.**r w. »* &* J*.* » ^ \?V*~ * ft r '.£.■■ %'«r :i ■f *■>»- ,, -^ ^:y20t:OZOZCZCZQLQZQ^LlQllA^ g; Surg-eon General's Office ' ^ITHDKAWlJ-EOSt-i'rcH^NGE Sfen0 ^TCuGGmGQG GOGOo.nr.y ~i ■.'Gcgg^ PRINCIPLES and OBSERVATIONS APPLIED TO THE MANUFACTURE and INSPECTION OF POT and PEARL ASHES. ------------------------------^--------, by DAVID TOWN SEND, Inspector of Pot and Pearl Ashes for the Commonwealth of Massachusetts. IPuoltfljeo accowins to aa of <£oitgre(fc. V/Tit-i- M* PRINTED at BOSTON, *y ISAIAH THOMAS & EBENEZER T. ANDREWS, Faust's Statue, No. 45, Newbury-Street. MDGCXCIII. THE following obfervations relate to an extenfive bufinefs 2 and are dtfgntd, in the plpinejl manner, to convey profitable in- formation to thofe interefled in it, who have not hifure or oppor- tunity tofearchfor the principles therein contained, in the writ- ings of profefjional Chemijls. PRINCIPLES and OBSERVATIONS. lOT and Pearl Ames have for a long time been amongft the moft valuable articles of ma- nufacture and commerce in this part of our coun- try. To preferve and improve fo great a branch of bufinefs is an object interefling and important to' this Commonwealth, and, as fuch, has employed the attention of the Legiflature. " An Act to af- certain the quality of Pot and Pearl Afhes, and for the more effectual Infpection of the fame," is intended to effect this falutary purpofe ; and the operation of it ought to remedy evils which have deprived our citizens of the commercial advan- tage of their own manufadure, and our manufac- turers of the higheft market price for their Afhes, unlefs they tranfported them to the State of New- York for infpection. For, under our old law, the infpedion was fuperficial. The confequenee was, that the moft indifferent Afhes came to our mar- ket ; even the refufe from New-York was often brought to Maffachufetts for exportation ; while it became an object to many, who fought a mar- ket for Allies of the firft quality, to fend them \^I'KJD^A\,r:j r: - . jJtCE:*?:-_-*- from 4 from Maffachufetts, by an expenfive tranfporta- tion, that their real value might be ftamped upon them by the fuperiour credit of the New-York brand. A difference of price current obtained between New-York and Maffachufetts Afhes, both in Europe and America ; and Afhes export- ed under the advantage of the New-York brand, would fell from three to four pounds per ton higher than that from Maffachufetts. To put a flop to this ruinous traffic, the Le- giflature thought proper to frame the new law, adopting a mode of infpedion fimilar to that pradifed in the State of New-York, that we might participate of the benefits naturally re- fusing to us from this important export. Much therefore depends on the execution of this law, and it may be of ufe to enquire into the principles on which the infpedion and examina- tion are conduded, that they may be fairly and generally underftood. The excellence of Pot and Pearl Afhes is in proportion to the quantity and purity of the al- kaline fait they contain ; and, it appears, that in this proportion they are eftimated by thofe who confume them. The very beft kind is fought after by chemifts and druggifts,—for the bleaching of fine threads, linens and cottons—and for the manufacture of the fineft glafs. The dyers and calico printers require fuch as will not impart colour, or leave the leaft ftain or tinge in their work. PEARL PEARL ASH, Firfi Sort. This is the alkaline fait in a'W/^/ftate, and in a high degree of purity. It isaperfedly white fub- ftance, uniform in its texture and appearance thoughout, diffolves eafily in water, gives a clear and colourlefs fluid without fediment, except a very fmall portion of white earth, fuch as is de- pofited on every folution of the pureft alkaline fait that can be obtained ; and containing fo lit- tle of neutral falts as neither to be injured by them in its ufe, nor depreciated in its value by their weight. Such as this is fupplied in great quantities from many of our manufadories, and commands the higheft price. PEARL ASH, Second Sort. Some Pearl Afh falls fhort of this high de- gree of purity, not being properly calcined, or, as the term is, pearled throughout. If pearled in kettles, the finer part is an heavy meal-like fubftance; the lumps, hard and flinty 5 the whole of a yellow or greenifh caft. If pearled in the oven, and not properly manufactured, it is gene- rally very blue, not eafily diffolved, and unlike that large light porous lump fo much preferred in the London market. Another kind, is of a dull dead white, inclining to grey, occafioned by not fettling the lye, or by dipping it fo as to difturb the fediment, of which a very little will diffufe 6 diffufe throughout, and materially depreciate a very large quantity of Pearl A(h. All thefe how- ever are valuable, being rich in the genuine fait, and are ufed in a variety of bleaching, and for many purpofes which make them in demand ; but not at the firft price; therefore, they are de- nominated the fecond fort. PEARL ASH, Third Sort. When the appearance of Pearl Afh is totally different from the above defcription, is of various colours, hard of folution, and the folution charg- ed with colouring matter, depofiting a dirty, dark fediment, it is unfit for the nicer purpofes in the arts, and therefore-, fuffers fuch a reduc- tion of price, as operates to the exceeding lofs and injury of the manufadurer, if imprudently he offers it at market. Whenever Pearl Afh, under the beft appearance, is found to contain a great portion of neutral falts, it is undervalued accordingly. POT ASH. THERE are many articles bleached, of fo firm a fabric, as nottobefufficiently adedupon by the al- kaline fait, inamildftate. To be thoroughly whit- ened, they require a greater degree of caufikity. The manufacture of foap alfo creates an im- menfe demand for the cavftic alkali, a quality in the alkali necelfary to diffolve the oil or fat in the compofition of foap, and render it mifcible with water. °nr 7 Our Pot Ajh is this cauftic alkali. The ap- pearance of it, very different from Pearl, foon changes from the adion of the air upon its fur- face j therefore, to form the firft opinion of it by the eye, it is neceffary to break the lumps. POT ASH, Firft Sort. The beft is generally of a light ftone grey, or marbled white and grey, with a cryftaline core ; cauftic or burning to the touch, and, although in appearance like a ftone, and. almoft ' as hard, it fo greedily attrads moifture from the air, that when expofed to it but for a fhort time the furface of this ftone-like fubftance complete- ly diffolves. This, which is denominated firft fort of Pot Afh, is however very far from being a pure fait; as any one may eafily obferve, by letting a folution of it reft, until it depolits a fediment. Yet, it is the beft that is generally fent to the market, and until there is a further improvement of this manufadure, muft be confidered as the ftand- ard. POTASH, Second Sort. Beside the foregoing, there are large quanti- ties of Pot Afh, of different degrees of purity, of various colours, that, on examination, merely by the eye, mew marks of heterogeneous mixture, arifing from want of fufficient attention to what is called by the manufadurer, fettling the lyes ; whereby 8 whereby the finer earthy parts of the wobd-afhes get enveloped with the fait : or, for want of pro- per management of the fire, not continuing it long enough, or not raifing it fufficiently to de- ftroy what the workmen call the fulphur. This fulphur which is the inflammable or black colour- ing matter, is moft injurious to the purity of the alkaline fait, and cannot be feparated from it in large manufadories, but by fire, as is hereafter explained. This impurity, in its different degrees, is feen at once, by the different fhades of red it gives the Pot Afh. In the brighteft pink coloured, where it is clear, without an edging of coal black, or mixed or marbled with light grey, the black colouring matter is in fo fmall degree that it is placed with the firft fort. If it is of a deeper red, it fhews a greater quantity of this colouring matter, and by wetting a piece of it, and rub- bing it a little, there may be difcovered a very confiderable degree of foulnefs, that is not in the Pot Afh before defcribed, andis therefore denomi- nated the fecond fort. POTASH, Third Sort. d I When Pot Afh is of fo deep or dark liver coloured red as to turn black on expolingit but a fhorttimeto the air j orwhen wet and rubbed, it ap- pears foul and black as the blackeft ink, interfperf* ed throughout its whole fubftance with fmall black _9^ black fpecks, as if fprinkled with duft of char- coal, or imperfedly melted ; it is then almoft as impure as what are called black, or Pot Afh falts. If, as was obferved of Pearl A#i, with the beft appearance, Pot Afh contains neutral or foreign falts in quantity, it is depreciated accordingly. The foregoing obfervations contain a very ge- neral defcription of the Pot and Pearl Afhes brought to the feaports of this Commonwealth, for exportation, together with an account of fome of the ufes to which they are applied. Further remarks may be of ufe to fome manufadur- ers of Aflies, and may perhaps enable them to condud their bufinefs with more eafe, fatisfac- tion, and certainty of fuccefs, than they have hi- therto been ufed to ; whereby they may prevent fuch great lofs as is fuftained in tranfporting fo heavy an article by land carriage, ftjme hundreds of miles, as they fometimes do, in a depreciated ft ate t when it has not been properly manufactur- ed. That there may be an underftanding of the principles that fhould dired in this manufadure, previous to an account of the proceffes by which Pot and Pearl Aflies are made, it will be neceffi- ry topremife, that, although all alkaline falts ob- tained from vegetables when abfolutely pure, are precifely the fame ; yet, there is a difference be- tween Pot and Pearl Afhes, though made from the fame lye, which admirably adapts them for different ufes. This difference exifts in nothing IO but the comparative mildnefs of the one, and the caufticity of the other : therefore, the terms mild and. cauftic have been ufed, to exprefs the different prope^ies of the fame alkaline fait under different forms. The mild quality depends on a principle, next to fire and water, the moft ac- tive agent in this bufinefs. It has been very lit- tle attended to by manufacturers, although long known amongft chemifts by the name of gaz, fix- able or fixed air, and now generally denominated the aerial acid. This is abforbed from the common air, often from fpring water ; and Pearl Afh in its utmoft ftate of purity and perfedion, is now known by the name of the aerated alkali. The cauftic quality of Pot Afh depends on the ahfence of this aerial acid, and fuggefts the pro- priety of the different modes that are practif- ed to obtain the fame alkaline fait, well prepar- ed, for different purpofes. From the beginning, through every ftage of the manufadure of Pearl Afh, this aerial principle applies itfelf, and its operation will be particularly attended to, when we come to the pearling procefs. The common hard wood throughout this country furnifhes alkaline fait in great abundance : what is' called foft wood, fuch as every ipecies of pine, is well known to yield but little.* From the * S. Bfodget, Efq; now living in Haverhill, formerly a fcicntific manufacturer ofAfhes in this town, has bellowed indefatigable attention on experiments, that fliew the different quantities of falts produced froi.i'different forts of wood, growir " ' n the manner of burning wood, either abroad in the open air, as in clearing up the land, or in chim-* neys, for common fuel, it is evident, that when reduced to wood afhes, the contained fait muft be blended with a variety of fubftances, which con- ftitute its impurity. In this ftate the manufac- turer receives it. It is his bufinefs to free it from thefe foreign fubftances j and in proportion as he effeds their feparation, will be the excellence of his Pot or Pearl Afh. Although thefe fubftances of impurity are al- moft infinite, yet they may be claffed under three heads j ift. Some earthy fubftances infoluble in water. 2d. Colouring matter. 3d. Neutral falts.-f' As the difference between Pot and Pearl Afhes has been ftated to be but a different manufadure of the fame fait -, whereby it acquires the differ-r ent properties already noticed, the two proceffcs for their manufadure muft be treated of feparate- ly ; therefore, the firft obfervations-will be con- fined to the procefs for the manufadure of Pearl Afh. Experienced he has been careful to prefcrve, as ufeful knowledge, which, together with other'facts his accurate obfervation has furnifhed, or his expe-r rience confirmed, it is hoped he will be induced to communicate. + Another fource of impurity not mentioned above, though it might he comprehended under the article, cole;i.mg matter, is from m-r ; this united with alkaline fait, fixes fo ftror.ga dye, that the bell morlp hithertopraclifed for its feparation will not indemnify the manufanur- Vr of Pot Afli, for the trouble and expenfe of it. Therefore, al- though even this may he feparated with great care and trouble, it will be moll for his interei!. whenever the water to be made ufe of in leeching is found to be from a fpring impregnated with iron, to frek for a new fupply where it may be had more pure, «rr give up the at- ":mpt to make good Alhefy 12 Experienced manufadurers find an effential difference in working wood afhes that have been colleded from abroad, or *that have been long expoied to the air ; and thofe that are recently made under furnaces, or even in common chim- neys. They remark, that falts from wood burn- ed abroad, when clearing up the land, will not eafily melt, but will pearl without difficulty, and are often determined in their arrangement for making Pearl or Pot Afh, from this circumftance. Many conjecture the caufe of this difference to arife from the common earth or dirt which un- avoidably mingles with wood afhes when colled- ed from the ground. But as leeching them and fettling the lye, fo as completely to feparate all that is earth from the falts, does not difpofe them to melt, this opinion appears without founda- tion. The true caufe is the principle already hinted at. It is the combination of the aerial acid, which is made evident by a variety of experiments, {hewing, that wood afhes, when expofed to the air of the atmofphere, freely imbibe this princi- ple frQm it, and that depriving them of this prin- ciple, is fufficient to render the alkaline fait from them cauftic, and difpofes it to melt. The PROCESS for the MANUFACTURE ©f PEARL ASH is carried on by feveral opera- tions : LEECHING. J3 LEECHING. The firft confifts in diffolving and wafhing out all the falts from the indiffoluble earth or dirt, with pure rain or river water, if to be pro- cured -, in filtering, or ftrainingit nicely, and in let- ting all fediment fubfide, or fettling the lye. This is called leeching the wood afhes.* It is fo well underftood and pradifed by many of our manu- facturers, that it would be unneceffary to be mi- nute, did not too many adhere to the old mode of finking huge leeching vats under ground. Defeds in them are thereby fo concealed, that a great lofs of lye may be fuftained before the workman difcovers the leak. The heavv com- pad mafs they contain, is not fo eafily foaked and waflied as a fmaller body : not readily admit- ting the water throughout its whole fubftance, paffages are fometimes formed by gutters through various * It has been firongly recommended to begin this manufa&ure by calcination, or burning the wood allies in an oven or furnace. But the experiments hitherto made, have only ferved to prove this an ex- penfiveand troublefomemode, without the advantage boalied of and promifedby Mr. S.Hopkins, the author of this fuppofed improvement. Water is the proper folvent of all falts, and where the combuf- tion apd incineration of wood afhes has been complete, it is a fafi not to be controverted, that boiling water will thoroughly diffolve and warn out all the falts, of every kind, blended with the earth in wood alhes. If the wood has not been completely reduced to afhes, but to alhes mixed with coals, then would it not be better, by fining them, to feparate the coals, which, thrown under the furnace for fuel, would be calcined with profit ? Another advantage to be derived from this mode would be, leffening the quantity of colouring matter that is imparted by coals, &c. therefore would fa- cilitate an after part of the psocefc. H various parts of the vat, where any quantity of water will run without penetrating beyond the neighbourhood of the channels it has made ; and although the water paffes through the aflies un- til it becomes taftelefs, and receives no augment- ation of weight (which is the criterion to deter- mine when wood afhes are leeched) yet much of the contents of fuch a vat may be ftrongly im- pregnated with falts.* A more important objedion is, that the lye after it is ftrained and fettled cannot be brought to the kettle in that ftate of purity that is necef- fary, unlefs it is fettled again; for it muft be drawn up from the ciftern by the fudion of a fmall pump, or dipped out with a bijcket or la-r die, either of which, however carefully perform- ed, difturbs the fediment, that is always depofited? although the lye has been well filtered, and ren- ders it foul, befide occafioning an increafe of la- bour. Leeching * It is not improbable that fome partial experiments with wood afhes, thus imperfeftly leeched, may have given rife to the opinion that dead afhes (i. e. fuch as already have been leeched) might, under the operation of the fuppofed improved mode of burning allies, af- ford a fufficient quantity of alkaline fait, for another manufacture of Pearl Afh. However the opinion of this extraordinary creation of alkaline fait prevailed ; its efFeft was, that although the rational foundation of hope and expe&ation, (i. e. that theprinciple on which the new product was to be obtained) was concealed in profound myftery, hereafter to to be revealed ; the idea was fo captivating as to engage num- bers in a new projeft, who deflroyed their well conftrufted, furnaces, to ere£t fuch as on experiment became ufelefs, and entered into incre- dible contracts for leeched afhes, that would not py for their tranfpor- tation. Within the term of two years, this bufinefs terminated in difappomtmer.t, to the lofs ana mortification of all who purfued it. 11 Leeching is better performed in vats placed above ground, where they are always under the eye and examination of the workman. In (mall vats, the wood aflies can be more eafily and tho- roughly drenched than in large ones ; inftead of vats that will contain 80 or 100 bufhels, thofe that do not exceed 30 are to be preferred. Each vat is to be provided with a falfe bot- tom, fo tightly placed above the true one, as to admit nothing below but what is diffolved and carried down by the water ; for this pur- pofe, there fhould be a number of fmall holes, cracks or channels, in the falfe bottom, covered over with ftraw, to prevent the paffage of the earth while it admits the lye. The diftance of the falfe bottom from the true one (which forms a receiver for the lye, and is called the ciftern of the vat) fhould not be lefs than fix or eight inches, that the fediment which falls, may reft at the bottom of the ciftern; while the lye is drawing off from a faucet placed at a convenient diftance above it. The upper part or body of this vat is to be filled with the wood afhes, within two or three inches of the top, and as much water is to be poured on them as they will abforb, and will cover them to the brim of the veflel. This done over night, the lye may be run off in the morning. The number of vats fhould be in proportion to the extent of the manufadory, and the num- ber of kettles employed, fo that there may be a i6 conftant/upply of ftrong lye, for boiling down. This part of the buiinefs fhould be managed af- ter the manner pradifed in diftilleries, to have a fiicceflion of a certain number of vats ready to work off, and furnifh every day's boiling : and where it is pf adicable, they fhould be fo arranged that the lye may be conveyed from one vat to the other, and from them into the kettles by a fpout. Whenever the lye toward the clofe of leech- ing becomes fo weak as not to pay the expenfe of time and fuel to boil it down, it fhould be thrown on to another vat until it becomes taftelefs, and receives no augmentation of weight by the leech- ing. The vat is then to be emptied, the falfe bottom taken out, the whole examined and clean fed for ufe again. The foregoing operation gives a folution of all the falts of every defcription that were contained in the wood afhes, effedually feparated from the earthy impurities, but yet combined with the co- louring matter. This folution is next to be boil- ed down to the confiftence of brown fugar, to prepare the falts for the firft calcination or fcorch- ing, which- is the fecond operation, defigned to feparate and deftroy the colouring matter, and convert black falts into white. This colouring matter, known to workmen by the name of ful- phur, fometimes improperly called the cauftic fulphur, or oil, has been denominated, by the moft celebrated chemifts, the inflammable principle, 1L and is, according to one of them, " the material which, with iron, forms Pruffian blue in alka- line falts, occafions their impurity, and requires much trouble to be perfectly feparated."f In fad, ashas been faid, it cannot be feparated in large manufadories but by fire. SCORCHING. FOR this .purpofe, when the falts are of the above confiftence,.they are to be thrown into a furnace fo conftruded, as to admit the utmoft force of flame immediately upon the falts, while they are expofed to a continued current of air. The furnaces in common ufe for fcorchinp- and pearling, are well conftruded ; they com- pletely reverberate the flame on the falts, at the fame time that they admit a continued ftream of air neceffary in this operation, which is a genuine calcination, and cannot otherwife be performed* In this fituation the falts are to be frequently ftirred, that every part of them may prefent its furface to the two powerful agents. A ftrong fire may be applied, but not fo intenfe as to melt them. When the falts have this tendency, the greateft care muft be taken to avoid it, by moderating the fire, and by keeping the door of the furnace open, to expofe them ftill more to the air -t for if they t Cb<*mical Dictionary, Article Pruffian Blue, i8 begin to run, it is difficult to proceed with thd operation, which, if imperfedly performed, muft difappoint the hope of the manufacturer for a fuc- cefsful termination of the pearling procels. This firft calcination is known to be finifhed, if the falts, when wet or dilfolved, have loft the irrong difagreeable fmell of black lye, as well as the colour, which is now changed for white. To SEPARATE NEUTRAL SALTS. THE next operation is, to wafh away the co- louring matter that has been feparated, though not completely deftroyed by fcorching, and to feparate the neutral falts. Thefe objeds are very conveniently effeded at one and the fame time, fimply by folution, in fuch a quantity of boiling water as will take up the alkaline falts, but when cold will not held the neutral, falts in folution. This point is at- tained fufficiently accurate for this manufacture, and depends on the different degrees of folubility of different falts,* When * Several kinds of neutral falts are found with the alkaline fait leeched from wood alhes; they vary in their quantity and proportion from a variety of circumftances, according to the kind of wood they »re made from, and the ftate of it when burned. From old dry per- ifhing wood, the neutral falts are in great abundance : If the wood has long been foaking in fea water, uncommon quantities of marine, or fea fait, will be found. Water from wells and fprings diffolves different falts it meets with in its paffage through the earth, and when made ufe of inftead of rain or river water, it increafes the neutral falts, 19 When falts produced from good found wood are fairly made, without any defigned adultera- tion, a folution of them that will weigh a very little more than one quarter heavier than the fame meafure of pure rain water, when drawn into a receiver, where it muft beat reft until cold, will depofit the neutral falts in chryftals round it ; and while this is taking place, if the falts have been well fcorched, the remaining co- louring matter, and all fediment, will be found to have fubfided at the bottom of the receiver. Here it cannot be too ftrongly impreffed on the workman to avoid every thing that will in the leaft degree difturb the fediment. It is an objed fo important to be attended to, that it cannot be amifs to repeat the injundion on this head, that he ought never to take this lye from the receiver by pumping or dipping. He will ever be apt to dip too near, and the fmalleft quantity falts, and fometimes diminifhes not only the proportion, but the abfolute quantity of alkaline falts already obtained in the wood alh- es. Thofe acquainted with the nature of falts readily perceive how this muft happen, when a neutral fait, with an earthy bafis, is diffolv- cd in an alkaline lye. The earthy part of the neutral fait is drop- ped and exchanged for a portion of the alkaline fait taken up to form a new neutral fait. This leffens the quantity of alkaline fait by as much as is taken up to form the new combination, and in exchange for it is added the earthy impurity, while, although the kind of neutral fait is dif- ferent, the quantity remains the fame. On a fair calculation, tlii will be found to.caufe no trivial deduction from the real quantity of alkali which might be obtained from the fame wood afhes if pure rain water was ufed. On an average five hundred bulhels of wood aflies are drenched and leeched jor * ftnijle ton of Pt»t or Pearl AjJt. 2© quantity of fediment raifed, will diffufe through the whole fuch a dull white appearance, more or lefs inclining to grey, as induces a fufpicion in the purchafers of Pearl Afh, particularly on the other fide of the water, of a mixture of lime, which fufpicion has depreciated great quantities of afhes otherwife good. This is eafily avoided, by drawing off the white lye from a faucet placed above the fediment, as defcribed under the head of leeching. If cannot be objeded to the above mode of feparating the neutral falts, that fome fmall por- tions of the alkaline fait will be thrown down with them ; becaufe, waffling the cryftals of neu- tral falts in cold water, not fufficient in quantity to diffolve them, will diffolve the remaining alka- line fait, which, with the fediment, may be thrown onto one of the vats for a new procefs. By the above mode may be drawn off into the ket- tles, nicely cleaned to receive it, a pure white lye, to be boiled again down to falts for the finifhing operation, which isthefecond calcination, called pearling, PEARLING. IF fcorching has been well performed, the pearling operation is made eafy ; being little more than drying the white falts in the pearling oven or furnace, v/ith a moderate clear flame. It is 21 an operation fimilar to fcorching, but does not require the fame force of fire; the falts having been previoufly freed from their impurity. When boiled to the confiftence of falts, they are to be thrown into the pearling furnace, and continued under this laft operation in the manner they were fcorched, until they are perfedly whitened, and found to be of the defcription of the firft. fort of Pearl Afh. It is to be again noticed, that as fome falts are found more tender than others (i. e.) more difpof- ed to melt, they require more particular care and attention to moderate the fire and increafe their expofure to the air. There is another mode of pearling much prac- tifed of late, which will be found exceptionable, whenever the requifites for this operation are tak- en into confideration. It has- already been ob- ierved that pearling is a genuine calcination ; and, that a continued ftream of air is fo neceffary in the operation, that it cannot otherwife be per- formed. It is evident that this cannot well be had in the bottom of a deep kettle -, for, when heated, the air is expelled from it. A broad or fhallow pan would anfwer better; but no con- trivance can exceed the furnace that will throw a clear flame diredly upon the falts. Befide that it is impradicable to expofe the falts to fuch currents of frefh air in the kettle as in the furnace ; it is obvious, that when the fire under the kettles is likely to be raifed too high. 22 high, by the time the operator is apprized of, it, it is often too late to prevent the mifchief it muft occafion, on account of the continuing heat of the iron. Therefore, the falts, for want of fufficient expofure to the air, and by reafon ©f too great heat, have not imbibed their portion of the aerial acid, and are thereby rendered caiiitic, and more difpofed to melt. Kence the reafon, that, although two or three manufadurers, by extraordinary care and cau- tion, have produced Pearl Afhes of the firft fort in this mode ; yet, in this way, great quantities have been fent to market imperfedly pearled;. much of it fine, not well dried, heavy, and like meal of a yellow tinge -y while the lumps begin- ning to melt, are externally hardened, and of the fame or a greenifh hue. The caufticity of this kind of afhes gives it an * appearance of greater ftrength. But this pro- perty cannot be a recommendation of it, while thofe who ufe it for nicer purpofes, where the mild alkali, or firft fort of Pearl Afh, is required, find it too corrdfive, orfharp, for their work. This kind of kettled afhes is in difrepute in the London market j and on account'of its cor- rofive quality, is fometimes fufpeded of being heated with lime. This fufpicion, however, muft be groundlefs ; for, did the manufadurer attempt to ufe quicklime in- kettling afhes, it would inevitably melt the fait. To il To finifh the obfervations on the manufadure of Pearl Afh little remains to be faid, except what relates to putting it up or packing it for the market. Neatnefs in this part of the bufi- nefs quickens the fale, and often enhances the price of the article, above the difference made in its intrinfic value. The eye of the puYchafer, particularly in the London market, is prejudiced, beyond what is commonly imagined, even againft good afhes when not fhewn to the beft advan- tage.* If Pearl Afh is tight packed, the lumps arc broken, and it is made fine : It is true the pro- perty of it is in no degree altered ; it is equally as good for every poffible ufe as though it were in large lumps, fmoothed by rolling loofely in the cafk j yet it does not meet with the fame ap- probation, and has been frequently complained of. A want of neatnefs, which proves an effential injury to Pearl Afh, is frequently occafioned by a mixture of fcorched falts : it is impracticable to feparate them when repacking, efpeciallv if the Pearl Afh has been pounded almoft to pow- der, to crowd the greateft poffible quantity into a cafk. This impurity is too often in fuch pro- portion as to denominate the Pe^rl Afh fecond fort; * A letter lately received from a houfr in London that perhaps deals as largely in afhes as any one houfe in Europe, contains the following obfervation. " Small afhes, however pure, wili not recom- ■icnd ihemfilves in England like bold &.H of a good colour." 24 fort. To prevent it altogether, it is found moft convenient and beft to ufe feparate furnaces; one for fcorching, another for pearling. Where the bufinefs is not fufficiently extenfive to afford the expenfe of two, the fingle furnace, after it has been ufed for fcorching, fhould be moft atten- tively examined, and thoroughly cleanfed of all remains of fcorched falts. The hearth alio fhould be noticed, and repaired if neceffary, that there may be no pieces crumbled from the bricks of the furnace found amongft the Pearl Afh.* By * Sometime in the courfe of the laft feafon, amongft fix or feven cafks of Pearl Afh fent to the Infpe&ion Store, one of them was marked fecond fort ; becaufe, with the Pearl Afh, there were fmall pieces of brick and mortar that had crumbled from the infide of the furnace, interfperfed throughout the calk. Theperfonwho brought U, alledged that the Pearl Afh being very good, fo trifling and acci- dental a mixture could net materially injure it for ufe'; therefore the fecond fort brand would depreciate the value of the Pearl Afh, and not the few foreign fubftances found with it. The owner and the Infpeclor, as is very common, differed in opinion^ and the Pearl Afh paffed as fecond fort. A workman from the glafs houfe came to the Gore, examined for himfelf, and liked the appearance of this Pearl Afh, and it was pur- chafed for that manufactory. When the melted compofition, wherein this was an ingredient, was to be blown into plates of glafs, it was fnapped in pieces by the brick, before the plates could be formed. By which mifchief the blaft was loft, and the proprietors, from this fingle cafk of Pearl Afh, in one evening fuftained an injury to the amount of between 30 and 4© dollars. 1L BY a different procefs the fame alkaline fait is obtained in a cauftic ftate, and is called POT ASH. IF the effential difference between Pearl and Pot Afhes is the comparative mildnefs of the one, and the caufticity of the other ; and if the mildnefs of the alkali in Pearl Afh depends on its combination with the aerial acid (a principle it abfoibs from the common air, or from hard water ufed in the manufadure of Pearl Afh) we are at once prefented with a key to that myftery whereby good Pot Afh can always be made. Prevent as much as poffible the combination of this aerial principle with the alkaline fait, while paffing through the different operations, to free it from its impurities : deprive it of what it unavoidably catches, and the procefs muft be fuccefsful. To prevent then this combination, the wood afhes, or the falts from them, fhould not be expofed to the open air -, for although the free admiflion of air is requifite in calcination, as has been infifted on throughout the pearling procefs ; the exclufion of it in fufion, facilitates that operation ; and melting down, as it is termed, is well known invariably to fucceed better the lefs the external air is admitted. The only rea- fon why alkaline falts fhould be melted into Pot Afh, is, that by the force of fo ftrong a fire, ___-------£—. the 26 the aerial acid may be expelled, that the alkaline fait may prefent as fmall a furface to the air as poffible, and thereby retain its remarkable caufti- ci ty. This remarkable property is greatly jncreafed by the ufe of quicklime, which property alfo in- creafes the fufibility of the alkaline fait, or its difpofition to melt ; therefore to deprive the al- kaline falts of the aerial acid which they had im- bibed from the air, or from the hard water ufed to diffolve them, quicklime may be ufed, not only without injury to the Pot Afh, but with ad- vantage. There is no fubftance in nature known to poifefs fo great a fhare of the aerial acid in its compofition as that which makes the beft of quicklime. This aerial principle being expel- led from limeftone by fire, in the manufadure of quicklime, it becomes a cauftic fubftance, ever ready to regain its natural ftate ; and it will moft greedily abforb what it has been/b violently deprived of, whenever circumftances favour it. Prefent alkaline falts in a mild ftate to quick- lime, and in proportion as they poifefs this aerial principle, it will be reftored to the quicklime, which will thereby become mild, or flacked* leaving the alkaline falts poffeffed of their original cauftic property. The foregoing principle admitted, directs ta the proper ufe of lime, and fhews that after it has 27 thus aded on the alkaline falts, it ferves only as a ftfainer, and therefore the lye ought to be as carefully drawn from it, as from any other earthy impurity. It alfo fhews the advantage that will refult by excluding the air as far as pradi- cable, from the wood afhes defignedfor this ma- nufacture, from the lye, and the falts, through every operation of the following PROCESS, for the MANUFACTURE of POT ASH. THE firft operation confifts in leeching, as for Pearl Afh. This has been fo particularly treated of, that a repetition would be ufelefs, although the moft minute attention to every circumftance there no- ticed, is indifpenfible. A difference too, to be obferved, is, that here unflacked lime may be ufed. The ftraw upon the falfe bottom of the vat is to be covered firft with wood afhes, then as much unflacked lime is to be thrown over it, as, when flacked, will make a layer ©f three or four inches; that the lye paffing through may not only be {trained, but that it may acquire a more cauftic quality. An additional quantity of lime may fometimes be requifite to be thrown into any part of the vat with the wood afhes, when they have been rendered more mild than ufual, by long expofure to the air. When 2% When the lye is leeched and fettled, it is to be drawn off into the kettles, and boiled down, for The Separation of Neutral Salts. THE boiling is to be continued until a fcum is obferved to colled on the furface of the lye, or, until it will weigh a little more than one quar- ter heavier than pure rain water. It is then to be taken from the kettles into a receiver, where it is to be again fettled by throwing into it another quantity of lime, unflacked,* toincreafe its cauf- ticity. The * Here an enquiry prefents itfelf that may be thought to deiierve more particular difcuftion. How much quicklime is to be ufed in a given quantity of lye ? No explicit anfwer can be given to this queftion. No definite quantity can be determined on for different parcels of lye, which already, without the addition of lime, poffefs different degrees of caufticky. (e. g.) From wood afhes recently burned, immediately taken from under a furnace before they are cold, and carefully leeched with pure rain or river water ; pr, if early in the feafon, even with good fpring water, no quicklime will be requi- fite. The falts have not been expofed to abforb the aerial acid, they will therefore be fufficiently cauftic, and will melt like oil. Take wood afhes of the fame defcription, that have been expofed to the air for months together, let them be leeched in the common mode, with water from the fame fpring in autumn, when it runs low and becomes hard ; the falts will have abforbed fo much of the aerial principle from the air, and from the water ; that unlefs quick- lime be ufed to abforb it from the lye again, they will prove extreme- ly hard to melt. A fimple experiment wi 11 {hew the difference between the two lyes, and tends to eftablifh the principle, that the ftate of the lafi lye de- pends on the aerial acid. To a glafs of it, pour by degrees a little fharp vinegar or other acid, and it will immediately be thrown into a Violent ftpe pf effervefcence, caiffed by the fudden cxpulfion of air the alkali has abforbed, which muft give place to the new union with a ftrpnger acid. But if the alkali is completely cauftic, no fuch effervefcence 29 The receiver is to be covered, where the lye fhould reft until it is cold, when it is to be drawn off as carefully from a faucet placed above the fediment, as direded for the white lye, defigned for Pearl Afh. In this way the neutral falts and all fediment will be left in the receiver, and the lye prepared for the laft boiling. For this, the utenfils, the kettles, and every thing about them, fhould be very clean, that no impurity fall into the lye. After it is drawn off and conveyed again into the kettles, they fhould be covered until the lye begins to boil, that it may not lofe of its caufticity. The covers may then be taken off, to favour its evaporation. When dried down to falts, the fire is gradually to be raifed; the kettles again covered for Melting. IF the precautions recommended have. been duly attended to, this operation, often tedious and expenfive, hazarding the lofs of kettles, and perplexing the workmen, becomes at all times eafy and expeditious, and melting down termi- nates the procefs to the complete fatisfadion of the operator. For by the time the alkaline fait is well melted, the laft impurity, the black co- louring matter is deftroyed ; but, if the alkaline fait effervefcence is feen immediately on the mixture of an acid ; there is no air to be expelled, and the union of the acid with the alkali qui- etly takes place. When then a violent effervefcence fuddenly commences on the mixture of an acid with the alkali, quicklime may be added to the lye with advantage. 3° fait is not cauftic, by being kept or freed from the aerial acid, and the neutral falts have not been feparated ; it is extremely hard to melt. And the black colouring matter* is fo ftrongly united to it, that if after a tedious length of time with exceffive fire, it is melted without breaking the kettles, the Pot Afh will be found red and foul, although the lye has been leeched and fettled in the moft careful manner. Dr. Lewis, one of the moft eminent of mo- dern chemifts, in his valuable little trea- tife on Pot Afh, obferves, when treating of the mixture of fea fait with American afhes, that " as almoft all the common forts of fea fait participate of the bittern of fea water, the com- bination of the vitriolic acid of that fait with the inflammable matter during fufion is probably the origin of the fulphureous taint }" (/. e. the black colouring matter) " in Pot Afh." If this is true, we are taught to explain the effed that all Other neutral falts, as well as fea fait, have on Pot * This colouring matter has been improperly called the cauftic fulphur, and the cauftic oil, from a conjecture that it was the caufe of cauflicity. This errour probably was fuggefled by obferving that black falts oftentimes retained a confiderable degree of cauftic fliarp- nefs, which they lofe at the fame time the colouring matter was de- fxroyed by calcination. However refpeaable the authorities are that formerly held this opinion, it is now a faa well eftablifhed, that the cauflicity of the alkaline fait does not refide in the in- flammable principle (i. e. in the black colouring matter) but that it is really diminifhed in proportion as the inflammable principle abounds. Neither has this colouring matter the properties of an oil—if it had, it would invariably form foap br its union with rh<- aHrari". 3* Pot Afh; for all other neutral falts found with the alkaline in wood afhes, are combinations of the vitriolic acid with different bafes ; therefore, the fame effed is to be expeded from the vitrio- lic acid in their# combination, as from the fame acid combined in the (b.ittern of fea water. Again, if hard water has been made ufe of in- ftead of foft, it has a fimilar effed on the Pot Afh; the fatys are very hard to melt, and the black colouring matter remains; and it becomes almoft impoffible by the common mode of man- ufaduring to deftroy it. , Water is . made hard, not only by neutral falts, but by the aerial acid.* Well and fpring water, although at fometimes fufficiently (oft and pure, when the fprings are low, become hard by this impregnation. Here is difclofed the myfterious caufe of Pot Afh falts melting eafier in the fpring and the fore part of fummer, when the whole earth is filled with water, than at the clofe of the feafon > when it is much exhaufted, and the fprings run low. At this latter feafon moft fpring water is hard, and it is generally faid to be impoffible to make good Pot Afh. Although rain or river water is al- ways to be preferred where it can be had, efpecial- ly at the feafon when it is thought impradkable to make good Pot Afh : Yet, indifputable experi- ments have proved, and muft convince all who make * The gaz ythich waters frequently contain, is another caufe of the hardnefs of water. Cneniic. Di&ionary. Note to the article r- make them fairly, that, according to the forego- ing theory, even lye made with fpring water may be fo deprived of neutral falts and the aerial acid, as that Pot Afh of a fuperior quality may eafily be made at any and every feafon of the year. If this is well underftood, the workman will no longer be aftonifhed that his Pot Afh has fometimes proved bad ; although, as he fuppof- ed, he had ufed the fame method to cleanfe it, (i. e. he had leeched, fettled, and drawn the lye from -all earthy impurity in the fame manner) as when it turned out good. He will hereafter regard the neutral falts as an impurity, and attend particularly to their feparation, while through the whole procefs he ftrives to prevent the union of the aerial acid with the alkaline falts, or carefully de- prives them of it when unavoidably combined. This done, melting down will foon be effeded, by gradually raifing the fire until a red heat is produced. Except when there is occafion to ex- amine the melting mafs, or to ftir it together with a ladle, it fhould be kept covered, increafing the fire until it becomes an uniform thin fluid. Iron kettles for coolers are now to be made ready, by heating them at the mouth of the furnace. A little tallow may be lightly rubbed over the in- fide furface of them, to prevent too ftrong an ad- hefion of the Pot Afh to the iron, which fome- times happens and is troublefome. The furnace is to be well tended with a continual fup- ply of dry fuel to keep up a very brifk fire, to- 11 ward the clofe of the procefs. In this ftate, the melted fait need be continued but for a fhort time to deftroy the inflammable principle, or black colour- ing matter; the deftrudion of which may be known by the eafy experiment of making a very ftrong fo- lution of the Pot Afh in a cup of water, immerfing therein a piece of filveror bright tin; if by this, the metal is not tarnifhed, the procefs is finifhed; and the Pot Afh is immediately to be dipped off into the coolers, taking efpecial care not to fuffer the leaft abatement of fire until the kettles arc emptied. When the Pot Afh becomes hard in the coolers, and cool enough not to endanger burning the cafk, before it has attracted moifture from the air, it fhould be packed in dry, tight, new cafks, that the air may not form a cruft upon its furface. One general obfervation applicable to moft kinds of bufinefs is peculiarly adapted to both the preceding proceffes, viz. that every opera- tion well conduded, makes eafy and fhortens thofe that come after, and is of fo much confequence to the fucceeding ones, that it is beft to repeat it, whenever any one is interrupted. Such management of the bufinefs, will, at once, put an end to all well grounded complaints, againft afhes, exported from Maffachufetts. In- ftead of fecond and third fort, which are a dead lofs to the manufacturing intereft, there need not be a fingle cafk but of an excellent quality. We fhall no longer hear of " mixed parcels of afh- ii es," fo various in their appearance, as to beget unfavourable fufpicions of their being the gen- uine fait. And a faithful comparifon with the ex- ports of our fifter State, New-York, formerly our rival in this important branch of commerce, will ceafe to be to our difadvantage. And while there is a market for afhes, thofe exported from Maf- fachufetts will meet with a quick fale, and at the higheft price. Added to this, which is per- haps the ftrongeft and moft perfuafive argument for the mode of manufaduring on the principles here advanced ; experience will prove it lefs trou- blefome, more expeditious, and lefs expenfive, than to manufadure fuch afhes as turn out of inferiour quality, and are denominated fecond and third forts. EXPERIMENTAL 35 EXPERIMENTAL ASSAY of ASHES. " TVi HE feveral operations to free afhes from. impurity, point to " the more effedual in- fpedion of the fame;" whereby the quality of any parcel may be more fully afcertained. A folution of Afhes in rainwater will determine - what proportion of fediment, or indiffoluble foul earth, is inveloped with the fait. By filtering it through loofe wrapping paper, what remains on the filtering paper may be accurately weighed ; it will alfo fhew the black colouring matter of red Pot Afh floating in the folution, like a mix- ture of lampblack. The weight of this impu- rity being comparatively nothing, the degree of foulnefs is judged of by the deepnefs'of the dye. Except fea fait, the neutral falts are eafily dif- covered by the ready method practifed by Mr. Blodget : It is to diffolve as much afhes as can be taken up in a tumbler of boiling rain water, and to cool it fuddenly by immerfing the tumbler in to cold water. The neutral falts will haftily fhoot, and form an apparent congelation. Sea fait, not be- ing obedient to the fame law, but being equally fo- luble in cold as in hot water, is not difcovered by this mode ; but by flow evaporation. Sea, or common fait, is feldom found in quan- tity, either in Pot or Pearl Afh, unlefs added by defign. A pretext is fometimes made ufe of, that it facilitates the melting of Pot Afh. Some have been il been induced to believe this, but they have de- ceived themfelves ; and where melting is the on- ly aim, a fingle fair experiment will determine them to give up the pradice, in favour of the pru- dent ufe of quicklime, previous to the melting ftage of the bufinefs. If Pot or Pearl Afh is overcharged with neutral falts, it is fufpeded by the touch and tafte. If inftead of the cauftic alkaline (alt, any other fait be mixed in Pot Afh, it will not give that acute fenfation of heat, on handling, or to the tafte, as the genuine fait never fails to excite ; for all neutral falts, except the metallic, excite rather the fenfation of cold than of burning heat. The adulteration with common fait has this ef- fed on the Pot Afh in a remarkable degree. A folution of Pot or Pearl Afh, containing com- mon fait, may alfo be difcovered by its tafte, if compared with a folution of afhes known to be free from it : And if thefe folutions are made in fix or eight times their quantity of pure rain wa- ter the difference will be very diftinguifhable. The degree of adulteration may be found by eva- porating a folution of afhes very gradually, until the neutral, and of courfc the common fait, will cryftalize, while the alkaline is held in folution. But, as the quantity of alkaline fait is the objed of the affay, and not what arc the different kinds of neutral falts blended with it, in Pot or Pearl Afh; the peculiar properties of that fait furnifh another mode ef examination that cannot deceive. Altroltnr 37 Alkaline fait is well known to poffefs the ftrongeft difpofition to unite with acids, to a cer- tain point caltedfaturation ; which totally de- ftroys the properties of both, conftituting a neu- tral fait : until fufficient acid is added to the al- kaline fait to bring it to this point, the alkali predominates, and the mixture retains its alka- line charader; beyond it, the acid prevails, A clean folution of Pot or Pearl Afh, freed from all fediment, contains nothing but fait. The queftion is, what portion of the contained fait is alkaline ? Add an acid until the folution is neutralized, and mark the quantity of acid confumed. If neutral falts have been already blended in the folution to be affayed, it is plain it will not take up as much acid to faturate it as an equal weight of a folution where no neutral falts are blended. Thofe afhes therefore which will take up the greateft quantity of acid to fa- turate them, contain moft alkaline fait. The point of faturation is pretty well known by the tafte, to thofe accuftomed to compound acids with alkalies. The four fliarpnefs of the one, and the corrofive heat of the other; are not to be diftinguifhed in the faturated mixture, be- caufe they have deftroyed each other. A ceffation of the effervefcence that takes place on the union of an acid with a mild alkali, is the ufual method to determine this point. But, if the alkali is completely cauftic no effervefcence takes place, for want of the aerial acid, that, difcharged by the union ii union of the mild alkali with a ftronger acid, occafions its effervefcence. The diftind properties of acids and alkalies in their adion on the blue juices of vegetables, have enabled chemifts to come at this point of fatura- tion with the greateft exadnefs. Alkaline folutions will invariably change the blue of vegetables to green. Acids will change. the fame blue to red, * while the neutral fait re- fill ting from a faturation of the two, produces no alteration of colour. Tinge a folution of alkaline fait, green, with fome vegetable blue, add an acid until the blue colour is recovered, and the point of faturation is gained. If more acid is added the folution will redden. The infinite variety of blue flowers, in the fea- fon of them, will fupply the blue colouring mat- ter * Profeffor Bergman fays, " The general rule, namely, that blue vegetable juices are made red by acids, and green by alkalies, is liable to two exceptions, already known, viz. lackmus is rendered more in- tenfely blue by alkalies, and indigo diffolves in vitriolic acid without any change of colour." Vol. II. page 129. What is find of lackmus and indigo is undoubtedly true ; ftill it does not furnifh any exception to the general rule, when it is remem- bered that neither of thofe fubftances is of the blue vegetable juice in its original ftate. Lackmus is a preparation of (he vegetable called Archil, which vegetable, in its natural ftate, gives out a red colour : but when bruifed, and the red juice is treated in a certain way with lime and volatile alkali, and evaporated to a confiftence, it is changed into 3 blue pigment called Lackmus. Indigo is well known to be obtained from a vegetable, by ferment- ition ; and fermentation totally changes the property of every vege- table and animal fubfr.mce. _39 tcr for this teft. But they are not always to be had frefh; lackmus, a preparation of archil, is re- commended becaufe it is not fo perifhable.—-In want of thefe, during the winter feafon, I acci- dentally made ufe of the red cabbage ; a ftrong in- fufion of it in rain water gives a good bjue; and I fince find this vegetable recommended in prefer- ence to all others, for the trial of alkalies and acids. It is fimply prepared by pouring boiling water upon the red cabbage leaves, cut fmall, and let ftand until cold, when it may be poured off for ufe. Any acid may be made ufe of, even vinegar. The marine acid, called fpirit of fea fait, as fold in the apothecarys' fhops will be found prefera- ble to any other, for the pur pole. Add to one part of fpirit of fea fait, ten parts ©f rain water, and the acid will be reduced to a fuitable ftrength for the trial. To afcertain with the utmoft precifion the ab- folute quantity of what is purely alkaline in any folution of falts, requires fo minute an attention to every variation of temperature from hot to cold; to the different degrees of preffure of the atmof- phere, in damp or dry weather, and to the precife ftrength of the acid made ufe of, as cannot be had without the affiftance of expenfive inftru- naents; and would prove much too tedious and troublefome for common bufinefs. Chcmift* 4° Chemical and philofophical refearches require this accuracy in experiments, left erroneous de- dudipns fhould be made from their refults. But it is by no means neceffary to be thus fcrupu- loufly exad to determine the purity and confe- quent comparative commercial value of Pot and6 Pearl Aflies. This may be.done with great eafe .and certainty, and with, little apparatus. The apparatus need confift only of a little vegetable blue, and fome acid prepared as above—two or three glafs tumblers, a vial that will contain four ounces of rain water, and a fmall pair of fcales and weights ; the weights to conform to the vial and contained water : e. g. one weight that will exadly balance or tare the empty vial—one that will weigh precifely as much as the quantity of rain water the vial will contain, i. e. four ounces. The four ounce weight may be marked 128 One two ounce do. do. 64 One ounce, 32 One half ounce, 16 One quarter ounce, 8 One eighth, 4 One fixteenth of an ounce, 2 One thirty-fecond, 1 By thus marking them they may be denominated carat weights. Take then one ounce, or thirty-two carats of fitch Pot or Pearl Afh, as having been faithfully made from good wood aflies, is known to be of the beft quality. Let it be pulverized, that folution may be more fpeedily made) make the folution of it in a tumbler, in four ounces of pure rain water. Take alfo an ounce of the Pot or Pearl Afh to be examined, make a like folution of it in a fecond tumbler in the fame quantity of rain water. When the folutions are complete, and the fedi- ment of each has fubfided, pour carefully from the firft tumbler half an ounce, or fixteen carats by weight, of the clear folution ; add to it one tea fpoonful of the vegetable blue infufion— take by weight of the prepared acid—add of it gradually to the folution that has in it the vegetable blue, and it will be found gradually to change colour, until, by repeated addition, the blue colour is reftored, which fhews the point of faturation. The laft additions fhould be made with great caution, or too much acid will fuddenly change the colour of the folution to a deep red. To carry this teft to a point inftantly difcernable, I have generally added the acid un- til it gave the folution the firft tinge or blufh of red, which although a degree beyond faturation, is as precife a point, and eafily determined. Af- ter this, the remaining acid is to be carefully weighed, and the quantity confumed in the trial to be noted. Proceed immediately to the examination of the folution in the fecond tumbler. Take the famii quantity, i. e. half an ounce by weight. Ufe the £«ne teft, and when, by the fame caution* under F fimilar 42 fimilar circumftances, the folution is brought, by the' acid, to the very firft blufh of red, weigh the remaining acid, which will fhew the exad quan- tity confumed. If then the fixteen carats weight of the folu- tion of the firft tumbler, which may be called of the ftanclard aflies, has taken up forty carats weight of prepared acid ; and the fame weight of the folution of the fecond tumbler, has taken but thirty-fix carats to bring it to the fame point, it is plain, that although the quantity of fait con- tained in each be the fame, yet, of the fait that is valuable, i. e. the alkaline fait, there is a differ- ence between them of ten per cent. The re- maining fait of the fecond aflies being of a differ- ent kind, fhews the exiftence or mixture of fome neutral fait that ought never to have been blended, or fhould have been carefully feparated in the manufadure. Every expenfe on fuch aflies (the original price of the ftock only excepted) being the fame with the firft, the profit of it muft be much reduced. In this way may be determined the compara- tive worth not only of Pot and Pearl Afhes, but of all Pot Afh Salts; and the manufadurer need no longer be fubjed to impofition in the pur- chafe of them. A very little pradice will fa- miliarize and make eafy the trial, and it will be found fufficiently expeditious. Thofe who colled allies at the ftores in various parts of the* country, may have it in their power to 43 to afcertain the quality of their purchafes : and the exporters, if they pleafe, may deter- mine, as well as the Infpedor, what afhes will be moft profitable to the confumer. The manufadurer likewife may always know how his afhes ought to be received at market ; and blind indeed muft he be to his pecuniary concerns, if ever he fuffers afhes of the third fort to be fent from his works. Let him rather, if by accident he is unfortunate in a procefs, and his afhes prove third fort, keep the advantage of working them over to himfelf : This will at all times afford him greater profit than to difpofe of them in any other way. Well perfuaded that nothing is wanting but the pradice, to convince of this fad ; may . .we not exped the time, which probably is not far diftant, when what are now denominated third fort of afhes, may not be known or heard of in the Maflachufetts market ? APPENDIX. APPENDIX. PEARL ASH FURNACE. XT is not eafy to give an accurate defcription of a Furnace, unlefs by reference to a plate where it is delineated. A general idea, however, of the Furnaces employed in the bufinefs treated of, may not be altogether ufelefs. A Furnace, whether for fcorching or pearling, fhould be exadly of the fame conftruction : If is properly called a reverberatory Furnace, and differs very little from the reverberatory Furnace " faid to be the invention of an Englifh phyfi- cian of the name of Wright : the ufe of which was firft introduced in England for fmelting ore;,, about the end of the laft century."* To defcribe the pearling Furnace in a more familiar manner :—The form of the body of it may be faid to be very much like a baker's oven, open on one fide. The greateft extent of the hearth is in length fix feet, in width four. The fire place and afh hole are on the fide of the open- ing. The fire place is feparatcd from the body of the Furnace by a partition wall, raifed about two or three inches from the hearth, running along the whole length of the fide. This wall leaves an opening of about four or five inches above it, for the paffage of the flame to the body of the Furnace. The grates to fupport the fuel APPENDIX. 45 feparate the fire place from the afh hole, and fhould be funk about fix or eight inches below the level of the hearth. Formerly the pearling Furnace was built with a fire place on each fide ; but of late, the fire place on one fide is found equally to anfwer. The diftance of the roof on the infide of th« Furnace, from the hearth to its crown or high- eft part, fhould not exceed fourteen or fifteen inches. It is ufual to have two chimneys to the body of this Furnace ; one at the entrance, to receive the flame and fmoke, when the door is open ; the other oppofite to it, at the fartheft end. This Furnace has alfo two doors; one at the fire place, about 12 inches wide, another at the opening at the front of its body, about 18 inches wide, and ten high ; through which the falts are thrown into it. The fire is led to play throughout a well con- ftruded Furnace, by three or four flues judiciouf- ly difpofed around it, at the bottom of the wall, diredly upon its hearth. Thefe openings commu- nicating with the chimneys, caufe a draught which circulates the flame over every part of it. POT ASH FURNACE. THE Furnace in ufe, for manufaduring Pot Afh, is of a different conftrudion. It confifts of two large iron boilers, or kettles, fet in brick work, 46 APPENDIX. work, that will hold from 50 to 70 gallons, mea- furingabout three feet over the top ; they fhould be very thick at the bottom to endure the fire, and provided with covers of plated iron. Under the kettles is the fire place and afh hole. At the mouth of the fire place is the door, at the fartheft end of it is the chimney. The grates that feparate the fire place fhould be funk below the bottom of the kettles at a diftance not ex- ceeding 14 inches ; the width of the fire place door fhould be about 18 inches. It is eafy to conceive that by this conftrudion, whenever the fire is urged fo ftrongly as to pro- duce a red heat in the kettles, and fometimes beyond it, that the draught from the afh hole will drive a great portion of the fire into the chimney, and even force the flame out at the top to a confiderable height. This is what generally happens on melting do{wn. Being defirous to attend particularly to thi9 operation, and aware of the inconvenience it muft occafion, when performed in the town of Bofton, where every blaze, out at the top of a chimney, excites an alarm, and fubjeds the proprietor of it to an expenfive penalty; I applied to Mr. Heath, an intelligent artift, an inhabitant of the town, to vary the conftrudion of the Pot Afh Furnace fo as to obviate this difficulty. He has effeded the purpofe completely. Inftead of carrying out the chimney from the fartheft end of the fire place, he there left a fufficient vacancy beyond the APPENDIX. 47 kettles, for the fire to pafs up to the flues, which he opened, one on each fide the kettles, to return the flame round them toward the mouth of the Fur- nace, and condud it into the chimney raifed dired- ly over the door. This improvement leffens the confumption of fuel, for by it, the fame fire is brought to act a fecond time on the kettles, is nearly expended round them, and not wafted in the chimney. POST SCRIPT. IT would be injuftice to the remarks on the fubjeft of Pot and Petri Afhes, not to notice an advertifement which appeared in the Gazette of the United States, publifhed July laft, at Philadelphia, and figned Samuel Hopkins. It is there afferted as an advantage arifing from Mr. Hopkins's method of manufacturing Pearl Afh, that " by calcining the afhes be- fore the leys are drawn from them, we obtain as great a quantity; at leaft of Pearl Afhes, as of common black falts;" and Mr.Hopkins adds$ " Pearl Afhes generally fells, when at market £50 per ton. The high- eft price for black falts is £25 per ton, and if converted into Pearl Afhes, it requires as much more labour and fuel as in the firft in- ftance, and a lofs from twenty-five to thirty per cent." Could this be realized, lucrative indeed would be the bufinefs. But if it fhould turn out that fpurious afhes are the produft of his fuppofed improvement ; that they are the alkaline fait confounded with a vari- ety of neutral falts, and a greater portion of earth than are found in Pearl Afh manufactured after the ufual mode ; although fo bleached by the aftion of the fire and air, as to give it the appearance of good " Pearl Aflies of a very fine white colour;" yet when accurately analyzed, even ihe 25 or 30 per cent, fuppofed to be faved in the weight of the Pearl Afh, may difcover itfelf tobe ftill the earthy and faline impurity, al- though deprived of colouring matter by calcination. If this is the refult of Mr. Hopkins's method, it will not be deem- ed prefumptuous to call in queftion his mode of manufacturing, although fanftioned by a patent, and recommended by the opinion of fome of the moft celebrated characters in thcUnjted States—characters juftly celebrat- ed 48 APPENDIX. ed for their diftinguifhed eminence in fcience.* In this inftance, how- ever, they appear complaifantly to have fubfcribed toMr.Hopkins's de- finition, where he fays, "Black falts are made by boilingdown the leys from common wood afhes, until they are perfectly dry ;" and " Pot Afhes are made by melting the black falts in a very ftrong fire, and lad- ing it out into coolers ;" without the leaft intimation that from the alkaline fait all others are to be feparated, to make the bejl of afhes :— For, in the alkali alone is the excellence of Pot or Pearl Afh. In- deed fome have vainly imagined that by Mr. Hopkins's method of manufacturing, an aftual tranfmutation of 25 or 30 per cent, is effect- ed, and that the faline impurities are converted into genuine alkaline fait. The gentlemen referred* to, who gave Mr. Hopkins their certifi- cate, could not entertain fuch an opinion ; for, although tartar is alka- lized by fire, and nitre by the peculiar inflammability of its acid, when burned, leaves its alkaline bafis uncombined, yet the ftrongeft fire of a glafs houfe has never effected the feparation of the vitri- olic acid from its alkaline bafis in vitriolated tartar, or the marine acid from the mineral alkali in fea fait. By force of fire they may both be melted, and perhaps evaporated ; but when diffolved, or condenfed, they are found the fame, and may again be chryftalized. No chem- ical facl is better known, or more thoroughly eftablifhed, than that the union of acids and alkalies in neutral falts, is too ftrong to be in the leaft effected by any fort of earth yet known ; therefore it is not to be expected that either the acid of neutral falts will be diffipated, or any new combination will take place in confluence of cal- eining them with the earth of wood afhes. Mr. Hopkins alfo fays, that " Pot Afhes made from calcined afhes are allowed to be much fuperior to thofe made in the common mode." However fair the Pot Afh may be made to appear by the previous calcination, unlefs the neutral falts have been feparated, it cannot be equally as good as that which is properly made, becaufe it does not con- tain the fame proportion of alkaline fait. There cannot be a more decifive teft to evidence this, than to take a fpecimen of each, and with the fame ingredients, under fimilar man- agement, to afcertain the quantity of foap they feverally produce. • David Rittenhoufe, Benjamin Rujb, James Hutebinfon, Benjamin Say, Cafper Wijler,jun. and John Pennington. FINIS. 1 ..-*-».. k^o" it ' ,-"#" M&*t -*?v *yri £K %n^ r,>