The acidity of the medium caused by 
the caries fungi renders it very favorable for their development, and 
when they have once found their way into a culture it might as well 
be thrown away at once. Again, notwithstanding the presence of 
the pieces of dentine, the solution sometimes becomes sufficiently 
acid to impair, if not to destroy, the vitality of the fungus. In 
this case the dentine becomes softened, but only a slight invasion 
of the tubules takes place. Then, of course, in the very last 
stage of caries other fungi, especially leptothrix buccalis, are 
present in the decomposing dentine, and sometimes produce an 
appearance in its superficial layers, which I have not attempted 
to reproduce artificially. It is not difficult, by a simple microscopic 
examination of the fluids of the mouth, as well as of carious 
dentine, to find forms morphologically identical with those described 
above. 
In figure five is seen in outline a portion of an epithelial 
scale from the human mouth, highly magnified, with the 
Fig. 5 20 
fungi lying upon the surface. The forms seen in figure six were 
obtained from a glass tube filled with starch 
and kept in the mouth over night, while figure 
seven is from carious dentine. 
The A caries fungus agrees 
morphologically with the fun- 
gus of sour milk as delineated 
by Pasteur. Later experi- 
ments, however, render it probable that the 
souring of milk is produced by an altogether 
different fungus, a short, thick bacterium, occurring in twos, seldom 
fours, which may also be found in the human mouth (though probably 
not deep in carious dentine), and will be considered at another time. 
In the case of both fungi the fermentation goes on independently 
of the presence of free oxygen. I have already shown that where 
only a trace of oxygen is present, in no way comparable with the 
amount of acid produced, the degree of acidity was as great as where 
there was free access of air. Whether, however, this trace of oxygen is 
essentia] to the life of these fungi—i. e., whether without it they would 
perish from asphyxia—is a question which we will not discuss here. 
It has been generally supposed that the production of lactic acid 
by fermentation from sugar is accompanied by the evolution of car- 
bonic acid; in fact, Fluegge says that no fermentation can go on 
without the production of carbonic acid. This statement will hardly 
be borne out by a study of the fermentation produced by the fungi 
of tooth caries. 
A glass vessel of five hundred c. c. capacity was filled with beef- 
extract-sugar solution, infected with a pure culture of caries fungi 
and made air-tight with a rubber stopper, carrying an efflux-tube 
for collecting the gas over mercury. After twenty-four hours, dur- 
ing which time 1,75 c. c. acid had been produced, one single gas- 
bubble was collected, which may have been due to a slight change 
of temperature, as well as to a veritable gas evolution. The splitting 
appears therefore to be perfectly smooth, and to take place in accord- 
ance with the simple formula— 
Fig. 6 
Tig. 7 
C6 Hlt 06 — 2C3 Hg 03. 21 
It presents a marked contrast to the stormy character of the butyric 
and alcoholic fermentations, in case of which the pressure of the gas 
evolved is often sufficient to burst the vessels containing the cultures. 
There is perhaps at nearly all times a sufficient amount of sugar 
in the oral cavity to enable the fungi of caries to carry out their 
characteristic ferment action. It remains, nevertheless, an interest- 
ing question, whether they have the power to form sugar out of 
starch ; i. e., whether they have any diastatic action. About thirty 
cultures in an aqueous solution of beef-extract and starch, and in a 
solution of starch in sterilized saliva, gave for the most part negative 
results; in exceptional cases a slight diastatic action appeared to 
take place, which I am inclined to regard as the result of some im- 
purity in the culture, or an error in the experiment. 
On the other hand, the fungi appear without doubt to possess 
the power to invert, or to render non-fermentable sugars fermenta- 
ble, since cane sugar, which is not fermentable, and does not reduce 
alkaline solutions of sulphate of copper, acquires both these prop- 
erties when subjected to their action. That this result is caused by 
the action of a ferment produced by the organisms, and which may 
be separated from them, is, I think, demonstrated by the following 
experiment: By making a number of cultures at one time in vessels 
of two hundred to five hundred c. c. capacity, and collecting the 
sediment which was deposited on the bottom of the vessels, I suc- 
ceeded in bringing together a considerable quantity of the fungi; 
this was then treated with ninety per cent, alcohol, filtered and 
dried in a porcelain vessel, thoroughly rubbed with sand, digested 
with water at twenty-three degrees Centigrade, and again filtered; 
the filtrate (which must be clear, and should contain the ferment in 
solution) was added to a solution of cane sugar, which then showed, 
in the long tube of a Mitscherlich polariscope, a rotation equal to 
5°,19. The solution was now allowed to stand four hours at a tem- 
perature of thirty-eight degrees Centigrade, after which time it pro- 
duced a rotation of only 4°,54, indicating a decrease of about two- 
thirds of a degree. The solution also produced a slight reduction of 
an alkaline solution of sulphate of copper; i. e., a certain portion of 
the cane sugar had been converted into invert sugar. 22 
In the presence of the fungi the non-fermentable sugar, by the 
action of the invertine produced by the fungi, takes up one mole- 
cule of water and is coverted into invert sugar, a mixture of levul- 
ose and dextrose, both of which are fermentable. 
C'la Hg 0 — C6 H18 06 -f- C6 H12 06. 
We may say, therefore, that the micro-organisms require sugar to 
produce fermentation, but that it is immaterial which kind of sugar 
is furnished them. The fermentation is most active between the 
temperatures thirty-five and forty degrees Centigrade. Above fifty 
degrees and below fifteen degrees Centigrade, little or no production 
of acid takes place. 
In addition to these two species of fungi, others of minor im- 
portance are occasionally met with in the mouth, and will receive 
attention at another time. 
I would not have any one think that I look upon the above as a 
thorough consideration of the fungi of tooth caries. To me it ap- 
pears very imperfect. Nevertheless, I thought it well to present the 
matter before the profession in the hope that others might be in- 
duced to take it up and help to complete the work thus begun. In 
the next number I will present the results of experiments relating 
to the action of various antiseptics, filling materials, etc., upon the 
fungi under consideration. 
Cane sugar, 
Levulose, 
Dextrose. 
THE INFLUENCE OF ANTISEPTICS, FILLING MATERIALS, ETC., UPON 
THE FUNGI OF DENTAL CARIES. 
Having established upon an experimental and scientific basis the 
fact that caries of the teeth is, to a certain extent, the direct result 
of the action of ferment acid or acids* upon the tissue of the tooth, 
followed, particularly in the case of the dentine, by the action of 
the ferment organisms themselves upon the decalcified tissue, it 
becomes a matter of the first importance to determine, first, by 
what means we may counteract the action of the acids or prevent 
their production; second, by what means we may save the already 
decalcified dentine from complete destruction. 
* The chief work in the production of caries is performed by lactic acid ; 
other acids are only auxiliary factors. Evidently there are three methods by which the desired end may 
be partially obtained: 
1. By repeated, thorough, systematic cleansing of the oral cavity 
and the teeth, we may so far reduce the amount of fermentable sub- 
stances in the mouth and the number of ferment organisms, as to 
materially diminish the production of acid. This is so self-evident 
that it needs no further comment. 
2. By the repeated application of alkaline substances we may, to 
a certain extent, neutralize the acids before they have acted upon 
the teeth to any considerable degree. 
3. By a proper and intelligent use of antiseptics we may destroy 
the organisms themselves, or at least render them inactive. It is 
this method which is especially applicable in the second stage of 
dental caries (i. e., the stage which follows the decalcification), and 
to which we will here give exclusive attention. We must, however, 
constantly bear in mind that by whatever method we proceed, a 
previous thorough cleansing of the teeth is absolutely indispensable. 
There is no known solution, alkaline or antiseptic, applicable in the 
human mouth, which will penetrate between the teeth or to the 
bottom of fissures and cavities, when these are filled with food, in 
sufficient quantity to have any appreciable effect. Therefore, before 
all antiseptics or alkaline washes come the toothbrush, toothpick, 
and floss silk. 
In my experiments for determining the action of various anti- 
septics upon the fungi of tooth caries, it appeared to me that by 
allowing the antiseptic to act upon the fungi in their natural 
medium, saliva, I could obtain results of more practical value than 
by experimenting upon them in artificial solutions, and in pure cul- 
tures, neither of which ever occurs in the human mouth. Further- 
more, since the fungi can attack the teeth only after a partial de- 
calcification, we have in the first place to demand of an antiseptic, 
not so much that it destroys the fungi, as that it prevents the pro- 
duction of acid by them.* Consequently, if an acid reaction failed 
to appear in a solution of saliva and sugar to which a certain anti- 
* The production of acid may be taken as synonymous with the development 
of the fungi, though the failure of the acid reaction to appear after a certain 
length of time does not necessarily indicate that the fungi have been devitalized. 24 
septic had been added, as soon as in a like solution to which no anti- 
septic had been added (control), it was taken as evidence of the 
activity and value of the antiseptic used. This method could of 
course be used only with substances having a neutral reaction. The 
solutions were also subjected to a microscopic examination, to render 
the evidence doubly sure. 
In the following table I have indicated the percentage of each 
antiseptic experimented upon which must be present in a sweet- 
ened-saliva solution, to prevent the appearance of an acid reaction 
in twenty-four hours, or in case of alkaline or acid antiseptics, to 
prevent the development of the characteristic fungi in the same time. 
For example, if to 100,000 parts of sweetened saliva we add one 
part of bichloride of mercury, the solution will not be found acid 
after the lapse of twenty-four hours, even though the control be- 
came sour in four or five hours. If we add only one part to 500,000, 
the acid reaction will appear somewhat later than in the control. 
This table is designed to show the comparative strength of the 
antiseptics most commonly used. The action of the antiseptics 
having an acid or alkaline reaction upon the fungi, was determined 
by the use of the microscope alone. 
by the use of the microscope alone. 
Production 
/ (Development 
of Acid 
of Fungi) \ 
Bichloride of mercury 
. .. .1-100,000 
1-500,000 
Nitrate of silver 
.. .. 1-50,000 
1-100,000 
Iodoform 
.... 1-5,000 
1-10,000 
Naphthaline 
. . .. 1-4,000 (?) 
1-9,000 
Iodine 
. ... 1-6,000 
1-15,000 
Oil of mustard 
.. . . 1-2,000 
1-5,000 
Permanganate of potas 
.. .. 1-1,000 
1-2,000 
Eucalyptus oil .. 
1-600 
Carbolic acid 
1-500 
1-1,000 
Hydrochloric acid 
1-500 
1-1,000 
Phenylic acid 
1-200 
1-500 
Liquid of Agate Cement 
1-250 
Liquid of Excelsior Cement 
1-225 
Lactic acid 
1-125 
1-250 
Carbonate of sodium 
1-100 
1-200 
Salicylic acid (Cone, alcohol sol.) 
1-75 
1-125 
Alcohol 
1-10 
1-20 25 
The experiments show that bichloride of mercury is about two 
hundred times as powerful as carbolic acid, and demonstrate very 
clearly the mistake of substituting weak solutions of this antiseptic 
(1-1,000, as I have seen recommended) for concentrated carbolic 
acid. One one-thousandth is only one-fifth as powerful as pure 
carbolic acid, which in many cases may be used with impunity. It 
is consequently useless to attempt to introduce the sublimate solu- 
tion for the purpose of sterilizing root canals, cavities before filling, 
etc., unless we may use at least a one-half per cent., if not a one per 
cent, solution. I see no reason, however, why this may not be done. 
In a few cases I have used a one per cent, solution for treating root 
canals, and do not hesitate, particularly with the rubber dam ad- 
justed, to wipe out cavities before filling with a two per cent, solu- 
tion, and see no possible evil which could result from it. A well- 
knoWn physiologist in Berlin has told me that he uses a one per 
cent, solution in his own mouth for aphthae, and with excellent 
results. We should not, however, overlook the fact that a one per 
cent, sublimate solution is only one-fifth as powerful as pure iodoform. 
As a mouth wash I have frequently used a one-tenth per cent. 
(1-1,000) solution myself, and have seen no bad results from it; I 
would not, however, recommend it to my patients in this strength. 
It has, besides, for me, an exceedingly disagreeable and lasting taste, 
which it is difficult to disguise, and produces an immediate in- 
creased secretion of saliva and mucus, which is very annoying. A 
one-fiftieth per cent, solution (1-5,000) may eventually be brought 
into use; in this concentration it is four times as powerful as a one 
per cent, solution of carbolic acid. The very high antiseptic power 
of nitrate of silver is particularly noteworthy. Why may it not be 
employed in place of the much more dangerous mercuric chloride? 
The action of tobacco upon the fungi is worthy of notice. Five 
grammes of old Virginia plug were boiled fifteen minutes in fifty c. c. 
of water, the loss by evaporation being constantly replaced; the 
decoction was then filtered, and a portion added to an equal volume 
of saliva with sugar. This produced a mixture scarcely stronger 
than that which many veteran chewers carry around in their mouths 
all day, and in it the fungi led only a miserable existence. 26 
Much more remarkable, however, was the action of tobacco smoke 
upon the fungi; the smoke from the first third or last quarter of a 
Colorado Claro cigar being found amply sufficient to sterilize ten 
c. c. of a beef-extract-sugar solution, previously richly infected with 
caries fungi. 
The apparatus used for this experi- 
ment (see figure one) explains itself. A 
current of water passing through the 
part B in the direction of the pro- 
duces a current of air through the part 
A, in the direction of the y which draws 
the smoke from a lighted cigar through 
the solution. The rate at which the 
cigar smokes may be regulated at will 
by the cock of the hydrant. 
In consideration of the strong antisep- 
tic power of tobacco smoke, we might be 
inclined to infer that tobacco smokers 
should never suffer from caries of the 
teeth; it is evident, however, that there 
are very many points in the dental arch 
to which the smoke never penetrates. 
In the preparation of cavities for in- 
serting fillings, it is naturally often next 
to impossible to remove all the carious 
dentine, and in all such cases it is es- 
pecially desirable that the filling material 
itself should possess antiseptic proper- 
ties, since we, in using such a material, 
not only destroy those organisms exist- 
ing in the carious tissue, but the mater- 
ial, if it remains permanently antiseptic, 
retards the working of the ferment or- 
ganisms from without, and the appearance of secondary decay. We 
need, therefore, a material for filling which is not only antiseptic at the 
time of insertion, but which remains permanently so after being 
inserted. 
(Fig. one.) 
а, Glass cylinder with infected 
solution. 
б, c, Glass tubes. 
d, d’, d\ Rubber tubing. 
e, Cigar (Colorado Claro.) 
B, Water air-pump. 
A current of water passing x 
through B in the direction of the V 
produces a partial vacuum in 
the bulb, and consequently a cur- 
, rent of air in the direction of the 
V or through the cigar, which if 
lighted will smoke at a rate deter- 
mined by the pressure under which 
the water is flowing. I have endeavored to determine the relative antiseptic power of 
different filling materials (cements, amalgams, etc.), not only at the 
moment of mixiug, but after they were thoroughly dry, after they 
had lain some hours in sweetened saliva, and after they had been an 
indefinite time in the human mouth. 
A large number of miniature test-tubes (homeopathic pill-tubes) 
were provided with cotton stoppers, and sterilized. Into each was 
brought one-half c. c. of beef-extract-sugar solution, previously in- 
fected with carious fungi (pure culture). To the first tube was 
added a small drop of a one per cent, sublimate solution; the second 
tube was left untouched, and into the third, fourth, fifth, etc., were 
brought the filling materials whose antiseptic virtues were to be 
tested; these were in the form of cylinders two m. m. in diameter, 
and three m. m. long; if old fillings from the mouth were used, 
pieces were taken having approximately the same size. 
These tubes now being placed in the incubator, their contents be- 
came cloudy one after the other. In those tubes which contained 
fillings of but slight antiseptic power, the development of the fungi 
proceeded rapidly, and the cloudiness soon appeared. If, on the other 
hand, the filling was strongly antiseptic, the development of the 
fungi was hindered, and the cloudiness appeared later. The first 
tube to which the sublimate solution had been added of course re- 
mained clear, and by comparing the others with this it was easy to 
see just when the turbidity began to show itself; the second tube, 
containing no antiseptic and no filling, served as control, and the 
space that intervened after the control became turbid till any one 
of the other tubes became turbid, was a measure of the antiseptic 
power of the material in that tube. 
As the result of a great number of experiments, I have been able 
to get together the following table: 
When the control tube becomes turbid in 5 hours, then: 
A tube containing an old oxy-phosphate filling becomes turbid in... 5 hours. 
“ “ “ oxy-chloride “ “ “ “...5 “ 
“ “ a gold cylinder becomes turbid in 5 “ 
“ “ a Hill’s stopping cylinder becomes turbid in 5 “ 
“ “ an amalgam cylinder (kept 12 hours in saliva) be- 
comes turbid in 5t “ A tube containing an agate cylinder (kept 12 hours in saliva) becomes 
turbid in 5£ hours. 
“ “ an old amalgam filling becomes turbid in 5 A “ 
“ “ an amalgan cylinder (mixed dry) becomes tur- 
bid in 5$ “ 
“ “ an amalgam cylinder (mixed becomes tur- 
bid in 5£ “ 
“ “ an oxy-phosphate cylinder (12 hours in saliva) be- 
comes turbid in 5£ “ 
“ “ an amalgam cylinder (12 hours old) becomes tur- 
bid in 5§ “ 
“ “ an old filling of tin and gold becomes turbid in.. 5k “ 
“ “ an oxy-phosphate cylinder (12 hours old) becomes 
turbid in 6 “ 
“ “ an agate cylinder (12 hours old) becomes turbid in. “ 
“ “ an iodoform cement cylinder (12 hours in saliva) be- 
comes turbid in 6? “ 
“ “ a pyrophosphate cylinder (mixed dry) becomes 
turbid in 7£ “ 
“ “ a pyrophosphate cylinder (mixed wet) becomes 
turbid in ?f “ 
“ “ an oxy-chloride cylinder (12 hours old) becomes 
turbid in 9 “ 
“ “ a piece of dentine from a tooth impregnated by a 
copper amalgam filling becomes turbid in. 11 “ 
“ “ an iodoform cement cylinder (12 hours old) becomes 
turbid in 12 “ 
“ “ an iodoform cement cylinder(fresh)becomes turbid in? “ 
“ a globule of mercury becomes turbid in — “ 
“ “ a cylinder of black oxide of mercury becomes tur- 
bid in — “ 
“ “ a cylinder of any copper amalgam becomes tur- 
bid in — “ 
“ “ any old copper amalgam filling becomes turbid in — “ 
“ “ a cylinder of oxy-chloride (fresh) becomes tur- 
bid in — “ 
The (—) signifies that the solution remained permanently clear. 
We see from these results that the only filling at present in use 
which exerts a continual anti-ferment* action upon the walls of the 
* I use the terms anti-ferment and anti-septic interchangeably, though the 
former is, perhaps, preferable, since we are treating of ferment, and not septic 
organisms. tooth and its immediate surroundings, is the old copper amalgam; 
not only that, but the very substance of the tooth containing such 
a filling itself becomes antiseptic, a piece of bluish or bluish-green 
dentine from such a tooth very powerfully retarding the develop- 
ment of the fungi, and, indeed, in two cases completely destroying 
them. Secondary decay in such a case would be next to impossi- 
ble, where anything like cleanliness was observed. 
This result is well supported by observations which I have had 
abundant opportunity to make for the last five years, here where 
this material is so extensively used, and 1 do not hesitate to say 
that if our only object is to check the destruction of tissue by 
caries, there is no material at present in use with which this object 
may be so surely accomplished as with a good copper amalgam. It 
is a material, however, which I have never used, though I am not 
aware of any bad effect produced by it beyond the discoloration of 
the tooth. Skogsberg’s iodoform cement came into my hands too 
late to complete the experiments with it. It has undoubtedly strong 
antiseptic properties, which it does not completely lose even when 
exposed to the saliva, and might no doubt be used to great advan- 
tage as a foundation for permanent fillings. Old fillings of tin and 
gold possess slight antiseptic power, still less (almost zero) old 
amalgam fillings (not copper). The very inconsiderable power of 
amalgams to prevent the development of ferment fungi is a source 
of some surprise, since we have been accustomed to look upon 
them as very active in this respect. It is probably a mistake to 
attribute the hardening of dentine under amalgam fillings to the 
antiseptic action of the amalgam, since, in the first place, it possesses 
this power to but a slight degree, and in the second place the hard- 
ening may take place under fillings of gutta percha equally well. 
If we dry the cavity but indifferently well, and then choose a piece 
of gutta percha which we thiuk will about fit the cavity, warm it 
and stuff it into the cavity, we of course can expect only bad 
results. If we proceed as follows we will obtain excellent results, 
as I have seen time and again: Adjust the dam, excavate carefully, 
especially the margins, wash with a strong antiseptic, dry thoroughly 
with bibulous paper and then with the hot-air syringe, till the sur- 30 
face of the dentine becomes whitish, paint with a thin solution of 
copal varnish, dry again with warm air, then put in the gutta 
percha in small pieces, one after the other, being sure that each 
piece sticks to its place, especially along the margin, just as if you 
were making a filling of gold. A piece which has once moved in 
its place must not be allowed to remain, as a leak will be the result. 
Remove such a filling after two years, and the cavity will often be 
found in an excellent condition for a gold filling. 
The oxy-chlorides when first mixed, are powerfully antisep- 
tic, but soon lose their energy when exposed to the action of 
saliva. 
The oxy-phosphates are very much inferior to the oxy-chlorides in 
antiseptic power, and should never be used in cavities where there 
is much soft dentine. This conclusion is borne out by my own 
experience in practice, and by that of others with whom I have 
conversed on the subject. Dr. Paetsch first called my attention to 
the disastrous results of such a practice, and his testimony was 
confirmed by that of Dr. F. P. Abbott, and others. 
It must not be expected that the results given in the above table 
are absolutely free from error. The experiment is attended with 
more difficulties than are at first sight apparent; especially does the 
sterilization of the filling materials themselves involve much time 
and labor, and the results are not always constant; this was espe- 
cially the case with iodoform cement. Amalgams and phosphates 
gave quite constant results. The tests with some of the materials 
were made over twenty-five times; with others, such as copper amal- 
gams, where there was no doubt as to the result, only a few experi- 
ments were made. 
Caries of the teeth, except in the later or last stage, is the result 
of a ferment process, and the organisms found in the deeper parts 
of decaying dentine, which I have isolated and obtained in pure 
culture, are ferment organisms. The decomposition of the pulp 
and contents of the root canal, attended by bad-smelling products, 
is, on the other hand, a putrefactive process, in which entirely dif- 
ferent species of fungi are concerned. Whether or not the results 
which I have obtained for the fungi of caries would apply equally well to those putrefactive fungi, is a question which can be settled 
only by experiment upon pure cultures of the same. 
Although I have now, as I think will be granted, established upon 
a sure basis a fact that caries of the teeth may result directly from 
the action of acid-producing fungi in the presence of fermentable 
carbo-hydrates, the conclusion would hardly be justifiable that, by 
keeping the mouth constantly and perfectly free from all ferment- 
able substances, or by repeated application of antacids or antisep- 
tics to all parts of the teeth, or by all these means together, we 
could ever banish dental caries from the oral cavity. A most pow- 
erful influence, which we do not well understand, is exerted by the 
nutritive processes in the teeth themselves. 
I am assured by men who have grown old in the practice of den- 
tistry, that mouths which have long been under their observation, 
and which practically have been completely free from caries for 
years, at once, on account of some sudden change of health, shovy 
a general breaking down or crumbling of the teeth, en masse, in the 
space of a few weeks. It has also been my experience that patients 
who have been dismissed by their dentists in America, with the 
assurance that according to previous experience their dentures 
would require no treatment for one or two years, have come to me 
a few weeks later with teeth looking as though they had not been 
under the hands of a dentist for years. Some say the ocean voyage 
spoiled their teeth; others attribute it to a change in the climate, 
food, health, etc. 
At any rate, we have here a cause which lies without the domain 
of both bacteria and acids (either ferment or otherwise). The lime- 
salts of the teeth are supposed to form, with the organic matter of 
the tooth, a definite chemical compound, and it is probably due to 
this fact that simple salts of lime are so much more readily soluble 
in weak acids than pulverized tooth-bone, or that the tartar upon 
the teeth is so much more easily soluble than the teeth themselves; 
so that when any one rinses his mouth with vinegar, and after- 
wards finds lime in the vinegar, we know that the lime, in by far 
the greater part, if, indeed, we may not say altogether, came from 
the tartar. Now, though there is no positive evidence for the supposi- 32 
tion, it is certainly not altogether improbable that, as a consequence 
of certain derangements in the nutritive functions of the teeth 
resulting from a change of health, etc., etc., a dissolution of the 
affinity between the lime-salts and the organic matter may take 
place, thus setting free the easily soluble lime-salts, which are then 
carried away in solution or washed out mechanically. 
This is a supposition only, which I bring forward because facts 
in this case are absolutely wanting. If it should, perchance, con- 
tain a trace of truth, then adult and pulpless teeth should be less 
subject to these sudden attacks of caries than young teeth with 
living pulps. 
There still remains much hard work to be done, before the subject 
of dental caries may be dismissed as having received a final solu- 
tion in all its different phases. There are men enough in the pro- 
fession, however, who are willing to work, and who do not shrink 
from the tasks yet to be performed. 
THE FUNGI OF DENTAL CARIES ; THEIR PURE CULTIVATION AND 
EFFECT UPON LOWER ANIMALS. 
In the May number of the Independent Practitioner will be 
found the description and illustrations of two species of micro- 
organisms which I had, up to the first of March, 1884, obtained 
from carious dentine. These species I isolated by inoculating 
culture liquids with very small pieces of carious dentine, taken 
from near the border of the normal tissue. If the fungus was 
not at once obtained in the pure state, a second culture tube was 
inoculated after the method of fractional culture, with a minimum 
portion of the first, and so on. 
It soon, however, became apparent that the capture of these two 
species by no means ended the work ; on the other hand, new forms 
continually presented themselves, and in order to be able to deter- 
mine definite characteristics for each species, resort was had to the 
culture on plates of gelatine prepared with beef extract, calf’s 
broth, malt decoction, etc. 
The beef-extraqt gelatine, for example, I prepare as follows : 
200 c. c. water -f- 3,0 beef extract -f- 3,0 sugar, are first neutralized, then slowly boiled for five minutes, and filtered (filter and all other 
vessels, of course, sterilized) After cooling, 8,0 of the finest gel- 
atine is added and gradually heated till the gelatine is dissolved ; 
it is then cleared with the white of an egg, and all together kept 
at the boiling point for about five minutes, stirring constantly to 
prevent burning ; it is then passed through a filter, surrounded by 
a bath of boiling water, into glass tubes with cotton stoppers (both 
sterilized), and kept in a refrigerator. When to be used it is melt- 
ed in warm water and poured upon sterilized cold glass plates, 
which may be m.0,15 long by m. 0,07 wide, and placed in the 
moist chamber. The layer of gelatine should be about two in. m. thick. 
Suppose now we have a culture containing different species of 
fungi, and we wish to separate them. A thin platinum wire with 
one end melted into a glass rod is sterilized in the flame of a bun- 
sen burner, and on cooling dipped into the impure culture and 
lightly drawn across the surface of the gelatine; the fungi which 
adhered to the platinum wire are thereby scattered in a row upon 
the surface of the gelatine, and in a short time we will find that at 
certain points in the row one form of fungus has developed, and 
at other points other forms. Now if we take upon the end of our 
platinum wire a small quantity of fungi from one of these points 
and draw it across the surface of a second plate, we will, in parts 
of this line, invariably obtain a pure culture of one of the species 
in the original impure culture, nearly every species being distin- 
guished by some characteristic in the form which it takes in grow- 
ing, and in its action upon the gelatine. Having obtained a pure 
culture in this manner, test-tubes containing gelatine are inoculated 
with it. In these it may be kept in a pure state for weeks, or 
months, while the plates are always short-lived. 
The gelatine method of pure culture has oue great disadvantage 
in the low melting point of the gelatine. Twenty four to twenty- 
five degrees Centigrade is the highest temperature 
to which they can be exposed without danger of 
melting, and this, to fungi which are accustomed 
to a temperature of thiity-seven degrees Centi- 
grade, is not always a matter of indifference. I 
have succeeded in isolating three species, besides 
Fig. L 34 
the ones described- in the May number of this journal, and, for the 
purpose of distinguishing them only, I will 
designate them by the Greek letters y, d and e. 
These fungi are shown in Figs. 2, 3 and 4. In 
Fig 1 I have reproduced the fungus described 
on page 226 as a caries fungus, for the sake of 
comparison. When the species «, y and o are 
isolated, it is not difficult to tell one from the other ; when, how- 
ever, they are mixed together, it is next to impossible to determine 
which is which, and especially is this the case with a and y. Their 
modes of development on gelatine are, however, so different, that 
we possess therein a ready means of distinguishing between them. 
The a fungus, sparingly inoculated into gelatine 
tubes, presents in a few days the appearance which 
I have attempted to represent in Fig. la. It may 
be compared to a bunch of grapes, which presents 
all gradations from the fully developed berry to 
the little green one ; the masses of fungi are 
globular or ovoid, exceedingly fine, and semi- 
transparent, presenting altogether a strikingly beautiful culture, 
which it is impossible to even approximately represent by drawing. 
It furthermore forms a 
button upon the sur- 
face of the gelatine ; 
the latter becomes soft- 
ened but not liquefied. 
On the plates it pre- 
sents soft, milky ridges 
or knots, raised some- 
times a m. m. above 
the surface of the gela- 
tine, and obtaining a 
width at the base of 
three to six m. m. The 
y fungus differs from all other fungi that I have yet found in 
decaying dentine, in that it completely liquefies the gelatine. The 
culture tubes present, therefore, a funnel-shaped area of liquefied 
Fig. 2 
Fig. 3 
Fig. 1« 
Fig. 2 a 
Fig. 3 a gelatine, while the fungi themselves fall to the bottom of the fun- 
nel (see Fig. 2a). 
This fungus forms furrows in the plates, 
and if the plate is turned on its edge the 
whole mass of fungus flows from one end 
of the furrow towards the other, or slides 
quite off the plate. 
The 3 fungus (Fig. 3) forms completely 
opaque masses which may have a slight 
yellowish tinge, provided the gelatine itself is yellowish. It has a 
small surface growth, and liquefies the gelatine only to a slight 
extent. In cultures on plates which are two or three days old, the 
row of fungus appears to lie in a trough, or depression in the gela- 
tine. It does not move, however, when the plate is turned on 
edge (see Fig. 3a). 
F'or the fungus of Fig. 4 I have not yet been able to establish 
definite peculiarities of growth. As far as my observations have 
at present extended, it differs from that of Fig. 3, in that it is 
almost entirely wanting in surface growth, and forms colorless 
masses, even in colored media. It does not liquefy the gelatine. 
Viewed by transmitted light it appears to have a bluish tinge, and 
a slight opalescence. It grows, however, very slowly, and I have 
consequently as yet been unable to establish certain and definite 
characteristics for it. The fungus described on page 227 grows 
still more slowly at gelatine temperature, and I cannot at present 
give any microscopical features by which cultures on gelatine may 
be distinguished. 
The most important feature connected with all these fungi, espe- 
cially the coccus forms, is that they possess a ferment activity ; in 
other words, they are capable of producing acid out of sugar, or, in 
the human mouth, out of starch, by the aid of the diastatic action 
of the saliva. They may consequently all be looked upon as fac- 
tors in the decay of the teeth. I would not venture to say that 
the a fungus is more concerned in the process of caries than all 
the rest together; nevertheless, such is the constancy with which I 
have found it, that if any one else should make the assertion I would 
Eig. 4' 36 
have no reason for contradicting him. Cultivated in liquid sub- 
strata, none of them form films or skins upon the surface of the 
liquid, but powdery or fleecy precipitates upon the bottom and 
sides of the vessel. None, so far as I have observed, produce an 
evolution of carbonic acid in solutions containing sugar, nor do 
they appear to suffer when the access of oxygen is restricted. 
A question of great importance, not only for dentists but for 
general physicians, and, in fact, for everybody, is that relating to 
the possible pathogenic nature of these fungi. We find in the 
works of Leyden and Jaffe, Haussmann, Bollinger, James Israel, 
etc., sufficient ground for the statement that “ these fungi, in all 
parts of the human body which they reach, can play the same ma- 
lignant role as upon the teeth.” Gangrene of the lungs, abscesses 
of the mouth and throat, chronic pyaemia, etc., etc., have by vari- 
ous authors been ascribed to the action of the fungi of the human 
mouth. Raynaud, Lannelongue, and Pasteur produced what they 
called maladie nouvelle by inoculating rabbits with the saliva of a 
child bitten by a mad dog. And A. Fraenkel has in a number of 
cases produced sputum-septicaemia by inoculating rabbits with his 
own saliva. 
We ask ourselves then the question : may not many of our 
obscure cases of infectious disease which now and then appear 
after extraction, or other dental operations, and which are, without 
further examination, attributed to the unclean instruments or hands 
of the dentist, be the result of an infection produced by micro- 
organisms in the patient’s own mouth ? If a man’s saliva contains 
organisms which, when brought into the blood of a rabbit, occa- 
sion death in twenty-four hours, would it be a matter of no conse- 
quence to produce so large a wound in his mouth as that caused 
by the extraction of a tooth ? For the purpose, if possible, of 
throwing some light upon this question, I have undertaken a series 
of experiments for determining whether the organisms which are 
most commonly found in the human mouth possess the power of 
producing death (by septicaemia or otherwise) by inoculation. 
These experiments, as well as the others recorded in this article, I 
have in fact only begun. My absence from home, however, pre- vents my carrying them on during the summer months, and I have 
determined, therefore, to present the results which I have already 
obtained, few and imperfect as they are. 
The inoculations have thus far been performed on three rabbits, 
one rat, and six white mice. They were made partly with a mix- 
ture of the two fungi a and y, and partly with saliva which had 
been kept in sterilized calf’s broth for fifteen hours, at blood tem- 
perature. 
Each rabbit received 1 c. c. of the infected liquid, injected directly 
into the lung or abdominal cavity; the rat 0,2 c. c., and the mice 
0,1 c. c. 
Exp. 1. Small rabbit inoculated with 1 c. c. in the abdominal 
cavity. 
In the course of a few hours the rabbit appeared evidently ill; 
refused to eat, and remained quiet in the corner of the cage. In 
twenty-four hours diarrhoea appeared, with a slight elevation of 
temperature. These symptoms increased during the next day, till 
fifty hours after the time of inoculation it was found at the point 
of death. The examination showed the blood to be almost entirely 
free from organisms, and no indication of septicaemia. Living 
fungi were found, however, in the abdominal cavity, and a large 
part of the right lobe of the liver was completely riddled with 
masses of fungi; also in the faeces were found enormous numbers, 
which, morphologically, were identical with those in the liver, their 
entrance into the alimentary canal from the liver being easily 
accomplished. I unfortunately neglected, however, to establish 
their identity by the proper cultures. 
Exp. 2. Rabbit inoculated as in Exp. 1. 
The animal manifested a slight indisposition on the second day, 
from which it soon recovered. 
Exp. 3.. Rabbit inoculated in the right lung with saliva which 
had been kept in sterilized calf’s broth for fifteen hours, at thirty- 
seven degrees Centigrade. No effect apparent. 
Exp. 4. White rat, injection in abdominal cavity. 
The animal remained well. 
Exps. 5-11. Seven white mice; five inoculated in abdominal 38 
cavity with a and y fungi ; two in the lungs with saliva in calf’s 
broth. Of the former two died at about the fortieth hour under 
the same symptoms as in Exp. 1. Great numbers of fungi were 
found in the abdominal cavity, which by culture on gelatine proved 
to be the y fungus. A number of colonies were likewise found in 
the liver. Microtome sections of the liver of th-e rabbit stained in 
Fuchsine show, when examined un- 
der the microscope with sufficient 
light to drown the tissue, a distri- 
bution of the fungi very similar to 
that often seen in the outermost 
layers of carious dentine. (See 
Fig. 5.) Of course, no definite con- 
clusion can be drawn from a few 
experiments. They are, however, 
sufficient to show that these fungi 
certainly do possess a pathogenic 
character, and when brought into other parts of the human body 
may be able, under predisposing conditions, to produce disastrous 
results. Especially the continual swallowing of these fungi in 
great numbers may, by their ferment activity alone in the course 
of time, produce very serious derangements of the stomach and 
alimentary canal, since the small percentage of hydrochloric acid 
in the stomach, even in the presence of the normal quantity of 
pepsin, is not sufficient to devitalize them. It was with a certain 
degree of satisfaction that I have failed thus far to find the coccus 
of sputum-septicEemia in my own saliva. It is, however, very 
desirable that experiments should be made with the saliva of many 
persons, for the purpose, if possible, of determining in what pro- 
portion of cases this fungus is present. 
Messrs. Underwood and Milles have endeavored to repeat some 
of my earliest experiments in the production of artificial caries, 
but under those very abnormal conditions against which I entered 
warning in the Independent Practitioner, page 229. Failure 
was the necessary result. They performed, further, a very elabor- 
ate experiment, lasting six months, in which the baths became so 
Fig. 5 putrid and offensive that “they quit the experiment with relief.” 
They naturally produced no caries, thereby furnishing an admira- 
ble confirmation of the fact to which I have so often called atten- 
tion, that it is impossible to produce even a trace of caries by 
putrefaction alone. They tried a third experiment, putting the 
fungi under such abnormal conditions that they could not produce 
acid, and of course failed again, once more confirming the fact 
that I have long since established, that we can have no caries with- 
out acid. With these experiments they risk the statement that 
artificial caries is probably an impossibility. The production of 
artificial caries is a fait accompli, and to deny its possibility is 
only to endanger the reputation of him who denies. 
They state further that they can find no softened dentine which 
does not contain micro-organisms. This, however, is contrary to 
the experience of a great many American microscopists, and, 
moreover, as I have elsewhere stated, I shall take with me to the 
next meeting of the American Dental Society of Europe several 
hundreds of specimens of carious dentine, and be ready to show 
the areas of softened, non-infccted dentine, on any one or on all of 
them. 
Messrs. Underwood and Milles understand me, in the third place, 
as being of the opinion that all the micro-organisms connected 
with caries of the teeth are only different forms of one fungus. 
The readers of the Independent Practitioner know better. I 
have stated simply that one of the many fungi found in the human 
mouth in connection with caries of the teeth, may produce different 
forms of development. This is the fungus which I have designated 
by the prefix ft. It is scarcely necessary to add that I am 
always prepared to prove its existence microscopically, as well 
as on the authority of many of the best mycologists of Germany. 
No one, I think, will deny that within the last few years I have 
done a large amount of work, and contributed some evidence to- 
wards the solution of the problem of dental caries. The amount of 
material dealt with, and the ground gone over, have been so exten- 
sive that it has been absolutely impossible, with the greatest efforts, 
to remain as long by each step as would have been desirable. It 40 
may be, therefore, that at some points the subject has not been 
presented with sufficient clearness or decisiveness; it may be, too, 
that at some points the conclusions have been faulty, since I make 
no pretension to infallibility. Time will show whether this is the 
case. At present I know of no important change which I could 
make, if I were to re-write all my contributions of the last three 
years. 
I desire to give, in closing, a very short resume of the work which 
I have accomplished. 
1. I convinced myself by the examination of some thousands 
of slid.es of carious dentine, that micro-organisms were always pres- 
ent, and that they, without any doubt, were the cause of various 
anatomical changes which were found to take place in the struc- 
ture of the dentine during caries. (Here, of course, the question of 
priority does not suggest itself; Leber and Rottenstein, as is well 
known, were the first to give definite expression to this fact) 
2. I proved, at the same time, that the invasion of the micro- 
organisms was not, in the majority of cases, simultaneous with the 
softening of the dentine, but that large areas of softened dentine 
could be found that contained no fungi. Of all those who exam- 
ined my preparations in America, no one, whatever his theory, ever 
once denied this fact. I concluded from this that the softening 
of the dentine went in advance of the invasion of the organisms. 
3. I determined by analyses of masses of carious dentine, suf- 
ficiently large to give reliable results, that the softening of the 
dentine is of the nature of a true decalcification. That the decal- 
cification of the outer layers is almost complete, and diminishes in 
degree as we advance towards the normal dentine. Furthermore, 
that the same relations maintain in dentine softened in a mixture 
of saliva and bread, or in weak organic acids; also, that in a mass 
of carious dentine the lime-salts had been removed to a much 
greater extent than the organic matter. 
4. I maintained from the first that the softening of the dentine 
was produced by acids, for the most part generated in the mouth 
by fermentation. I had, however, no direct proof of this. 
5. I proved that fungi exist in great numbers in the human 41 
saliva and in carious dentine, which have the power to produce 
acid under conditions which are constantly present in the human 
mouth. I determined this acid, for one of the fungi, at least, to be 
the ordinary ferment, lactic acid. 
0. I produced caries artificially, which under the microscope 
cannot be distinguished from natural caries, by subjecting sound 
dentine to the action of these fungi in fermentable solutions. 
7. I determined the influence of various antiseptics and filling 
materials upon the fungi of caries. 
8. I isolated various forms of these fungi, and determined in 
part the conditions most favorable to their development, their 
characteristic reaction upon gelatine, their physiological action, 
their effect when inoculated into the system of lower animals, and 
their possible connection with certain obscure diseases generally 
attributed to the carelessness of the dentist. 
My continual search has been after facts, and such facts as I have 
obtained I have presented before the profession, never putting 
before them either theory or speculation, nor anything which was 
not the result of severe and continued labor, and in this spirit I 
propose to prosecute this work, as well as any other that I may 
undertake in the interest of the profession. 
Berlin, May 21, 1884. 
Note—Since writing the above, I have succeeded in producing death by 
septicaemia of both mice and rabbits, by injecting into the lung saliva from the 
mouth of a perfectly healthy person. THE INDEPENDENT PRACTITIONER. 
VOLUME V, 1884. 
A PRACTICAL MEDICO-DENTAL JOURNAL, 
EDITED AND PUBLISHED BY 
PRACTICING DENTISTS FOR PRACTICING DENTISTS. 
A full corps of the very best writers in the medical 
and dental professions as contributors. 
Entirely independent of all schools, cliques, and 
advertising firms, it is outspoken and impartial in its 
judgment of professional matters. 
It is especially devoted to the interests of those 
engaged in the practice of dental medicine and medical 
dentistry. 
That which is new and useful in Medicine, Surgery, 
Dentistry, and Pathology is given to its readers in an 
intelligent and concise form. 
Editorial communications should be addressed to 
Dr. W. C. Barrett, No. ii West Chippewa Street, 
Buffalo, N. Y. Send all business letters to Dr. 
William Carr, 35 West Forty-sixth Street, N. Y. 
ABBOTT, FRANK N. Y. 
BARRETT, W. C Buffalo. 
BODECKER, C. F. W...N. Y. 
CARR, WILLIAM N. Y. 
FRANCIS, C. E N. Y. 
MONTHLY, 
HILL, O. E Brooklyn. 
JARVIE, WM, Jr. . .. Brooklyn. 
MILLER, W. D. ..Berlin, Ger. 
NORTHROP, A. L N. Y. 
PALMER, S. B Syracuse. 
$2.50 per annum.