THE 
 
 ART OF BLEACHING. 
 
\ 
 
THE 
 
 ART OF BLEACHING 
 
 PIECE-GOODS, 
 COTTONS, and THREADS, 
 
 OF EVERY DESCRIPTION, 
 
 Rendered more eafy and general by Means of the Oxygenated, 
 
 Muriatic Acid ; with the Method of rendering painted or 
 
 printed Goods perfectly white or colourlefs. To which 
 
 are added, the moll certain Methods of bleaching 
 
 Silk and Wool ; and the Discoveries made by 
 
 the Author in the Art of bleaching Paper. 
 
 ILLUSTRATED WITH NINE LARGE PLATES, 
 IN QUARTO, 
 
 REPRESENTING ALL THE UTENSILS AND DIFFERENT 
 MANIPULATIONS OF THE BLEACHING PROCESS. 
 
 AN ELEMENTARY WORK, 
 
 COMPOSED FOR THE USE OF MANUFACTURERS, BLEACHERS^ 
 DYERS, CALLICO PRINTERS, AND PAPER-MAKERS, 
 
 By PAJOT DES CHARMES, 
 
 EORMERLY INSPECTOR OF MANUFACTURES, MEMBER OF THE 
 LYCEUM OF ARTS, OF THE SOCIETY OF INVENTIONS AND 
 DISCOVERIES OF THE PHILOMATHIC SOCIETY, IN FRANCE. 
 
 TRANSLATED FROM THE FRENCH, 
 With an Appendix. 
 
 LONDON: 
 
 I>RINTS» FOR Q. G. AND J. ROBINSON, PATER-NOSTSR-RO"VV, 
 
 . 1799- 
 
CONTENTS. 
 
 CHAPTER I* 
 
 Jr\.N Explanation of the Difficulties which attend the 
 Method of Bleaching, described in rhe fecond Volume 
 of tue Annales de Chimie, when pra£tifed by inexperi- 
 enced Operators - page i 
 
 CHAP. II. 
 
 The Methods fubftituted inftead of thofe enumerated in 
 the foregoing Chapter - - -6 
 
 CHAP. III. 
 
 The Composition of Lutes - r « 12 
 
 CHAP. IV. 
 
 The Method of difpofing the Apparatus for Diftillation 
 
 19 
 
 CHAP. V. 
 Preparation of the Materials - * 43 
 
xlv CONTENTS, 
 
 CHAP. VI. 
 The Diftillation g 52 
 
 CHAP. VII. 
 Concerning the alkaline Lixivium or Lees - 74 
 
 CHAP. VIII. 
 Refpe&ing the Preparation to be given to the various 
 Kinds of Goods « - - or 
 
 CHAP. IX. 
 Concerning the firft Immerfion - - in 
 
 CHAP. X. 
 Jnftruc"lions with Regard to the Quantity of Lixiviations 
 and Immerfions - - - 126 
 
 CHAP. XI. 
 An Account of the Quantity of Linen, and Cotton 
 Thread, bleached at each Immerfion, and the Colours 
 acquired by thofe Subflances - - 134. 
 
 CHAP. XII. 
 Of the Firft Dreflings - 140 
 
 CHAP. XIII. 
 Of the Laft Dreflings - 154 
 
 CHAP. XIV. 
 Concerning Proof Liquors - . 17a 
 
 CHAP. XV. 
 The Methods of remedying fuch Accidents as happen 
 during the Courfe of Bleaching - - 178 
 
CONTENTS. xv 
 
 CHAP. XVI. 
 The Method of taking out Spots of Ruft or Iron-mould, 
 Tar, Fruit, Wine, Sec. - - - 189 
 
 CHAP. XVII. 
 The Expence of Bleaching different Kinds of Goods, of 
 Linen, Hemp, or Cotton, by the oxygenated muriatic 
 Acid, at per Ell, or per Pound - - 193 
 
 CHAP. XVIII. 
 
 The Method of bleaching yellow Wax, nankeen Stock- 
 ings, and other Articles which have acquired a dark 
 Colour by keeping ; Linen flamed by Dampnefs, and 
 the Madder Grounds of printed Goods - 207 
 
 CHAP. XIX. 
 The Method of difcharging the Colour of painted or 
 printed Cottons, or Linens, and every Kind of Dye on 
 Cloth or Thread, before or after it is wrought up 21$ 
 
 CHAP. XX* 
 
 The Methods of taking out the Dye from Silk and Wool 
 
 228 
 
 CHAP. XXI. 
 Dying by the oxygenated muriatic Acid - 232 
 
 CHAP. XXII. 
 
 Various Properties of the oxygenated muriatic Acid 236 
 
 CHAP. XXIII. 
 On the Podibility of applying the Refidues to Profit 250 
 
 CHAP. XX r V. 
 The Method of bleaching Hemp and Flax in the unma- 
 
xvi CONTENTS. 
 
 nufaftured State, as well as Thread and Piece-goods^ 
 by the Afliitance of Water only - 261 
 
 CHAP XXV. 
 The Method of Bleaching written or printed Papers and 
 Rags, whether unbleached, dyed, or coloured . 266 
 
 CHAP. XXVf. 
 - - * - 271 
 
 CHAP. XXVII. 
 Fabrication of crude Alkali (cendres Gravelees) with the 
 Lees of Wine - - - - 276 
 
 CHAP. XXVIII. 
 The Method of bleaching Wool - - 280 
 
 CHAP. XXIX. 
 The bleaching of Silk - - . 291 
 
 Explanation of the Plates - 296 
 
 Appendix - » - - 245 
 
PRELIMINARY OBSERVATIONS, 
 
 BY THE AUTHOR. 
 
 iHOUGH the illuftrious Swedifh che- 
 inift Scheele was the firft who obferved the 
 property of the oxygenated muriatic acid, 
 which was alfo a difcovery of his own, of 
 difcharging vegetable colours, has acquired 
 the ftrongeft claim to the gratitude of the 
 public, it is equally true, that the celebrated 
 French chemift Berthollet has eftablifhed an 
 equal claim to the acknowledgments of the 
 world, by his active and able exertions on an 
 object of fo much confequence to the com- 
 merce of the linen and cotton manufactures. 
 The different memoirs which he has pub- 
 lifhed on this fubjedt, particularly that which 
 is inferted in the fecond volume of the An- 
 
 b 2 nales 
 
Vlll PRELIMINARY OBSERVATIONS. 
 
 nales de Chimie — the fcientific application he 
 has made of this acid to difcolour the feve-* 
 ral vegetable fubftances which conftitute the 
 raw materials of 'manufactures — the particu- 
 lar developement, which the profperity of 
 thole manufaclures led him to confider as ne-» 
 cerTary to excite emulation among {peculate 
 ors, foon afforded very promifing remits, 
 as might naturally be expected from the 
 publication of fo ufeful a procefs. Manu- 
 facturers in all parts of the nation were in- 
 duced to confult chemical and philofophical 
 men, in order to obtain information refpecH* 
 ing it : the happy confequences which have 
 rewarded their labours in this refpect, are 
 truly honourable to the zeal of the parties 
 themfelves, and have added to the reputa- 
 tion of their guide in this new department 
 of refearch. 
 
 The knowledge which I had acquired re- 
 fpecting the inconvenience and delay of the 
 
 common 
 
PRELIMINARY OBSERVATIONS. IX 
 
 common procefs of bleaching— the incalcula-» 
 ble advantages which I faw mull attend the 
 method propofed by Berthollet — the new life 
 which the manufactures of thread and piece-* 
 goods, and the commercial tranfadtions de- 
 pendent thereon, would certainly receive : — 
 thefe views, added to the defire of knowledge, 
 and a wifh to contribute to the propagation 
 of a difcovery which promifed an increafe of 
 our riches and our enjoyments, engaged me 
 to verify the procefs defcribed in the Annales 
 de Chimie. My intention was, in the firft 
 place, to make myfelf mafter of the procefs, 
 and then to propofe, with confidence, this 
 new method of bleaching to the manufac- 
 turers, merchants, and bleachers, in my de- 
 partment of infpedtion, to whom this fpecies 
 of induftry might prove advantageous, and to 
 give them every information in my power. 
 But I foon found that it would be in vain to 
 defcribe and publifh this method, which 
 
 would 
 
X PRELIMINARY OBSERVATIONS* 
 
 would be in a fhort time forgotten or confined 
 to a few individuals, if it were not rendered 
 more economical, lefs dangerous, and more 
 amply defcribed with regard to the manipu- 
 lations, or practical part, fo as to be rendered 
 eafy and perfectly adapted to the comprehen- 
 fion even of workmen totally unacquainted 
 with chemical operations. For I knew that 
 mailers have feldom the time, or will take 
 the trouble, to operate themfelves, but moft 
 commonly coafide their work to men upon 
 whom they can depend. I therefore took the 
 utmoft pains to render the difcovery of 
 bleaching with the oxygenated muriatic acid 
 of general ufe. As I had the good fortune to 
 be fuccefsful in my trials, I fhall endeavour 
 in the following work to defcribe the procefTes, 
 by the afiiftance of which I fucceeded. 
 
 I firft give an account of the principal diffi- 
 culties I experienced in operating, according to, 
 
 the 
 
PRELIMINARY OBSERVATIONS. Xl 
 
 the directions in the memoir before-men- 
 tioned ; difficulties which the author him- 
 felf would not have failed to remove, if he 
 had himfelf operated in the large way. I 
 then defcribe the methods which I have 
 thought proper to fubftitute, inftead of feve- 
 ral of thofe which are there pointed out : and, 
 laftly, I defcribe, with the greateft precifion 
 and minutenefs, the different operations 
 which are indifpenfably neceffary to give 
 linen, hempen, cotton and mixed goods, a 
 perfect bleaching, equal in colour to the beft 
 which are met with in the market, and are 
 known in France by the names of the white 
 goods of Troyes, Rouen, Senlis, &c. 
 
ADVERTISEMENT 
 
 BT THE TRANSLATOR. 
 
 X HILOSOPHICAL men, as well as manu- 
 facturers, will, no doubt, receive with fatif- 
 fa&ion the following treatife on a new art of 
 great importance to fociety, and truly honour- 
 able to philofophical chemiftry. It is unne- 
 cessary to enlarge on the value of a procefs, 
 which has been eagerly and univerfally 
 adopted as foon as ever it was known, and 
 its principal difficulties removed. Neither 
 will it require any argument to fhew the 
 advantage which practical men muft receive 
 from a detailed and very faithful account of 
 procefTes, conducted on a fcale of fufficient 
 magnitude for commercial purpofes. 
 
 a i When 
 
VI ADVERTISEMENT. 
 
 When we reflecl: on the ftate of thofe arts 
 which are mentioned in the title pr.ge, and 
 the numerous applications this new method is 
 ftill capable of, as well as the utility of teach- 
 ing it to all who are in any refpect concerned 
 in bleaching, it will fcarcely be queftioned, 
 but that this elementary treatife muft prove of 
 great public benefit. 
 
 WILLIAM NICHOLSON. 
 
 Newman-ftreet, June 13, 
 1799. 
 
THE ART 
 
 OF 
 
 BLEACHING COTTONS, THREAD, &c. 
 
 BY 
 
 THE OXYGENATED MURIATIC ACID, ' 
 
 RENDERED OF MORE EASY AND GENERAL USE *. 
 
 CHAP. I. 
 
 An Explanation of the Difficulties which attend the 
 Method of Bleaching, defcribed in thejecond Volume 
 of the Annales de Cbimie, when praclifed by inex- 
 perienced Operators. 
 
 V_>/NE of the firft difficulties, in the operation 
 illuftrated by the plate annexed to the memoir 
 in the Annals of Chemiftry, is to obtain in the 
 
 depart- 
 
 * It was intended that this work fhould have been publifh- 
 cd, in 1791, by the General Adminiftration of Commerce 
 (in France) ; but the fuppreflion of that board, in the courfe 
 of the fame year, prevented its appearance. Since that time, 
 other circumftances have been unfavourable to the author's 
 intention of publifhing the refults of his experiments on tha 
 new method of Bleaching. — Ncte of the Jutbar. 
 
 B A fhort 
 
i The Art of Bleaching 
 
 departments fuch furnaces as are there pre- 
 ferred to be ufed. They can fcarcely be had 
 but by fending to Paris, where they are made : 
 and if it be even fuppofed that thefe furnaces 
 might conveniently be made at a diftance from 
 the capital, they would flill appear to be coftly, 
 fuitable only to a fmgle matrafs, not calculated 
 to fhew the procefs which takes place in the 
 veffel, fubje£r. to be heated too fpeedily, and 
 liable to render part of the lutes difficult to hold ; 
 laftly, they do not always fecure the operation 
 from the confequences of an abforption of 
 the water of the tub into the intermediate vef- 
 fel (notwithstanding the tube of fafety), in fuch 
 cafes where the heat is not kept up and urged 
 particularly towards the end of the diftillatiom 
 or where any negligence has taken place in the 
 agitation which is required for the fpeedy ab- 
 forption of the gas, or where the tubes of com- 
 munication are too fmall. 
 
 2. The greatefl addrefs and precaution are 
 required for the proper application of the re- 
 curved tube, which on the one hand communi- 
 
 A fliort table of fynonimes is added at the end of this 
 work, for the ufe of thofe who may be unacquainted with the 
 new nomenclature. — P. D. C. 
 
 The method of Bleaching, to which the prefent chapter 
 be:}is reference, is defcrihed in my Chemical Dictionary, ait. 
 Bleaching. — Note of the Ttaiflator. 
 
 cates 
 
Cottons, Thread, &V. $ 
 
 cates with the matrafs, and on the other with the 
 intermediate veffel. The flighteft agitation, whe- 
 ther in attending the lutes, fupplying the fur- 
 nace with coal, &c. is fufficient to break this 
 tube, and likewife that which communicates 
 to the tub. The difagreeable confequences of 
 fuch an accident, w T hen the apparatus is in a 
 ftate of activity, and the difengagement of the 
 gas muft continue to take place, are too obvious 
 to need defcription. The fame accident may 
 happen whenever the tube is put in its place, 
 or taken out to clear the matrafs. To this we 
 may add, the difengagement and frequent re- 
 newal of fo many ftoppers of cork, which are 
 corroded by the gas and the acid during their 
 paffage, and the adjuftment of the lutes requir- 
 ed to cover and defend them. The care and vi- 
 gilance required to maintain the feveral lutes of 
 the whole communication muft be extreme. 
 
 3. The pneumatic tub or veffel having no 
 cover, muft fuffer a large quantity of gas to 
 efcape during the courfe, and particularly to- 
 wards the end of the operation, which is not 
 only attended with lofs, but renders it impoffible 
 to remain for any length of time in the place of 
 diftillation, without being greatly and even in- 
 fufferably incommoded. 
 
 4. It is not a flight talk to conftru£t the fides 
 
 » 2 or 
 
4 The Art of Bleaching 
 
 or borders of the inverted veffels in the pneu- 
 matic tub, to retain and concentrate the gas 
 in a proper manner. The memoir affords no 
 explanation of the manner of conftructing cr 
 adjufting thefe parts, and, confequently, leaves a 
 degree of uncertainty, which expofes fuch ope- 
 rators as may not be aware of the great import- 
 ance of the perfect clofure of thefe parts, to the 
 probability of making very confiderable mif- 
 takes. 
 
 5. The long fucceffion of lixiviations and im- 
 merfions prefcribed in this memoir, which are in- 
 difpenfible according to that procefs, is produc- 
 tive of much Iofs of time and inconvenience. 
 
 6. The method of compofing the lutes, parti- 
 cularly thofe which are proper for this diftillation, 
 not being explained, any one who is not ac- 
 quainted with the means of doing this, or can- 
 not conveniently procure them, will be much 
 embarraffed, more particularly if his refidence be 
 in the country, where the practical chemifts of 
 the vicinity, if any, may either be unprovided in 
 this refpe£t, or not difpofed to fupply either the 
 lute, or the initruclions for making it. 
 
 7. Laftly, I have found, by my own experience, 
 that, independent of the difficulties here enume- 
 rated, the fingle obttacle of keeping the lutes in 
 a proper ftate during the whole courfe of the 
 
 diftillation, 
 
Cottons, Thread, &c. 5 
 
 diftillation, together with the no lefs effential 
 requifite of preventing the danger of immerfions, 
 are quite fufficient to repel the efforts of the 
 moil zealous and obltinate in this kind of ope- 
 ration. 
 
 Such are the leading impediments to which 
 every one, whether he be a practical chemifl or 
 not, will find himfelf expofed in an attempt to 
 follow in the large way the procefs of bleaching 
 defcribed in the fecond volume of the Annales 
 de Chimie. It was, therefore, of effential con- 
 fequence to diminifh, or rather to remove thefe 
 difficulties, without which this important art 
 might be confidered as of no value to the public. 
 It will be feen in the account of the methods 
 I have employed, whether 1 have fucceeded in 
 rendering the application and practice of this 
 new procefs much more advantageous and prac- 
 ticable, by perfons the leaft acquainted with 
 chemical manipulations. 
 
 CHAP. 
 
The Art of Bleaching 
 
 CHAP. II. 
 
 The Methods fubjlimtt J inflcad of thofe enumerated in 
 thefcrcgoir.g Chapter. 
 
 X SHALL, in the firft place, defcribe the fur- 
 nace I have made ufe of, which I have endea- 
 voured to render of the greateft poffible utility, 
 without increafing the expence of fuel. 
 
 A fimple calk of the proper height, or four 
 pieces of wood framed together (fee plate I, fig. 
 i and i *), fupport the furnace. The hearth 
 is difpofed upon boards defended by tiles placed 
 on a bed of clay. The walls or fides are formed 
 of bricks, likewife connected with clay. 'J his 
 furnace would be equally ufeful and folid, and 
 perhaps lighter, if it were lined with plaifter, 
 like thofe portable furnaces commonly ufed in 
 Paris,' which it confiderably refembles in its 
 manner of fupport. It is ufually double, and 
 ought in fact to be fo, when the operations are 
 intended to be made on a fcale of fome extent ; 
 and confequently it is divided in the middle by 
 a partition. At the front of the furnace above 
 
 * The defcriptions of the plates, by literal reference, are 
 found at the end of this work.— N. 
 
 there 
 
Cottons, Thread &c. 7 
 
 there are two openings, which may be either 
 round or fquare, adapted each to receive a 
 fquare or cylindric capfule, with a ledge, and 
 flat or rounded at bottom. Behind, and on the 
 fame level as the capfule, there is a vent or pipe 
 which conveys the heat and vapour of the char- 
 coal, which is burned in a chafing-difli, or upon 
 a portable grate, beneath, or round the capfules, 
 into a kind of refervoir, which being difpofed 
 a few inches higher than the capfules, ferves to 
 place along fquare bafon of fheet-iron with pro- 
 jecting edges, which is kept filled with fea fait 
 or muriate of foda to the height of an inch and 
 a half, in order that it may be dried during the 
 diftillation. At the two oppofite extremities are 
 two fmall apertures, which are opened or clofed 
 as may be found expedient for the pailage of the 
 heat or fmoke, and therefore operate like re- 
 gifters. In the empty fpace, at the back part 
 of the furnace, beneath the drying place, there 
 is an opening in the fide, into which troughs or 
 boxes of fheet-iron are put, containing the mix- 
 tures of muriate of foda, and manganefe, ready 
 prepared before hand. In this place they are 
 kept dry, and in readinefs to be poured into 
 the vefiels, the evening before the diftillation. 
 
 The opening through which the chafing-difli 
 
 is introduced, which is likewife on the fide of 
 
 b 4 the 
 
8 The Art of -Bleaching 
 
 the furnace, is not quite fo much raifed as the 
 bottoms of the capfules, which, though fup- 
 ported by their rims on a level with the top of 
 the furnace, have neverthelefs their bottoms 
 placed on a fmall bar (verguillon). This open- 
 ing may be fliut during the diftillation by a plate 
 of iron, or any regiiler whatever which does not 
 permit the accefs of air from without, except at 
 its lower part. The furnace, it may be perceiv- 
 ed, is portable, and on that account can be 
 placed in any part of the laboratory, as conve- 
 nience or new arrangements may require. 
 
 If, in order to anfwer any particular purpofe, 
 or without attending to expence, the preference 
 fhould be given to furnaces of baked earth, I 
 would then advife the ufe of fuch as have their 
 chimnies on the fide, without a dome. Many 
 furnaces of this kind have lately been conftrufted 
 at Paris, by Laffineur, rue Mazarine. Their 
 upper part, which is flat, and on a level with 
 the chimney, allows the placing of capfules ; 
 and the chimney, which is at the front, renders 
 it eafy to take out the wood or charcoal which 
 is put into a fire-place, provided with its alb- 
 hole in the fame manner as the other furnaces 
 which have a dome. This furnace is round, 
 portable, lefs coftly, and appears to rne to be, in 
 other refpedls, much more convenient than tha t 
 
 defcribed 
 
Cottons, Thread, &c, 9 
 
 defcribed in the Annals : befides which, they 
 may be made of any required fize. 
 
 2 = Inftead of the matrafs, the intermediate 
 veflel, and the tubes which communicate from 
 this laft veflel to the diftilhng and the pneu- 
 matic apparatus, I have fubftituted a tubulated 
 retort, to which I have adapted a recurved neck 
 of glafs or lead, the beak of which is placed and 
 luted to a fmall leaden fupport in the form of a 
 funnel j and this laft piece is adjufted to the end 
 of a tube, of the fame metal, within the pneu- 
 matic tub, whofe lower extremity is bended to 
 a right angle, and performs the office of the glafs 
 tube in the apparatus of Berthollet. This tube, 
 as w T ell as the additional neck of the retort, 
 may likewife be made either of pottery, ftone 
 ware, or, which is ftill better, of porcelain. 
 
 Inftead of the retort, and its neck of glafs or 
 lead, I have ufed, with no lefs but even with 
 more advantage, a body or bottle tubulated at 
 the fhoulder. Above the neck of this body or 
 veflel is applied a pipe, which at the fame time 
 forms the communication and the interior tube. 
 I (hall hereafter fliew the method of difpofing 
 this apparatus. 
 
 3. The pneumatic veflel, to which I adjuft a 
 cover, is divided into three parts by two falfe 
 bottoms, fixed in the veflel itfelf by means of 
 
 its 
 
I o The Art of Bleaching 
 
 its conical figure, or upon a hoop, or mafles of 
 wood, fixed with pins. I (hall alfo, in the pro- 
 per place, give an account of the manner of 
 fixing and difpofing thefe falfe bottoms, as well 
 as of other kinds of veffels, not without their 
 peculiar conveniences. 
 
 4. I have considerably diminished the lixivia- 
 tions and immcrfions. In the chapter which 
 treats of thefe fubjecis, it will be feen in what 
 manner I have proceeded in Amplifying thefe 
 important operations. 
 
 5. I mail alfo defcribe the method of compo- 
 fing two lutes, which I have found very ufeful ; 
 one made with the cake of linfeed, and the other 
 known in chemiftry by the name of fat lute. 
 The latter, though mere expenfive and difficult 
 to make, appears to me to deferve the prefer- 
 ence. 
 
 6. By fuppreffing the intermediate veflel, and 
 by the fubftitution of a retort or tubulated bot- 
 tle inftead of the matrafs, together with the re- 
 curved neck or tubes of lead inftead of the tubes 
 of glafs ; when once the connecting part is well 
 luted, in the manner hereafter to be defcribed, 
 no further trouble or inconvenience follows from 
 the lute?, becaufe there is but one to take care 
 of, namely, that of the beak of the neck placed 
 on the tube which pafles into the pneumatic 
 
 veflel. 
 
Cottons, Thread, &c. II 
 
 veffel. This lute being renewed, if thought fit, 
 at each diftillation, and a little attention being 
 paid to apply it well, is never found to fail. The 
 operator is, therefore, at liberty to employ his 
 time in the lixiviations and immerfions. It 
 will hereafter be feen in what manner I have 
 fucceeded in removing the danger of thefe im- 
 merfions. 
 
 In this early ftage of our defcription, it is 
 eafy to perceive how much lefs troublefome our 
 apparatus muft prove, than that to which we 
 have referred in the firft chapter. Neverthelefs, 
 as it is of confequence that the inhabitants of 
 the country, to whom my attention has been 
 principally directed in this work, mould be in 
 no refpect expofed to failure in the fraalleft par- 
 ticular, I (hall proceed to give the molt minute 
 accounts of the ufes and arrangement of the 
 apparatus j and, in the firft place, I mall treat of 
 the 'utes. 
 
 CHAP, 
 
12 Tie Art of Bleaching 
 
 CHAP. III. 
 
 The Compoftlion of lutes. 
 
 FAT LUTE. 
 
 JL HE obfervations I (hall offer on this parti- 
 cular lute are partly extracted from Baume's 
 Chemiftry. I have thought it proper to add 
 fome ufeful obfervations for the fake of besrin- 
 ners. Take any quantity of good grey or blue 
 clay : I have always found fullers-earth (iirgile 
 a foulon) excellent for the purpofe. The clays of 
 Gentilly and of Vanvres, near Paris, are Iikewife 
 very good. The clay is to be dried in thin cakes, 
 which may be fpeedily done in an oven after 
 the bread is drawn ; the dried clay is to be 
 pounded finely, and fifted ; a certain quantity of 
 this clay, together with a fufficient dofe of boiled 
 linfeed oil, rauft then be beaten in an iron or 
 bell-metal mortar for a long time, until the 
 fmalleft lumps have difappeared, and the whole 
 mafs ihall form a pafte, of an uniform colour, 
 rather folid and tenacious, but, neverthelefs, not 
 adhering to the hands: this is called fat lute. 
 
 A large quantity of this lute may be prepared 
 beforehand, more efpecially when the operations 
 
 are 
 
Cottons, Thread, &c. i* 
 
 are to be performed in the large way, and almoft 
 continually. That which has been made for a 
 twelvemonth is more pliant and better, but it 
 muft be kept in a cellar, in a covered earthen 
 pot. When it has become too dry to be 
 handled, it may be eafily foftened, by firft 
 warming it, and afterwards beating it in the 
 iron mortar, with as much of the boiled linfeed 
 oil as may be found neceffary. 
 
 The lute, which has ferved for one diftillation, 
 may be ufed again, after the burned or decom- 
 pofed parts have been feparated : thefe parts 
 may be known by the white or yellowifh colour, 
 and the dry or brittle confidence which the lute 
 illumes at thofe places. Lute which is worked up 
 again is fo far from being worfe, that it is more 
 flexible and tenacious. In this manner, the old 
 fat lute, or that which has already been ufed, 
 may be advantageoufly mixed with new lute. 
 It is particularly effential that the burned por- 
 tions mould be rejected from this mixture 5 if 
 this be not done, the lute will not dry as it 
 ought, and, fo far from being foft and flexible, it 
 will be harm, fhort, and continually difpofed to 
 give way, by flicking to the fingers. 
 
 When the quantity to be mixed, or kneaded 
 up again, is very fmall, the trouble of beating it 
 in the mortar may be avoided, becaufe the ope- 
 ration 
 
14 The Art of Bleaching 
 
 ration is performed very well, by kneading the 
 matter with the hands. For this purpofe, a 
 portion of the lute already kneaded in the mor- 
 tar, and foaked with oil, may be taken and 
 rolled in the veiTel containing the pounded and 
 fifted earth ; the portion of earth which adheres 
 may then be worked in ; and, by a repetition of 
 this manipulation, the mafs will fpeedily become 
 enlarged, and muft be ftrongly compreffed, rolled 
 out, and doubled again, until it is found that it 
 pofiefTes the requifite foftnefs and tenacity, and 
 does not crack when doubled. 
 
 If it mould happen that the lute mould become 
 too foft by excefs of oil, and clay is not at hand 
 to correct this fault, the mafs will foon acquire 
 firmnefs by expofing it to the open air upon 
 parchment, or upon a plate. It muft not be 
 laid upon paper, becaufe it is very difficult to 
 feparate this material entirely ; and if any parti- 
 cles mould remain, there would be reafon to fear 
 that, when incorporated in the mixture, they 
 would either prevent the perfect adhefion of the 
 lute, or would allow the paffage through that 
 kind of void, or pore, which the fragments of 
 paper would form. It is, moreover, to be re- 
 marked, that this lute cannot be too fmooth 
 and uniform. It ought not to afford any per- 
 ception of inequality when it is handled, or 
 
 kneaded> 
 
Cottons, Thread, &V. 15 
 
 kneaded, nor indicate the prefence of foreign 
 fubftances, fuch as fand, ftraw, earthy particles, 
 &c. which are capable of preventing the inti- 
 mate connection of its parts. 
 
 I ftrongly infift on the perfection of this lute, 
 becaufe it is the foul of diftillation. 
 
 Boiled linfeed oil is thus made : two pounds 
 of common linfeed oil being put into a faucepan, 
 or proper vefTel, of copper, iron, or pottery, add 
 three ounces of red litharge, finely powdered and 
 lifted ; after ftirring the whole well together* 
 place the vefTel on the fire, heating it gradually, 
 until the litharge is completely difTolved. It is 
 neceflary to ftir the mixture very frequently 
 with a wooden fpatula, until the whole folution, 
 which at firft acquires a brick-duft colour, is 
 completed : it is then to be removed from the 
 fire, and, when cold, transferred into a ftone or 
 earthen vefTel, and kept well corked. This is 
 the boiled linfeed oil above directed to be ufed 
 in making the fat lute. 
 
 When this oil, which is blackifh after boiling, 
 is well made, it congeals in the vefTel as foon as 
 it is cold. When it is required to be poured 
 out, it may be rendered fluid by bringing it near 
 the fire. To fave the trouble of heating it, it 
 may be poured, as foon as made, into a plate or 
 fhallow vefTel, or left in the vefTel ufed for boil- 
 ing 
 
1 6 The Art of Bleaching 
 
 ing it. It is feldom neceflary to heat it for the 
 mere purpofe of mixture ; the quantities re- 
 quired for this purpofe may be taken up with 
 the fingers, or in any other manner. 
 
 It is proper to obferve, that the veflel in which 
 the oil is boiled muft be fumciently high, to 
 afford a fpace for the fuelling of the fluid ; for, 
 as foon as the heat begins to ael:, it will rife 
 and overflow the veffcl, if particular attention 
 be not paid to it. As foon as this procefs 
 begins, the veffel muft inftantly be taken off 
 the fire, and the mixture ftrongly agitated by 
 plunging the fpatula in it, at the fame time 
 blowing ftrongly at its furface with the mouth ; 
 by which means the ebullition will be checked. 
 After this event lias happened two or three 
 times, it may with certainty be concluded, that 
 the oil will be fufficiently coniiftent to form a 
 good fat lute. By cooling, it immediately con- 
 geals, as has been remarked, to the confiftence of 
 plaifter, of a black colour, inclining to brown. 
 
 The lute made of linfeed oil cake is thus 
 made : 
 
 The cake is firft to be broken and pounded 
 in an iron or bell-metal mortar, and afterwards 
 fitted. through a iilken fieve ; ftarch is then to 
 be boiled up, to the confiftence of fize or glue ; 
 a fmall piece of this, being powdered with the 
 
 flour 
 
Cc:U;ts y Thread, &c. 17 
 
 flour of the oil-cake, is to be worked in a plate, 
 or with the hands ; more of the flour may then 
 be added, and the kneading continued until the 
 mafs is abfolutelv without any lump, or in- 
 equality, and its confidence has become nearly 
 the fame as that of the fat lute ; after which it 
 is to be kept in a plate, or covered wooden 
 bowl, in the cellar, for ufe. The fame care 
 mud be taken with this, as with the fat lute, not 
 to wrap it in paper, but in parchment, if thought 
 neceftarv. 
 
 This lute dries and hardens much on its outer 
 furface, which remains uninjured at the place 
 where it is applied; but it is decompofed more 
 fpeedily than the fat lute, on account of its 
 peculiar property to become hard and flirink 
 with a firong heat. In this ftate, in confe- 
 quence of the action of acids, it aflumes a yellow 
 colour, and is then good for nothing: it mull be 
 renewed. 
 
 A very good lute is likewife made with equal 
 parts of the flour of almonds, of linfeed, and of 
 itarch, kneaded together. It muft be under- 
 ftood, that the latter is to be boiled to the con- 
 fidence of ftarch. 
 
 To thefe different lutes we may add that 
 which is compofed of lime and white of egg, 
 
 c which 
 
1 8 The Art cf Bleaching 
 
 which has the property of acquiring a consider- 
 able degree of hardnefs. 
 
 Among all thefe lutes, that to which I have 
 conftantly given the preference, and is always 
 kept in fight in the prefent work, is the fat lute. 
 The lute of white of Qgg and lime, retained by 
 a cloth and a bandage, may be advantageoufly 
 ufed as a covering to the fat lute *. 
 
 The fat lutes adhere very much to the hands, 
 during the kneading, or working ; but it is not 
 difficult to wafli off the remains after the opera- 
 tion : nothing more is neceffary, than to ufe 
 warm water and foap, or foap leys, after having 
 previoufly wiped off the greater part with blot- 
 ting paper. 
 
 * Faujas de St. Fond, in his Voyage en Ecoue, mentions 
 the following lute, communicated to him by. the celebrated 
 Dr. Black, of Edinburgh. That chemift confrdered it as 
 impermeable to every fpecies of gas. 
 
 This lute is composed fimply of the pafte of almonds, in 
 the ftate it poffefles after extraction of the oil ; it is foftened 
 with a fmall quantity of water, in which glue ha<, been dif- 
 folved; the glue may even be difpenfed with.— Note of the 
 Author. 
 
 CHAP 
 
Co 1 tons, TBread, &?r. ig 
 
 CHAP. IV. 
 
 The Method of dt/pcfing the Apparatus for Dtf- 
 tillation. 
 
 T 
 
 IT has already been remarked, that our diftil- 
 ktion may be performed either in a retort, or 9 
 tubulated body or bottle. There can be no 
 difficulty in properly placing thefe veiTels. The 
 jun£Hon of the neck or tube, communicating; 
 with the pneumatic veflel, is the only obje£t 
 which requires particular care. The manner 
 of joining thefe two parts, by means of lute 
 alone, will be explained below. 
 
 As the ufe of the retort requires more atten- 
 tion with regard to its form, and the applica- 
 tion of the additional part, the following details 
 will be of ufe to prevent accidents. 
 
 When the retorts are new, and have not be* 
 ore been luted to any additional part, it is ad- 
 vifable either to rub a fmall quantity of warmed 
 wax on the parts where the lute is to be ap- 
 plied, that is to fay, the neck of the retort, as 
 well as the correfpondent part of the addi- 
 tional piece, or to fuffer a fmall quantity of 
 ftarch or pafte to dry upon thofe parts j without 
 
 c z this 
 
 fi 
 
20 The Ait of Bleaching 
 
 this precaution the lute could not be eafily ap- 
 plied ; it would Aide and roll upon the glafs in- 
 ftead of adhering. 
 
 Care muft afterwards be taken to fix round 
 the neck of the retort a mafs of lute, fomewhat 
 greater than is fuppofed to be neceffary to fill 
 the additional part to the place where it is to 
 be fixed, in order that by the forcing of that 
 piece upon the neck of the retort, the lute may 
 extend and apply itfelf more intimately. The 
 fame attention muft alfo be paid to the mafs of 
 lute, which is required to fecure the beak of 
 the additional piece in its connection with the 
 pneumatic apparatus. Thefe obfervations are 
 of more importance, in order that the two pieces 
 may, by this compreftion, be made to operate as 
 if they formed one entire vefTel. 
 
 To apply thefe lutes with eafe and conveni- 
 ence, the retort is to be held in one hand, in 
 fuch a manner as that its belly or lower part 
 may not touch or reft upon any thing whatever, 
 becaufe the flighted blow upon this very thin 
 part will break it. 
 
 Before the lutes are applied, care muft be 
 taken to introduce the neck of the retort into 
 the additional piece, and mark with lute or wax 
 upon the additional piece the place where the 
 extremity of the retort touches it internally; 
 
 and 
 
Cot 'ens, Thread, &ff. 21 
 
 and in like manner, on the retort itfelf, the place 
 where the extremity of the additional piece 
 touches its neck. By means of thefe marks it 
 is eafy to eftimate the thicknefs of the mafles 
 of lute, by placing the two veffels near each 
 other in the refpeftive portions they ought to 
 have when fixed. Laftly, they are united toge- 
 ther by Hiding the recurved additional piece 
 upon the neck of the retort, which is to be held 
 firmly by its neck, refting the hand on the 
 furrounding part, if the retort is (mall; or hold- 
 ing it by the recurved part, if it be large, or the 
 additional piece mould be too long and heavy. 
 The greateft attention muft be paid not to turn 
 the parts round, during this operation, more 
 than is abfolutely neceffary to bring them toge- 
 ther ; and if this can be done without any turn- 
 ing at all, it will be dill better, as the lute will 
 hold more effeaually. The neck of the retort 
 muft be entered into the additional piece as far 
 as it is capable of comprefling the lute, or nearly 
 to the marks made upon the pieces before they 
 were put together. In this fituation the lute } 
 which forms a mafs round the edge of the addi- 
 tional piece, muft be raifed fo as to cover both 
 furfaces, after having firft preffed it as firmly 
 as poffible into the joint; fmoothing it upon 
 the two pieces, fo as to prevent the fmalleft 
 
 c 3 opening 
 
22 The Art of Bleaching 
 
 opening or crack. It is advifable after all to 
 fpread a thin coating of the boiled linfeed oil 
 over the lute, which not only renders it fmoother 
 and more perfect, but by the denfity it acquires 
 from evaporation it forms a kind of varnifh or 
 pellicle, which fupports the late, and prevents 
 the fiffures which might be formed during the 
 actual operation. Whenever in the courfe of the 
 work the lute ihould appear too dry, it mull be 
 fupplied with a thin coating of oil. 
 
 While the lute is thus fpread and applied on 
 the external part of the additional piece and the 
 neck of the retort, the compound apparatus is 
 to be held by the additional piece only, and the 
 retort left to be fupported untouched in the air, 
 by its infertion at the neck only. 
 
 Inftead of luting the additional piece to the 
 retort, (imply at the extremity of th^ neck of 
 this laft, and at the place where the wider part 
 of that piece touches the retort, we might apply 
 the lute upon the whole furface comprehended 
 between thofe parts. But I have found that it 
 is fufheient if thefe two parts be made fecure. 
 A retort luted in this manner forms one fingle 
 and entire body with its additional neck ; and 
 with very little care and attention, the lute will 
 feldom or ever have occafion to be renewed 
 before one or two months' fervice. 
 
 The 
 
Cot tens, Thread, &u o§ 
 
 The tube on which the recurved additional 
 piece refts during the diftillation, and through, 
 which the gas is introduced into the pneumatic 
 tube, is, as I have remarked, entirelv of lead. 
 If i be not caft, it ougiu to be carefully joined 
 with ftrong folder ; and, for fear this lair mould 
 fail, it will be prudent to cove/ it with a coating 
 of yellow wax, pitch, or melted pitch. 
 
 At the beginning o^ my experiments, I made 
 thefe tubes of the fame fize as thofe of the ba- 
 rometer ; I afterwards had them of eight or nine 
 lines (| inch Engliih), and did not find that the 
 diftillation was lefs advantageous. The greater 
 diameter even feemed to be preferable, becaufe 
 the gas was tranfmitted with more facility, and 
 the abforption feemed to be more effectually op- 
 pofed. 
 
 That part of the tube (if foldered as before 
 mentioned) which pafifes under the lower falfe 
 bottom, ought to be carefully bended with -a 
 round corner, before it is coated with the wax 
 or pitch ; and in the bending it is fafer to caufe 
 the foldered part to lie within the angle. It 's 
 likewife proper to ftop the mouth of the tube 
 with paper, or a cork, during the time of wax- 
 ing or tarring, in order to prevent any introduc- 
 tion of thofe fubltances into its cavity, taking 
 care to withdraw this temporary (topper before 
 
 c 4 the 
 
24 The Art of Bleaching 
 
 the apparatus is applied to actual ufe. It is 
 not abfolutely neceflary to coat any other part 
 of the tube, but that which is to be placed 
 within the pneumatic apparatus, becaufe it is 
 eafy to fto.p any other part, out of which the 
 gas might iflue, with foft wax or lute. 
 
 The extremity of this tube, in which the re- 
 curved neck of the additional piece is to be in- 
 ferted, rauft have the form of a fmall funnel, net 
 only for the purpofe of affording the moft con. 
 venient fupport, and the more ready adaption 
 to the various fizes of thofe necks, but alfo be- 
 caufe it more readily fupports the only kind of 
 Jute which in this work we fuppofe to be ufed. 
 This lute is never deranged, if care be taken to 
 prefs it againft the internal furfaces of this fmall 
 funnel, and of the glafs or lead of the additional 
 piece, fo as to unite them as much as poflible, 
 it being always underltood that the lute is good, 
 and polTdTcs the properties before defcribed in 
 treating of that fubflance. 
 
 I have remarked that the ufe of the retort 
 with its additional neck might be difpenfed 
 with, by fimply ufmg a body or bottle with a 
 neck (even a wine bottle may be ufed in cafe of 
 neceflity, provided its bottom be either very thin, 
 or very gradually heated). In the orifice of the 
 neck of thefe veflels, is to be adapted a tube of 
 
 lead. 
 
Cottons, Tbread y Cifr. 25 
 
 lead, properly bended, and of a due fize. This 
 method is in fact very advantageous and eccmo 
 mical ; but care muft be taken to join the tube, 
 if it be of meet-lead, particularly in the parts 
 below the bottle which are liable to become 
 heated, a fhort time before the end of the diftil- 
 lation ; to join it, I fay, without folder, by 
 fufing the two edges together. For in procefs 
 of time the folder, though ever fo ftrong, yet 
 becaufe it contains tin, is liable to exceflive cor- 
 fofion by the oxygenated muriatic acid, which, 
 notwithstanding its heat, is not found to attack 
 lead in any perceptible degree. 
 
 But it may, perhaps, be more convenient to 
 caft fuch a tube at one heat, as well as the ad- 
 ditional piece in the apparatus, with the retort; 
 unlefs, indeed, it mould be practicable to have 
 it made of ftoneware or porcelain, the latter of 
 which is the leaft permeable to the gas. Or 
 we might, with more advantage, make ufe of a 
 thick tube of common glafs, which might be 
 eafily bended in a charcoal fire, and might be 
 adapted to the tubulated bottle, as well as the 
 leaden tube. But the danger of its breaking, and 
 the difficulty of procuring others in cafe of need, 
 together with the expence, have led me to reject 
 this, as well as the tubes of pottery or porcelain. 
 
 In order that the tube adapted to the neck 
 
 of 
 
a 6 The Art of "Bleaching 
 
 of the bottle may accurately fit, and prevent all 
 cfcape of the oxygenated muriatic acid, it is de- 
 fended by lute in fuch a manner, that it (hall 
 not be thruft into the neck of the bottle, with- 
 out extruding a portion of that fubftance; and 
 a border of luting muft then be applied round 
 the place of junction, which will effectually pre- 
 vent the efcape of any vapour which might ifTue 
 through the firir. luting. Laftly, the whole fur- 
 face of this external luting is to be fmeared 
 with boiled linfeed oil; after which the diftil- 
 latory apparatus may be confidered as perfectly 
 fecure. 
 
 If a tube of glafs be ufed, it may be fo adapt- 
 ed by grinding with emery as to fit the neck of 
 the glafs body, and require no luting. The 
 lame might be done v%ith a tube of porcelain, if 
 the material were fufriciently fine. 
 
 With regard to the other neck which I have 
 recommended, as well in the bottle as in the 
 retort, it ferves not only to introduce the mate- 
 rials when the leaden tube is previoufly luted in, 
 but likewife to admit the external air, if by 
 chance an abforption fhould be perceived to 
 take place ; that is to fay, if the water, by a 
 diminution of the heat, which leaves a kind of 
 vacuum, mould rife from the pneumatic appa- 
 ratus into the body: though even in this cafe 
 
 there 
 
Cottons, Thread, &c. 2T 
 
 there would be no reafon to fear its breaking 
 notwithftanding its being confiderably heated, 
 as at the end of the operation. I have expreftly 
 made the trial feveral times, and always with- 
 out any accident. The fluid becomes gradually 
 heated in its pafiage along the (ides of the tube 
 or neck of the diftiiling apparatus, before it 
 enters and mixes with the matter in the body 
 itfelf; and again, if the tubulated bottle and 
 tube be made ufe of, the water riling through 
 the latter and falling in the middle of that con- 
 tained in the yeffel, cannot directly touch the 
 fides before it becomes mixed. But, at all events, 
 if the fmalleft abforption be feared, it will be 
 fufficient to raife the Hopper and return it to its 
 place the inftant after the introduction of the at- 
 mofpheric air. Inftead of a glafs Hopper, a cork 
 may be ufed, which muft be carefully luted 
 round the neck, if there be any reafon to think 
 that the vapour mould find its way through, in 
 confequence of the neck being not perfectly 
 round. 
 
 With regard to the pneumatic veflfel, the fol- 
 lowing is the method of placing and fixing the 
 falfe bottoms. (See plate I. and If. and plate 
 IX. figs, i, 2, 3, 4, 5, and 6.) 
 
 A common wooden hoop is plained flat on 
 the fide which is to bear the falfe bottom, and 
 
 fixed 
 
28 The Art of Bleaching 
 
 fixed within the caflc with pegs which do not 
 pafs quite through the ftaves. The falfe bot- 
 tom, fecured together by two dove-tails, is plac- 
 ed upon this hoop, and fixed there by fimilar 
 pegs, which penetrate part of the bottom it- 
 felf, and by that means prevent it from either 
 rifing or turning. The cavities between the 
 falfe bottom and the fides are then to be clofed 
 round with caulker's fluff {brai fa), or melted 
 pitch. It mull' be remembered, that the verti- 
 cal axis with its crofs arms is to be placed be- 
 neath each falfe bottom. The arms are fixed in 
 a mortice by means of two pins, which prevent 
 them from vibrating or getting loofe. The 
 leaden pipe in which the extremity of the addi- 
 tional neck is to be inferted. is not to be put 
 into its place till the firft falfe bottom is immove- 
 ably fixed. A notch is fuppofed to have been 
 cut in this bottom to admit the tube; and when 
 it is duly placed, the vacant fpace is to be made 
 good, firft with tow and then with melted 
 pitch. 
 
 Inftead of the wooden hoop, which affords a 
 folid fupport for the falfe bottom, it may anfwer 
 the purpofe very well, if cleats or blocks of 
 wood, three inches thick, be pinned on, at dif- 
 ferent parr> of the circumference ; or, which is 
 ftill better, if the trouble be taken to fit the 
 
 falfe 
 
Cottons, Thread, &cj iy 
 
 falfe bottom fo well, that it may bear fimply 
 upon the inclination of the ftaves, which natu- 
 rally oppofe its defcent. This method would 
 certainly be the quickeft, and is not very dif- 
 ficult to be done. 
 
 When the falfe bottom is thus fixed, it muft 
 be retained in its place by pins placed at certain 
 diftances, and afterwards made tight by caulk- 
 ing. 
 
 In order that the tube may not be expofed to 
 vary in its pofition, a mark muft be made on 
 the edge of the funnel which terminates one of 
 its extremities, by which it is eafy to afcertain 
 the pofition of the bended part below, and place 
 the fame in the moft favourable fituation. It. 
 will be convenient to fix the pipe in this pro- 
 per fituation, by means of two pegs, which 
 muft be drawn out previous to the laft fixing of 
 the falfe bottoms. 
 
 When the firft or lowed falfe bottom is fe- 
 cured in its place, the fecond arm of the agita- 
 tor is to be faftened to the axis, and the other 
 falfe bottom is to be placed and made faft in the 
 fame manner as the firft. 
 
 It is particularly neccffary to place thefe two 
 partitions in fuch a manner, as that the holes of 
 communication may not be in the fame vertical 
 line, but as far as poftible from each other, that 
 
 is 
 
30 The Art of Bleaching 
 
 is to fay, diametrically oppofite. This diipofw- 
 tion is neccfTary in order that the gas may have 
 time to concentrate in one part, before it ef- 
 capes to the other. For the fame feafon, it is 
 proper to direct, the lower opening of the leaden 
 tube to that extremity of the diameter which is 
 oppofite the pipe of communication from the 
 firft to the fecond bottom, in cafe one diftilling 
 vefTel only is ufed. If two or more communi- 
 cate with each pneumatic apparatus, the open- 
 ings of the tubes muft be refpecYively difpofed 
 at equal diftances, as far as pofiible from each 
 other, and from the opening in the falfe bottom 
 next above them. 
 
 If inftead of falfe bottoms the preference 
 fliould be given to inverted tubs [cuvettes), the 
 following method mav be ufed to make the rims 
 or tides, and to fix them immoveable. (See 
 plate IX. fig. i, 2, 3, 4, 5, and 6.) 
 
 The rim may be made in two ways ; either 
 by fhort ftaves, fixed with wooden hoops as 
 ufual, fcarfed or hooked together at their two 
 extremities, or tKe, by fimply fixing a broad 
 wooden rim. like that of a fieve, round the bot- 
 tom of this inverted vefTel, by means of fmall 
 wooden pins with heads. 
 
 Eoth thefe methods are good. The fecond 
 has the advantage of taking lefe room and being 
 
 cheaper. 
 
Cottons , Thread* <3c. 3 1 
 
 cheaper. If this method be ufed, the points 
 of the pins muft be made a little thicker than 
 the ilem, in order that they may be lefs difpofed 
 to draw out of the holes bored in the bottom. 
 With regard to the joining of the two ends of 
 this kind of broad hoop, it may be effected very 
 firmly by fewing them together with a fiat ftrip 
 of ofier, as is done in the better fort of chip 
 boxes, or it may be very well managed by 
 means of two pins with heads, which may be 
 driven through the overlapping part, and fe- 
 cured at the other fide by driving a fmall wedge 
 into the tail of each pin. With regard to the 
 empty fpaces or openings which may be be- 
 tween the rim and its bottom, they muft be 
 flopped with glaziers' putty (mafiii du vitrier), 
 which may be fmooihed with oil. This putty 
 is of excellent fervice when the muriatic acid is 
 ufed without potafh j but it is foon deftroyed if 
 potafh be put into the pneumatic veffel. \n 
 this cafe the internal part of the places of junc- 
 tion muft be pitched or caulked, as has been 
 already fhewn. 
 
 The method of making thefe inverted velTels 
 with Haves and hoops, has the advantage of 
 being clofe, and not requiring any particular 
 caulking. 
 
 Laftly, inftead of thefe inverted veffals, the 
 
 operation 
 
32 Tic Art of Bleaching 
 
 operation may be performed merely by flat 
 beards without rims, provided, however, that 
 the upper board be fome inches broader on 
 everv fide than the lower, in order that the bub- 
 bles of <ras may be forced in their afcent to 
 ftrike each board in fucceilion, and remain for a 
 fhort time in contact with it. The effential 
 circumflance in this arrangement will be to 
 keep the upper part of the vefiel well clofed, 
 which is to be defended at the hole which ad- 
 mits the axis of the agitator by a central tube 
 to retain the gas ; and the partial efcape which 
 might take place between that axis and the 
 covering, mult be more effectually prevented by 
 a cloth foaked in alkaline lees. This method, 
 betides its convenience, requires lefs care in fix- 
 ing, but it renders it necefTary to work the agi- 
 tator more frequently, in order to haften the 
 abforption of the gas in the water. I have de- 
 termined to relate all the methods which I have 
 fuccefsfully praclifed, in order that thofe who 
 may undertake any work of this nature, may 
 determine for themfelves, not only with regard 
 to general motives of preference, but likewife 
 the facility with which their own fituation.or 
 circumftances may enable them to carry the 
 fame into execution. 
 
 The next object is to fix thefe inverted vefTels 
 
 in 
 
Cottons, Thread, &c» 32 
 
 In the pneumatic apparatus. This is a very 
 iimple operation, and confifts merely in fixing 
 pieces of wood or brackets, three inches in 
 length, under each of the two bars which con- 
 heel: the pieces of the bottoms of the inverted 
 vefTels together. The bracket pieces are fatten- 
 ed to the fide of the veffel with oak pegs, and 
 the crofs-bars which reft upon them are fecured 
 by pins of the fame material driven above them 
 and on each fids, in fuch a manner that the 
 central perforation is in its true place, and the 
 whole is incapable of being removed or dif- 
 turbed. 
 
 In this operation, as I have already recom- 
 mended with regard to the falfe bottoms, it is 
 advifable to place the revolving axis in its pro- 
 per fituation, in order to afcertain that it is not 
 likely to be impeded in its action, It is bell, 
 indeed, to avoid fixing either the two inverted 
 vefTels or the two falfe bottoms, if thefe be ufed, 
 until the clear movement of the agitator has 
 been afcertained ; without which precaution, 
 there might probably be occafion to difplace 
 them, either in whole, or in part, to remove 
 the impediments which might prevent the free 
 motion of the parts. 
 
 From the defcription I have here given, it 
 may be feen that my pneumatic vefTels have 
 
 d only 
 
3 4 The Art of Bleaching 
 
 only two falfe bottoms or inverted veflels. I 
 think it advifable not to ufe more, becaufe I 
 have remarked that three cf thefe veflels requir- 
 ing a greater depth, the diftillation became 
 much more laborious, particularly when I made 
 ufe of the intermediate apparatus. *i. The lutes 
 did not fo well refift the preflure of the vapour. 
 i. It was not difengaged with the fame fpeed, 
 and confequently the operation was more tedi- 
 ous. It is better, therefore, to ufe ihallower 
 veffels, and enlarge their dimenfions in the dia- 
 metral direction, as I have conftantly founds 
 The proportions which have appeared to me to 
 be advantageous for a fmall common workfhop, 
 are i \ foot in height, 32 inches in diameter be- 
 Jow r , and 36 inches diameter above, all infide 
 meafure. 
 
 With regard to the kind of wood for con- 
 tracting the veflels, it has appeared to me to be 
 a] molt a matter of indifference. I ufed fir, oak, 
 and cheftnut, without obferving that either the 
 one or the other were productive of any incon- 
 venience to the quality or clearnefs of the liquor, 
 imlefs that, at the nrfl or fecond diftillation, the 
 degree of force was a' little altered, by foaking 
 into the wood. That kind of wood may, there- 
 fore, be ufed which can the moft readily be pro- 
 cured. I muft, however, obferve, that the large 
 
 calks 
 
• Cottons, Thread, &V. 35 
 
 calks in which oil is brought from Languedoc, 
 which are moftly made of cheftnut-tree, are very- 
 convenient when cut in two to form the pneu- 
 matic veffels. They have even an advantage 
 over the oak and fir cafks, becaufe they are 
 clofer in the joints, better hooped with iron 
 and wooden hoops, and impregnated with the 
 oil, in confequence of which they are not fub- 
 je£t to become dry, how long foever they may 
 be out of ufe, provided they are kept in a clofe 
 place ; whereas the tubs of fir wood require to 
 be aim oft conftantly filled with water. Oak 
 does not contract fo foon as fir. 
 
 It muft alfo be obferved that the white deal 
 muft not be ufed, becaufe it tranfmits water like 
 a fponge. The yellow deal is to be preferred, 
 becaufe it undergoes lefs alteration from the 
 fluid, no doubt on account of the refin it con- 
 tains. But if the ufe of the white deal, or 
 any other fpongy wood cannot be avoided, it 
 will be proper to paint the veffel within and 
 without with one or two good coatings of white 
 lead. I have had the great fatisia£tion to ob- 
 ferve, that this treatment not only prevents the 
 water from palling through, but likewife that 
 the oxygenated muriatic acid does not attack 
 this colour, or if it does attack it, a long courfe 
 of time muft be required for that purpofe. 
 p 2 Melted 
 
36 The Art of Bleaching 
 
 Melted pitch or tar likewife afford a good de- 
 fence for fuch wooden materials as have this de- 
 fect. A mixture of vellow wax and refin is 
 likewife of excellent fervice as a coating for the 
 whole internal furface of the pneumatic veffcl, 
 including the inverted veffels and the aqifa fc or. 
 
 Befides the falfe bottoms, or inverted vc-fiels 
 we have defcribed, each apparatus rni owife 
 
 have its cover chamfered, to fit the hfer- 
 
 ence, with apertures to admit the tul. the 
 
 central axis; together with two other.,, n at&efr, 
 one of confiderable fize, to receive a funnel 
 through which water is poured as occal on re- 
 quires, and the other fmaller, to be opened on 
 fuch occallons, in order that the air may efcape. 
 The cover being nailed, or rather fattened with 
 wooden pins, in its place, is afterwards fecured 
 by glueing Hips of paper over the line where it 
 is applied to the veflel. 
 
 Inftead of the wooden pneumatic veffel, it 
 might be more advantageous to ufe fimilar 
 veflels of grit-ftone (gres), rolled or caft-lead, or 
 cement of loriot *. Manufacturers mufl form 
 
 an 
 
 The author does not appear to fpeak from experience in 
 fhis place. It is not probable that any manufacturer would 
 be tempted to incur the expence of fione veflels ; but it is 
 neverthciefs proper to remark, that every (lone which could 
 
 with 
 
Cottons* Thread, &rV» 37 
 
 an eftfmate of the advantages to be derived 
 from the expences they incur. If leaden vef- 
 fels be ufed, it will be proper to defend the 
 fo 1 Wed places with one or more coats of white 
 leadi or putty, or refin, or pitch mixed with 
 bees-wax. I have tried thefe prefervatives 
 againft the deftru&ion of the folder, and found 
 them anfwer very well. 
 
 As it is ufeful to poffefs a knowledge of the 
 height and quantity of water contained in the 
 tub, there is a tube of glafs fixed againft its 
 outer fide, the lower end of which is bended 
 and enters the vefTel about five or fix inches 
 from its bottom. This part, into which the 
 tube is ftuck by firm prefTure, is to be previoufly 
 defended by lute, which is afterwards trimmed 
 •and laid fmooth upon the fides of the tube and 
 1he vefTel. 
 
 Laftly, as it is efientially neceiTary to afcer- 
 tain, from time to time, the flrength of the 
 liquor, and to draw it off upon occafion, I have 
 ufefully availed myfelf of a brafs cock, covered 
 with feveral coatings of white lead for this pur- 
 
 with facility be wrought, contains lime or clay, or both ; the 
 former of which would no doubt be fpeedily corroded by the 
 liquor, on which it would alfo have a pernicious effect. It 
 is not likely that clay would be more durable. So that on the 
 whole there is no temptation to ufe, and many reafons to rejefl, 
 the earths. — T. 
 
 d 3 ^ pofe. 
 
3 S The Art of B Je aching 
 
 po r e. By means of this cock, it is eafy to draw- 
 oft any fmall quantity of the fluid at pleafurei 
 It has likewife the advantage of readily rilling 
 the narrow-mouthed (lone- ware, or glafs vefTels, 
 in which the liquor may be kept when there 
 may be any to fpare, or in cafe it is thought fit 
 to pre er- e a quantity always in readinefs. 
 
 When it is required to draw off the acidulated 
 water with fpeed and in abundance, it is con- 
 venient to ufe one or more wooden tubes or 
 fpigots, which may be opened feparately, or all 
 at once, into appropriate veffels. But it is moft 
 convenient that they mould have ftoppers of 
 cork only, becaufe thofe of wood, though covered 
 with tow, are very apt to burft the wooden tubes 
 by their fwelling ; befides which they very fel- 
 dom fit with accuracy, unlefs turned with ex- 
 traordinary care. 
 
 With regard to the intermediate vefifels men- 
 tioned in the Annales de Chimie, in cafe the 
 operator is determined to ufe them, it is proper 
 to avoid ufing ftoppers of cork to clofe the 
 orifices, and fupport the tubes at the fame time. 
 For this fubftance being very fpeedily afted 
 upon by the corrofive gas, expofes the lutes 
 and clofures to frequent derangement, as well 
 as the tubes which pafs through them. At the 
 beginning of my operations, I fupplied the place 
 
 of 
 
Cottons, Thread, &c. 39 
 
 of thefe Hoppers as follows, when the necks 
 were of a larger diameter than the tubes. I 
 made Hoppers of glafs, with flanches on the 
 fides. Thefe were ground with emery upon 
 the necks themfelves, and they were perforated 
 quite through with a hole, no larger than was 
 proper to admit the paflage of a glafs or leaden 
 tube. This tube was coated with lute of fuf- 
 ficient thicknefs, that it could not pafs through 
 the hole without forming a protuberant piece, 
 which I prefled and fmoothed againH the tube 
 as well as the orifice. Or if the Hoppers of 
 cork fhould, neverthelefs, from convenience be 
 chofen, the necks may be covered with lute, 
 and the Hoppers forced in. In cafe the interval 
 be fmall, the parts may be heated a little, co- 
 vered with virgin-wax, and then forced into the 
 neck, and the fmall vacuities which may re- 
 main may be filled up with the fame wax, 
 melted and poured out of a fpoon. Inftcad of 
 lute, yellow wax may alfo be ufed to fix the 
 tube of fafety ; and the fame operation may be 
 performed with regard to the glafs or leaden 
 tube, which communicates from the tub to the 
 intermediate veffel. Stoppers and tubes luted 
 in this manner, are, in fome meafure,, fixed for 
 ever ; for when the wax is once hardened, they 
 are in no further danger. 
 
 D4 If 
 
4© The Art of Bleaching 
 
 If the operator be fo fituated, that he can 
 order the intermediate veflels of whatever 
 form he chufes, it will be advifable to have 
 the orifices of no greater diamerer than juft 
 to fuffer the tubes to pafs through. No other 
 defence will then be neceflary, than that they 
 Ihould be covered with lute at the time of 
 placing them, which will render them fuf- 
 ficiently firm. The rim, or border of thefe ori- 
 fices, ought like wife to be large enough to fup- 
 port the mafs of lute which it is proper to ap- 
 ply round the tube. 
 
 It may not, perhaps, be impoffible, that fkil- 
 ful workmen, of which there are many at the 
 glafs houfes, mould execute tubulated retorts 
 with a recurved neck, in the form of an adopter. 
 Such veffels would be particularly convenient. 
 The tubulated bottles exhibited in fig i and 2, 
 plate IX, may be fubflitufed inftead of retorts, 
 with the greateft advantage. In my lateft ope- 
 rations on bleaching, I have always preferred 
 them, becaufe mere convenient,' lefs coflly, and 
 lefs fubjeft to accidents. 
 
 As it is of utility to know the method of 
 grinding the ftoppers here defcribed, as well as 
 thofe of the tubulated retorts or bottles which 
 may be wanted, becaufe the ftoppers are ufually 
 fold in the original rough ftate, at fuch works as 
 
 arc 
 
Cottons, Thread-, &c. 45 
 
 are not in the vicinity of glafs grinders, and con- 
 sequently cannqt be ufed in the works we have 
 defcribed, I fhall point out the method I have 
 made ufe of. The tool which I have conftrucled 
 for this purpofe, plate II, fig. 1, confifts merely 
 in a kind of vice or clams, in which the nob of 
 the ftopper may be fixed, and of which the 
 handle being inferted in the centre of a brace, 
 receives and communicates the rotatory motion 
 imprefled upon this laft by the hand. 
 
 As the orifices, neither of retorts, bottles, 
 &c. nor of their (toppers, are accurately round, 
 it is neceflary, in order to reduce the firft irre- 
 gularities, that a kind of ftopper made of iron 
 fhould be ufed in the firft place before the ftop- 
 per itfelf. Common fand-ftone, powdered and 
 lifted, may be ufed in the firft place, and after- 
 wards fine fand which has been lifted through a 
 clofer fieve ; or otherwife the fand may be ufed 
 firft, 'and when the whole internal face of the 
 neck has loft its polifh, it muft be ground a 
 ihort time with fine fifted or warned emery. 
 If fand or grit-ftone cannot eafily be procured, 
 emery of different degrees of finenefs may be 
 made ufe of. Care muft be taken to wet the 
 ftopper from time to time before it is covered 
 with fand, or to drop it from a fpoon with one 
 hand, between the ftopper and the neck, while 
 
 the 
 
az Tie Art of L 
 
 the other is employed in turning th2 brace. ft 
 is Jikewife neceflary to wet the ftopper -when 
 the grinding matter is too party, or the rotation 
 takes place by (tarts. If this be not attended 
 to, there will be great danger of breaking either 
 the ftopper or the tube. 
 
 This method of grinding is expeditious enough. 
 A quarter of an hour, or half an hour at moft, 
 *s fufficient for each (topper ; but if greater ex- 
 pedition be required, it will be neceflary that 
 two perfons (hould apply to the work, one to 
 turn, while the other applies the grinding ma- 
 terials and water. 
 
 CHAP. 
 
Cottons, Thread, £?r. 43 
 
 CHAP. V. 
 
 Preparation of the Materials, 
 
 JL HE knowledge of difpofing the diftilling 
 apparatus to the greateit advantage, is not the 
 only point in which thofe who are defirous of 
 praclifing this new method of bleaching, with 
 the oxygenated muriatic acid, fhould be in- 
 ftrucled. It is very effential to prepare the ma- 
 terials for producing this acid, which are, as is 
 well known, the muriate of foda, manganefe, 
 and the fulphuric acid, or (imply the muriatic 
 acid and manganefe. But this laft mixture is 
 lefs convenient to be obtained, and is likely to 
 prove expenfive, if the manufactory be not (o 
 Situated as to obtain the acid at a low price. 
 I fliall therefore fpeak at length of the firft mix- 
 ture only, and fliall (imply obferve, with refpecl 
 to the fecond, that there is no ri(k when it is 
 ufed of breaking the diftilling veffels by the 
 drying, and the incruftation of the materials; 
 and alfo that the vapour'of the muriatic acid, 
 when poured out, is particularly offenfive and 
 injurious to refpiration. It is likewife lefs eafy 
 to procure the muriatic than the fulphuric acid, 
 
 becaufe 
 
44 T&e Art of Bleaching 
 
 becaufe' the fabrication of this laft in France 
 is more widely eflablilhed. 
 
 The proportions of the mixture of muriatic 
 acid and manganefe, which I found to anfwer 
 very well, are five ounces and a half or fix 
 ounces of cryftallifed manganefe to one pound 
 of the acid; that is to fay, about two pounds 
 and a half of manganefe for (even pounds of 
 the muriatic acid at 25 °. This is the propor- 
 tion fuitable to the pneumatic veflel, of which 
 the capacity has been already defcribed. 
 
 The grey muriate of foda * dried on an iron 
 plate, in the part of the furnace defcribed in a 
 preceding chapter, and ftirred from time to time 
 till it appears white, is to be pounded and fifted 
 through a fieye ot moderate finenefs. It is efTential 
 that this fliould be done, in order that it may mix 
 more intimately with the manganefe, without 
 which the fulphuric acid could not decompofe 
 it with the fame facility, and a lefs quantity of 
 gas would be produced. The diftilling veflel 
 being likewife flrongly heated towards the end 
 of the diilillation, there would be reafon to fear 
 that the coarfe fait might fall more fpeedily to 
 
 * The regulations of the fait duties in Great Britain are 
 fuch, if I miftake not, as prevent this coarfe fait from being 
 ufed in Great Britain. T. 
 
 the 
 
Cottons, Thread, (3c. 45 
 
 the bottom than the manganefe, and form a 
 cruft which would endanger its breaking. 
 
 The observations here made with regard to the 
 grey muriate of foda, are equally applicable to 
 the white muriate. 
 
 The manganefe muft alfo be pounded very 
 fine, and fifted through the fame fieve as the mu- 
 riate. The good quality of this mineral fub- 
 ftance is known from its cryftallization, in 
 fine brilliant needles (lightly adherent to each 
 other. Not that it is to be fuppofed that the 
 other kinds may not produce as much oxygen, 
 buc the cryftallized fpecimens are to be preferred- 
 For it is more eafily pounded, is ufually more 
 pure, and lefs difficult to be cleared of quartz, 
 fpar, &c. and likewife, from its cryftallization, it 
 prefents a larger furface to the action of the 
 acid. 
 
 The white muriate of foda has not appeared to 
 me to be preferable to the grey. It is true that it 
 contains lefs impurity, but it likewife contains 
 an equal quantity of water, and is dearer. The 
 grey muriate of foda, on the contrary, befides its 
 being much cheaper, contains a certain quan- 
 tity of muriate with an earthy bafis, which let- 
 ting go its acid at a certain heat, fuch as takes 
 place towards the end of the diftillation, permits 
 
4^ The A; t cf Bleaching 
 
 the operator to ufe a lefs quantity of fulphuric- 
 acid to decompofe the muriate of foda. 
 
 The fulphuric acid, if it be purchafed in the 
 rectified ftate, ought to mark at leaft 6c° below 
 Zero, on the Areometer for falts and acids of 
 MofTy, which is the inftrument I fhall always 
 refer to in the courfe of this memoir *. As it is 
 neceffary to dilute the acid with its own weight 
 of water, which then caufes it to mark about 38 
 or 40 , it would be much better either to make 
 it of this ftrength at firfr, or to procure it with- 
 out being rectified, becaufe, as Berthollet well 
 obferves, it would be ready for ufe, and lefs ex- 
 pensive in the charges of rectification and car- 
 riage. 
 
 If the rectified fulphuric acid be ufed, it is pro- 
 per to obferve that the acid muft be poured into 
 the water, and not the water upon the acid, on 
 account of the heat and efTervefcence which is 
 produced by the mixture. Thefe are much \eh 
 in the firft cafe. It is advifable, moreover, in the 
 mixture of thefe two liquids, to pour the acid 
 gently, and along the fides of the glafs at two 
 
 * I have not been able to learn the principles upon which 
 this inftrument is conftructed. It is much to be regretted 
 that instruments for afcertaining fpecific gravities, are not 
 conftantly made to denote the numbers in the ufual tables 
 where water is taken as unity,— .J*. 
 
 or 
 
Cottons, Thread, &c. 4y 
 
 or three different times, with an interval of fe- 
 veral minutes, taking care to turn the face on 
 one fide, to avoid the drops which may fly- 
 about. As the union of thefe two fluids pro- 
 duces, in a very fhort time, fuch a degree of heat, 
 that it becomes impoflible to touch the bottom, 
 of the veffel with the hand, it is bed to make 
 the mixture in veffels of (tone-ware, or earth 
 well baked, with handles, and a neck, if it be 
 poflible to procure them of this kind, in order 
 that they may be lifted with eafe and conveni- 
 ence, when it is required to pour the diluted 
 acid upon the mixture of muriate and of man- 
 ganefe in the diftilling veffels. Common earthen 
 veffels may be ufed, but they are more readily 
 penetrated by the acid, which fplits and de- 
 compofes them in procefs of time. 
 
 The proportions, according to which I would 
 advife the procefs to be performed with the 
 greateft fpeed and economy of time, are four 
 pounds of muriate of foda, twenty ounces of 
 cryflallized manganefe * (lefs of this being re- 
 quifite than of fuch as is not cryflallized), and 
 forty-four ounces of fulphuric acid at 6o°, di- 
 
 * Our beft mangarrefe is brought from the duchy ofDeux- 
 ponts, from a place named Hombourg ; it is ufuaily mixed 
 with quartz and other matters.— -Note of the Author, 
 
 luted 
 
4S The Art of Bleaching 
 
 luted with three pounds and a quarter of water. 
 I have fometimes ufed only forty ounces of 
 water, and did not find the operation the lefs 
 effectual. Thefe proportions are adapted to a 
 veffel containing fourteen vefTels of water, each 
 containing fixtcen Paris pints, and the materials 
 are expofed to diftillation in a retort, one foot 
 in height from the lower part of its neck, and 
 eight inches in diameter or width in its body *. 
 I muft obferve befides, that the moft elevated 
 retorts are to be preferred, becaufe their roof 
 and necks are lefs liable to be heated, and the 
 lutes on that account are lefs liable to crack 
 or be decompofed. The bottles, or tubulated 
 balloons to be ufed inftead of the retorts, mould 
 have nearly the fame proportions. Inftead of 
 white glafs, the common green bottle-glafs may 
 be ufed with almoir. equal advantage. For 
 though it is lefs tranfparent, it is always fuf- 
 ficiently fo to allow the operator to fee what 
 pafles within the veffels. The only change fuch 
 veflels will undergo is, that the bottom, which 
 ought to be chofen thin, is liable to be decom- 
 pofed, or converted into the porcelain of Reau- 
 
 * This height is neceflary, in order that one third, or one 
 fourth part at leaft, may remain for the fwelling or effervef- 
 cence of the contents, — Note of the Author. 
 
 mur, 
 
Cottons, Thread, &c. 49 
 
 mur, if the muriate of foda fhould encruft the 
 bottom fo as to leave no humidity between 
 them. But this change does not render them 
 lefs ferviceable. 
 
 The prefent is certainly the place to fpeak of 
 the attempt I have made, to procure the fulphu- 
 ric acid without the intermedium of nitre, and 
 to defcribe the apparatus I made ufe of for that 
 purpofe. It confifted of a pitcher or pot of 
 ftone-ware, perforated at bottom, the neck 
 of which communicated with two fmall two- 
 necked glafs bodies connected together, and 
 each half filled with water. Under each of 
 thefe glafs vefiels was lighted charcoal, to keep 
 the water in a ilate of evaporation, and under 
 the earthen pot there was likewife fire to heat 
 and enflame the fulphur, which was put into 
 the pot through the opening oppofite the neck. 
 This opening, which draws in the external air 
 for the combuilion of the fulphur, was clofed 
 with a ftopper, perforated like the nozel of a 
 garden-pot. 
 
 The fulphur, thus enframed, foon filled the 
 vacant part of the glafs veffels with its whitiih 
 cloudy vapour. This vapour, meeting that of 
 the water, combined with it, and fell in acidu- 
 lous drops on the lower water, over which the 
 
 e vapour 
 
$0 The Art of Bleaching 
 
 vapour of the fulphur circulating for a time, docs 
 alfo probably combine with it to a certain point. 
 Another proof that this condenfed water did 
 combine with the vapour of the fulphur is, 
 that the fame vapour, received in drops beyond 
 the fecond glafs vefTel by means of a recurved 
 adopter, came out in the acid ftate, reddening 
 the tincture of turnfol, and effervefcing with 
 alkalis when concentrated. I have twice re- 
 peated this experiment with fuccefs, and with 
 fcarcely any inconvenience. 
 
 I likewife attempted to burn fulphur and 
 heat water, in two feparate veffels communi- 
 cating with a third. The two vapours com- 
 bining together in the receiving vefTel, likewife 
 produced by their condenfation a fluid, which 
 afforded the fame indications of acidity as that 
 of the former experiment. 
 
 When fulphur was burned in an earthen 
 vefTel, and its vapour communicated into an 
 earthen jar, in which water almoft boiling was 
 poured, the refults were the fame. 
 
 It is probable that if thefe experiments were 
 repeated more at large, with a fuitable ap- 
 paratus, a longer feries of glafs veffels, and 
 proper furnaces, the fuccefs would be more 
 complete. I intend at forne future time to re- 
 fume 
 
Cottons, Thread, &c, 51 
 
 fume this procefs, and fliall haften to commu- 
 nicate my fuccefs to the public, if fuccefs mould 
 attend my endeavdurs *. 
 
 * Chaptal made a great number of experiments in the 
 large way, for the purpofe of difcovering the means of acidi- 
 fying fulphur, without the expence of nitre. Upon the whole 
 they were unfuccefsful. The manufacturer who may be 
 difpofed to enter into this refearch, is advifed firft to read 
 Chaptal's paper in the Annales de Chimie, II. 86. or the full 
 abflraft of the fame paper in my dictionary of Chemiftry, 
 art. Sulphur. T. 
 
 E Z 
 
 CHAP. 
 
5* The Art of Bleaching 
 
 CHAP. VI. 
 
 'The DiJlHlation. 
 
 JL HERE arc two methods of making the oxy- 
 genated muriatic liquor, namely, with fmell and 
 without. Each has its advantages and incon- 
 veniences. I fhall defcribe both methods, be- 
 gining with the liquid which has fmell. 
 
 In the firfl place, we mutt fuppofe the cover 
 of the wooden vefTel to be fixed with its pegs, 
 and pafted round with (trips of paper. For this 
 laft purpofe, the pafte of wheat flour is prefera- 
 ble to ftarch, becaufe more tenacious. 
 
 The wooden vefTel mult alfo be fupplied with 
 river w r ater, either before or after the patting of 
 the flips of paper, which feldom require to be 
 renewed. The water in the tubs, of the fize 
 already defcribed, muft rife to the height of 
 about fixteen inches, or within an inch or two 
 of the top, which may be eafily known by the 
 index tube on the outfide. Every inch in vef- 
 fels of that fize anfwers nearly to fixteen Paris 
 pints (or very nearly the fame number of Eng- 
 jifli quarts). 
 
 Whenever this vefTel is filled with water after 
 
 the 
 
Cot I oris, Thread, &c. 53 
 
 the covering is fixed and clofed, whatever may 
 be its construction, it is of importance, that the 
 fmall aperture in the covering, near that pro- 
 vided for the infertion of the funnel, mould be 
 unclofed, to permit the efcape of the internal air. 
 This is the more efTential (though the hole may 
 be a mere gimlet hole), particularly in the 
 conftru&ion with falfe bottoms,: becaufe the 
 ftream of water being conftant, when once 
 the lower partition is filled, if the air above 
 the fecond cannot efcape, the water, inftead of 
 entering the veflel, will be driven back beneath 
 the flips of paper, or along the axis of the agi- 
 tator. 
 
 When the veffel is filled with water to the 
 proper height, the retort muft be placed in its 
 bed, upon a thicknefs of half an inch at moft, of 
 fine fand or dry fifted allies, and the neck of its 
 adopter muft be adjufted in the funnel of the 
 leaden tube. The retort is then to be fteadily 
 fixed by pouring fand round it, to fill the vacant 
 fpace between it and the capfule of the furnace. 
 In this fituation the muriate and the npanganefe, 
 being previoufly mixed as equally as poilible, 
 are to be poured through the neck into the re- 
 tort, by means of a glafs, leaden, wooden, or 
 paper funnel, perfectly dry. The goodnefs of 
 the mixture is feen by its uniform blacknefs 
 
 e 3 throughout, 
 
54 The Art cf Bleaching 
 
 throughout, no particles of the white muriate 
 being in this cafe feparately vifible. 
 
 After the introduction of the muriate and the 
 manganefe into the retort, great care muft be 
 taken to clean the ftopper and the neck, in 
 order that no vapour may rind its way through, 
 when once the fulphuric acid is poured in. It 
 is necefTary, therefore, that the neck and its 
 ftopper, being previoufly wetted, fhould clofe 
 the retort, as it were, hermetically. For the 
 flighted odour would be fufncient to retard the 
 operation, by rendering the workfhop extreme-? 
 ]y inconvenient. This odour of the oxygenated 
 muriatic acid very readily diffufing itfelf through 
 the whole fpace of the laboratory. 
 
 When the neck of the retort or bottle, for the 
 fame obfervation applies to both, the beak of 
 the adopter muft be properly luted to the leaden 
 funnel. For this purpofe a piece of lute is to be 
 rolled out in the hands, and applied round the 
 neck of the adopter, ftrongly preflirrg it as well 
 on the fides of the funnel as againft thofe of 
 the adopter, and finifhing by foftening each fide 
 and uniting the whole with the finger dipped in 
 boiled linfeed oil. 
 
 In the ufual courfe of regular practice, the 
 pneumatic vefifel or vefTels are filled with water> 
 the diftilling vefTels duly placed and luted, and 
 
 the 
 
Cottons, Thread, 6fV. $$ 
 
 the mixture of muriate and manganefe introduced 
 the evening before the day of diftillation, after 
 having cleaned and cleared the fame veflels from 
 their refidues *. By means of this preparatory 
 work, there remains nothing more to be done 
 at the beginning of the day-work, than to pour 
 in the fulphuric acid, which during the night 
 has had time to cool, in the earthen or (tone- 
 ware veflels, in which it was previoufly mixed 
 with water. Not that it would not be advan- 
 tageous to pour it while yet warm, after having 
 diminifhed its temperature, by plunging the 
 veflel in cold water ; but there would be reafon 
 to fear, that the proper degree of heat might not 
 eafily be adjufted, and that the diftilling velTel 
 might be endangered by the fudden applica- 
 tion. 
 
 It might alfo be practicable to advance the 
 diftillation, by pouring in the fulphuric acid in the 
 evening, immediately after the introduction of 
 the mixture of muriate and of manganefe ; but 
 there would be reafon in this cafe to fear that 
 the greateft part of the gas afforded by the diftil- 
 lation might be loft by derangement of the 
 Jutes, if the operation were not overlooked dur- 
 
 * A fufiicient number of diftilling velTels ought always to be 
 in readinefs, to be difpofed for the diftillation of the following 
 day. Author, 
 
 E 4 ing 
 
$6 The Art of Bleaching 
 
 ing the interval. This management would not 
 in fact be fuitable to a manufactory, in which 
 the work was not continued both day and night. 
 
 With regard to the fulphuric acid, it is to be 
 introduced gently through a glafs or leaden 
 funnel, in order that the air which efcapes may 
 not throw up drops of the acid on the face or 
 hands of the operator. When the acid is pour- 
 ed in, the neck muft be flopped by turning the 
 ftopper with a flight preffure. 
 
 If the acid has been poured in warm, and the 
 muriate is very dry, and well mixed, the fulphuric 
 acid not more diluted than has been prefcribed> 
 and the manganefe of a good quality, bubbles 
 of air will be heard to pafs into the wooden 
 velTel, through the leaden tube, at the end of 
 two or three minutes'. If the above requifites 
 be wanting, the efcape will not take place till 
 fomewhat more than a quarter of an hour. In 
 either cafe it is necefTary, a few inftants after 
 the pouring of the acid, to place a charing dim 
 with lighted charcoal beneath the vcfTel which 
 holds the retort. 
 
 About half an hour after the pouring of the 
 acid, a confiderable effervefcence takes place, 
 which fometimes fwells the materials as high as 
 the neck of the retort, if this laft be too fmall 
 for its charge. The bubbles of the froth are 
 
 /. lar S e > 
 
Cottons, Thread, (3c. 57 
 
 large and covered with a kind of pellicle, formed 
 by a portion of the mixture carried up during 
 the agitation. This intumefcence lafts about 
 two hours, during which time the bubbles of 
 oxygenated muriatic acid gas are moft abund- 
 antly difengaged in the water. They even fuc- 
 ceed with fuch rapidity, that the intervals are 
 not diftinguifhable, and an inceffant noife is 
 heard in the pneumatic veflel, which very often 
 lafts three or four hours, according to the ma- 
 nagement cf the fire, and the goodnefs and ac- 
 curate mixture of the materials. The agitation 
 produced by this rapid efcape is commonly 
 fuch, that it is fcarcely neceffary to move the 
 agitator. 
 
 The fire is not to be renewed till the expira- 
 tion of two hours, even though it may have 
 gone out in the mean time. After this, it is not 
 to be renewed till the end of an hour and a half, 
 and after that period at the end of an hour, and 
 fo forth, without any perceptible increafe of its 
 intenfity. It will be fufficient after thefe periods 
 to keep up the fire, excepting that during the 
 laft two hours the fire mufl be maintained with- 
 out fufTering the charcoal to be almoft burned 
 away, as in. the former cafes, before it is re- 
 newed. The chafing dim mull be raifed upon 
 bricks, to bring it nearer the retort, during the 
 
 laft 
 
5 8 The Art of Bleaching 
 
 laft hour. Imuftobferve, with regard to this chaf- 
 ing dim, that the grate mud not be too open, left 
 the charcoal mould be too rapidly confumed. 
 After the intumefcence of the mixture has 
 ceafed, the rapid efcape of bubbles does not 
 diminifh for a long time, in confequence of an 
 effervefcence which conftantly proceeds. It is 
 true that this continually diminiihes, and to- 
 wards the end of the diftillation the bubbles 
 which pafs into the tube appear only at inter- 
 vals, notwithstanding the marter k tort 
 mav, by the gradual augmentation of the heat, 
 be brought into the ftate of ebullition. This heat 
 is fuch, that eight or nine hours after the com- 
 mencement of the operation, the hand can 
 fcarely be endured near the aperture, or the 
 neck of the retort, or other diftillatory vefiel, 
 though between the fourth and fixth hours the 
 fame parts are fcarcely warm. The diftillation 
 of one or more retorts or bodies into a fingle 
 veftel, according to the dofes before mentioned, 
 takes ufually eleven or twelve hours, and even 
 lefs ; the time for Hooping the diftillation is 
 known from the efcape of the bubbles being 
 very flow, and the noife lefs perceptible. This 
 flight noife is even a mark to form a judgment 
 of the concentration of the gas, and the degree 
 of faturation of the water. In order to hear the 
 
 bubbles, 
 
Cottons, Thread, t!£c. 59 
 
 bubbles, it is often neceflary to apply the ear 
 againft the tub. Moreover, the adopter of the 
 retort begins to be heated, and the lute upon 
 its neck becomes a little foftened. Another in- 
 dication that the procefs is near its termination 
 is had from the Ions: vibrations of the water in 
 the indicatory tube, placed on the outfide of the 
 tub, and like wife in the tube of fafety, when an 
 intermediate veffel is ufed. 
 
 If a proper regard be not paid to the figns here 
 enumerated, and the diftillation be not Hopped, 
 there will not only be a lofs of time and fuel, 
 and a diftillation of mere water ; but the fleam 
 when an intermediate veffel is ufed, will 
 drive the water through the tube of fafety, and 
 itfelf immediately follow, if not inftantly re- 
 medied by diminifhing or removing the fire, 
 and cooling the neck of the retort and its 
 adopter with a wet cloth, or, which is better, by 
 drawing the ftopper of the retort for an inftant. 
 
 As foon as the diftillation is flopped, the im- 
 pregnated fluid of the pneumatic veffel is to be 
 drawn ofT into tubs, or other veflels, proper to 
 receive the goods which are previoufly difpofed 
 therein. If it be not convenient to ufe it im- 
 mediately, the liquor may be left in the tub 
 without fear of any perceptible diminution of its 
 virtue, provided the cover and its joinings be 
 
 well 
 
6o The Art of Bleaching 
 
 well clofed with lute and ftrips of paper pafled 
 on, and likewife that the fpace between the 
 axis of the agitator and the cover be fimilarly 
 fecured. It may likewife be drawn off in ftone-i 
 ware bottles well clofed with corks, covered 
 With lute at the place of their contact. In this 
 manner the liquid may be preferved till wanted. 
 I have kept it for feveral months without its 
 goodnefs having been impaired. 
 
 I muft obferve in this place, that if it be 
 wiihed that the liquor at the upper part of the 
 veflel fliould be equal in ftrength to that of the 
 lower, without retarding the diftillation (which 
 may be ufelefsly prolonged for upwards of 
 twenty-four hour?, by an erTecl: ot the concen- 
 tration of the gas in the bottom of the vefieh 
 and the refinance it then oppofes to its intro- 
 duction, which Angularly contributes to inereafe 
 the heat of the retort) ', I have found no better 
 method, than that of drawing off the liquor, 
 either into earthen pitchers or veflels tilled with 
 merchandize ready for immerfion. I have done 
 this after a limited time, and repeated proofs of 
 the good quality of the fluid. At the end of 
 eight hours diftillation, I drew off one fourth of 
 the contents of the veflel ; a fecond fourth two 
 hours afterwards ; a third fourth after ten hours 
 and a half, or eleven hours 5 and the reft after 
 
 twelve 
 
Cottons, Thread, 6fa gi 
 
 twelve hours diftillation, which formed the con- 
 clufion. * 
 
 When the liquor is entirely drawn off from 
 the veffel, it mud again be immediately filled 
 with water, or at leaft to the height of five or 
 fix inches above the return of the leaden tube, 
 otherwife the gas, which continues to efcape 
 from the diftilling veffel and then affords no re- 
 finance, might attack the pneumatic veffel it- 
 
 The fire mufl be taken from beneath the re- 
 tort as foon as the diftillation is fmifhed, not 
 only to prevent the effeft of the gafeous vapours, 
 which (till continue flowly to efcape, from act- 
 ing on the fides of the tub, but likewife to dif- 
 pofe the retorts or bodies to receive a quantity 
 of warm water, which is to be poured in up to 
 the neck. There is no reafon to fear an excefs 
 of quantity, and the hotter the veffels are the 
 better. It is effeniial, however, that it be not 
 poured in cold, for fear of breaking the glafs. 
 The adopter is then to be unluted from the 
 neck of the leaden tube, if the operator chufes ; 
 and in order that no vapour may efcape into the 
 workthop, a bit of lute or a cork may be ap- 
 plied to the beak of the adopter. The fand 
 bath eafily permits the retort to be raifed and 
 returned again to its place ; as well as the ap- 
 plication 
 
6z The Art o/Blsaciririg 
 
 plication of the lute or ftopper to the neck of 
 the adop'.e , this 'aft baing railed with one hand 
 while the cork is put m with the other. 
 
 Neverthelefs, as the lutes which connect the 
 adopter with the retort are fomewhat foftened 
 towards the end of the operation, it would be 
 more prudent to leave every thing in its place, 
 for fear of deranging thofe lutes. This danger is 
 greater when the adopter is of lead, becaufe 
 the great length of this additional piece tends 
 to force the luting ftill more on that account. If 
 it be required to proceed immediately to a new 
 diftillation, the retort or bottle with its capfule 
 or pan mull: be immediately taken from the fur- 
 nace, and another fubftituted in its place ready 
 prepared during the former diftillation. This 
 neceflarily requires a double fet of veflels. 
 
 When the diftilling veflel is cold, or nearly {o, 
 the whole of its contents muft be fhaken, by 
 holding this veflel by the neck with one hand, 
 and applying the other to its bottom. The ftop- 
 per mull then be taken out, and the veflel 
 fpeedily inverted, Ihaking the relidue to facili- 
 tate its efcape. In this laft Situation the retort 
 is to be held by its neck with one hand, and its 
 fide gently refting againft the other. The vef- 
 fels into which the water and refidual matter of 
 the retorts are poured, mould rather be of ftone- 
 
 ware, 
 
Cottons, Thread, &c. 63 
 
 ware, pottery, or lead, than of wood, unlefs 
 thefe laft be oil veflels, which are lefs fubje£t to 
 dry in the part above the fluid. If this cir- 
 cumftance be not attended to, there will be 
 danger of lofing great part of the contents. 
 
 It is moft convenient to difengage the retorts 
 or bodies while they are flill warm, which con- 
 tinues to be the cafe the next morning after 
 diftillation, in confequence of the heat of the 
 fand bath. If they be left to cool entirely, the 
 fulphate of foda will cryftallize, and it will be 
 neceffary to dilTolve in hot water fuch larger 
 portions as cannot pafs through the neck. 
 But this inconvenience is not likely to happen, 
 unlefs the quantity of water laft added be too 
 fmall, and the refidues have been left undif- 
 turbed for feveral days. The fame obferva- 
 tion is applicable to that kind of incruftation 
 which is formed by the muriate, if not properly 
 pulverifed, dried, or mixed ; this cannot be fepa- 
 rated from the bottom of the retort, but by 
 means of hot water poured at different fuccef- 
 five times. It is like wife effential to leave no 
 crufl: or depofition of muriate, or other matter, 
 in the veflels which are emptied, unlefs the fame 
 be moveable, in which cafe the rifk is lefs. 
 But if the urgency of bufinefs mould then re- 
 quire that the fame veflels be ufed without en- 
 tirely 
 
64 The Art of Blenching 
 
 tirely clearing them, it will be neceffary to 
 range this refidual matter on one fide, where it 
 will be lefs expofed to the heat, and will afford 
 a greater degree of facility for the nitric acid to 
 acl upon it. 
 
 In order that the vapour which exhales from 
 the diftilling veflels may not prove inconvenient* 
 it is necefiary to pour in a fmall quantity of al- 
 kaline lixivium in the firft place, which inftantly 
 deftroys the fmell. This may be done imme- 
 diately after the end of the diftillation, and the 
 weak alkaline folution may fupply the place of 
 the water ufed for diluting the refidues. At 
 the inftant of pouring this lixivial water, a 
 ftrong effervefcence takes place ; for which rea- 
 son it is proper to pour it in by feveral fucceflive 
 portions, waiting a little between each time. 
 
 The oxygenated muriatic acid obtained in 
 this manner has a moft keen and penetrating 
 odour. It cannot be breathed even for a few 
 inftants, without the danger of a moft obftinate 
 and violent cough. Its aclion is fometimes fo 
 flrong that the operator will fall down fenfclefs, 
 if he fliould determine to continue his work 
 with his nofe over the veflels. Running of the 
 nofe, afthmatic affecYion of the breaft, headach, 
 tears and fmarting of the eyes, bleeding at the 
 nofe, the fenfation known by the name of the 
 
 teeth 
 
Cottons, Thrtad, &c. $j 
 
 teeth fet on edge, pains in the fmall of the back, 
 and even fpitting of blood, are the ordinary in- 
 conveniences to be expected, when the pure 
 oxygenated muriatic acid is ufed as is prefcribed 
 in the /Innales de Chimie. It is even impoffible 
 to Tupport for feyeral fucceffive days an em- 
 ployment fo deftru&ive to the health, if the 
 lutes be not carefully attended to, and the vef- 
 fels for immerfion of goods be not covered and 
 placed in a med, through which a ftrong cur- 
 rent of air pafTes. I am moreover perfuaded 
 that there is not, perhaps, any perfon who has 
 fuffered fo much as myfelf in this refpecl, on 
 account of the earneftnefs with which I at. 
 tempted to bring this procefs of bleaching to 
 perfection, or rather to make it more generally 
 ufeful. The ftrong expectoration to which I 
 was expofed, agitated the fyftem fo much, that 
 I found it impoffible to retain any food on my. 
 ftomacb, and was for forty-eight hours, without 
 intermiffion, not only deprived of fleep, but con- 
 tinually emitting faliva, with acid and corrofive 
 humours from the eyes and nofe in fuch abund- 
 ance, particularly from the eyes, that it was 
 fometimes five or fix hours before I could open 
 them to fupport the light. My fituation, at 
 thofe periods, was fo difagreeable, that I could 
 not lie a moment on my back, and a very fhort 
 F tim 
 
66 The Art of Bleaching 
 
 time on my fide. The ereft pcfition was leafl 
 painful j but I was foon obliged to fit or lie 
 down, in confequence of the pain I felt, at every 
 attack of the cough, in the mufcles of the back 
 and thighs. 
 
 The difficulty, or rather the impoffibility, of 
 fupporting fuch painful exertions for any length 
 of time, induced me to contrive a mafk of card, 
 with glafs eyes, which allowed me, for a certain 
 fpace, to work with my face over the veffels for 
 the immerfion of goods, to turn, prefs, and wring 
 the pieces without fear of any ferious inconve- 
 nience. I likewife occafionally made ufe of a 
 handkerchief, moiftened with alkaline lixivium, 
 which I bound round my head to defend my 
 nofe and mouth from the effect of the odour, but 
 thefe means were merely palliatives. 
 
 As it is of great confequence that the opera- 
 tor mould be defended againft fuch accidents, or 
 at leaft be able to diminifh their confequences, 
 it may be of fome advantage to know, that X 
 have had the pleafure to experience, that the 
 black extract of liquorice, which I chewed be- 
 fore I expofed myfelf to refpire this vapour, 
 almoft always pfoduced a good effect, by di- 
 miniming the cough, and in fome inftances pre- 
 ferving me from it. I therefore was particularly 
 careful to ufe this extract, previous to expofing 
 
 myfelf 
 
Cottons, Thread, &c. Cy 
 
 myfelf to the danger of refpiring the gas, at the 
 fame time taking care not to omit the ufe of my 
 moiftened handkerchief, or mafk. 
 
 A folution of fugar in warm or cold water, 
 fipped or drank flowly, likewife appeafed the 
 cough very much after a certain time. The 
 warm folution was rather the moft effectual. I 
 likewife occafionally fipped or drank milk for 
 the fame purpofe. 
 
 Being at length, however, worn out with 
 fuffering, and unable to purfue my experiments 
 on bleaching with the requifite convenience, I 
 endeavoured to make the acid without fmell, 
 avoiding, at the fame time, any confiderable in- 
 creafe of expence. The following procefs fuc- 
 ceeded bell of any that I tried. It confifts 
 fimply in adding to the quantity of water pro- 
 per for each pneumatic veffel, a quarter of a 
 pound, at moft, of carbonate of pot-afh, or of 
 foda, for every pound of muriate of foda which 
 has been taken in the mixture of the matter for 
 diflillation. This quantity is fufficient, abfo- 
 lutely, to prevent the fmell of the acid, and per- 
 mit the operator to work with his face uncover- 
 ed over the neutralized fluid, without rifking 
 the fmalleft inconvenience. The water may be 
 difpofed, for this purpofe, in two different man- 
 ners ; either by previoufly diflblving the clari- 
 
 F a fied 
 
6S The Art of Bleaching 
 
 fied pot-alh in the refervoir of water appro- 
 priated to fill the vefTels, or it may be fimply 
 poured into the latter vefTels after it has been 
 difTolved, fettled, and drained by itfelf. This 
 latter method is preferable to the other. For 
 this purpofe, after having difTolved the alkali in 
 a fmall portion of water, it is to be poured in 
 at different times at the commencement, and 
 towards the end of filling the pneumatic vefTels. 
 Thefe precautions muft be more efpecially at- 
 tended to when the vefTel has falfe bottoms, be- 
 caufe the folution of pot-afh, in that cafe, mixes 
 lefs readily with the water. I muft here re- 
 mark, that the falfe bottoms, inftead of being 
 placed horizontally, muft be fomewhat inclined 
 towards that fide, in which the aperture of com- 
 munication, through which the gas pafles, is 
 made. This inclination prevents any of the 
 fluid from remaining in the vefTel at the time of 
 drawing off, which might happen if there were 
 not a decided flope towards the place of com- 
 munication. 
 
 If it fhould, however, be defired to prepare a 
 folution of pot-afh proper to fill the vefTels, it 
 muft be diluted till it marks no more than one 
 degree beneath zero on the areometer of MofTy 
 already mentioned. But this arrangement is 
 attended with trouble, and requires more vef- 
 Tels, 
 
Cottons, Thread, &c. 6f 
 
 fels, and confequently more room, without pro- 
 ducing any advantage fuperior to that which is 
 derived from pouring the ftrong folution of pot- 
 afh to the water at the time of filling, according 
 to the directions already given. 
 
 It fometimes happens, that the laft portions 
 of the impregnated fluid, at the time of drawing 
 ofF ; have a flight degree of fmell ; either becaufe 
 the agitators have not been fufficiently attended 
 to, or becaufe the falts are conftantly difpofed 
 to fall to the bottom of the veffel. To avoid 
 this inconvenience, about a fourth or an eighth 
 part of the alkaline folution may be referved, 
 not to be poured into the veffel till half an hour 
 before the diftillation is (topped. The agitator 
 is then to be turned, and the fuperior liquid 
 will be without fmell as well as the reft, be- 
 caufe the combination takes place inftantly. 
 The fame effect will follow, if the folution of 
 pot-afh be put into the bottles or veffels ufed to 
 draw off the liquid : nothing more being re- 
 quired in this cafe, than to pour a few glaffes of 
 the lixivium into the receiving veffel, which, 
 when filled, mult be covered up or corked. In 
 order that the feparate folution of pot-afh, which 
 is poured into the pneumatic veffel at the time 
 of filling it with water, may not be fubject to 
 Remain in part upon the falfe bottoms, to the 
 F 3 prejudice 
 
70 The Art of Bleaching 
 
 prejudice of the water beneath, it is poured 
 through wooden or leaden pipes, terminating 
 above in a conical part or funnel, and of fuch a 
 length as refpeclively to communicate with the 
 feveral cavities into which the veflel itfelf is 
 divided. By this expedient it is rendered cer- 
 tain, that the pot-afh, which is required to be 
 depofited in the feveral compartments, will be 
 fpecially poured into each. But as the alkaline 
 folutk-n does not immediately and intimately 
 mix with the whole of the water, but is dif- 
 pofed to flow infenfibly from the upper com- 
 partments to the lower, by reafon of its weight, 
 care muft be taken to pour no greater quantity 
 into the loweft compartment than four-fixths of 
 the faline folution, referving the two other 
 fixths for the fecond or firft compartment, and 
 forbearing to pour them in till the whole, or at 
 leaft the greatefl: part of the water has been 
 poured into the veffel. 
 
 The neceffary attention for diftilling the acid, 
 as well as the dofes of the materials, are the 
 fame whether the odour be prevented or not. 
 The only difference confifb in their effects, 
 as we fhall hereafter fee. The colour of both 
 folutions is abfolutely the fame. That which 
 contains pot-afh feems rather Iefs limpid, par- 
 ticularly the firil portions drawn off, on account 
 
 of 
 
Cottons, Thread, fcfo 7 x 
 
 of the faline deposition which is ftirred up by 
 the rapid motion of the fluid as it iffues out. 
 A fimilar effeft happens when the veflfel has 
 been newly painted ; in which cafe, the liquor 
 decompofes the paint by feizing the oil, and 
 from this caufe flows out with a foapy, or milky 
 appearance. 
 
 Inftead of pouring the pot-afh into the veflej, 
 as has been defcribed, I have very often ufed 
 the following method. To prevent the effluvia 
 from rifing from the veflfel in which the goods 
 were to be immerfed, I Amply poured my folu- 
 tion of pot-afh into one or two pots, and after- 
 wards fprinkled it upon the furface of the li- 
 quor contained in the bleaching veffel. This 
 afperfion was fufficient to check the fuffocating 
 exhalation of the muriatic acid gas. I fre- 
 quently ufed powdered chalk for the fame pur- 
 pofe, and with equal efFe£t. 
 
 I muft obferve, that I did not refolve upon 
 making this new liquor without fmell, until 
 after I had repeatedly afcertained, that it is im- 
 poffible to refift, for any length of time, the dif- 
 ficulties which refult from the method and the 
 jproportions defcribed in the Annates de Chimie. 
 I am even of opinion, that this method of bleach- 
 ing would be renounced altogether, if the ope- 
 rators were literally to follow thofe inftruclions 
 
 F4 
 
7 2 The Art of pleaching 
 
 in preference to my method, or fome other me-r 
 thod on fimilar principles. 
 ' I muft particularly remark in this place, that 
 the agitator muft by no means be neglecled. 
 It is necefiary to turn it feveral times together 
 at the end of every half or quarter of an hour, 
 to favour the abforption of the gas in the water, 
 and to deftroy its odour by facilitating its com- 
 bination with the pot-afh. If this be not done, 
 in cither cafe, the gas beneath the firft falfe bot- 
 tom will pafs too fpeedily into the fecond. This 
 pafTage muft be prevented as much as poftible, 
 until it is fuppofed that the water in the lower 
 compartment is nearly faturated. 
 
 It muft alfo be remarked, that when a 
 pneumatic veflel has once been ufed to make 
 one of thefe liquors, it muft not be changed in 
 its application ; for nothing more fpeedily de- 
 ftroys the veflel and the agitator, than alternate- 
 ly ufing them for both. On the contrary, when 
 the fame veflel- is conftantly ufed for the fame 
 liquor, the action of the muriatic acid is fcarce- 
 ly, in any refpecl, perceptible. 
 
 Laftly, I muft remark that the ftrength of 
 the liquor may be increafed at pleafure, as Ber- 
 thollet alfo obfervcs, by putting lefs water into 
 tbe veffels. I have feveral times obtained it at 
 fuch a degree of concentration, as to mark be- 
 tween. 
 
Cottons, Thread, &c, 73 
 
 twcen ten and twelve of the areometer of 
 MofTy. In this (late i*s colour was evidently 
 of a lemon yellow, a little inclining to green. 
 This liquor contained no pot-am, and was de- 
 figned for particular ufes. 
 
 CHAP 
 
74 The Art of Bleaching 
 
 CHAF. VII. 
 
 Concerning the alkaline Lixivium or Lees, ' 
 
 JL HE method of making the lees is not a 
 
 matter of indifference, whether we attend to the 
 faving of time, or of alkali. The following is 
 that which I would, from my own experience, 
 advife, and which I have fince learned is the 
 method ufed in Ireland. It is well known, that 
 the white colour of the Irifh linens is highly ef- 
 teemed. The method has always fucceeded 
 perfectly well with me. 
 
 Upon a kind of iron platform, compofed of 
 two or three concentric rings, connected to- 
 gether by crofs pieces of the fame metal, as 
 may be feen in the figures, i, 2, 3,4, Plate III, 
 which refts on the bottom of a boiler fet in a 
 furnace for the faving of fuel, are placed the 
 piece-goods, thread, &c. in folds or parcels, 
 When thefe different kinds of goods are to be 
 immerfed together in the alkali, the piece-goods 
 muft always be placed at the bottom. When 
 the boiler is thus charged, the alkaline folution, 
 at the ftrength of a degree and a half under zero 
 
 of 
 
Cottons, Thread, &V. 75 
 
 of the areometer, muft be poured in till the mafs 
 of goods are foaked, and covered to the depth 
 of at leaft an inch or two without preffing them 
 too much down. Or the alkaline folution may- 
 be poured in, accordingly as the goods are placed 
 in the copper. This lafr. method would be pre- 
 ferable, in my opinion, in all cafes where there 
 was no reafon to fear that the goods might lie 
 too clofe. To prevent thefe from rifing and 
 floating above the furface of the lees, a flat 
 cover is fitted to the boiler, which ferves to re-r 
 tain the heat, and prevent any dirt from falling 
 upon the goods. 
 
 A judgment is formed that the pieces are in, 
 a ftate to be taken out of the fluid, when this 
 laft under the cover in the middle of the heap 
 is too hot to admit of the hand being held in it, 
 pr when it fimmers round the circumference of 
 the boiler and throws up white bubbles, which 
 circulate towards the centre. It is not neceffary 
 that the lees fhould boil ; the effential conditions 
 are, that it fhould be fufflciently ftrong, abun- 
 dant, and hot ; and that it fhould properly pe- 
 netrate the goods which are fubmitted to its 
 action. I have frequently thought it fufhcienr, 
 between the two immerfions in the bleaching 
 liquor, to plunge the goods (previoufly wafhed 
 and ftraitened out) for a few minutes into the 
 
 lixivium* 
 
76 The Art of Bleaching 
 
 lixivium, which was very far from pofleiTing the 
 degree of heat above mentioned. The cloths 
 and piece-goods, which were treated in this 
 manner, bleached perfectly well. 
 
 In order to obtain a criterion refpecling the 
 time confumed in one boiling of the lixivium, I 
 mult obferve, that 3,600 French pints (or about 
 900 Englith wine gallons) of the alkaline folu- 
 tion, in a boiler fet in the manner juft defcribed, 
 will be rendered juft boiling hot in three quar- 
 ters of an hour at moft; and if pit-coal be 
 ufed, the quantity of fuel required, for this pur- 
 pofe, will be one-third part lefs than if wood be 
 ufed. 
 
 When the goods are to be taken out of the 
 copper, the cords or chains which are fixed to 
 the exterior circle of the ftage are to be raifed, 
 and hooked to the fall or rope of a crane placed 
 on one fide of the boiler ; by turning which 
 crane the whole of the goods are raifed out of 
 the copper, and after they have drained for a 
 certain time, the mafs is conveyed and placed 
 upon two crofs-pieces over a tub defigned to re- 
 ceive the fubfequent drainings ; after which, the 
 feveral pieces are prefled or wrung, and after- 
 wards rinfed in a ftream, if the manufacturer 
 poiTeffes that convenience ; or, otherwife, they 
 are warned by means of the revolving cy- 
 linder, 
 
Cottons, Threap &c. 77 
 
 linder, or other machinery. Thefe operations 
 are to be repeated as often as the goods are 
 taken out of the alkaline lixivium, according to 
 the nature of the merchandize ; for it may eafily 
 be imagined, that piece-goods, hofiery, and 
 thread, will require different kinds of manipu- 
 lation. 
 
 As it is of effential confequence to lofe as 
 little as poffible of the lixivium in this procefs, 
 it will be proper to wring or prefs the goods 
 before they are rinfed. Piece-goods may be 
 advantageoufly wrung by means of a fixed hook, 
 and a handle or wooden crofs, to which a fimilar 
 hook is adapted that moves with the handle. 
 See Plate IX. fig. 9. Thefe hooks being 
 placed refpe&ively at the two fides of a trough 
 intended to receive the wafte lees, the piece it- 
 felf muft be palled and repaired a number of 
 times over the hooks, as is reprefented in the 
 figure, until either the whole piece is thus 
 wound up, or as much of it as can be con- 
 veniently wrung at a time. 
 
 With regard to thread, it may be prefTed or 
 wrung with the pin ; and hofiery may be treated 
 in the fame manner. But it is more advifable 
 to wring this laft article feparately by hand, un- 
 lefs the operator poflefTes a prefs fuited to both 
 the laft-mentioned articles. By this engine the 
 
 goods' 
 
7$ The Art of Bleaching 
 
 goods may be cleared of the alkaline lee, with 
 more eafe and expedition, and with much lefs 
 injury. 
 
 In order to economife the fire in the fufion of 
 the alkali made ufe of in new lees, as foon 
 as the old has been drawn out of the boiler, 
 which may be done by means of a fyphon, or a 
 cock, as may be moft convenient, the neceflary 
 quantity of water may be immediately poured 
 in with the pot-afh or crude foda broken in 
 fmall pieces, if the purified fait be not ufed. In 
 this manner the folution may be accomplished 
 for the following day. The heat of the boiler, 
 and its fire-place, fuppofing a fmall quantity of 
 the fire to remain, the regifters of the furnace 
 being fhut, and the boiler covered up, will 
 be fufficient to melt the alkali in the courfe of 
 the night. It is neceflary to break the pot-afh 
 into pieces of the fize of a nut before it is 
 thrown in, particularly that kind which is known 
 in France by the name of pot-afh of York, the 
 pieces of which are as hard as ftones, and can- 
 not eafily be broken but by a mallet upon a 
 ftone pavement. The Spanifh foda is equally 
 hard. 
 
 The method of pafling the goods through the 
 heated alkaline lixivium, as here defcribed, is 
 particularly fuited for works upon a large fcale. 
 
 But 
 
Cottons, Thread, Sfa, 79 
 
 But when the manufacturer intends to confine 
 himfelf to the bleaching of fmall articles, fuch 
 as hofe, night-caps, thread, &c. without med- 
 dling with the larger piece-goods, it will be 
 equally advantageous to uie a fimple boiler, pro- 
 perly difpofed in a common fire-place, with a 
 barrel and winch above it, as is exhibited in 
 Plate II. fig. 4, 5, and 6. For the faving of fuel, 
 this boiler maybe fet in brick- work ; and like the 
 great boiler before defcribed, it may have a fur- 
 rounding cavity for evaporating the old lees, 
 which will be very ufeful if it be no more than 
 four inches in height, and of the fame width. 
 
 New lees, which have already been ufed for 
 the immerfion of one piece of cloth, are not to 
 be rejected on that account; As the folution 
 lofes fomewhat of its ftrength on account of the 
 matter which it extracts from the cloth, and 
 with which it enters into combination, it muft 
 be reftored by adding one-third or one-fourth of 
 lixivium from the refervoir, which likewife fup- 
 plies that portion which was carried away in the 
 goods, and partly recovered by draining, rinf- 
 ing, or preffure. The firft lixivium, after two 
 boilings, can only be poured on dyed goods, be- 
 caufe it is then loaded with extractive matter, 
 which in a great meafure faturates it, and ren- 
 ders it black and vifcid to fuch a degree, that it 
 
 fome- 
 
8o The Art cf Bleaching 
 
 fometimes takes a curdled or gelatinous appear- 
 ance on cooling. 
 
 The fecond lixivium may commonly be ufed 
 three or four times for the fame objects, taking 
 care to flrengthen it every t m with one-third or 
 one-fourth part of new lees ; after which it is to 
 be thrown, like the others, into the refervoir. The 
 third and fourth lixiviums mav likewife be ufed 
 feveral times, but without adding new lees, be- 
 caufe they take up but little colouring matter; 
 It is eafily afcertained by the tafte, whether they 
 have any remaining active faline parts. Many 
 perfons, particularly laundreffes, afcertain whe- 
 ther their alkaline lees has loft its force, by rub- 
 bing it between their finger and thumb. They 
 eftimate its quality according to the degree of 
 lubricity it exhibits. The quality of the two 
 fTrft lixiviums may be afcertained to a certain 
 point by the ufe of the areometer. When they 
 mark three degrees under zero, they are cer- 
 tainly too much loaded with extractive matter, 
 and w T ill produce no other effect on the goods, 
 than to give them a brown colour, to the abfo- 
 lute lofs of time. It is advi fable to keep the 
 lees at the fame degree of force, either by ad- 
 dition, or by changing them altogether, for the 
 firft two or three immerfions of the fame goods ; 
 diminiftiing the ftrengtbj however, one-third or 
 
 one- 
 
Cottons, Thready &c. 8t 
 
 one-fourth as foon as the pieces have acquired 
 an uniform colour, which will happen, at fartheft, 
 at the fecond immerfion in the bleaching liquid. 
 When the goods have arrived at this ftate, 
 weaker lixiviums may be advantageoufly ufed, 
 becaufe there remains fcarcely any thing more 
 of impurity to be carried off ; and the fubfe- 
 quent procefs may be confidered merely as a 
 brightning of the colour, by detaching the fmall 
 portion of impurity which may remain fixed in 
 the texture of the thread itfelf. 
 
 The old faturated lees bein£ taken out of the 
 boilers, are to be added to the other lees of the 
 fame kind, arifing from the drainings into refer- 
 voirs appropriated for that purpofe. This fluid 
 is of ufe to foak piece-goods or thread, in or- 
 der to clear them of their drefTing, or the im- 
 purity attached to the latter during the {pin- 
 ning. With regard to the lees which are ob- 
 tained by preffure or wringing of the goods, if 
 they be not too highly coloured, they may, as 
 well as all the others, be added to the lees in 
 the boiler. 
 
 As foon as one boiling or immerfion is made, 
 if the lixivium be in a good ftate, whether by 
 the addition of frefh lees or not, the next im- 
 merfion may be immediately proceeded upon in 
 order to take advantage of the heat, in cafe 
 
 « the 
 
Sz The Art of Bleaching 
 
 the courfe of bufinefs requires it ; but for this 
 purpofe it is neceffary to have another frame or 
 platform ready prepared, with the proper quan- 
 tity of goods for immerfion. But if there only 
 remain a fmall number of pieces which require 
 to be plunged in the alkali, they may be thrown 
 into the fame bath without reftoring it, or even 
 heating it up again. Nothing more will be ne- 
 ceffary than to cover up the boiler, and leave 
 the goods immerfed for a fufficient time, that 
 they may be well penetrated with the alkaline 
 folution. I have often found this manner of 
 proceeding very convenient for piece-goods, 
 hofe, or thread, in fmall quantities, without 
 making ufe of the frame or platform. 
 
 It muft not be overlooked, that whenever the 
 goods are taken out, the copper muft be exa- 
 mined with a ftaff, in order to difcover and take 
 out any fmall articles which might be forgotten, 
 and would be in danger of burning if they were 
 to remain at the bottom of the copper during 
 the time of the fubfequent procefs or charge. 
 
 It muft alfo be remarked, that it fcldom hap- 
 pens that any piece which may have been fub- 
 je&ed to two frefli fucceliive lixiviations, even 
 though it may have been a dyed piece, will re- 
 ceive any advantage from a further repetition. 
 The third immerfion, to which it might be fub- 
 
 jecled, 
 
Cottons, Thread, &c. 83 
 
 je£ted, with the hope of clearing it of an addi- 
 tional portion of impurity, will be found to pro- 
 duce fcarcely any effect, and the liquid will take 
 up little or no colour. It fometimes happens, 
 that the fecond lixivium, even though of con- 
 iiderable flrength, is equally ineffectual. 
 
 It is of great importance that the alkaline 
 lees mould be always as clear and limpid as p*f- 
 fible. Their value may be eftimated by ob- 
 serving the readinefs with which they abforb 
 the colouring matter from the goods. The tubs, 
 in which they are kept, ought, therefore, to be 
 made of fir ; becaufe thofe of oak, or chefnut, 
 though very carefully treated with lime water, 
 always become more or lefs coloured in procefs 
 of time. It is true, that the colour of the lees 
 is of, comparatively, little confequence for the 
 firft two or three immerfions of dyed goods 
 [des pieces bifes). But this is not the cafe when 
 the goods have once acquired an even colour, 
 and require only to be brightened. It is then 
 highly effential, for the faving of time and la- 
 bour, that the lees fliould be as clear and limpid 
 as pofiible. 
 
 The new lixivium, or lees, is good whenever 
 it marks one degree and a half beneath zero j 
 and 1 have obferved, that it is not necefTary it 
 lhould be ftronger. At a higher degree of 
 
 o 2 firength, 
 
84 The Art of Bleaching 
 
 ftrength, it would foon become as foul or co- 
 loured as the weaker folution ; and it is ufelefs 
 to confume the alkali to no purpofe, and com- 
 municate a dark colour to the goods, which by 
 that means become more difficult to wafh or 
 rinfe. Care mult alfo be taken to rinfe them 
 after the lees, until the water, if the opera- 
 tion be performed in the warning apparatus, 
 flows off very clear ; or, on the contrary, if the 
 goods be expofed to a dream of water, they 
 muft not be taken out till it has been afcer- 
 tained, in various parts of the pie'ces, that the 
 water, upon wringing, comes out very clear. If 
 this precaution be not attended to, the pieces, 
 thus imperfectly rinfed, would be in danger of 
 becoming yellow inftead of white, by immerfion 
 in the bleaching liquor ; and even to acquire a 
 very tenacious and difagreeable ruddy tinge, 
 either partially, if the rinfing have been partial, * 
 or totally, if it have been entirely neglected. 
 
 The activity of the fixed alkali, or pot-afh, may 
 be increafed, by throwing into the boiler in 
 which this fait is put for folution, one-third or 
 one-fourth of its weight of well burned and very 
 white lime, of the belt, quality ; which is to be 
 tied up in a bag or cloth. By this management, 
 the calcareous earth is lefs capable of render- 
 ing the lees turbid ; or if it mould efcape, it will 
 
 fall 
 
Cottons, Thread, &c. 85 
 
 fall to the bottom when the folution cools. The 
 lime may alfo be feparately diffolved or diffufed, 
 and the pot-afh diffolved in this folution inftead 
 of pure water ; a method which may be prefer- 
 able to the other. It is fcarcely neceflary to 
 add lime to the foreign pot-afh, moil of them 
 contain a certain quantity ; particularly thofe 
 which are imported from the north of Europe, 
 or from America. 
 
 The ufe of lime has appeared to me to pro- 
 duce a greater effe6t at the commencement, 
 than towards the end of the bleaching. At 
 this latter period, the different operations to 
 which the merchandize has already been fub- 
 je£ted, the caufticity of the lees, and the fmall 
 grains of calcareous earth which they may con- 
 tain in fpite of every precaution, would be likely 
 to impair the ftrength of the goods, particularly 
 during the operations of wringing, or the prefs. 
 But the ufe of lime has appeared to me to be 
 pf advantage at the beginning, becaufe I have 
 found reafon to conclude, that the goods which 
 are thus treated acquire a decided whitenefs in 
 lefs time than the others. 
 
 As it may happen, that the boilers ufed for 
 the lixiviations may leak at the place of the 
 rivetting, and manufacturers may find them- 
 selves embarraffed at a diflance from proper 
 g 3 work- 
 
86 The Art of Bleaching 
 
 workmen, I conclude, that the following method 
 of repairing them may be acceptable. It con- 
 fines in beating a certain quantity of lime, flaked 
 by expofure to the air, and fifted with a fmall 
 quantity of the white cheefe called a la pie*. 
 The mixture is to be ftirred or beaten without 
 ceafmg ; and the lime muft be fucceffively added, 
 until the mixture begins to acquire a certain 
 confidence. The damaged part of the copper 
 being then well cleaned and wiped, this cement 
 is to be very firmly applied, fpreading and ex- 
 tending it at the edges as well as poilible. The 
 cement foon hardens, and the copper may be 
 ufed as before. By this means every kind of 
 fmall fra&ure, or opening, may be eafily flopped 
 without difplacing the boiler. 
 
 The fame kind of lime fifted, and mixed in a 
 fimilar manner with leaven, may be ufed with 
 equal advantage. I have had occafion to ufe 
 both thefe cements, and it appears that the falts 
 exercife no a&ion upon them ; or, if they acl at 
 all, it muft be in a manner fcarcely perceptible. 
 
 As it may be of advantage, in certain places, 
 inftead of ufing pot-afh, to give the preference 
 
 * I am not acquainted with this kind of cheefe ; but it 
 may eafily be fuppofed, that experiment will point out, which 
 of the feveral kinds the manufacturer may have at his dif- 
 pofal may be the beft. I fuppofe a very fmall quantity of 
 water is to be added.— T. 
 
 in 
 
Cottons, Thread, &c. 87 
 
 in France to the alkali, known by the name of 
 /alia, which can now be bought one-third part 
 cheaper than formerly, before the impoft of page 
 was fuppreffed ; I fliall defcribe the manner of 
 calcining it, in order to deprive it of the colouring 
 matter with which it is combined. The common 
 baker's oven may eafily be ufed, at leaft pro- 
 visionally, inftead of a calcining furnace. It is 
 to be heated as if for bread, taking care only to 
 place the wood on one fide, in order that the 
 part of the floor which remains free, may be wcli 
 heated by the circulation of the flame. The 
 crude falin is to be thrown into this vacant 
 part by means of a fliovel or any peel ; for which 
 purpofe, the common peel, belonging to the 
 oven, may anfwer very well. The alkali may, 
 without inconvenience, be difpofed to the height 
 of two or three inches over the whole clear fur- 
 face of the floor of the oven, as far as to the 
 diftance of five or fix inches from the mouth ; 
 and in order that the coal of the finall wood 
 may fall thereon as little as poffible, by fpark- 
 ling, rolling, or bounding, the largeft pieces, 
 or faggots, muft be placed neareft to the fait. 
 At the commencement of the operation it is 
 neceffary to turn up the alkali, and renew its 
 Surfaces from time to time ; for which purpofe, 
 vhe bended part of the poker may be very ufe- 
 g 4 ful. 
 
88 The Art of Bleaching 
 
 fill. This precaution is the more effentia], be* 
 caufe it prevents the fait from adhering to the 
 bottom of the oven by the aqueous fufion. 
 Some famples of this fait, at the firit impreilion 
 of the fire, decrepitate more or lefs, which arifes 
 from the muriate of foda, or fulphate of pot-aih, 
 which is almoft conftantly found in every kind 
 of incinerated vegetables ; and it is fometime3 
 the confequence of adulteration, to which that 
 of Lorraine is more particularly fubject. Thq 
 oven is to be more and more heated, and the 
 fait ftirred until it ceafes to emit fumes, and be- 
 gins to lofe its fmoaky or black appearance, and 
 becomes white throughout internally, as well as 
 externally. 
 
 When the fait is firft put into the oven, the 
 heat ought not to be greater than for baking 
 bread. It may be of advantage to begin the 
 operation immediately after the bread is drawn, 
 becaufe ihe heat which is already in the oven, 
 will render the confamption of fuel lefs than 
 would otherwife have been required for the cal- 
 cination. 
 
 After the fait has once become white, the 
 fire is to be kept up as fteadily as poffible, with- 
 out increafing it ; and the greater!: care muft be 
 taken, left the fait, by too ftrong heat, fhould 
 form itfelf into clots or malfes. Whenever this 
 
 happens, 
 
Cottons ', Thread, &c. - 89 
 
 happens, the pieces mult be broken fmall with 
 the rake or poker ; for the internal part of fuch 
 Jumps, though white on the outride, would very 
 probably retain its dark colour. If the fait be 
 imperfectly, or not at all calcined, it will afford 
 a folution of a yellow-blackiih colour, fimilar to 
 that of old lees highly charged with colouring 
 matter, as is the cafe with that which has been 
 ufcd for the firft immerfion of piece-goods, or 
 thread. The effeft of fuch a folution would be 
 very different from that of the clear and limpid 
 folution, which it is abfolutely neceffary to pre- 
 pare for thefe operations. 
 
 When the fait appears white throughout, and 
 ignited in certain places, when it is turned oveiy 
 it will be proper to take it out of the oven. 
 The fire is then to be gently diminifhed till no 
 more combuftion remains than is convenient to 
 give light for drawing out the fait. The latter 
 is then to be drawn with an iron rake, or the 
 bended part of the poker, to the mouth of the 
 oven ; where it may be received in troughs of 
 (lone, or plate-iron, or caft-iron pots, of fufficient 
 fize to contain the whole. The fire may be fuf- 
 fered to decay, until the oven mall have ac- 
 quired the proper temperature to begin the 
 fecond calcination, if required ; which is to be 
 managed as before, taking care only, that the 
 
 fait 
 
90 The Art of Bleaching 
 
 fait be rather more frequently ftirred at the 
 commencement, becaufe the floor of the oven is 
 always fomewhat hotter than at the commence- 
 ment of the firft calcination. The operator 
 muft alfo endeavour, as much as he can, to pre- 
 ferve his alkali from the fmall pieces of char- 
 coal which fly in fparks from the wood, though 
 thefe are not abfolutely of much confequence, 
 becaufe they fwim on the furface of the water 
 in which the calcined fait is afterwards dif- 
 folved ; in which fltuation they may be taken 
 off" with the fcum which ufually rifes from this 
 fait, though in lefs quantity than from the or- 
 dinary pot-afh ; which laft fait is expofed to a 
 itronger heat, and is ufuallv mixed and calcined 
 with calcareous earth, or other earthy matter, 
 either to increafe its caufticity, or to add to its 
 weight. The coal and the fcum obtained in 
 this folution, are not to be thrown away, but 
 may be difpofed upon a cloth or fieve over the 
 refervoirs containing the new lees. As thefe 
 fubftances retain a fmall quantity of fait, it is 
 advifable to pour water upon them feveral 
 times ; after which, they may be thrown into 
 the oven at the next calcination. 
 
 If the calcination of this alkali be carefully 
 managed, there will be no incruftation upon the 
 pavement in the oven ; but if that event lhould 
 
 happen, 
 
Co! Ions, Thread, &c. 91 
 
 happen, the oven would not be lefs proper for 
 baking bread. The only effect it will have upon 
 this article of food, would be, that the bottoms 
 of the loaves would be rendered more uneven. 
 Thefe incruftations may eafily be removed by 
 ftriking them with a hammer while they are flill 
 hot, or by raking them off after the oven is cold, 
 and the alkali has began to attract the humidity 
 of the air. In this ftate the flighteft blow will 
 detach all the faline incruftations, which may 
 have fixed themfelves to the pavement of the 
 oven *• 
 
 The Jalin lofes twelve or fifteen per cent 
 when thus converted into pot-alh, accordingly 
 as it is more or lefs humid at the time of calci- 
 nation. 
 
 The procefs here defcribed, is practicable by 
 women as well as men. The whole was ex- 
 
 * In the fecond year of the French republic, I had occa- 
 fion to direct my attention particularly to the inquiry after 
 certain fubftances proper to afford alkali by incineration; that 
 of the marc or (talks of grapes appeared tome, among others, 
 to deferve the notice of thofe who are engaged in the manu- 
 facture of pot am. I have, therefore, inierted at the end of 
 this work, the two memoirs which I at that time addretfed to 
 the different committees of the national convention, which 
 were fpeciaily charged to excite the zeal of the citizens to- 
 wards the molt proper means of fupplying the faltpetre works 
 with the requifite quantity of vegetable alkali. 
 
 ceedingly 
 
92 The Art of B leaching 
 
 ceedingly well managed by a woman, to whom 
 I gave inftru6tions. In an oven capable of bak- 
 ing two meafures of flour, each weighing twenty- 
 five Paris pounds (or twenty- feven pounds avoir- 
 dupois), an hundred pounds of alkali may be 
 eafily calcined, in three or four hours, at a fingle 
 heat, at no greater expence than twelve or fifteen 
 fols, in fuch wood as is ufed by the bakers. 
 
 After this defcription of calcining the impure 
 alkali, it mav not be amifs to point out the me- 
 thod of obtaining the alkali from the old lees, 
 which were formerly thrown away. For this 
 purpofe, I prefer the following method. In- 
 ftead of covering with mafonry, or brick-work, 
 that fpace which remains above the nanch or 
 horizontal part of the boiler for lixiviation, an 
 additional piece is to be applied round the cir- 
 cumference, fo as to form a circular cavity or 
 external boiler. The heat which this channel 
 undergoes from the continual action of the flame 
 beneath, very fpeedily evaporates the old lees, 
 with which it is for that purpofe filled. When 
 the lees are thus rendered very thick by evapo- 
 ration, they are conveyed to a boiler, or pot 
 of caft-iron, properly placed upon a calcin- 
 ing furnace; fee Plate III. dcr. j y 8, 9, io, and 
 11. The lees muft not be fiiffered to become 
 
 entirely 
 
Cottons, Thread, &c. 93 
 
 entirely dry in the circular cavity, which fur- 
 rounds the great boiler, left the copper fhould 
 be burned or oxyded. 
 
 The old lees, when brought to a pellicle in 
 the evaporatory apparatus firft mentioned, are, 
 as already obferved, to be conveyed to the boiler 
 of caft-iron, where they may be heated to dry- 
 nefs without any danger of breaking the veffel ; 
 particularly if it be made of foft grey iron. The 
 refidue muft be ftirred as frequently as polfible, 
 efpecially towards the end of the procefs, in 
 order to prevent the fait from adhering ; which, 
 in that cafe, would render it neceffary to dW it 
 out with a chiflel and mallet, unlefs there were 
 time for it to foften by the humidity of the air ; 
 or the operator might choofe to fprinkle it with 
 water to produce the fame effect. 
 
 In order to take the utmoft advantage of the 
 heat of the evaporating apparatus, it muft be 
 duly fupplied with lixivium as foon as that which 
 has been evaporated to a pellicle is taken out; 
 and in cafe there fhould be no foul lees to evapo- 
 rate, it will be proper to fill the external channel 
 with water, to prevent the copper from burn- 
 ing. This hot water may be drawn off for ufe, 
 by means of a fyphon or cafk, when required. 
 
 The heat which is carried up the chimney 
 may alfo be converted to an ufeful purpofe, by 
 
 placing 
 
94 3Tfe Art of Bleaching 
 
 placing another fmall copper over the flue, into 
 which the old lees may be put ; where they 
 will obtain a certain degree of concentration 
 previous to conveying them into the circular 
 channel. In this laft veffel they will be (till 
 farther concentrated, previous to the laft evapo- 
 ration in the iron-pot, in which they are reduced 
 to the irate of pot-afh, or JaUn. This feries of 
 veifcls may be ufed with great profit and advan- 
 tage. 
 
 o 
 
 CHAP. 
 
Cottons, Thread, &c. 05 
 
 CHAP. VIII. 
 
 RefpeSiing the Preparation to be given to the various 
 kinds of Goods. 
 
 T, 
 
 HE preparation necefTary tQj.be given to 
 piece goods, before they are immerfed in the 
 oxygenated muriatic acid confiits, firil, in {bak- 
 ing them about twelve hours in water to dif- 
 folve, and clear off the dreffing, which is ufually 
 either common (larch, or thin parte of flour. If 
 the piece be foaked in a trough, it mull be dif- 
 pofed in very open folds, and covered with 
 water. If the foaking be performed in a river, 
 or ilream, it mult be expofed to the current, 
 after having fattened it to a poll fixed for this 
 purpofe. It would be much better to form a 
 kind of refervoir, defended all round by planks, 
 as well as at the bottom, in order that the pieces 
 might fwim therein, without being expofed to 
 damage or dirt ; and the water might pafs in 
 and out by two fluices. When the goods have 
 foaked for a convenient time, they are taken out 
 fold by fold, and then preiTed or wrung by the 
 wring, fig. 9, PI. IX ; or, if time permits, they 
 are fuffered to drain on the horfe. With regard 
 
 to 
 
96 The Art of Bleaching 
 
 to the goods foaked in troughs, as the water be- 
 comes very foul, it would not be amifs to foak 
 them again in frefh water till the fluid comes off 
 very clear. In fact, there cannot be too much 
 attention paid to clear the goods perfectly of 
 their dreffing. This previous treatment difpofes 
 them for the fubfequent operations, by render- 
 ing the extractive colouring matter more eafily 
 to be difcharged. A fulling-mill would be very 
 ufeful for thefe workings and rinfings. 
 
 The fecond operation to which the piece- 
 goods are to be fubje&ed, is that of maceration ; 
 which confifts in foaking them in old lees which 
 has been ufed, and is referved for this purpofe. 
 In the macerating troughs the pieces are like- 
 wife to be difpofcd in folds ; not only becaufe 
 they occupy lefs room, but likewife becaufe they 
 will be lefs preffed together, and the maceration 
 will be more equally effected. The quantity of 
 lees muft be fufficient to cover the goods ; and in 
 order that thefe may not rife above the fluid, 
 they may be preffed down by means of loaded 
 planks, or which is ftili better, by pieces of wood 
 capable of being fixed fo as not to prefs the 
 goods, but Amply to prevent their riling above 
 the furface. In this fituation they muft be left 
 for at leaft forty-eight hours, even in fummer, 
 without any fear of inconvenience. For greater 
 
 certainty 
 
Cottons, Thread, &c. qj 
 
 certainty, however, this procefs may be managed 
 according to the heat of the atmofphere. It is 
 known that the maceration operates in a proper 
 manner when the lixivium is covered with an 
 infinity of white bubbles, and begins to emit a 
 fetid fmell ; and the piece-goods have aflumed 
 a clear yellowifli ruddy colour, inftead of the 
 grey or dark colour they had before their kn- 
 merfion. This, at leaft, is the cafe with almoft 
 all the linens of Picardy, in confequence of the 
 fpreading of the linens in the field, where the 
 impurities are fo far from being detached, as 
 when the clearing is performed in water, that 
 they become fixed, and acquire more colour. 
 This maceration is accelerated if the lixivium 
 be ufed hot, as it is when rejected from the 
 boilers. It would fcarcely be imagined how 
 much the maceration in the old lees, when thus 
 managed, advances the bleaching of the goods. 
 It anfwers the fame purpofe as two immerfions 
 in the copper ; whence it is evident, how much 
 it faves of time, labour, and expence. 
 
 Inftead of macerating the goods in the old 
 lees, I have fometimes ufed with advantage a 
 cold bath of lime water, or milk of lime. The 
 grey piece-goods when deprived of their dreffing, 
 or even without that previous preparation, were 
 plunged in this liquid? and after having re- 
 mained therein no longer than five or fix hours, 
 
 h thev 
 
98 The Art of Bleaching 
 
 they were taken out, of a ruddy yellow colour, 
 and in a proper ftate for the aclion of the lixi- 
 viums. 
 
 In order that the pieces fct to macerate may 
 not be too clofely prefled againft the bottoms of 
 the veffels, bundles of white ofier twigs, or 
 merely flicks deprived of their bark and laid 
 acrofs each other, may be difpofed upon the 
 bottom. The fame remark is applicable to the 
 firil foaking, required to clear them of the drefl*- 
 ing. This firft operation is performed merely to 
 fave the lees, for when the operator is preffed 
 for time, the foreign matter contained in piece- 
 goods, that is to fay, the faliva of the fpinners, 
 and the ftarch of the weavers, is cleared off as 
 perfectly as in the old lees when the goods are 
 fubmitted to maceration. 
 
 When the maceration is carried to the dclired 
 point, the lees are to be drawn off, the goods 
 taken out, and wrung or prefled in the manner 
 already defcribed, and rinfed in the ftream, or 
 in a veflel where it may be worked until the 
 water, which is repeatedly poured on, comes off 
 clears or, in preference to this laft procefs, the 
 goods may be paffed through the fulling appa- 
 ratus, if the manufacturer poffeffes one. See 
 the plans and parts of this mill in the Plates IV. 
 and V. After the fulling or rinfing, the goods 
 are left to drain on a proper ftage, or preffed or 
 
 wrung 
 
Cottons, Thread, &c. 99 
 
 wrung to fuch degree that they may remain 
 only moift or humid. For too great a quantity 
 of water if retained would weaken the aftion 
 of the oxygenated muriatic acid. 
 
 If the operator do not poffefs the advantage 
 of a fulling^ftock, but fimply that of a ftream of 
 water, the warning of thefe piece-goods may be 
 haftened, by beating them on a ftage, level with 
 the furface of water, by means of dyers' fticks 
 or poles, which are very well adapted for this 
 operation. 
 
 Care mull be taken that the troughs or other 
 wooden veffels in which the goods are foaked or 
 macerated, be clear of every crack or fplinter, 
 otherwife there would be danger of tearing them 
 in taking out, becaufe the fermentative procefs 
 occafions them to expand and prefs againft the 
 fides of the veffels. 
 
 The obfervations we have made with refpe£i 
 to piece-goods of linen or hemp, are alfo ap- 
 plicable to thofe containing cotton, taking care 
 to proportion the time of foaking and macera T 
 tion to the coarfenefs or fmenefs of their tex- 
 ture. 
 
 Particular attention muff be paid after the 
 rinfing or clearing of the piece-goods, fubfe- 
 quent to the firft foaking or maceration, and 
 even after the firft lixiviations or boilings, to rub 
 
 H 2 them 
 
ioo The Art of Bleaching 
 
 them well with black foap, and afterwards to 
 clear them out, particularly along their felvedges; 
 for this part, being always clofer than the reft, 
 requires to be made very fupple, in order to 
 open it to the aclion of the lees and the acid. 
 Without this precaution it might, probably, be 
 neceffary after the feveral operations to rub 
 them feparately by hand, and the bleaching 
 would be retarded by requiring feveral extraor- 
 dinary immerfions to prevent thefe parts from 
 being lefs perfectly white than the reft. If the 
 rinfing and clearing be well performed at the 
 commencement, the beauty and evennefs of the 
 white colour, and likewife its acceleration, will 
 be much promoted. It is alfo highly advan- 
 tageous, particularly to fine goods, that the 
 whole piece fhould be foaped and cleared after 
 the laft lixiviation and rinfing, till the water 
 flows off limpid. I do not hefitate to recom- 
 mend this particular manipulation, as well after 
 the maceration as after the laft immerfion in the 
 lees, becaufe the whitenefs which it affords is 
 proportionally more brilliant and folid. 
 
 It is proper to add, that it will be likewife 
 very ufeful to proceed with the fame attention 
 and care in rinfing the goods after each lixivia- 
 tion. This part of the work being well per- 
 formed, has more effeel than is ufually fuppofed 
 
 ©n 
 
CotionSy Thread, &V. ior 
 
 on the folidity of the white colour in many- 
 piece-goods which are efteemed in the market. 
 Out of the various kinds I fhall only mention 
 thofe called De Laval, which, after drefling, ex- 
 hibit the mod beautiful milk white ; but which 
 have the fault of not preferving it when they are 
 brought into the ufual wafh, during the courfe 
 of wear. This fault is particularly attributed to 
 the expofure of the goods in the field, before 
 they are properly cleared of the extractive 
 matter detached by the lees. 
 
 I forgot to mention, that for numbering and 
 marking the cloths, red ochre {/anguine) may be 
 ufed as well as lamp-black ground with oil ; 
 but the mark traced with red-ochre upon a 
 moiftened place, is more expeditioufly made, 
 and equally tenacious. 
 
 Linen, thread, hofe, mittens, and gloves, of 
 the fame material, mud undergo the pre- 
 parations of fteeping in water, and in the old 
 lees, with the ' fame care. Sewing thread, 
 hofe, and gloves, only require more time to 
 arrive at the defired point in the lees, on ac- 
 count of the firmnefs of their texture, which 
 fwells confiderably, and acquires a degree of 
 rigidity, that oppofes the extraction of the 
 impurities which this operation is defigned to 
 remove. 
 
 Hj The 
 
1 o 4 The Art of Bleaching 
 
 The firft thing to be done in the management 
 of thread, is to make good the faftenings of all 
 the fkeins, large or fmall ; for there are many 
 places in which the loops are either imperfectly 
 or not at all fattened by the fpinners. As thread 
 fwells up more than half its own bulk by wet- 
 ting, it is neceffary to loofen all the faftenings 
 already made, in fuch a manner that the thread 
 may lie very loofe in the loop $ for if it were 
 otherwife, there would be reafon to fear an in- 
 equality in the bleaching. One perfon may 
 loofen, and tie up again, all the fkeins of one 
 hundred pounds of thread in a day, This is 
 work for women rather than men. 
 
 When the fkeins are made up, a firing is 
 paffed through two or three fkeins, according to 
 their thicknefs ; upon one end of which firing, a 
 certain number of knots may be made to denote 
 the owner of the article, whofe name is fup- 
 pofed to be entered in a book oppofite the fame 
 number. This affemblage of fkeins is called a 
 hank, fee Plate II. fig. 1 1. An account is like- 
 wife taken of the weight of the thread, and the 
 number of hanks, togetherwith its quality,asmay 
 be neceifery. Thefe. different obferyations muft 
 be entered in the day-book as foon as the goods 
 are received, for fear of omiffion or miflake. 
 The fame care mull be taken to regifter the 
 
 quality, 
 
Cottons, Thread, &V. 103 
 
 quality, number, and weight, of the piece- 
 goods under the name of the proprietor. 
 
 The firings for tying up the hanks ought to 
 be previoufly boiled in water, as well for the 
 purpofe of clearing them of the drefling, which 
 the manufacturer may have applied for the pur- 
 pofe of glazing them, as to render them fupple, 
 and prevent their curling up when acled upon 
 by the hot lees. The fame firings may be ufed 
 for a long time. 
 
 The foaking in water requires a lefs time for 
 thread than for piece-goods, becaufe there is no 
 drefling to be diffolved, but merely the impurity 
 which it may have acquired during the fpin- 
 ning. The thread is to be difpofed in layers in 
 the fleeping veffelsj taking care to place the 
 end of the firing of each hank upon the hank 
 itfelf, in ord.er that there may be no difficulty in 
 taking them out. It is likewife advifable, to 
 place thofe articles together which belong to 
 the fame perfon. Attention muft alfo be paid, 
 to place a kind of bafket-work, as was directed 
 with regard to the piece-goods, in order that 
 the lower parcels while preffed by the upper 
 may continue to be furrounded with water. 
 Fine goods ought always to be placed the laft ; 
 and in order that no part may rife above the 
 furface, they muft be kept down either by a 
 
 h 4 cover 
 
104 The Art of Bleaching 
 
 cover perforated with holes, or boards properly 
 difpofed. Thread may Hkewife be foaked as 
 well as piece-goods, by expofure to a current 
 of water ; but for this purpofe it is neceffary to 
 pafs the hanks over poles fixed beneath the 
 water. When the thread has remained feven or 
 eight hours in the water, it is eafily taken out 
 after the water is drawn off. It may then be 
 wrung on the pin, or preffed, after having been 
 rinfed, if convenient, in clear water. 
 
 It is then to be arranged in the fame manner, 
 one ftratum crofs-wife over the other in the 
 troughs for maceration, as has been directed 
 for the freeping ; or, if the fituation and con- 
 venience of the operator permit, it may be fuf- 
 pended upon flicks. But it will require more 
 time to macerate or heat in this manner, though 
 the goods will by that means acquire a more 
 equal colour. When they are fuppofed to be 
 well cleared, as we have obferved refpefting the 
 piece-goods j they are then to be taken out, 
 wrung or preffed, then rinfed or warned in clear 
 water, and wrung a fecond time, or hung up to 
 drain. When the thread is wrung on the pin, 
 care muft be taken to twift the hanks three 
 times in three different parts of their circum- 
 ference, drawing it out each time with as much 
 ftraitnefs and equality as poffible, to difpofe and 
 
 arrange 
 
Cottons, Thready &c. 105 
 
 arrange the threads. This operation is likewife 
 neceffary for the perfect wringing out of the 
 fkeins in every part. The precaution of extend- 
 ing the hanks upon the pin for the due arrange- 
 ment of the threads, is particularly neceffary for 
 double thread, which is apt to curl up by the 
 impreffion of the heat. If they be left in this 
 fituation, there would be reafon to fear, that 
 the bleaching would be lefs perfect in the curled 
 parts. 
 
 Inftead of wringing the thread on the pin, 
 which requires much time, it would be ftill 
 better to clear it of the water by the beetle, or 
 by the prefs, as by this treatment the thread 
 would be lefs fubjeft to injury. 
 
 With regard to the time of maceration for 
 thread, it requires in general lefs time than 
 piece-goods, by reafon of the clofe texture of 
 the latter. The time, likewife, depends on the 
 finenefs or quality of the article, the tempera- 
 ture of the air, and the goodnefs of the lees. 
 
 With regard to ftockings, gloves, and mit- 
 tens, they require at leaft as much time, if not 
 more, than cloths, to be properly macerated. 
 This muit be managed according to the clofe- 
 riefs of their texture, and the other relative cir- 
 cumftances already mentioned. 
 
 Cotton, as well as linen thread, muftbe made 
 
 into 
 
1 06 The Art of Bleaching 
 
 into hanks, then foaked in water, and difpofed irt 
 crofs-layers, if troughs be ufed. Cotton imbibes 
 water with great difficulty, and is lefs difpofed 
 to adhere together than linen thread, which is 
 not fo foft and porous. It therefore always 
 fwims at the top of the fluid in fpite of every 
 precaution which can be taken, unlefs it be 
 kept down by the methods before defcribed. 
 The cotton being difpofed in crofs-layers, and 
 thus loaded, the troughs (which, as well as.thofe 
 for piece-goods, ought to be fquare, for the 
 more convenient difpofition of the feveral ar- 
 ticles) are to be filled with water. 
 
 On account of the difficulty of imbibing 
 water, which depends on a certain oil, gum, or 
 refin, it is naturally impregnated with, cotton 
 requires at leaft as much foaking as piece-goods. 
 Though it may not appear foul, it never fails to 
 render the water of a darkifh colour by its im- 
 purities. The foaking, likewife, affords a faving 
 of lees, for if the cotton were to be put into the 
 lees, without this previous treatment, the cop- 
 per would hold but a fmall quantity. 
 
 After twenty-four hours, or lefs time, of im- 
 merfion, the cotton is to be taken out, and 
 wrung or preffed, after rinfing in clear water, if 
 thought ncceffary. It cannot be left to drain 
 of itfelf, unlefs the procefs be conducted very 
 
 leifurely 
 
Cot Ions, Thread, &c. 107 
 
 leifurely indeed, for it requires a long time to 
 clear itfelf of water in this manner. 
 
 The cotton is not to be macerated. After 
 fteeping in water it is boiled in the lees. A 
 good folution of black foap may on fome occa- 
 fions be ufed inflead of the lees ; but the lees 
 are always more effectual, and need not be made 
 ftronger than three quarters of a degree below 
 zero. But the folution of black foap muft not 
 be neglected for thread foiled by the oil of the 
 jennies or fpinning machines ; for fome of the 
 girls who manage that procefs take fo little 
 care in greafing the fpindles, that the bobbins 
 of thread are fpotted with a thick black oil, 
 which it is advifable to rub, previous to lixivia- 
 tion, with a good folution of black foap. If 
 this be not done, it will be very difficult to dif- 
 charge the fpots : in fpite of every care they are 
 fometimes vifible upon the hanks even after 
 the bleaching. I muft here remark, that I re- 
 commend black foap in preference to the white, 
 becaufe it is more active, and does not contain 
 thofe fmall ftones, or grains, which fometimes 
 abound in the white foap, and may injure the 
 goods, or the hands of the operator. Black 
 foap, indeed, has a ftronger fmeJl, but this is 
 diiiipated in the courfe of the fubfequent pro- 
 cefles. 
 
 Night- 
 
10S The Art of Bleaching 
 
 Night-caps, ftockings, focks, mittens, and 
 gloves of cotton, are to be tacked together as 
 foon as received, and marked with threads paflf- 
 ing through each pair ; upon which a greater 
 or lefs number of knots is to be tied, and an 
 account taken in the day-book of every circum- 
 ftance relating to their number, quality, &c. 
 which may be neceflary to prevent miftakes, or 
 confufion, in the fubfequent delivery to the re- 
 fpecHve proprietors. 
 
 Thefe goods, when marked and tacked to- 
 gether, are not to be fteeped in pure water ; but, 
 on the contrary, in a good folution of green or 
 black foap as hot as poffible, in order that the 
 black and oily marks, and the impurities with 
 which they always more or lefs abound, may- 
 be eafily detached by rubbing them with the 
 hands. 
 
 "When the ftockings, night- caps, &c. are 
 taken out of the fuds, thev mull be rinfed and 
 cleaned in clear water, and afterwards wrung 
 by hand. They cannot be treated in any other 
 manner, excepting by the prefs, without danger 
 of breaking fome of the flitches. 
 
 After this treatment the feveral pieces may- 
 be conveyed to the troughs for immerfion in the 
 bleaching liquor ; but the work fucceeds much 
 better if they be previoufly boiled in the lees. 
 
 With 
 
Cottons y Thread, &c. 109 
 
 With regard to flax and hemp, which it may- 
 be required to bleach in the rough, it will be 
 proper in the firft place to give them a lixivia- 
 tion, on account of the difficulty of macerating 
 them in this ftate, though it is not abfolutely 
 impracticable to do it, by tying them up in fmall 
 feparate parcels. The different knots of flax, 
 muft, therefore, be difpofed on the bottom of 
 the boiler, firft covered with a piece of wicker 
 work, upon which a coarfe cloth is fpread. 
 The different knots are to be mixed as little as 
 poffible, taking care to make a flight fold, or 
 return, at the head of each knot. They are to 
 be preffed by hand the fame as the ftockings. 
 For rinfing and walhing them, it is likewife ne- 
 ceflary that this mould be done by hand, hold- 
 ing each parcel by the head, and repeatedly 
 plunging and moving it about in water. This, 
 at lealt, is the management I have thought it 
 beft to adopt in my trials. 
 
 It is to be remarked, that the exhaufted and 
 unferviceable folutions of the oxygenated muri- 
 atic acid may be ufcd inftead of water for the 
 lixivium, if it be fufficiently concentrated to 
 mark one degree beneath zero on the areometer. 
 I have fometimes ufed it to advantage for cotton 
 goods, after the laft, and even the fecond, boil- 
 ings. This liquor was not lefs difpofed to be- 
 1 come 
 
no The Art of Bleaching 
 
 come coloured, by diffolving the extractive parts 
 of thread and piece-goods, notwithftanding the 
 acid with which the pot-afh appeared to be 
 combined. It feems probable, that the acid is 
 but flightly attached to the alkali, and may be 
 driven off by a ftrong heat -, as, in facl, I thought 
 I perceived in feparate evaporations *. 
 
 * This laft observation feems to apply to fuch bleaching 
 liquor only, as may have been deprived of its fmell by pot-afh> 
 and not to that in which chalk, or lime, may have been ufed; 
 
 CHAP, 
 
Cottons, Thread, &c. gjg 
 
 CHAP. IX. ' 
 
 Concerning the fir ft Immerfion. 
 
 T. 
 
 HE firft, as well as the laft, immerfions may 
 be made with the acid without fmell, compofed 
 with the proportion of pot-afh already pointed 
 out ; but in cafe this proportion mould be ex- 
 ceeded, it muft not be ufed but for the two firft 
 immerfions. In every cafe thefe ought to be 
 made with the acid without fmell, becaufe this 
 liquid acls with more fpeed and equality. We 
 fhall prefently mention the reafon why, in cafe 
 of a greater proportion of pot-aili, no more than 
 the two firft immerfions ought to be made in 
 this inodorous oxygenated muriatic acid. 
 
 When the immerfions are to be made, if the 
 apparatus is fo placed, that the trough or back 
 defigned for that purpofe is placed below the 
 ipigot of the pneumatic veiTel (fee Plate I. fig. i, 
 2), the muriatic acid is to be drawn off to the 
 necelfary height, in order that the goods which 
 are folded in equal folds may be covered at leaft 
 two or three inches. But if the arrangement 
 be not made in this manner, the liquor muft be 
 
 drawn 
 
112 The Art of Bleaching 
 
 drawn off in pitchers, or conducted to the vef- 
 fels of immerfion by leaden or wooden tubes, 
 provided thofe vcfTcls be placed on the ground, 
 or low enough for that purpofe. With refpect 
 to what remains in the pneumatic veffel, which 
 is fhewn by the degrees on the external tube or 
 £ase, after the moveable veffel of immerfion is 
 conveyed away on caftors, if the bleaching li- 
 quor be fuppofed to be fufficiently ftrong, and ; 
 is not immediately wanted, it may be drawn off 
 in ftone-ware bottles of that kind which is ufed 
 for nitrous acid ; or, if requifite, the diftillation 
 may proceed to its entire termination. I muft 
 only remark, that when the liquor is thus partly 
 drawn off, the diftillation is renewed though 
 there be no increafe of the fire, becaufe the gas 
 which efcapes from the diftilling veffels under- 
 goes lefs refiftance from the diminished column 
 of water. This is even a method, as I have al- 
 ready remarked, to render the liquor in the fe- 
 cond partition equal in Strength to that in the 
 firft ; for otherwife there will always be a dif- 
 ference between them, which, neverthelefs, 
 fpecdily difappears when the whole, of the fluid 
 contained in the pneumatic veffel is drawn off 
 at once, and poured into the fame veffel for im- 
 merfion. 
 
 I mall now proceed to defcribe the method 
 
 of 
 
Cottons, Thread, &c. 113 
 
 of fubmitting piece-goods to the a&ion of the 
 oxygenated muriatic acid. 
 
 1. Above the veffel for immerfion is placed 
 the winch, or reel, ufed by dyers. The piece- 
 goods, if there be many pieces, are fewed to- 
 gether, or fattened with firings in fuch a man- 
 ner, that they form a large loop, or endlefs web, 
 which is pafled over the reel, fo that by turning 
 one part rifes as the other defcends, and the; 
 whole length is fubje&ed to the aaion of the 
 acid. One workman turns the handle gently, 
 while another Handing in front of the cloth, 
 takes it by each felvedge, and conduas it into 
 the liquor. Two round fmooth Haves may be 
 ufed for the fame purpofe. The perfon who 
 manages the immerfion takes care to prevent 
 the piece from folding breadthwife, and guides 
 the cloth in fuch a manner, that it may continue 
 open and expanded as it defcends into the 
 veffel. 
 
 This procefs of turning muft be continued for 
 half an hour, in which time the liquor, almoft 
 in every cafe, has produced its whole effeft in 
 equalizing the colour. It is then taken off the 
 reel, and left in the acid for another quarter of 
 an hour ; after which it is palled again over the 
 reel, and left in the liquor till the time of tak- 
 ing it out, which may be done immediately, if the 
 
 * fluid 
 
! 14 The Art of Bleaching 
 
 fluid no longer acts on the goods, and mould 
 appear (till of value to operate upon other 
 pieces. This may be immediately afcertained, 
 either by the appearance of the fluid, of which 
 experience will render the operator a fufficient 
 judge, or by the proof of indigo or cochineal, 
 pointed out in the Annals of Chemiftry, of 
 which I fhall hereafter fpeak. 
 
 If the liquor do not retain fufKcient ftrength 
 for new, or dyed pieces, but enough for fuch as 
 are in a more advanced ftate (which circum- 
 ftances, and qualities, will be foon learned by 
 experience) , or if it be proper for cotton itock- 
 ings, or thread only, they may immediately be. 
 immerfed after having wrung the cloths by the 
 wring over the trough, in order to fave the acid 
 they have imbibed, and bring them to a ftate 
 fit for boiling. Every time the piece-goods arc 
 wrung, it is necelTary to arrange them in folds 
 on a clean table, or board, whence they may be 
 carried and arranged in. the fame manner upon 
 the frage of the lixiviating boiler. 
 
 In cafe there be no particular hafle required 
 to boil the goods, after it has been afcertained 
 that the acid exerts no further action upon 
 them ; and fuppofing, likewife, that no other 
 goods are at hand to be immerfed in the fluid, the 
 yiects may be difengaged from the reel, and left 
 
 in 
 
Cottons, Thread, &c. n r 
 
 Sn the bleaching liquor until they are wanted 
 for the boiling. This prolonged immerfion can 
 do no harm, and only exhaufts the acid more 
 completely. Laftly, when this liquor is entirely 
 cxhaufted, it is either to be thrown away, or elfe 
 referved for the purpofes hereafter to be men- 
 tioned. This firft folution, it may be remarked, 
 has ufually a ruddy yellow colour. 
 
 The veflel, or back, for immerfion ought to be 
 fquare, or at leafl, long like a bathing tub, be- 
 caufe the piece-goods are much better flowed 
 in fuch a veflel. It ought to be fomewhat more 
 than five quarters long, and three quarters wide, 
 thefe dimenfions being beft fuited to our piece- 
 goods (in France). The height may be propor- 
 tioned to the quantity or length of the pieces 
 intended to be depofited therein at the fame 
 time, and the mafs of fluid which muft, confe- 
 quently, be poured in. 
 
 The mixed goods of cotton and thread, or 
 cotton alone, being more fufceptible of the 
 fpeedy aftion of the acid than fuch as are en- 
 tirely of linen ; and among thefe the fine being 
 more fpeedily affeaed than the coarfe, they 
 muft accordingly be taken out as early as expe- 
 rience may have mown to be proper for their 
 effeaual bleaching. The other goods which lie 
 beneath, and require to remain a longer time in 
 
 1 2 the 
 
1 1 6 The Art of Bleaching 
 
 the fluid, will be more advantageoufly a&ed 
 upon, becaufe they will be lefs preffed, and will 
 float in a greater volume of the bleaching liquor. 
 Inftead of paffing the goods over the reel or 
 winch in the manner here defcribed, which re- 
 quires the time and attention of two perfons, 
 the goods might be previoufly difpofed in a 
 frame of one ell in breadth. This frame, fee 
 Plate VIII. fig. i and 2, is provided with a 
 number of pins with heads, over which is pafled 
 the fame number of loops attached to the fel- 
 vedge of the cloth, at the diftance of an ell 
 afunder. By this means the pieces are fuf- 
 pended in a zig-zag form, and not only occupy 
 a fmall fpace in the veffel, but likewife become 
 of a very even colour, in confequence of the free 
 accefs which the acid obtains to the whole of the 
 furface when the apparatus is plunged therein. 
 This operation may be performed by a pulley 
 fattened to lines which fufpend the frame. The 
 latter may thus be eafily taken out with its 
 charge, and be left to drain above the vefTel it- 
 felf, or any other veffel appropriated to that 
 purpofe, in cafe the liquor lhould be found fuf- 
 ficiently ftrong to admit a fecond frame pre- 
 vioufly prepared. If this fhould not, however, b£ 
 the cafe, the fluid is to be difnofed as before 
 
 J A. 
 
 directed. 
 
 With 
 
Cottons •> Thread, &V. ny 
 
 With regard to linen and hempen thread, and 
 knit or woven goods of the fame materials, they 
 may be managed as follows. 
 
 Over a trough for the immerfion, fee Plate IX. 
 fig. 7 and 8, are placed clean poles or fticks 
 cleared of the bark, upon which the fkeins of 
 thread, {lockings, night-caps, or mittens in pairs, 
 are to be hung. After the acid is introduced, 
 each hank, or pair of ftockings, &c. is to be 
 fucceflively turned, by immerfing that part into 
 the liquor which was before upon the pole. In 
 this manner the operator proceeds from one 
 pole to the other, and returns fucceffively to 
 thofe goods which were flrft turned. Care 
 muft be taken to open them well at the time of 
 turning, in order that they may prefent a greater 
 furface to the fluid. Inftead of turning the 
 poles fingly in this manner, it might be fo ma- 
 naged by a band, or other mechanical contriv- 
 ance, that the whole might turn together upon 
 turning one (ingle piece of the fet. This me- 
 thod would be lefs tedious and fatiguing for the 
 workmen. 
 
 It is advifable, that the troughs for the im- 
 merfion of threads mould be as nearly as pofli- 
 ble of a fquare figure, in order that they may 
 hold a greater quantity of hanks ; and the 
 diftance between each may be very nearly 
 equal, for the purpofe of exhaufting the bath 
 
 J 3 with 
 
1 1 8 The Art of Bleaching 
 
 with uniformity; excepting that the diftance 
 between the fides of the veffel, and the thread 
 may be lefs confiderable. 
 
 . As the bleaching liquor is liable to lofe its gas 
 more fpeedily in proportion to the extent of its 
 furface, it might, perhaps, be proper to have the 
 troughs rather deep than broad, in order that 
 the gas may be more effectually retained ; and 
 fmce it is effential, that the bleaching liquor 
 fhould act with the utmoft pollible equality 
 upon the threads, inftead of pouring it into the 
 troughs wherein thefe are difpofed and arranged 
 upon poles, it would be more advantageous to 
 caufe it to rife gradually to the height of the 
 hanks or poles ; a condition which may eafily be 
 obtained by means of one or more tubes of lead 
 or wood ; the bended parts of which might be 
 laid under the middle of the bottom of the 
 trough. Thefe tubes being fixed along the in- 
 ternal fides of the trough, may be furnifhed at 
 their upper extremity with a funnel of wood, or 
 of lead, for the reception of the fluid. After 
 the fluid has been poured in, great care muft be. 
 taken to keep the funnels clofed. 
 
 Thefe are the methods which it is convenient 
 to ufe, to fubject threads to the action of the 
 oxygenated muriatic acid, when the operator is 
 in pofiefiion of a certain quantity; but when, 
 on the contrary, the quantity he poflefles is 
 
 Qnall, 
 
Cottons, Thread, m. I i 9 
 
 fmall, or his operations on a fmall fcale, certain 
 pieces of bafket work, with handles, for which 
 fee Plate II. fig. 2 and 3, may be ufed, feveral of 
 which ma v be placed one above the other in a 
 found or fquare trough of oak or fir, it being of 
 110 oonfequence which of the two kinds of 
 wood be ufed ; upon each bottom a fingle layer 
 of hanks is to be difpofed, taking care that it 
 ftiall be covered with the bleaching liquor at 
 leaft one inch or two in depth, and to turn them 
 upfide down, at firlt every quarter of ari hour, 
 and afterwards every half hour j laftly, after one 
 hour's- immerfion the thread may be taken out, 
 if its colour be equal, and other thread put in, 
 if the- blfeachmg liquor continues ' to pofTei*s 
 ftrength.- In a word, this procefs is to be ma- 
 naged like the other already defcribed ; it mull, 
 however, be remarked, that the bleaching liquor 
 may appear to poffefs fome ftrength by the tell 
 of cochineal or indigo, though it may not have 
 fufficient for the bleaching procefs ; thefe nearly 
 exhaufted folutions are to be referved either for 
 the kind of preparation hereafter to be pre- 
 fcribed, or thrown away if no immediate ufe 
 prefents itfelf 3 'or otherwife they may be kept 
 for ufes which I {hall defcribe when I fpeak of 
 piece-goods. The colour of the bleaching li- 
 quor which has been ufed for the firft immer* 
 1 4 fion 
 
no The Art of Bleaching 
 
 fion of linen or hempen thread or flockings is or* 
 a ruddy yellow, the fame as that which has been 
 ufed for piece-goods. 
 
 Brown or white cotton threads are to be fteeped 
 and turned in the oxygenated muriatic acid, in the 
 •fame manner as thread of flax or hemp ; namely, 
 upon poles, or in bafkets ; with this difference, 
 neverthelefs, that they require to be turned only 
 haif as often. A good half-hour is fufficient for 
 the firfl: immerfion, after which time they are to 
 be taken out, and other thread put in, if the 
 bleaching liquor continues ftrong enough for 
 ufe, for it very felplom . happens that the new, 
 "bleaching liquor is incapable of ferving more 
 than once for cotton. .This, liquor does not un» 
 dergo any remarkable change of colour. 
 
 ^Stockings,, night-caps, gloves, mittens, and 
 focks of cotton, may be very well managed with 
 regard to the immerfion, in the fame manner as 
 linen or cotton thread ; but as this fort of bulky 
 articles occupy a coniiderable fpace, and cannot 
 conveniently be laid on the other, it is adyifable 
 to arrange them fcparately in layers in the 
 troughs,, which may be of any form, either round 
 or fquare, though the latter form is moil con- 
 venient, and, upon the whole, to be preferred. 
 Thefe articles are to be difpofed in layers upon 
 platforms of clear ofier work, provided, as has 
 
 already 
 
Cottons, Thread, &V. iai 
 
 already been obferved, with four handles, upon 
 which the other platforms are to be placed. No 
 more than three can be put into one trough. 
 As the articles placed upon the uppermoft plat- 
 form might rife to the furface, which would ex- 
 pofe. them to an inequality of colour, another 
 platform, or piece of bafket-work, with a rim, 
 may be placed above them, which muft be fo 
 managed as to prefs the goods in a Tmall degree, 
 and -prevent their rifing. Two or three ranges 
 of night-caps, ftockings, Sec. are fufficient upon 
 each platform. 
 
 . It is eafily known: when the cotton ftockings, 
 or night-caps, have .remained a fufficient time in 
 the firft bleaching liquor. Nothing more is ne- 
 ceflary for this purpofe than to hold them up to 
 the light i in which pofition they ought not to 
 fhew thofe opaque fpots, which are of a more 
 or lefs ruddy colour, according to the nature of 
 the goods, or' at leaft very few of thofe fpots 
 ihould appear. 
 
 Cotton ftockings^. with .clocks, are more diffi- 
 cult to bleach in that part, and muft be care- 
 fully pulled open every time they are immerfed 
 in the liquor, becaufe they are very fubje£t tq 
 ihrink up. It is advantageous to turn them in- 
 iide-out previous to the fecond immerfion. 
 
 The prefent remark with refpeel to cotton 
 
 ftockings 
 
f $ l The Art of Bleaching 
 
 (lockings is Hill more flrongly applicable to 
 ribbed thread (lockings. The fingers of gloves 
 are likewife more difficult to bleach at their ex*. 
 tremities, becaufe the texture is clofeft at that 
 part. It is even prudent to turn ribbed (lock- 
 ings infide-out feveral times during the courfe of 
 the immerfion, for which reafon it will be moft 
 convenient to place them always near the top of 
 the veffei. Common cotton (lockings, and other 
 goods, may remain in the fluid without being 
 turned during their immerfion, becaufe they 
 are more loofe and fpongy. They may be left in 
 the liquor about half an hour. Cotton manu- 
 factured into goods is more difficult to be pene- 
 trated than the fimple thread. By means of 
 cords paffing through the handles of the lowef 
 platform, upon which all the others reft, the 
 whole fyftem may be very eafily raifed by a 
 pulley. In this fituation they mud be left to 
 drain above the trough -, after which, the pieces 
 arc to be preflfed feparately by the hand, or all 
 at once by mechanical means, if the operator be 
 provided with an apparatus. 
 
 If the acid be dill good, other (lockings are to 
 be immerfed in it, either in their firft (late, or 
 in different itages of the procefs j the raw ar- 
 ticles mufl be immerfed in lefs quantity than 
 thofe which are partly bleached : if the liquor 
 
 be 
 
Cottons, Thread, fcfr. 2 
 
 be nearly exhaufted, it is to be referved pur- 
 suant to the recommendation alrcadv given. 
 
 The obfervation which we have made with 
 regard to night-caps, ftockings, &c. made of 
 cotton, in which the greater or lefs effecT: ma 7 
 be feeu by holding them up to the light, is alfo 
 applicable to gloves and ftockings of linen 
 thread : but, as it has already been remarked, 
 thefe goods are much more difficult to bring to 
 an equal colou ; for however loofe the texture 
 may be. the linen thread always fvvells confider- 
 ably, fo as to render ftockings ft iff and inflex- 
 ible. The texture in this fituation is fo difficult 
 to be penetrated, that the bleaching is as it 
 were entirely fuperfkial. It is better, therefore, 
 when ftockings are required to be well bleach- 
 ed, that the thread mould have been cleanfed 
 at leaft before the knitting or weaving, by 
 which means it becomes more difpofed to open 
 and imbibe the acid. Stockings, of linen thread 
 entirely in the raw ftate, without having been 
 cleared of their firft impurities, are very un- 
 pleafant for the bleaching liquor to operate 
 upon, and ftill more when they are ribbed or 
 have clocks. Thefe goods are liable to a very 
 unequal colour. 
 
 In general, all kinds of looped or flocking 
 ^ork of flax or hemp, muft be fuffered to ret 
 
 main 
 
124 The Art of Bleaching 
 
 main in the liquor at lead half as much longer 
 than other goods ; that is to fay, from two to 
 three hours, for the acid does not penetrate 
 them and give them an equal colour, unlefs it 
 be'fuffered to operate for a confiderable time. 
 They muft not even be lixiviated until their co- 
 lour is nearly equal. If it mould happen that 
 they do not acquire an uniform colour during 
 the firft immerfion, they mult have a fecond, 
 which muft, in both cafes, be of confiderable 
 ftrength, and in which they muft be kept a fuf- 
 ficient time to undergo the effect without the 
 intermediate action of the lees. This obferva- 
 tion is equally applicable to all other piece- 
 goods of linen, or ftockings of cotton. 
 
 With regard to knots of flax or hemp, they 
 are to be bleached in the fame manner as the 
 ftockings and night-caps, by difpofing them 
 as much as poflible in thin ftrata ; be caufe fila- 
 ments are naturally much difpofed to become 
 entangled, and form a clofe mafs. Knots of 
 flax are bleached very fpeedily, that is to 
 fav, by one or two immerfions lefs than are 
 required for thread of middling finenefs. It 
 muft, neverthelefs, be obferved, that they muft 
 not be bleached until after having been beaten 
 and combed, becaufe they muft always be 
 foaped after the bleaching, on account of their 
 
 adher- 
 
Cottons t Thread, Z3c. X25 
 
 adhering together while drying, a circumftance 
 which can hardly be prevented. If this be not 
 attended to, there will be confiderable lofs. 
 Knots of flax bleached in this manner, and 
 afterwards combed, appear to the eye as beauti- 
 ful and mining as white filk. 
 
 It muft be remarked, that if the (loop of 
 flax or hemp obtained from this bleaching, or 
 bleached feparately, be cut, in cafe the ftaple be 
 too long, and afterwards carded, it has a lingular 
 reiemblance to the cotton of Siam, which is 
 very plentiful in the market, and known to have 
 the fhorteft ftaple. When it is well carded, no 
 difference can be perceived between the two 
 articles ; neither is it poffible to diftinguifli them 
 in fpinning. I have had an opportunity to 
 weave fome of this thread at the end of a web : 
 of cloth, where it might have been taken for 
 real cotton. I have likewife had an oppor- 
 tunity of ufing it in candle wicks, in which 
 there was no perceptible difference between it 
 and cotton, either with regard to the colour, or 
 clearnefs of the light. It will, no doubt, be a 
 very interefting object to afcertain all the advan- 
 tages which the commercial world may derive 
 from this application of the oxygenated mu- 
 riatic acid. 
 
 CHAP. 
 
tafi The Art of Bleaching 
 
 CHAP. X. 
 
 Inftrufticns with regard to the Quantity of Lixivi~ 
 at i ens and Immerfions. 
 
 JL HE number of immerfions for hempen or 
 linen goods is commonly three for fine goods, 
 fiich as hollands, cloths, lawns, &c. &c. five 
 for common cloths, and feven for the coarfeft. It 
 may alfo happen, that an immerfion extraordi- 
 nary may be required for each of thefe kind of 
 goods, according to the accidents they have 
 met with, the greater or lefs degree of clofenefs 
 in their texture, and the dark colour of threads 
 here and there paffing through the cloths, par- 
 ticularly in thofe known at Laval under the 
 name of toiles brindellees. This name is ^iven 
 to them on account of threads paffing through 
 them, which are faid to be dyed by the manu- 
 facturer for the exprefs purpofe of rendering it 
 heavier, and on this account more advantageous 
 in the fale. The dark threads of thefe cloths 
 can never be bleached by the common method j 
 whence a judgment may be formed of the ad- 
 vantage of the new method ia bringing thefe 
 
 goods 
 
Cottons, Thread, &c. f 2 -i 
 
 goods into the market, which, though fine and 
 equal in beauty and general whitenefs to thofe 
 of Flanders, Ireland, and Silefia, are neverthe- 
 lefs greatly deprefled in price, on account of the 
 fmgularity In the colour, which renders them at 
 leaft twenty per cent lefs valuable. 
 
 From the number of immerfions here pre- 
 fcribed, it will follow that the lixiviations may- 
 be reduced to two for fine cloths, four for mid- 
 ling cloths, and fix for the coarfeft kind, fuppof- 
 ing the moft perfeft white to be required 5 for 
 if a commoner colour fhould be thought fuffi- 
 cient, one lixiviation, and one immerfion, may be 
 deduaed from each kind of goods ; whence it 
 follows, that for a middling white no more will 
 be required than to give one or two immerfions 
 to the fine goods, two or three for thofe of me- 
 dium finenefs, and three or four for goods of the 
 moil inferior quality. 
 
 With regard to piece-goods of cotton, the 
 coarfeft will not require more than four immer- 
 fions, and three lixiviations. For fuch as confift 
 of linen and cotton mixed, no regard mult be 
 paid to the cotton, but to the thread, which al- 
 ways, during the procefs, remains behind in its 
 degree of perfeaion. Neverthelefs thefe are 
 bleached more fpeedily than if they were en- 
 tirely of linen, becaufe the cotton, which is in- 
 termixed, 
 
128 The Art of Bleaching 
 
 termixed, renders the goods more penetrable by 
 the acid. In general no more than five immer- 
 sions and lixiviations are required for ihe coarfeft 
 goods of this kind. The fame advantage of 
 fpeed is alfo obtained in other open-worked 
 goods, which admit the acid more readily into 
 their texture. 
 
 Linen and hempen threads are affected nearly 
 in the fame manner as piece-goods ; that is to 
 fay, the fine thread requires no more the three 
 immerfions, and two lixiviations, the middling 
 four or five, and the double or fewing thread, or 
 threads of coarfe quality, fix or feven immer- 
 fions ; whence it follows, that three or four lixi- 
 viations are fuflicient for fine thread, five or fix 
 for clofe coarfe thread, and fix and a half for 
 fewing thread of the fame quality. The latter 
 threads requiring more care and attention, are 
 likewife more difficultly penetrated by the acid. 
 
 Gloves and flockings of hemp or linen follow 
 nearly the fame proportions, with the addition 
 of half a lixiviation and one immerfion more, 
 according to their quality, the clofenefs of their 
 texture, and the inequality of the thread. 
 Ribbed flockings, or fuch as have woven clocks, 
 will, likewife, in fome cafes require an additional 
 immerfion. The fame proportion is to be ob- 
 ferved in thefe goods wheji they are mixed, as 
 
 was 
 
Cottons, Thread, &c. 129 
 
 was (hewn with regard to mixed cotton goods, 
 excepting that an extraordinary immerfion, or 
 half immerfion, is given on account of the linen 
 thread, which fvvells up by moifture, and al- 
 ways becomes white fomewhat more (lowly. 
 But, on the whole, fingle threads bleach more 
 quickly than piece-goods, becaufe the threads 
 are more difengaged and feparate from each 
 other, and being lefs compreiTed admit the fluid 
 into contact with greater facility, with the ex- 
 ception only of dyed or fewing thread. But 
 this facility in the bleaching is fully counter- 
 balanced by the care which thread requires tQ 
 prevent its becoming entangled or broken. 
 
 Three immerfions are fufficient to bleach the 
 coarfeft cotton thread, fuch as that which is in- 
 tended for cotton wicks ; and accordingly no 
 more than two are required for common threads 
 with the appropriate lixiviations, it being al- 
 ways understood that the fineit white colour is 
 here meant. It is of no confequence whether 
 the cotton be of a dark colour, or inclined to 
 white : the latter, which is naturally more foul 
 or impure, might be expected to bleach more 
 fpeedily, but it frequently acquires the pro- 
 per degree of whitenefs more flowly than the 
 other. 
 
 Gloves, mittens, focks, night- caps, and ftock- 
 K ings, 
 
1 30 The Art of Bleaching 
 
 iflgs, of cotton, require no more than three im« 
 mcrfions, and fometimes two are fuflicient, ac- 
 cording to the quality and clofenefs of their tex- 
 ture. Hence it may be obferved, that the 
 number of lixiviations cannot exceed two for 
 the molt common goods, and it is, therefore, eafy 
 to regulate the procefs for an imperfect white. 
 This colour, however, is feldom required on 
 cotton. 
 
 I mud obferve, that by the words half lixivia- 
 tion, I underftand that the lees poflefs no greater 
 ftrength than one degree at molt for thread and 
 piece-goods, and half a degree, or three-fourths, 
 for cotton, if the lees be new ; but other wife 
 the operator may ufe fuch as have already been 
 applied, and have not been reftored to their 
 original ftrength. When the fame term is ap- 
 plied to immerfions, I mean to fpeak of the 
 bleaching liquor, diluted with one-fourth of its 
 weight of water, or fuch as has already been 
 ufed for the firft white, and ftill retains ftrength 
 enough for the immerfion of pieces already ad- 
 vanced in their bleaching. 
 
 When the muriatic acid without fmell is well 
 made, the operator fees with pleafure that one 
 quarter of an hour after the immerfion of thread, 
 a white, and, as it were, foapy lather comes up 
 to the top. This is a good fign, for it very 
 
 feldom 
 
Cottons, Thread, &V. i«i 
 
 feldom happens, that pieces immerfed in a 
 bleaching liquor which produces fuch an effect, 
 do not obtain an even colour. I muft, moreover, 
 remark, that it is not neceffary to dry the goods 
 before their immerfion in the lees, or the bleach- 
 ing liquor. It is fufficient that they be well 
 wrung, or cleared of their water to fuch a de* 
 gree, as only to remain moift. We might even 
 plunge them into the bleaching liquor immedi- 
 ately after their rinfing, or wringing out of the 
 lees, if it were not that this management di- 
 minifhes its ftrength in fome degree. 
 
 On the fame principle we may plunge the 
 goods;, when taken out of the bleaching liquor, 
 into the lees without rinfing, but merely after 
 ftrong preffure, though the rinfing appears to 
 deferve the preference. To fave time and trou- 
 ble, however, I would advife the operator to 
 omit the rinfing when he is defirous of haftening 
 his work ; the only rifk which this omifTion af- 
 fords, is that of weakening or neutralizing the 
 lixivium to a greater degree, which by this 
 means will not ferve for fo many boilings. It 
 is proper alfo to remark, that if a lixivium thus 
 neutralized, but not loaded, with colouring 
 matter (which may be productive of deception 
 if the ftrength be not afcertained by the tafte) 
 be ufed, the goods will come out dyed of a 
 k z nankeen 
 
132 The Art of Bleaching 
 
 nankeen colour, and the operator will be af- 
 tonifhed that they do not bleach though fleeped 
 in a new and ftrong bleaching liquor. This 
 laft, on the contrary, ferves only to deepen the 
 nankeen tinge ; but, as I have before remarked, 
 this accident does not happen, excepting when 
 the lixivium is entirely exhaufted, and neutral- 
 ized by frequent immerfions of goods therein. 
 This effect does not ufually happen, until after 
 the lees having been ufed five or fix times with- 
 out being renewed. The remedy for this acci- 
 dent will be siven hereafter. 
 
 I (hall conclude the prefent chapter by ob- 
 ferving how ufeful it is to rinfe, and cleanfe the 
 <roods as foon as thev have undergone their lixi- 
 viation, that is to fay, a few minutes after tak- 
 ing them out ; they are at that time more open 
 in their texture, and more difpofed to part with 
 the impurities which the lixivium may have 
 detached. 
 
 In the rinfing of threads, they mull not be 
 held by the firing of the hanks, but, on the con- 
 trary, the hand muft be paffed through all the 
 fkains, and thus held, they muft be ftirred 
 round in the water. By this treatment the 
 thread is better cleanfed, becaufe it remains lefs 
 entangled, and more open. If the operator 
 have the advantage of a river, or flream, the 
 
 fliorteft 
 
Cottons, Thread, &c. 133 
 
 ihorteft method will be to loop them all on a 
 pole, and hold them fufpended in the water. 
 The poles are to be fixed in an ofier bafket, in 
 order that fuch hanks as may be accidentally- 
 detached, during the a& of turning, or placing 
 them, may not be carried away by the ftream. 
 This is much more expeditious, and lefs embar- 
 rafling. 
 
 CHAP. 
 
&34 The Art of Bleaching 
 
 CHAP. XI. 
 
 An Account of the Quantity of Linen, and Cotton 
 Thread, bleached at each Immerfwn, and the Co- 
 lours acquired by thoje Sub/lances. 
 
 1 HE quantity of pounds of linen, or hempen 
 thread, which may be patted into a bath com- 
 pofed of the whole contents of a pneumatic 
 vefiel of the acid without fmell, obtained ac- 
 cording to the dofes and proportions before 
 prefcribed, may be eftimated at fixty or fixty- 
 two pounds for the firft immerfion, and eighty 
 for the fecond and following immerfions. In 
 order to avail himfelf of this datum, for piece- 
 goods which are to be plunged in the liquor, 
 the operator mud take care to weigh them be- 
 forehand, previous to deeping them to clear off 
 their dreffing. This quantity is alfo fufceptible 
 of variation, according to the quality of the 
 thread. Thread of middling quality is here 
 meant. 
 
 The quantity of cotton which may be patted 
 through a fimilar dofe of the fluid, is from eighty 
 to ninety pounds, of middling quality, for the 
 
 firft 
 
Cottons, Thread, &c. 135 
 
 firlt. immerfion, and one hundred for the fecond. 
 According to this rate the operations mud be 
 regulated for other objects, fuch as flockings, 
 night-caps, gloves, &c. 
 
 It is more advifeable to diminifh than increafc 
 this quantity of goods, to have them more perfect, 
 more equal, and of a better white. The fuc- 
 ceeding immerfions will produce a greater effe£t 
 upon threads thus treated. 
 
 The bleaching liquor which has been ufed 
 for cotton becomes flight! v charged with colour- 
 ing matter, and at the firft immerfions acquires 
 a pale amber colour. The latter immerfions do 
 not change it, but leave it clear and limpid. 
 The fame obfervation is applicable to both the 
 oxygenated acids ; that is to fay, the acid with 
 fmell, and that which is without. 
 
 As it is of effential confequenee to be aware 
 of certain events, or facts, by which the progrefs 
 of the bleaching may be afcertained, I mall here 
 point out the gradations of colour, which the 
 pieces aflume after each immerfion in the oxy- 
 genated muriatic acid without fmell, made ac- 
 cording to the proportions here defcribed. The 
 firft immerfion gives the thread, or piece goods, 
 a reddiih colour, fiightly inclining to yellow ; 
 the fecond, a colour inclining to ruddy yellow ; 
 k 4 the 
 
136 The Art of Bleaching 
 
 the third, a whitifh yellow ; the fourth, a white, 
 
 fiightly inclining to a ruddy tinge ; and by the 
 
 fifth and fixth, the white becomes clearer and 
 
 clearer. Thefe are very nearlv the fhades which 
 1 
 
 are aflumed by coarfe goods, for the line goods 
 frequently pafs to the fecond or third gradation 
 by one fmgle immerfion. 
 
 When the liquor is ftrongly concentrated in 
 pot-afh, fuch as that which is denoted in the 
 annals of chemiftry by the name of Javelle, the 
 goods immediately, and without previous lixi- 
 viation, aflume the third colour ; but I have ob- 
 ferved, that it is difficult to bleach them further 
 without ufing the fulphuric acid, to remove the 
 lees with which they are loaded. It muft, 
 moreover, be remarked, that in order to obtain 
 this tone of colour, it is fufficient that the lixi- 
 vium be diluted with water, fo as to mark two 
 or three degrees only on the aerometer inftead 
 of eighteen or twenty, which it may mark after 
 it is prepared by diftillation. 
 
 There are fome who do not approve the co- 
 lour which the thread acquires after the firft 
 immerfion, but it may immediately be reduced 
 by fteeping the goods in cold or hot lees. The 
 latter produes its effect more fpeedily ; and after 
 fubfequent rinfmg and drying, the goods retain a 
 
 grey 
 
Cottons, Thread, &i. 137 
 
 grey white colour, more or lefs deep accord- 
 ing to the fhade it has received. Many venders 
 prefer this grey, or reduced colour, on account 
 of its preferable fale in certain markets. 
 
 With regard to the bright and perfect white, 
 there are very few perfons in the provinces who 
 care for it, or appear to give it an exclufive 
 preference. Two reafons may be given for this: 
 firft, becaufe a prejudice is unfortunately efta- 
 bliflied againft the fpeed with which the new 
 invented method of bleaching operates : and 
 fecondly, the confumer is conftantly perfuaded, 
 whether the bleaching may have been performed 
 in this manner, or in the field, that when the 
 goods have attained an extreme degree of white- 
 nefs, they cannot be as durable as fuch as are 
 lefs white. It is thought to be rotten, or burnt, 
 and this opinion leads to a preference in favour 
 of fuch linens, and even cottons, which preferve 
 after bleaching a folid ihade of grey, or dulnefs 
 in the white. 
 
 From a prejudice of the fame kind it is, that, 
 in many countries, the women, particularly the 
 peafants, prefer their linen, whether for cloth- 
 ing or houfehold ufe, fimply cleared without 
 bleaching. The orders of proprietors, or pur- 
 chafers, mult therefore be attended to, and the 
 
 number 
 
13S Tie Art of Bleaching 
 
 number of immerfions and lixiviations regulated 
 accordingly. 
 
 It may be confidered as a rule, that when the 
 goods no longer communicate a perceptible co- 
 lour to new lees, they are entirely finifhed, and 
 confequently, that every fubfequent lixiviation, 
 or immerfion, will be attended with abfolute 
 lofs, unlefs the immerfion is necefiary to clear 
 off the laft lees, on the fuppofition that fimple 
 rinfmg in a large quantity of water may not be 
 fufficient. 
 
 I muff, neverthelefs, remark, that thread 
 bleached by the oxygenated muriatic acid, may 
 be ufed by the fempftrefs with much more 
 fpeed and briiknefs than thread of the fame 
 quality bleached in the field ; it is lefs brittle, 
 and, on that account, is better for the weft, as 
 well as the warp. It likewife may be ftruck much 
 more effectually home to its place in weaving, 
 and does not afterwards move. I received this 
 valuable obfervation from impartial and unpre- 
 judiced manufacturers, for whom I bleached 
 thread according to this method for making 
 handkerchiefs. 
 
 Before I conclude the prefent chapter I mud 
 obferve, that the conjunction of the old and new 
 methods of bleaching may be of incalculable 
 
 advantage. 
 
Col tons j Thread, &c. 139 
 
 advantage. For however great may be the 
 fpeed of bleaching by the oxygenated muriatic 
 acid, it is fcarcely poffible to adopt it in an 
 extenfive manufactory, to the exclufion of the 
 method of expofure in the field, without very 
 heavy charges in workfhops, tools, and utenfils; 
 I would therefore advife, that the entire bleach- 
 ing, without expofure in the field, fhould be 
 confined to fuch goods as are intended to re- 
 ceive, what may be called, a half or three-quar- 
 ters white; and that thofe which require a 
 higher bleaching fhould be finifhed by expofure 
 in the field. By this arrangement the produc- 
 tion of each kind of white colour will be dif- 
 tributed, fo as to be very fpeedy, and to acquire 
 the requifite degree of perfection in a very eco- 
 nomical manner for the manufacturer, under all 
 the heads of time, expence, and labour. The 
 high price which may be afforded by a piece of a 
 perfect white, and fine quality, will be a compen- 
 fation for the price of common goods intended 
 for ordinary ufe. 
 
 CHAP. 
 
140 The Art of Bleaching 
 
 I 
 
 CHAP. XII, 
 
 Of the Fir ft Dreffmgs. 
 
 N order to give more clearnefs to the white 
 colour of bleached goods, it is ufual to give 
 them certain dreffings. Fine piece-goods, few- 
 ing thread, (lockings, gloves, and other articles 
 of thread, or cotton, are more particularly fub- 
 je£ted to this treatment. The following inftruc- 
 tions may be fufficient to fhew the management 
 of thefe feveral articles, after they have been 
 fubmitted to the laft immerfion. 1. The piece- 
 goods are firft to be prefled, or wrung, in the 
 fame manner as after taking them out of the 
 muriatic acid, and in this Hate they are to be 
 immerfed in water, rendered four by fulphuric 
 acid, to fuch a degree that it may mark from 
 two and a half to three e grees of the areometer 
 of MofTy. The lrifh manufacturers, who ufe 
 this acid in preference to four milk, for the 
 bleaching their piece-goods, compofe their 
 bath of one hundred parts of water to one of 
 acid. This proportion communicates to the 
 water a tafte refembling that of ftrong le- 
 monade. 
 
 The 
 
Cottons, Thread \ teV. 141 
 
 The French bleachers, particularly thofe of 
 Mayenne and its environs, who are accuftomed 
 to pafs their piece-goods through fulphuric acid, 
 compofe their bath of fixty pots of water to one 
 pot of fulphuric acid, and they leave their goods 
 immerfed therein during the whole night. The 
 bath may be ufed cold, but it is more effectual 
 and fpeedy in its operation when heated, and 
 appears betides to throw out the colour to more 
 advantage. If it be thought proper to ufe the 
 heated bath, it will not at all be neceflary that 
 it fhould exceed the heat which the hand can 
 conveniently fupport. But it is advifeable in 
 that cafe, to pour in the fulphuric acid at the 
 time when the hot water is added, or elfe to 
 mix it with one of the meafures of cold water, 
 which may be ufed to dilute the mixture, or to 
 cool it. At the time the hot water is poured 
 out of the boiler, the acid mull be poured 
 gently, and with care, becaufe it is liable to fly 
 about * i and the greateft attention muft be paid 
 to mix it well with the water, in order that the 
 bath may be equally acid throughout. 
 
 The goods which are immerfed in the bath 
 
 * This danger is obviated by a&ually plunging the neck 
 of the bottle in the water. The fulphuric acid immediately 
 quits the bottle, in confequence of its fuperior weight. — T. 
 
 may 
 
I4& The Art of B'(a:hin* 
 
 may be left for half an hour, or an hour, with- 
 out the leaft apprehenfion of any ill confe- 
 quence. I have even left them for twelve or 
 fifteen hours without the fligheft accident. The 
 bath mult be left covered whether it be hot or 
 cold, principally in order to prevent any acci- 
 dental dirt, or other impurity, from falling into 
 the fluid. The jjoods muft not be too much 
 prefied together : the lefs they are prefTed, the 
 fooner the acid will produce its efFecl, and con- 
 fequently the lefs time will be required for them 
 to remain in it. 
 
 When the goods are taken out of the bath 
 thev muft be prefTed or wrung, and then kept 
 in a ftream. or large mafs of water ; that is to fay, 
 until upon rinfing them out in various parts, and 
 applying the tongue to the part that is cleared, 
 no acid tafte fhall be perceived. If any fuch 
 tafte remain, the goods muft be immerfed again, 
 if in a running ftream, or the water muft be 
 changed if they be fteeped in troughs. 
 
 When the goods are ready for taking out, 
 they are to be wrung with the winch, or hook, 
 before defcribed, and prefTed, and then pafTed 
 through the blue liquor if necefiary. The blu- 
 ifh caft may be given in two ways, either by 
 paiTmg them through a hot or cold folution ot 
 
 the 
 
Cot I ens, Thread, &c. 140 
 
 the foap, in which a fmall quantity of fine in- 
 digo has been diffufed in the ufual manner by 
 means of a bag ; or otherwife the piece may 
 merely be plunged in a folution of white foap, 
 without any kind of blue, while it ftill contains 
 a fmall portion of acid. In the latter cafe, the 
 acid contained in the cloth immediately deve- 
 lopes in the bath a flight tinge of Prutiian blue, 
 anting from the particles of iron combined with 
 the alkali of the foap, which tinge is diftributed 
 very equally on the whole piece. I mult re- 
 mark, that I have always ufed white veined, or 
 mottled foap, to produce this laffc kind of blue. 
 As a certain degree of experience is neceffary 
 in the ufe of this fecond method, which, never- 
 thelefs, pofTerTes the recommendation of eco- 
 nomy, I would advife the operator to make ufe 
 of the former, until, by trials, he is fo far accuf- 
 tomed to the fecond as to have no fear of mif- 
 take. 
 
 The piece-goods being then well preffed are 
 always dried upon lines of hemp, or, which is 
 ftill better, of hair ftretched on poles properly 
 difpofed under cover j the pieces are held on 
 the lines by the ufual wooden peg or clamp of 
 the laundrefTes, or they may be hung over poles 
 cleared of the bark, and covered with coarfe 
 cloth, in order that the goods may not receive 
 
 anv 
 
1 44 The Art of Bleaching 
 
 any fiain from the wood. It feems, upon the 
 whole, a matter of indifference, whether the 
 drying be performed in the fhade, or in the 
 fun-fhine. 
 
 With regard to common or coarfe cloths, 
 which require no very extraordinary bleaching, 
 they are never blued unlefs it be required. In 
 every cafe, as it is effential that the blue mould 
 be given with as much evennefs as pofhble, care 
 mult be taken to pafs the pieces over a reel 
 placed above the veflel exprefsly appropriated 
 to this purpofe. 
 
 Linen or cotton thread, Sec. is drefled in the 
 fame manner as has been directed for piece- 
 goods. Thefe may be plunged in a bath of ful- 
 phuric acid upon poles, or in the fame manner 
 as has been directed for the bath of blue. It is 
 not neceffary to turn them, becaufe the poles 
 are fixed in the veffel beneath the furface of the 
 liquor j or, inftead of this method, they may be 
 difpofed in layers in bafkets of white willow. 
 The bath of fulphuric acid may be ufed for all 
 kinds of goods, though in procefs of time it af- 
 fumes a flight amber colour ; it is poffible, 
 neverthelefs, to ufe it without danger until it is 
 entirely exhaufted, taking care only to reftore it 
 from time to time, by the addition of that quan- 
 tity of acid which may be neceflary to keep up 
 
 its 
 
Cottons, Thread, &rV. t^c 
 
 its ftrength ; when, however, the bath of acid 
 has at Jaft acquired too deep a colour, it muft 
 be entirely renewed. 
 
 Linen and cotton threads are likewife plunged 
 in the bath of blue, after having immerfed them 
 in the acid upon the poles ; but in order that 
 this part of the preparation may be diftri- 
 buted equally, the fkeins muft be turned once 
 or twice half round; they may likewife be 
 preffed by the hand, provided the quantity be 
 Co fmall as to render the economy of time an 
 object of no confequence. 
 
 Every kind of wood may be employed with 
 nearly the fame advantage, for the baths of ful- 
 phuric acid or blue, without fear of fpotting 
 the goods. I have ufed oak, cheftnut, white- 
 wood, and deal. The latter, however, is pre- 
 ferable, if at hand. Great care mould be taken, 
 that there fhould be no nails in it ; and before 
 the pieces are plunged in either of the baths, 
 the acidulated water muft be well ftirred, in 
 order that the acid, or the blue, may be equally 
 diftributed. Stockings, night-caps, gloves, &c. 
 of thread or cotton, require particular manage- 
 ment. After the bath of fulphuric acid, and 
 before they are paired through the blue, it is 
 always advantageous to give them a good folu- 
 tion of white foap, in which they muft be well 
 
 L rubbed, 
 
146- The Art of Bleaching 
 
 rubbed, for the purpofe of completely removing 
 the fpots of oil or greafe of the manufacturer, 
 which may have refilled the black or greeri 
 foap, or the lees, to which they have been 
 fubjected during the procefs of bleaching ; 
 for it very feldom happens, that they are en- 
 tirely clear of fuch fpots, becaufe the dirt of 
 the hands with which almoft all this kind of 
 goods are covered, frequently prevent their 
 being feen. The oxygenated muriatic acid 
 having likewife little or no action on fat or 
 oily bodies, the different objects fo fpotted 
 might be plunged to little purpofe in that fluid. 
 Stockings, gloves, Sec. when taken out of 
 the falution of foap, are to be cleared in clean 
 water, after which they are to be fubjected to 
 the prefs, or wrung, previous to palling them 
 through a flight infufion of blue. The fecond 
 method of communicating the blue tinge, as 
 before defcribed, may here be ufed, that is to 
 fay, they may be plunged in the folution of foap 
 immediately upon taking them out of the acid, 
 and rinfing them, if the goods have no fpot 
 upon them, which it is eflential previoufly to 
 tlifcharge. After they have received the blue, 
 they are to be preffed, or wrung, and dried 
 upon cords, firfr. turning them infide-out, for 
 fear of foiling the place of contact. This pre- 
 caution 
 
Col tons, Thread, &c. 147 
 
 caution ought to be trfkefi beforfe they are 
 paffed through the blue, and at the time of 
 taking them -out of the folution of foap. 
 
 Linen or cotton thread requires its harks to 
 be opened and feparated, in order that it may 
 dry more fpeedily. This is the raoft certain 
 method of preventing the entangling of the 
 thread, and their confequent breaking, which 
 would not fail to happen fooner or later, efpe- 
 cially with fingle thread, if the operator were 
 to fuffer them to dry before they were feparated 
 from each other. This feparation is to be made, 
 after they have been preffed, or wrung out of 
 the laft fluid. It is time enough, neverthelefs, 
 to do it when they are half dry, and in this ftate 
 it is, in fa£t, rather more convenient. 
 
 The following method is very convenient to 
 untangle the thread, particularly iuch as is fine, 
 and reftore it to its original flare, when, in con- 
 fequence of the operations of bleaching, the 
 ikeins may have been mixed in fuch a manner 
 as to endanger their breaking, if an attempt 
 were made to clear them by any other means. 
 It confifts fimply in extending each fktin fepa- 
 rately, and flightly, under water. By turning 
 and returning them, and afterwards extending 
 them with the hand, the threads will very foon 
 arrange themfelves, and obtain their original 
 
 *• * fituation 
 
148 The Art of Bleaching 
 
 fituation gently, without obftacle, and without 
 giving any caufe to apprehend their breaking. 
 
 If by accident the thread fhould become dry, 
 while too much intermixed to be cleared and 
 wound off in this ftate for wefts, warps, or other 
 ufes, nothing is more effectual to clear the fkeins, 
 than {lightly 1 rubbing them with linfeed oil, here 
 and there. This method is ufed for entangled 
 filk ; and I have found it fucceed perfectly well 
 with thread. 
 
 The operator mult be aware not to foap 
 cleared objects (fuch as callicoes, or other linen, 
 or cotton goods, dyed or printed) in the foapy 
 folution, which has been ufed upon pieces taken 
 out of a ftrong oxygenated muriatic acid, even 
 though they may have firft paffed through a 
 bath of fulphuric acid. For this folution of 
 foap does not fail to acquire the property of 
 bleaching and difcolouring other goods, unlefs 
 the goods which were foaped have, after being 
 taken out from the muriatic acid, been im- 
 merfed in clear water for a long time. I have 
 ieveral times beheld this effect with furprize ; I 
 have frequently remarked, even that pieces, 
 which after being taken out of the bleaching 
 liquor, have undergone an immerfion in the ful- 
 phuric acid bath, Hill retained a fufricient quan- 
 tity of muriatic acid to affume a yellowilh tinge 
 
 after 
 
i Cottons, Thread, &c. 1 49 
 
 after they had paflfed through an infufion of in- 
 digo. This laft fometimes aifumes the fame 
 tinge after an interval of twenty-four or thirty 
 hours. 
 
 To avoid this inconvenience, it is neceffary 
 not only to cleanfe the piece by rinfing after 
 its laft immerfion, but likevvife to give it a flight 
 immerfion in a foapy or alkaline water, from 
 which it mult be afterwards well cleared. 
 
 The bath of indigo muft be compofed in fuch 
 a manner, that it may not be neceffary to reftore 
 it during the immerfion of the fame article 5 
 otherwife there would be a danger of its receiv- 
 ing different fhades of blue. 
 
 There is much lefs danger of this in ufing the 
 azure blue (powder blue of the market)^ the 
 different fhades of which are all previoufly pre- 
 pared, and fold in this feparate diftincl ftate. 
 In either cafe it is neceffary to plunge the goods 
 in the bath, at the moment when the colour 
 is fufpended, and to leave them in it no longer 
 time than is neceffary for them to imbibe it. 
 
 I have before recommended, that the waters 
 of the immerfions, or bleaching liquor, fhould 
 be preferved, even though too weak to aft (en- 
 fibly upon the pieces already in part bleached. 
 They are ufeful in this part of the procefs ; that 
 \s, after the drefting with foap, for fuch articles as 
 
 L 3 ?W 
 
1 50 The Art of E! caching 
 
 are not to be patted through the blue : for thrs 
 lair, dreinng is not agreeable to every one, be- 
 caufe it gives a greyifh tinge to fuch parts as 
 are not of a very firm white. After the immer- 
 sion i:i f jap- water, and the fubfequent rinfing, 
 the goods, being firft we]l preffed, are thrown 
 into this exhaufted bleaching liquor, where 
 they foon acquire a clearnefs, which has a very 
 good effect. After they have remained in this 
 fluid for half an hour, they are to be prefTed and 
 dried as before directed. It may alfo be re- 
 marked, that the fame referved bleaching li- 
 quor, though exhaufted, is excellent for clearing 
 and rinling thread and ftockings from their lixi- 
 vium when they are already bleached. If it 
 were applied to no other ufe, it is preferable 
 for this ufe to common water. The feveral ar- 
 ticles are much more fpeedily cleanfed, and ac- 
 quire a certain degree of improvement in the 
 general appearance of their colour. 
 
 Some perfons require in their goods a certain 
 drefung, as it may properlv be called, which af- 
 fords, particularly to fuch as are of open tex- 
 ture, an appearance of firmnefs, which they 
 lofe when folded. The drefling may be given 
 in a more or lefs durable manner. The firft 
 method confifts in drying the goods, with, 
 fcarcely any wringing, nnd battening the drying 
 
Cottons, Thread, &c. 151 
 
 as much as poflible. This dreflmg is, as may 
 eafily be imagined, one of the mod innocent; 
 but its effect difappears by handling, or car- 
 riage, or by one iingle time of wear. The fe- 
 cond dreffing, which is permanent till after 
 warning, confifts, as all the world knows, in in- 
 corporating ftarch with the powder-blue for 
 fuch objects as require it, or ufing it without 
 blue for thofe which do not. The dofe mull 
 be varied according to the quality and kind of 
 the goods, and the choice of the proprietors. 
 
 There are likewife certain articles, to which 
 a greater or lefs appearance of firmnefs is given, 
 by a dreffing of glue or gum-arabic, which is 
 mixed with the ftarch after both have been 
 boiled feparately. 
 
 There are alfo certain articles, fuch as linens, 
 which are frequently drefled with a decoction 
 of rice. 
 
 Thefe different goods are always hot-prefled 
 by means of a cylinder; which operation gives 
 them the proper degree of firmnefs. 
 
 As every object which can be of ufe to acce* 
 lerate the work, and diminiih labour, is of great 
 importance, 1 mall here defcribe the machine 
 with which the Englilh, who are the inventors, 
 wafh their fine linens. 
 
 It confifts in a kind of churning inftrument 
 x. 4 (fee 
 
j 5 2 The Art of Bleaching 
 
 (fee Plate II. fig. 15 and 16), the circular part of 
 which has four holes bored in it, into which are 
 fixed pins of white-wood, rounded at their ex- 
 tremities. They are more or lefs long, according 
 to the depths of the troughs in which they 
 are ufed. The handle of this inftrument is a 
 crofs, or T, with which the pins at the other 
 end may be moved in different directions, and 
 ufed to agitate the {lockings, and other fmall 
 articles deposited in the troughs, containing the 
 folution of foap. This inftrument being moved 
 in various directions, is very convenient in cauf- 
 ing the fuds to lather, and to impregnate the 
 linen with great expedition. It appears to me, 
 that fuch an inftrument may be ufeful to cleanfe 
 (lockings, gloves, and other articles of cotton 
 or linen thread, which may be required to be 
 bleached or difcoloured, as I fhall hereafter 
 more fully explain. 
 
 I have been informed by an Englifh woman, 
 whom I faw make ufe of this machine, that 
 they have others of the fame kind in England, 
 of a fize adapted to common warning ; and even 
 fome of fuch large dimenfions as to be moved 
 by horfes. If this be practicable, it might, at 
 leaft, be worth trying. And for this reafon it 
 is, that I have thought proper merely to de- 
 scribe the fmall inftrument I have myfelf feen. 
 
 Thg 
 
Cottons , Thread, &fa 133 
 
 The fame recommendation may be offered in 
 favour of another machine, which is ufed in 
 England to rub coarfe linen, It confifts fimply 
 in two ftrong planks with grooves, the upper- 
 mod of which is moveable -, the motion which 
 it gives to the cloth palfed between them 
 caufes the foap, or lees, in which it is plunged, 
 to lather, and contributes to clear it of its im- 
 purities. 
 
 The Englifh likewife ufe, with advantage, 
 for wafhing clothes, two grooved cylinders, 
 running one upon the other, by means of a 
 handle above the veifel of water, between 
 which cylinders a number of pieces of cloth 
 are palfed at a time, their extremities being 
 fewed together, fo as to form a long loop, 
 or endlefs web. A few turns of the cloth 
 between the cylinders (the lower of which is' 
 abfolutely covered with water) are fufficient to 
 cleanfe it from all the impurities which the lees 
 have opened and detached. I have not thought 
 it neceffary to give a defign-of thefe two ma- 
 chines, which are executed and ufed with fuc- 
 cefs at St. Denis, as well as at Beauvais. 
 
 CHAP. 
 
1 54 T'-( Ari of Bleaching 
 
 CHAP. XIU, 
 
 Of the lafi Drejjings. 
 
 _L IECE-goods, bleached by the oxygenated 
 muriatic acid, if left to themfelves during the 
 courfe of bleaching, are fubject, from the na- 
 ture of their thread and texture, to fwell and 
 contract; and, confequently, to lofe, in their di- 
 menfions, particularly in length. It is efTential, 
 therefore, not only in order to recover this mea- 
 fure, but likewife to render the piece more uni- 
 form, fofter, and more equal in its grain, that it 
 fhould receive a proper drelTmg, to re ft ore its 
 original irate. The neceiTary treatment for pro- 
 ducing this erle£t, i^ by means of an apparatus 
 defcribed in Plate VI. fig. i and 2. It confifts 
 of a light frame of wood-work, on the upper 
 part o: which there are ieveral light bars fixed 
 acrofs, very near one another ; and on each fide 
 is a grooved piece. The piece-goods are drawn 
 between thefe bars and the ftretcher j after 
 which they are rolled on a wooden cylinder 
 moved by wheel-work, turned by one or two 
 p jpj u».< prdi the degree pf tenfion rer 
 
 quired 
 
Cottons, Thready &c. i$* 
 
 quired to be communicated. This dre fling Qn 
 the roller may be performed either with 6t 
 without the application of heat; the piece 
 being either humid or dry. 
 
 It mull be drefled in a dry ftate, without 
 heat, when nothing more is required than to 
 foften the grain, and to reftore its original di- 
 menfions. On the contrary, the operation is 
 performed with the afliftance of heat on the 
 humid piece, where it is required not only to 
 l?e ftretched but dried at the fame time. Inde- 
 pendent of the force of tenfion to which the 
 piece is fubjecled in the direction of its length, 
 the perfon employed to roll it upon the cylinder 
 mutt be careful to pull it out by the felvedges, 
 to the fame width as that part which is fixed- 
 upon the cylinder already. The piece muft 
 then remain at leaft twenty-four hours upon, 
 the cylinder, that the folds, or wrinkles, may be 
 totally effaced, and its original dimeniions per- 
 manently reftored. The rollers, or cylinders, 
 mould be covered with cloth, to prevent the: 
 bleached goods from being foiled, a«4 iron 
 plates muft be placed beneath for the purpofe 
 of drying them, when it is required that this 
 operation mould be performed at the fame time 
 s^s they are llretched and rolled. 
 
 \Yhen the obje$ of the manufacturer is 
 
 fimply 
 
« j 6 72? ^ 0/ Beaching 
 
 limply to take out the folds or wrinkles of the 
 piece, without altering its grain, it is to be fuc- 
 ceffively paffed over feven wooden rollers, dif- 
 pofed one over the other in fuch a manner, that 
 by turning one, the fix others, over which the 
 piece is rolled, muft likewife turn. The handle 
 of this apparatus is fixed to the lower roller, 
 and requires one perfon to turn it. I have not 
 thought it neceflary to make a drawing of this 
 machine, as it is now ufed in many manufac- 
 tories and workfhops. 
 
 When it is required to comprefs the grain of 
 the piece, or to glaze it, it muft then be patted 
 through a hot calendar, fee Plate VII. fig. i, 2, 
 3, which confifts in a folid frame of wood-work, 
 in which moves a brafs cylinder, kept at a cer- 
 tain degree of heat, by means of balls or bars of 
 iron heated in a furnace, prepared for the pur- 
 pofe. This cylinder is placed between two others 
 of walnut-tree, and of twice the diameter. Before 
 its arrival at thefe cylinders the piece is pafTed 
 over and under feveral bars, as well as through 
 a ftretching frame. This machine is ufually 
 moved by a horfe, though there are fome which 
 are worked by hand, but, of courfe, with 
 lefs expedition. In either cafe, that is to fay, 
 whether they may be intended to act with or 
 without heat, although the former is prefer- 
 
 able, 
 
Cot tens, Thread, &c. 157 
 
 able, the machine is always fet in motion by a 
 train of wheel-work, to procure a fomewhat 
 greater degree of tenfion, and more perfectly to 
 efface the folds. When the piece paffes under 
 the heated cylinder, it is to be (lightly fprinkled 
 with water, by means of a fmall broom or rod. 
 In fome bleaching works they ufe the mangle, 
 more or lefs loaded ; a well-known engine, con- 
 fiding of a fquare heavy box, which is made to 
 run backward and forward upon cylinders of 
 wood. This machine, which is commonly 
 moved by water, or by a horfe, does not glaze 
 the goods, but lengthens the meafure. It ne- 
 cefiarily implies the ufe of an engine, like that 
 defcribed in Plate VI. to difpofe the pieces upon, 
 the cylinders. The mangle is alfo neceffary 
 when the goods are required to be damaiked,, 
 that is to fay, when the effect of a wave is de- 
 fired upon their furface. This laft dreffing is 
 eafily obtained, by rolling the folds a flight de- 
 gree in zig-zag. 
 
 The following method is likewife very much 
 ufed for drying piece-goods by the dealers of 
 thofe articles. It is extremely iimple, and con- 
 lifts limply in a plate of copper or brafs placed 
 on an iron ftand, under which is placed a bafon 
 of charcoal, or burning embers. The piece 
 being palled over this heated plate, dries gradu- 
 
15S The Art of Bleaching 
 
 ally, and very fpeedily. This method is equi* 
 valent to a fecond paflirig through the ftretch- 
 ing engine, and ferves well for drying, but does 
 not reftore the original meafure. It is, how- 
 ever, perfectly well fiiited to ftockings night- 
 caps, &c. The heated plate lliould be kept 
 perfectly clean, left it thould foil the goods. 
 
 The method of drying, and giving uniformity 
 to piece-goods, being defcribed, it now remains 
 to be (hewn, how thread is to be arranged and 
 drefTed after drying on the pole. The prepar- 
 ation given to this article tends to clear the 
 thread from that roughnefs which it acquires 
 from handling, and never fails to exhibit when 
 dry. This is eafily removed by fhaking each 
 hank, either upon the pin or the hand, after 
 having rubbed it between the hands, or beaten 
 it with a mallet. The operation is particularly 
 necefTary for {keins of fewing filk, which, as I 
 have before remarked, are difpofed to curl up 
 and fhrink from their original meafure ; to 
 which they may, however, be very fpeedily and 
 conveniently reftored by means of a kind of 
 frame, fee Plate VIII. fig. 3 and 4, acrofs which 
 the fkains are to be pafied and ftretched, One 
 of the moveable crofs-pieces is to be raifed and 
 fixed, by means of the pins which enter into 
 holes difpofed in a zig-zag direction, at a fmal; 
 
 di fiance 
 
Cottons, Thread, &c. I59 
 
 diftance from each other, on the apparatus of 
 the "frame. It may eafily be underftood, that 
 each fkein being moiftened and wrung, and 
 afterwards patted over thefe crofs-pieces, muft 
 remain thus ftretched for a certain lime, that is 
 to fay, until it is dry, and by that means- forced 
 to preferve the length, which it has received 
 from this tenfion. But this laft preparation is 
 not ufually given, except to double or fewing 
 thread, which muft be fpread out as much as 
 pofhble upon the crofs-piece, in order to haften 
 the drying. 
 
 The Ikeins of lingle thread are afterwards to 
 be tied up in the middle, and put together 'by 
 fcores, or quarters of the hundred, in a bundle, 
 tied together with a ftein of the fame thread. 
 At leaft the finilhed thread, in fome provinces 
 of France, is thus made up for delivery from 
 the bleacher to the merchant or manufacturer. 
 With regard to fewing or double threads, they 
 are turned up in a fpiral or twift, and, in order 
 that they may lie clofe, this operation is made on 
 the pin. See Plate II. fig. 12. This, in France, 
 is called folding up in carrots. 
 
 Stockings, night-caps, 8cc. of thread or cotton v 
 as foon as dry muft be examined, to take up 
 the Hitches, or repair them,, for it very feldom 
 happens, particularly in flight goods, fuch as 
 
 ftockinssp 
 
1 6 o The Art of Bleaching 
 
 {lockings, that they pafs through the various ope- 
 rations here defcribed without fome flitch fall- 
 ing ; fhere is, indeed, little to be feared if the cot- 
 ton be knitted by hand, but moft goods which are 
 wove in the flocking engine, which is employed 
 in preference for articles intended for fale, are 
 very unequally knit ; and many articles are 
 made, like the Engliih goods of the fame kind, 
 with two or three threads, which diminifhes 
 their ftrength ftill more. Stockings, gloves, 
 &c. after examination, turning, and repairing, 
 if neceffary, are difpofed in the prefs, folded in 
 three folds according to their length, then forted 
 according to their quality, fafhion, and dimen- 
 sion, in fixes or half dozens. After dreiling, if 
 required, they are then put into the prefs ; and 
 laflly, wrapped in blue or white paper, and 
 properly marked. 
 
 Thefe lafl dreffings are not commonly given, 
 unlefs the employer requires them ; otherwife 
 thefe kind of goods are returned as foon as dry, 
 even without turning them, for fear they fhould 
 be foiled in the carriage. In many places (lock- 
 ings are dried on the leg, in order that they 
 may recover the contraction they have under- 
 gone in the bleaching, for it is the property of 
 frame-work knitting to fhrink and draw up a 
 little when wetted. No more than one pair of 
 
 itockings 
 
Cottons, Thread, &fc. 161 
 
 ftockings is put on each leg; and to prevent 
 their fhrinking, as they dry, the upper part of 
 the leg is fixed with pins after the ftretching 
 has been carried to the required extent. The 
 forms, or legs, ought to be made of afh-wood, 
 and, if poffible, of a fingle piece, becaufe the 
 ftockings may be torn at the place where the 
 two pieces that form the foot and leg are joined 
 together, as is frequently the cafe with thefe 
 implements. The corners ought to be very 
 carefully taken off, to prevent the fame acci- 
 dent from taking place. 
 
 Stockings, whether of thread or of cotton, are 
 likewife finged with a hot iron, which is paffed 
 over the article, properly ftretched on the leg. 
 This preparation is not to be given but juft 
 before the laft bathe in the lixivium, or immer- 
 fion in the acid, on account of the reddifh brown 
 colour, which is the confequence of this procefs,, 
 and requires to be cleared off. 
 
 Inftead of this procefs with the hot iron, the 
 go )ds are fometimes pafled over a lamp of 
 burning fpirit of wine. Thefe particular drefT- 
 ings are only given to fuch goods as are re- 
 quired to have a very uniform appearance, and 
 the moft exquifite white, in imitation of goods 
 of the fame kind which we import from Eng- 
 land, 
 
 m Having 
 
ldz The Art of Bleaching 
 
 Having thus fhewn the method of drefiing, 
 fquaring. and drying the pieces, I fhall now 
 proceed to give directions for folding them. 
 This operation is ufually performed on the 
 ftick, becaufe it is very expeditious, and the 
 goods are in this way very properly folded. 
 
 Moft piece-goods are folded in two, acrofs 
 their length (fee Plate II. fig. 7) ; for this pur- 
 pofe, one of the ends of the piece is patted over 
 a moveable roller, previoufly fufpended at each 
 extremity in the loop of a cord, fixed to the 
 cieling of the work -mop : this length of the 
 cloth is thrown on the other fide of the roller, 
 and the workman continues to make the fold 
 he has began, by drawing what he has folded 
 equally over the roller. In this manner the 
 piece becomes completely folded up. Atten- 
 tion muft be paid, that it lhould fall upon a 
 ftage, or board, in order that it may not be ex- 
 pofed to injury, or dirt. 
 
 The cloth, thus folded in two, is carried to 
 a table (fee the lame Plate, fig. 8 and 9) to be 
 folded in this ftate, in equal and regular folds. 
 The length of the intended fold is taken with 
 the piece itfelf, which is applied to two flat 
 iron bars, fixed on each fide of the table, and 
 pierced with different holes, to fix the fupports 
 which determine the length of the folds ; after 
 
 which, 
 
Cottons, Thread, &c. 163 
 
 which, with a firft rod refting on the two firft 
 fupports, the cloth is thrown over the rod, and 
 thence carried to the fecond, which is to form 
 the oppofite fold. In this place a rod is laid to 
 form the fold, and the cloth is again carried to 
 the oppofite extremity, where a fecond fold is 
 made over another rod. Hence the workman 
 proceeds, as before, to the other extremity, and 
 the fame procefs is thus repeated to the end of 
 the piece, drawing out thofe rods, as he pro- 
 ceeds, which were firft laid. It is not neceflary 
 to ufe more than four or five rods at each fide. 
 They are of poliftied iron, of the thicknefs of a 
 little finger ; the pins, or fupports, placed in the 
 holes of the flat bars of iron, ought to be fuffi- 
 ciently long to contain all the folds which the 
 cloth may require. The length of thefe folds 
 are proportioned to the extent, or volume, 
 which the piece is expected to occupy after the 
 folding. Experience will foon direct the ope- 
 rator in this matter. 
 
 To this operation fucceeds that of the prefs, 
 if the pieces are thought capable of it, with re- 
 gard to their bulk, and the facility in difpofing 
 them for that purpofe. On taking the piece 
 out of the prefs, when it is folded in equal folds, 
 whether fingle or double, it is turned inwards, 
 fp as to form one general fold, as may be feen in 
 
 M 2 Plate 
 
1 64 The Art cf Bleaching 
 
 Plate II. fig 10 ; in which fituation it is feeured 
 by firings of different fize, according to the qua- 
 lity of the piece. The piece thus packed to- 
 gether is ornamented with taffels of <n>ld thread 
 for fine goods, fuch as cloths, cambrics, muflins, 
 or of filk of different colours for more common 
 goods. With regard to coarfe goods, it is ufual 
 to knot the ftrings together in the front part of 
 the fold. 
 
 I muft here obfefve, that piece-goods lofe in 
 their length by bleaching about one ell, or an 
 ell and a quarter in twenty-five, according t© 
 their quality; and this lofs is reftored to them 
 again by the laft dreffings here defcribed. 
 
 With regard to the lofs of weight which 
 threads undergo, it depends much on the rot- 
 ting of the flax, according as it has been more or 
 kfs perfect. The linen threads of Flanders and 
 Artois, for example, which are rotted in water, 
 do not lofe more than 2c per cent j whereas 
 thofe of Picardv, of which the rotting in water 
 is fo far from fufficiently warning the thread, 
 that it acquires, on the contrary, a degree of im- 
 purity from the earth on which it repofes, in ad- 
 dition to that which is detached in the courfe of 
 time by the maceration, which its external part 
 has undergone, lofe more than one fourth of their 
 weight, generally ipeaking. Coarfe threads na- 
 turally 
 
Cottons y Thread, &c. 165 
 
 turally -k>fe more than others. In general the 
 lofs may be eftimated at twenty-five. or thirty 
 per cent, and eighteen or twenty-five for thofe 
 of middling quality. With regard to cotton 
 threads, the lofs is fcarcely three or four per 
 cent. Cotton piece-goods may lofe more in 
 proportion, on account of the dreiTing which 
 was added to their weight, and which mult firft 
 be diflbl.ved, and taken out of the cloth, before 
 it can be prepared for the difcolouring or 
 bleaching procefs. 
 
 Having treated of the ordinary dreffings ufed 
 in France, I think that the reader will receive, 
 with pleafure, fome account of the fingeing, 
 particularly ufed by the Englilh for light cotton 
 goods. Every one knows that muflinets are 
 ftriped, plain, and fpotted : muflins are more 
 beautiful in proportion as they are lefs downy, 
 or covered with fibres of the cotton wool. On 
 this account the Engliiri, who are like wife at- 
 tentive to ufe cotton of long ftaple for thefe 
 goods, take the greateft care to render them as 
 fmooth as pollible ; this may be obferved, par- 
 ticularly in their frame-work, and other cotton 
 goods, of which the beauty of the bleaching is 
 the more confpicuous, in proportion as the fur- 
 face of the article is fmoother, or lefs covered 
 with the light down, which is ohfervahle on 
 m 3 aU 
 
1 6 6 The Art of B leaching 
 
 all the articles of cotton when firft manu* 
 factured. 
 
 I have, therefore, prefumed, that my country- 
 men will learn with pleafure how the Englifti 
 manufacturers contrive to take off all this down, 
 which on a beautiful and fine piece of cloth is 
 fmgularly hurtful to the reflection and bright- 
 nefs of the white colour it has received. With 
 this view I have given a drawing of the machine 
 -ufed for this dreffing. See Plate VIII. figs. 5 
 to 10, and the defcription. It will be fufficient 
 to obferve in this place, that after having fewed 
 the muflins to the coarfe cloths, which are 
 nailed upon two rollers, with handles to ftretch 
 them, they are rubbed with a brufh to raife the 
 down. The brufh is pafled once or twice over 
 the face of the piece, after which a bended bar 
 of iron, more or lefs ignited, is fpeedily and 
 Jightly pafled over the upper furface. This bar, 
 according to its degree of heat, is pafled two or 
 three times over the fame place, and after it has 
 been repeatedly moved along one border, it is 
 infenfibly moved towards the other. When 
 the down of this firft length is well cleared off, 
 which is obferved by looking aflant upon the 
 furface of the piece, a new portion is ftretched, 
 by rolling another part of the piece, which is to 
 be treated as before. 
 
 Piece- 
 
Cot tens, Thread, &c, 167 
 
 Piece-goods which are intended to produce 
 an effect on both fides, are fmged on the back 
 as well as the face, but more flightly on the 
 former than the latter. It is neceflary to have 
 at leaft two or three irons, one of which is to 
 be heated, while the other is in ufe ; and the 
 greateft precaution mull be had to make them 
 very clean previous to each time of ufing; this 
 is done upon a rag, or a fine grained fand-ftone, 
 when they are taken out of the furnace in which 
 they were heated- This attention is neceffary, 
 for fear fome greafy fubftance, or tallow, might 
 attach itfelf to the face of the iron, and burn, 
 or penetrate the piece. The irons may be 
 heated indifferently with turf or pit-coal, as 
 well as. with wood. 
 
 Cotton cloths, or muilin, which are rendered 
 even and fmooth by this method, immediately 
 acquire by this treatment, which is always per- 
 formed at the commencement of the bleaching, 
 a brown tinge fimilar to that exhibited by linen 
 burned in ironing, but this colour moftly difap- 
 pears at the firft or fecond immerfion, without 
 any intermediate lixiviation. 
 
 This management with regard to cotton 
 goods, or mujflins, is equally applicable to li- 
 nens, though thefe are lefs fubjecl to the downy 
 m 4 covering, 
 
J 6 8 The Art of Bleaching 
 
 covering, on account of the length of the ftaplc 
 of which they are compofed. 
 
 It is very poflible to life the fame procefs 
 with ftockings, night-caps, and other fine knit 
 works in cotton, capable of being rendered 
 more valuable by their clear white colour, 
 which always feduce the confumer, who is, for 
 the moft part, lefs attentive to the quality of the 
 merchandize than its external appearance But 
 I have already remarked, that the mechanifm 
 to . difpofe knit, or frame-worked goods, to re- 
 ceive the fingeing, ought to be different from 
 that of piece-goods, and appropriated to the 
 form of the object. 
 
 There is another method alfo of fingeing cot- 
 ton goods and muflins, namely, by fpirit of 
 wine ; but this method never operates with the 
 fame fmoothnefs and equality as the red-hot 
 iron, and is alfo much lefs expeditious. Never- 
 thelefs, as it may be ufeful and applicable to 
 certain goods, the reader may confult Plate VI. 
 fig. i and 2, where I have defcribed the ma- 
 chine which may be ufed for this purpofe. I 
 need only remark, that inftead of the box 
 which contains the hot embers, another muft 
 be placed, containing a row of wicks for burn- 
 ing fpirit of wine. One man is fufficient to at- 
 tend 
 
Cot ton s t Thready Z3c. iSg 
 
 tend and direct this method, as well as the 
 former j and the fpirit of wine made ufe of may 
 be mixed with a certain proportion of brandy, 
 or otherwife it may be lowered in its ftrength, 
 as the operator may find beft fitted to his pur- 
 pofe T 
 
 CHAP. 
 
170 The Art of Bleaching 
 
 B 
 
 CHAP. XIV. 
 
 Concerning Proof Liquors, 
 
 'Y proof liquors, I underltand all thofe co- 
 loured fluids, which are extracted from vege- 
 tables by deco£Uon or fermentation, and which, 
 when mixed with the oxygenated muriatic 
 acid, are more or lefs changed, according as 
 the one or the other liquors is more or lefs 
 concentrated : thefe vegetable fluids, accord- 
 ing to the degree of alteration which they 
 undergo, are of ufe to afcertain the ftrength, 
 and more particularly to afford a judgment of 
 the ufe to which the muriatic acid may be ap- 
 plied, when after having been prepared accord- 
 ing to the directions already pointed out, it 
 has been applied to one or more immerfions. 
 It is true, indeed, that this acid might be more 
 concentrated by putting lefs water into the 
 pneumatic veffel, or by increafmg the dofes of 
 the ingredients ; but this would afford no ad- 
 vantage excepting for the purpofe of carrying 
 it from place to place, or for the more fpeedy 
 bleaching of coarfe goods, or other objecls of 
 the fame quality 5 fuch as towel pieces, coarfe 
 
 thread, 
 
Cottons, Thread, &c, jji 
 
 thread, twifts, and the like, of which there is 
 no reafon to fear an alteration in their texture. 
 For every other merchandize of a fine quality, 
 it is always prudent to dilute the acid in a cer- 
 tain proportion for its mpft advantageous appli- 
 cation. 
 
 A folution of one part of indigo in eight 
 parts of fulphuric acid, is particularly pointed 
 out by Berthollet as having been ufed by De 
 Croifille at Rouen. This preparation differs 
 from a folution of Saxon blue in no other re- 
 fpect than that this laft is made with one part 
 of indigo to four parts of the fulphuric acid. 
 Either of thefe compofitions may be digefted 
 in a matras, or fimply in an apothecary's phial, 
 placed on a water or fand bath, or in hot afhes : 
 at the expiration of feveral hours part of the 
 indigo, previoufly pounded and fifted through 
 (ilk, becomes diffolved. This folution, which 
 js of a very deep and denfe blue, is to be gently 
 poured by inclination into an appropriate veflel, 
 after which it is to be diluted with water, until 
 it marks one degree below zero on the areo- 
 meter of Mo fly. In this ftate it forms a proof 
 liquor, of which three parts will be rendered 
 cplourlefs by one feventh or eighth part of oxy- 
 genated muriatic acid, compofed in the manner 
 before defcribed. This liquor may be meafured 
 
 in 
 
1 7 a The Art of Bleaching 
 
 in the cap of the cafe of the areometer, and 
 then poured into a glafs cylinder, which is gra- 
 duated and {lands upon a foot. See Plate IX. 
 fig. 10 and n. 
 
 •I have thought proper in this place to men- 
 tion the kind of meafure which is made ufe ot 
 in this proof, becaufe the degree of itrength in- 
 dicated by the fluid is very frequently different 
 when the oxygenated muriatic, acid is poured 
 into a veifel of a different diameter. It is there- 
 fore efiential to ufe the fame meafure conftantly. 
 
 It muff, be obferved, that the oxygenated 
 acid may be ufed to advantage, as a fecond 
 bath for linen goods, already in the progrefs of 
 bleaching, or as a fir ft bath for cotton goods, 
 from the time its itrength is fuch, that one 
 iingle half part of the acid is required to render 
 three parts of the blue fluid colourlefs, until 
 that ftate in which it requires one entire part of 
 the latter to difcolour three of the blue. When 
 the bath is weakened to this degree, it is no 
 longer applicable but to the preparation. 
 
 Neverthelcfs, if there be a certain quantity 
 on hand, it may be ufed for fteeping and prepa- 
 ration, in cafe there is time for fuch goods as 
 are either cleared or uncleared ; for though the 
 acid be fo weak that it does not feem capable 
 of bleaching., neverthelefs it will act. in process 
 
 o 
 
Cottons, Thread, &fo 173 
 
 of time!, as long as it is capable of difcolouring 
 the proof liquor. For I have many times re- 
 marked, that however weak the preparation 
 may be in which the piece is thus immerfed* 
 the white colour of this laft does not fail to be 
 very perceptibly forwarded, when it comes to 
 be again fubjected to the aclidn of a newly-pre- 
 pared and ftrong bleaching liquor. This ex- 
 haufted fluid muft not, therefore, be rejected^ 
 even though one whole meafure mould be re- 
 quired to difcolour one meafure of the blue fo- 
 lution of indigo, with which it may be mixed. 
 In this manner trials may be made to afcertain 
 its ftrength, as foon as it is weakened to that 
 degree that three parts of the blue liquor are 
 difcoloured by one of the acid. The operator 
 cannot pay too much attention to the total ex- 
 haufling of the power of the bleaching liquor, 
 fince, upon the whole, thofe weak folutions may 
 be very profitably applied in a well-regulated 
 manufactory. When the liquor of the bath no- 
 longer acls upon the proof liquor, it is entirely 
 exhaufted of the oxygenated muriatic acid, 
 though it (till preferves a peculiar odour, which 
 is not difagreeable ; it then confilts of the com- 
 mon muriatic acid diluted with water, if it be 
 the refidue of a bath of the odorant muriatic 
 acid ; but, if, on the contrary, the fluid be the 
 
 refidue 
 
j 74 Tbe Art of Bleaching 
 
 refidue of the oxygenated muriatic acid without 
 finell, it contains likewife a combination of that 
 acid with pot-am. In either cafe the fluid may 
 be thrown away,, if the operator is not aware of 
 any peculiar purpofe to which it may be ap- 
 plied ; if he has fuch a purpofe in view, he may 
 referve it either for that obje£t, or for rinfing 
 fuch goods as are already bleached, and have 
 paired through the laft lees, as has before been 
 remarked, for which laft purpofe it appears 
 preferable to common water. 
 
 The tincture of cochineal may be ufed as a 
 proof liquor, according to the information given 
 in the annals of chemiftry. It is equally valuable 
 with the Saxon blue, and even made with lefs 
 trouble ; nothing more being required than to 
 boil a finall quantity of the cochineal, firft 
 cru flied in a marble or glafs mortar, or (Irongly 
 rubbed between the fingers; the decoction mult 
 then be filtered through cloth, or blotting-paper, 
 upon which it muit be poured (lightly by inclin- 
 ing the veflel, in order that the remains of the 
 infed may be feparated from the fluid. 
 
 Two parts of the tinclure of cochineal diluted 
 with water to half a degree below zero, require 
 two parts of the muriatic acid without fmell, 
 at the fame degree as that which is neceflary to 
 render the blue proof liquor colourlefs. The 
 
 tincture 
 
Cot tons y Thread y &V. 17 c 
 
 tincture of cochineal becomes converted to a 
 yellow colour. 
 
 It may here be remarked, that the violet li- 
 quor of Javelle concentrated to four degrees of 
 pot-afti below zero, requires no more parts to 
 difcolour three parts of the blue before de- 
 scribed, than are required of oxygenated muri- 
 atic acid to difcolour the fame quantity of blue ; 
 but the liquor of Javelle bleaches more fpeedily 
 and uniformly. 
 
 The tincture of turnfole may alfo be ufed 
 with no lefs advantage than cochineal, and is 
 prepared in the fame manner ; and, laftly, the 
 tincture of beet-root, and even wine itfelf r 
 may be ufed with equal convenience, if other 
 vegetable tinctures and decoctions be not at 
 hand. The juice of acacia and currants are alfo 
 fufceptible of affording the fame indications. 
 
 With regard to the colours which the differ- 
 ent tinctures affume, they are as follows : 
 
 The Saxon blue, or folution of indigo in the 
 fulphuric acid, becomes a yellow, more or lefs 
 inclining to fawn colour, whether it be mixed 
 with the oxygenated muriatic acid with fmell 
 or without. Its tint becomes deeper in pro- 
 portion as the blue is more intenfe. 
 
 The tincture of cochineal aflumes an orange 
 colour. 
 
 Red 
 
jy$ The Art of Bleaching 
 
 Red wine of Macon acquires an opal colour ; 
 the infufion of turnfole becomes of a light 
 amber colour with either of the acids, prepared 
 in the manner recommended in this treatife ; I 
 have, neverthelefs, obferved, that it does not 
 change with the fluid called the lixivium of 
 Javelle (leffive de Javellc), which neverthelefs 
 caufes a flight efTervefcence with vinegar. 
 
 It is very eafy for the operator to regulate his 
 procefs with regard to every kind of tincture or 
 irtfufion, which he may find it mod convenient 
 to ufe, whether of woods or roots, according to 
 the preparations I have laid down for cochineal 
 and indigo. The latter folution may be pre- 
 pared without the afliftance of heat, as follows. 
 After having poured the proper quantity of ful- 
 phuric acid into an earthen or ftonc ware 
 bottle, the pounded and lifted indigo is poured 
 in, and ftrongly agitated by the hand for an 
 hour, which is a fufheient time for the clots of 
 indigo, which are formed either at the furface 
 of the acid, or on the fides of the bottle, entirely 
 to difappear: during this agitation a ftrong 
 efTervefcence takes place in the fluid. The in- 
 digo, when well fhaken, and penetrated by the 
 acid, is foon difiblved, but it ufually require? 
 half an hour for that purpofe. This portion of 
 time is applicable to two ources of indigo in 
 
 one 
 
Cottons, Thread 3 &c. ijj 
 
 pound of the fulphuric acid. To this quantity 
 of acid half a glafs of water may be added. I 
 am convinced by experience, that this addition 
 renders the a£tion of the acid upon the blue 
 more fpeedy. 
 
 W CHAP. 
 
178 T. j Art of Bleaching 
 
 CHAP. XV. 
 
 The Methods of remedying fuch Accidents as happen 
 during the Courje of Bleaching. 
 
 T 
 
 H E accidents likely to happen in the 
 courfe of bleaching, may be diftinguifhed into 
 accidents of the diftillation, accidents of the immer- 
 fion in the alkaline or acid liquor, and accidents 
 of the dreffing. I fhall give a fhort account of 
 thefe three claufes of accidents, and at the fame 
 time point out their remedies. 
 
 Accidents in the diftillation. The principal ac- 
 cident which is capable of interrupting the dif- 
 tillation, is when the lutes of the adopter fuffer 
 the gas to efcape. The moft fpeedy remedy, in 
 this cafe, to prevent the exhalation of the acid, 
 which cannot be retained but with great diffi- 
 culty, feldom for any length of time, and then 
 very imperfectly, in confequence of its great 
 expanfion ; the fhorteit method, I fay, at lead 
 if the diftillation be not near its conclufion, is 
 to remove the fire immediately from beneath 
 the capfule of the retort, and to furTer this laft 
 to cool for a certain time, by railing it a little in 
 
 its 
 
Cottons, Thread, &c. 179 
 
 its fand-bath. If it be not poflible to take it 
 out of the furnace, together with its capfule, on 
 account of the heat, or its (ticking too faft, the 
 adopter muft be unluted from the funnel of the 
 ]eaden tube, and the aperture of this tube clofed 
 with a cork, or lute, to prevent the gas of the 
 pneumatic veflel from evaporating ; after which 
 the retort muft be raifed, and placed gently 
 upon a bag of ftraw, or on coarfe cloths folded 
 together; and then holding the retort by its 
 neck, near the flexure, the adopter muft be en* 
 tirely unluted, by twifting it round and drawing 
 it off. The orifice of the neck of the retort is 
 then to be clofed with a cork ftopper, but not 
 fo clofely but that a very fmall portion of gas 
 may be fufFered to efcape, for fear of an ex- 
 plofion. The ftopper of the neck may, for 
 greater fafety, be flightly raifed. This precau- 
 tion is neceflary, on account of the great ex- 
 panfion of the muriatic acid gas. The old lute 
 muft then be taken off, as well from the adopter 
 as the retort, and the places to which they 
 were applied muft be well cleaned, in order to 
 receive frefh lute, after having carefully wiped 
 off the moifture with a cloth or a fponge. If. 
 the lute which comes off be ftiU good, it may 
 be kneaded again, adding, if required) a fmall 
 N a quantity 
 
1 8o The Art of Bleaching 
 
 quantity of boiled oil, or it may be mixed 
 with new lute> if it be burned or decompof- 
 ed. This decomposition in the fat lute may 
 be known by the white or reddifh colour 
 which it acquires, and the facility with which 
 it breaks, on account of its having loll the glu- 
 ten which afforded it that toughnefs and tena- 
 city, on which its goodnefs chiefly depends. 
 
 With regard to the lute of linfeed cake, it 
 muft, in almoft every cafe, be totally renewed, 
 particularly when internally applied, becaufe the 
 heat hardens it too much to admit of its being 
 kneaded again, with any moderate degree of 
 facility ; the decompofition of this lute is known 
 by the yellow colour it acquires, and the con- 
 traction it undergoes from the e fife ft of the 
 heat. The lutes being kneaded to a proper 
 conliftence, and duly placed according to the 
 directions laid down in Chap. IV. the adopter 
 is to be fixed, previoufly removing the Hopper 
 from the mouth of the retort, and placing 
 another in that of the fmall end of the adopter, 
 to prevent any inconvenience from the vapour 
 which might iffue out during the time of fixing 
 it. This vapour is likewife condenfed within 
 the adopter, in confequence of its coldnefs. 
 The retort is then to be placed, as before, on the 
 
 furnace, 
 
Cottons, Thread, &c. i8t 
 
 furnace, the adopter uncorked, and its beak 
 luted into the tube of lead ; after which, the 
 iire is to be replaced beneath the capfule, and 
 the diftillation very fpeedily recommences, and 
 proceeds as ufual. This operation is a work of 
 fome delicacy; it requires to be performed with 
 fpeed, and great care muft be taken while plac- 
 ing the lutes and the adopter in their proper 
 fituations, to ftand always in fuch a pofition, that 
 the current of the external air may drive the 
 vapour from the operator himfelf. 
 
 If the accident here defcribed mould take 
 place towards the end of the diftillation, as it 
 may fometimes happen, in confequence of the 
 ftrong heat which, at that time, may foften the 
 lutes, it will be fufficient if the fire be taken 
 from beneath the capfule. The diftillation 
 foon ceafes when this is done, particularly if 
 care be taken to condenfe the gas, by the pru- 
 dent application of wet cloths on the neck of 
 the retort, as well as the adopter. 
 
 This inconvenience would not take place, if 
 the workmen in th.ofe glafs-houfes which are 
 principally employed in the fabrication of chy- 
 mical veflels could make retorts with necks re- 
 curved in the form of the adopter. Thefe kind 
 of yeffels maybe affiduoufly fupplied by making 
 
 n 3 ufe 
 
182 The Art of Bleaching * 
 
 life of a tube of lead, fo formed as to ferve inftead 
 of the adopter, as I have already obferved, with 
 regard to the tubulated bottles or bodies *. If, 
 by accident, the lute which is adapted mould 
 fail, or fuffer the gas to pafs through, it may 
 eafily be flopped, by applying new lute to the 
 place of junction. Inftead of the leaden tube, 
 we may fubftitute, with flill greater convent 
 ence (the danger of breaking excepted), a tube 
 of glafs, of which the end neareft the bottle, or 
 tubulated body, ihould be ground with emery. 
 Bv thefe means there would be no application 
 of lute, and confequently no danger to be 
 feared with regard to the filtration of the gas, 
 the efcape of which is eafily perceived by the 
 fmell which diffufes itfelf through the work> 
 fhop, and is more particularly perceived when 
 the nofe is applied near the veflels, or the lute. 
 But as this laft method of difcovering the place 
 where the lute has failed may be attended with 
 the moft ferious confequences, if the greateft 
 precaution be not ufed, it is more prudent to 
 apply an open bottle of ammoniac near the 
 
 * This laft method appears to me preferable to every 
 other ; becaufe it requires only a flight attention to the lute, 
 and can never produce thole dangers which arifc from the 
 ufe of retorts. — C. 
 
 fufpected 
 
Cottons , Thread, &c. 1 83 
 
 fufpe£red place ; at the inftant that it is pre- 
 ferred, a white fume is formed, which immedi- 
 ately points out the defective fpot. The bottle 
 muft be prefented above the current of air$ 
 which takes place near the lute, or in the w r ork- 
 fhop. If this precaution be not attended to, the 
 operator might be induced to remove a good 
 lute, inftead of one which was really defective. 
 
 On the other hand, if in the courfe of the dif- 
 tillation, and for want of keeping up the heat, the 
 fluid in the pneumatic veffel mould be abforbed 
 and rife into the diftilling apparatus, it is necef- 
 fary the inftant it is perceived to withdraw for a 
 moment the (topper out of the neck of the retort, 
 where, as I have already had occafion to obferve, 
 the abforption inftantly ceafes. Neverthelefs, if 
 for want of being obferved in time, the water 
 mould rife fo far as partly to fill the retort, or 
 body (for it never entirely fills it), the diftillation 
 will be ftopped, from the coldnefs of the water, 
 and its too great quantity. The ihorteft remedy 
 is to draw out the excefs of water, which is thus 
 introduced into the diftilling veffel, by the aiiift- 
 ance of a glafs pump, or fyphon, and afterwards 
 to heat the fame veflel, firft returning the water 
 into the pneumatic veiTel, if thought expedient : 
 but if the diftillation be properly attended to, 
 *fris accident can sever happen, 
 
 n 4 Accidents 
 
184 The Art of Bleaching 
 
 Accidents in the lixiviations and immcrfions. I 
 place the accidents arifing from thefe two opera- 
 tions in the fame clafs, becaufe they can fcarcely 
 take place, but by the joint operation of both. 
 
 Any article which is badly cleared of the lixi- 
 vium, and afterwards immerfed in the oxygenat- 
 ed muriatic acid, becomes almoft immediately 
 of a nankeen colour, particularly in the folds, 
 either in fpots where certain parts have not been 
 fufficiently rinfed, or ele the colour is general, 
 if the whole has not been well rinfed. 
 
 The fame accident happens if foot has fallen 
 on the linen or thread. The difference is fim- 
 ply in the colour, which approaches more to 
 brown. Thefe colours are capable of becoming 
 more and more deep if the mifmanagement be 
 not remedied as foon as perceived, and that be- 
 fore the goods are fubje£ted to other immerfions 
 in the alkaline lees, or of the oxygenated muria- 
 tic acid. The fame acident is to be expected, 
 if the goods, though white at the time of their 
 immerfion, arefuffered to remain too long in the 
 bleaching liquor. I his does not fail to happen, 
 particularly if r he articles which are fuffered to 
 remain even in a weak folution, are kept in that 
 fhte the whole night. The next day they 
 are found to be yellow, or charged with lix- 
 ivium. 
 
 The 
 
Cottons, Thread, Z3c\ 185 
 
 The remark which has here been made, con- 
 cerning the nankeen colour, takes place alfo 
 with regard to thofe articles which, though white, 
 have been immerfed in an exhaufted lixivium 
 or lees which have been ufed feveral fucceflive 
 times for the immerfion of goods taken out of a 
 ftrong muriatic acid, without previous rinfing. 
 Thefe articles, when taken out of fuch exhaufted 
 lees, and plunged into a new acid folution, un- 
 dergo a change even though they may have been 
 properly rinfed. I muft in this place remark, 
 that a lixivium may be exhaufted in confequence 
 of its combination with the muriatic acid from 
 the goods which are plunged in it, though they 
 may have been prefTed or wrung at the time of 
 taking them out of the acid. Such exhaufted 
 lees may, neverthelefs, indicate a certain degree 
 of ftrength by the areometer, though in fact 
 they do not poffefs it. 
 
 The only method of remedying thefe acci- 
 dents confifts in the ufe of water, flightly acidulat- 
 ed with fulphuric acid, no matter whether cold 
 or hot, but the hot folution operates more fpeed- 
 ily. The fpotted or tinged goods are to be foak- 
 ed in this water for a few minutes, or a quarter 
 of an hour, accordingly as the colour may be 
 more or lefs deep, in confequence of a feries of 
 
 lixiviations 
 
1 86 The Art of Bleaching 
 
 lixiviations or immerfions, more or lefs repeated. 
 In this fituation the offenfive colour is feen aU 
 mofi: immediately to difappear. 
 ■ % Inftead of making a fulphuric foliition ex- 
 prefsly for that purpofe, that which has ferved 
 for the drefling may anfwer very well : neither 
 of thefe reed be ftronger than has been there 
 directed, uniefc the goods be confiderably charg- 
 ed with colour, and there be a great quantity 
 to immerfe at once. The acidulated water is 
 tried by the areometer, and if, in confequence 
 of having been ufed, it mould not be fufficiently 
 ftrong, it may be reftored by adding the requifite 
 quantity of acid for that purpofe. It is necef- 
 fary when any new acid is poured in, to mix 
 it well with the water before any goods are 
 immerfed therein. 
 
 It muft, in this place, be obferved, that though 
 the thread and piece-goods may become charg- 
 ed with a foreign colour, in confequence of 
 the accidents here pointed out, both thefe arti- 
 cles are frequently very well bleached at the 
 under furface. It is even a proof that the muri- 
 atic acid has operated effectually, in caufing the 
 lixivium to produce fuch an effecl : but thefe 
 acidents are difficult to be obferved on objects 
 &mply cleared, or in the crude ftate. In the 
 
 latter 
 
-Cottons, Thread, "r. 187 
 
 latter cafe, a permanency of the original colour 
 may alone (hew the neceffity of ofing the ful- 
 phuric acid, particularly when the lees and the 
 muriatic acid which have been ufed are not at 
 all exhaufted. 
 
 Accidents at. fending the •preparation or drying, When 
 the piece-goods are immerfed in a folution of 
 foap, after having been taken out of the fulphu* 
 ric acid, while they are (till too ftrongly acidulated, 
 or if inftead of rinfing them they be immediately 
 conveyed from the acid into the folution of 
 foap, this laft folution is fubject to curdle, or 
 become immediately decompofed; whence the 
 operator has the mortification to obferve the 
 whole furface of the goods covered with an 
 infinite number of fmall fpots of oil, in the form 
 of clots, of a yellowifh colour, and very tenacious, 
 particularly on (lockings or cotton goods, be- 
 caufe they incorporate as it were with the nap 
 or texture of the goods : they difappear in eon- 
 fequence of much warning or rinfing. I muft 
 particularly mention an accident which may 
 happen to any one, namely, that of placing by 
 miftake (lockings or other bleached objects, 
 which have received their fir ft: treatment in the 
 folution of foap, upon articles which have been 
 expofed to the vapour of fulphur. I have placed 
 (tockV.L ;s upon gauze, which had been whitened 
 
 by 
 
i S 8 Tie Art of Bleaching 
 
 by fulphur, and found that after they had re- 
 mained in this fituation for the courfe of a night, 
 they became entirely of a brown-red at the 
 place of contact. They appeared as if burnt 
 or marked with an hot iron. This colour, which, 
 no doubt, was produced by the combination of 
 the volatile fulphuric acid, with the alkali of 
 the foap, with which the (lockings were ftill 
 impregnated to a certain degree, immediately 
 difappeared upon expofing them, firft, to the 
 action of a bath of the odorant oxygenated mu- 
 riatic acid, and afterwards to another of water, 
 Hightly acidulated with the fulphuric acid. 
 
 Every fait with excefs of acid, fuch as the 
 fait of forrel, removes the ruddy fpots here men- 
 tioned with equal eafe. It is true, that this 
 fait cannot with convenience be ufed, on account 
 of its dearnefs, but the refidue of the diftilling 
 veflels, that is to fay, the water which holds in 
 folution the refidue of the diilillation of the 
 oxygenated muriatic acid, is very ferviceable in 
 this procefs, and may be advantageoufly ufed 
 either hot or cold, to remove thofe very tena- 
 cious fpots, which are not at all capable of 
 being removed by foap or alkaline lees. 
 
 CHAP. 
 
Cottons, Thread, &c. 1JJ0 
 
 CHAP. XVI. 
 
 The Method cf taking cut Spots of Rujl or Ironmould, 
 Tar, Fruit, Wine, &c. 
 
 W HEN the fpots of oxyde of iron, com- 
 > monly diftinguifhed by the name of ironmould, 
 are fmall, they may eafily be taken out with fait 
 of forrel in powder, laid upon the fpot itfelf, 
 which is afterwards to be moiftened with a 
 fmall quantity of water; or the part which is 
 fpotted may be fleeped in a folution of the 
 fame fait. It foon becomes fainter, and at length 
 difappears, after which the place mufl be very 
 well rinfed. The fulphuric acid may be ufe- 
 fully applied inftead of the fait of forrel, as 
 Bertholet feems to affirm in his memoir ; and 
 I have proved with fuccefs, that, though the 
 fpots may penetrate quite through the cloth, and 
 be very broad, yet if they be foaked in a bath of 
 fulphuric acid, either warm or cold, when the 
 goods are taken out of the bath of muriatic acid, 
 
 the 
 
x 9<^> 5f2e Art of Bleaching 
 
 the effect will be that the fpots infenfibly dif- 
 appear. If the goods be of clofe texture, the 
 operation of the acid is flower *. 
 
 With regard to the fpots of ruft which are 
 frequently feen on thread or cotton ftockings, 
 they are produced by the needles of the engine, 
 and commonly disappear during the dreffing, 
 that is to fay, in the bath of fulphuric acid. The 
 fame obfervation is true of the fpots of ruft 
 which fometimes appear on the piece-goods, in 
 confequence of their having been in contact 
 with iron. In general, the older any ironmould 
 may be, the more tenacious it is, and the more 
 difficult to be effaced ; but every fpot may be 
 made to difappear in time. 
 
 It frequently happens that piece-goods are 
 fpotted with tar, during their carriage by water, 
 in boats, where they are liable to be placed 
 upon the pitchy parts of the veffels, or in con- 
 tact with tarred ropes. Thefe fpots may be 
 foon taken out, by rubbing them with oil of 
 olive, which diffolves the tar j or ftill better, by 
 holding the part id fpirit of wine, if this procefs 
 fhould be thought more convenient. The latter 
 
 * The fait of forrel is fold in London, in fmall bo:tles, 
 by the perfumers and apothecaries, under the name of fait 
 of lemon. The fulphuric acid, as prefcribed above, muft, 
 of couife. be diluted. — T. 
 
 method 
 
Cottons, Thread, &c. 191 
 
 method operates by the complete folution of 
 the tar. 
 
 With regard to fpots of wine, cyder, or anjr 
 kind of fruit, they may be effaced by drop- 
 ping a few drops of the oxygenated muriatic 
 acid upon them, which caufes them almoft in- 
 ftantly to difappear. But there are certain fruits, 
 fuch as plumbs, of which the fpots are more 
 difficult to efface ; they requiring one or two 
 lixiviations- Thofe that are grey, or reddifh, 
 at firft, affume a fine yellow colour in the muri- 
 atic acid, which does not difappear during a 
 fubfequent lixiviation, but requires a fecond 
 immerfion in the bleaching liquor. 
 
 I muft not omit a fecond very fimple and 
 economical method to rake out every kind of 
 fpot occafioned by fruits, fuch as ftrawberries, 
 goofeberries, &c. It confifts in caufing the 
 fpotted part to imbibe water, and afterwards 
 to burn one or two common brimftone matches 
 over the place : the fulphureous gas which is dif- 
 charged foon caufes the fpot to difappear. 
 
 There is a kind of indelible fpot which is 
 produced from red ochre and the charcoal black, 
 with which the weavers mark the turns of the 
 beam, in order to afcertain the length of the 
 chain of piece goods. This kind of mark, 
 
 whi£b 
 
192 The Art of Bleaching 
 
 which is impreffed on the goods at equal 
 diftances, is fo far from being effaced, that it 
 feems, in fome meafure, to receive ftrength 
 from the oxvgenated muriatic acid, notvvith- 
 ftanding the intermediate action of the lees. 
 
 CHAP. 
 
Cottons, Thready &c. 193 
 
 CHAP. XVII. 
 
 The Expence of Bkaching different Kinds of Goods, 
 of Linen, Hemp, or Cotton, by the oxygenated 
 muriatic Acid, at per Ell, or per Pound. 
 
 B 
 
 EFORE I proceed to give an account of 
 the expence of bleaching any quantity of ells 
 or pounds of goods, by the muriatic acid, I 
 mall, in the firft place, mention the prices of 
 the materials required to make the liquor, either 
 with or without fmell, of which I have before 
 defcribed the compofition. The prices are cal- 
 culated according to thofe of the articles to 
 be delivered at Abbeville, in 1791 *. 
 
 The fulphuric acid of Rouen, rectified for 
 
 * I have not reduced the numbers in this chapter to their 
 values in Englifh money, becaufe the difference of locality 
 would, even in that cafe, have rendered them of little im- 
 mediate utility. 
 
 As tranflator, I am obvioufly not at liberty to omit the 
 chapter, even if I were fo difpoGd. The Englifli pi ices of 
 the materials are given in the Appendix. — T. 
 
 o the 
 
194 ?7 ,<? Art of Bleaching 
 
 the market to 66 degrees, delivered at Abbe- 
 ville, willcoft ii fols the pound, wholefale. 
 
 Mangsnefe, cryftallized in needles, ready fort- 
 ed, from Pelletier, apothecary, rue Jacob, at 
 Paris, 8 fols, retail. 
 
 Grey muriate of foda, in the market of 
 Abbeville, 2 fols, retail. 
 
 Charcoal, weighing five or fix pounds to the 
 bufhel, according to the quality of the wood, 
 3 fols, retail, per bufhel. 
 
 Blue potafh, of Dantzick, or the yellow pot- 
 afh, in hard lumps, of York, 12 fols, whole- 
 fale. 
 
 Green or black foap, of Abbeville, 8 fols, 
 retail. 
 
 White marble foap, of Marfeilles, bought at 
 Abbeville, 1 2 fols, retail. 
 
 The fack of turf, containing four mannes, 
 8 fols, wholefale. 
 
 I fhall now fhew the expence of charging two 
 pneumatic veffels, by two fucceflive diftilla- 
 tions with the fimple apparatus, or by one 
 diftillation, when the apparatus has two of 
 thefe veffels, as well with muriatic acid which 
 emits no fmell, as with that in which the oda- 
 rante gas is not detained. 
 
 Expence 
 
Cottons, Thread t &c. 195 
 
 Expence of two pneumatic vejjels of the muriatic 
 acid, without Jmell> made according to the pro- 
 portions prefcribed in this Work. 
 
 Lit), s. d. 
 Sulphuric acid, five pounds and a half ---306 
 
 Manganefe, two pounds and a half - - - - 100 
 
 Grey muriate of foda, eight pounds ----080 
 
 One bufhel of charcoal of wood ------ o 3 o 
 
 Workman, one day -------«-ioo 
 
 Potalh, two pounds and a half ------ 1100 
 
 Total 7 1 6 
 
 Expence of two pneumatic vejfels of the odor ant 
 muriatic acid, made according to the proportions 
 prefcribed in this work. 
 
 Sulphuric acid, five pounds and a half 
 Manganefe, two pounds and a half - 
 Grey muriate of foda, eight pounds 
 One bufhel of charcoal of wood 
 Workman, one day - 
 Potafh 
 
 Liv 
 
 , s. 
 
 </. 
 
 3 
 
 
 
 6 
 
 1 
 
 
 
 
 
 
 
 8 
 
 
 
 
 
 3 
 
 
 
 I 
 
 
 
 
 
 
 
 
 
 
 
 S 
 
 11 
 
 6 
 
 Total 
 
 I fhall, in the next place, fhevv the expence 
 of lixiviating, or rather of boiling, two pieces 
 of cloth, each feventy-two ells long, of fuch a 
 degree of fmenefs, that two ells in length, on a 
 breadth of two-thirds, may weigh one French 
 pounds or of feventy-two pounds of thread, 
 
 o 2 fuch 
 
1 9 6 The Art of Bleaching 
 
 fuch as is commonly fpun in Picardy. I choofe 
 this kind of cloth in preference, as an example, 
 becaufe it feldom happens that coarfer goods 
 are required to be bleached even to the ordinary 
 white, which I muft be understood to mean in 
 the prefent inftance. 
 
 The proportion of ingredients for the lees re- 
 quired to fteep the feventy-two ells of cloth, 
 beforementioned, or the feventy-two pounds of 
 thread, are ten veffels of water, of eighteen 
 pints each, with about five pounds of potafh, 
 which gives a degree of (rrength, marking rather 
 more than one and a half, compofed according 
 to the directions in chap. VII. feparately, and 
 in a fmall covered portable boiler. 
 
 Expence of new lees, proper for one boiling of feventy- 
 two ells of cloth , or feventy-two pounds of thread, 
 of middling qualify. 
 
 Liv. s. 
 
 Potafh, five pounds, 3 Jivres - -> 
 
 Turf, two marines, or halt a fack, 4fbls J 
 
 It remains to be fhewn, what may be the 
 expence of bleaching the above feventy-two 
 pounds of fingle thread, or feventy-two ells of 
 cloth. I have before obferved, that cloth of 
 middling finenefs requires nearly four immer- 
 fions, two of which may be made in the muri- 
 atic acid without fmell, and two, if it be 
 
 thought 
 
Cottons, Thread, &c. 197 
 
 thought better, in the odorant acid, befides 
 four iixiviations ; and again, that one pneuma- 
 tic veflel is fufficient for (ixty pounds of thread, 
 at the firft immerfion, and from feventy-two to 
 eighty at the fecond. I (hall take feventy-two 
 pounds as the middle term, between the firft 
 and the Iaft immerfions, which, as well as the 
 Iixiviations, I will fuppofe to be made with 
 freih folutions. 
 
 Liv. j. 
 
 Two pneumatic veflels, for the two firft new im- 
 merfions in muriatic acid without fmell - 1* x 
 
 Two pneumatic vefTeJs, for the two other immerfions, 
 
 in the odorant muriatic acid - - n 3 
 
 Four new Iixiviations, or the quantity of potafh necef- 
 fary for that purpofe - 
 
 Two facks of turf 
 
 One day's work - 
 
 Total 
 
 Hence, the pound of thread of Picardy, con- 
 taining fixteen ounces, will coft 10 fols 10 de- 
 niers. With regard to Flanders thread, which 
 is cleared in water, the price will not, at molt, 
 exceed 8 fols, becaufe this article requires only 
 one immerlion, and a lixiviation lefs. Flanders 
 thread, likewife, as has been remarked, is fub- 
 jecl to a lofs of no more than twenty per cent. 
 
 If this calculation be, therefore, applied to 
 the bleaching of common coarfe cloth, two elk 
 
 03 of 
 
1 9 3 The Art of Bleaching 
 
 of which weigh a pound, the ell will not ex- 
 ceed 5 fols 5 deniers for the bleaching. 
 
 If it be, therefore, fettled to charge for the 
 thread of Picardy, or any other which is cleared 
 on the grafs, 12 fous the pound, or livre de 
 Marc ; for Flanders thread, or any other, which 
 is rotted or cleared in water, at 10 fols, upon an 
 average ; and for linen piece-goods, 8 fols the 
 ell, of fine or middling quality, the manufacturer 
 will find himfelf reafonably paid for his trouble. 
 Thefe are the ufual prices at the moft celebrat- 
 ed bleaching works of Lifle, Beauvais, Saint 
 Quentin, Senlis, Rouen, Rheims, &c. I mud, 
 however, take notice, that the dreffings are not 
 reckoned in thefe charges, which, with regard 
 to the piece-goods, amount to about 2 liards 
 per ell for cold calendering, and 1 fol for hot 
 calendering, including the folding, &c. There 
 are feme articles of which the price of the 
 dreffing amounts to half that of the bleaching : 
 thefe are fuch as require a degree of firmnefs, 
 by means of flarch, gum, or other fimilar mate- 
 rial, with blue, which, in certain markets, and 
 with regard to goods of a certain description, is 
 favourable to the fale. 
 
 The proper dreffing for thread amounts to 
 about 1 fol the pound, but is the objeti of a 
 particular agreement between the bleacher and 
 
 the 
 
Cottons, Thread, &c. 199 
 
 the owner. With refpe£t to the price of bleach- 
 ing double, or fewing, threads, my advice is to 
 charge 1 fols extra per pound, on account of the 
 greater difficulties they prefent, and the atten- 
 tions they require, as may be gathered from 
 what has been before faid on this fubjecl 
 
 Piece-goods, in general, require more care, 
 and are attended with more difficulty, than 
 threads, on account of their volume, their 
 weight, their texture, and the even white co- 
 lour required to be given, on both fides, as 
 well as towards the felvedges. It mult alfo be 
 remarked, that the felvedges having their tex- 
 ture clofed by the action of the temple, when 
 the cloth is in the loom, fometimes require, in 
 the middle of the bleaching procefs, to be 
 rubbed with foap, by hand, for which purpofe 
 black foap is to be ufed in preference. If they 
 be not opened to the action of the acid by this 
 treatment, there will be danger of the white 
 being lefs advanced towards the edge than on 
 the reft of the furface. This management may, 
 however, be avoided, if, at the time of fteeping 
 and macerating the cloth, as well as in the firft 
 lixiviation, the operator is careful to rub or clear 
 thefe parts, on account of the rirmnefs of their 
 texture. 
 
 From thefe feveral data, it will be eafy to 
 o 4 eftimate 
 
ceo The Art of Bleaching 
 
 eftimate the expence of bleaching finer thread, 
 for linens and lawns, as well as that of the ell 
 of thefe articles refpectively. For nothing more 
 will be neceffary, for that purpofe, than to con- 
 lider the account of the number of immerfions 
 and lixiviations which I have ftated to be necef- 
 fary for thofe goods. The thread of lawns, of 
 the ordinary finenefs, will run fix ells in the 
 piece to the pound, on a breadth of one ell. 
 
 Having thus fhewn the coft of bleaching 
 thread or linen goods, by the pound or ell, I (hall 
 proceed to examine that of the fame articles in 
 cotton ; for which purpofe I fhall choofe the 
 thread proper to make the commoneft wrappers, 
 which run two ells to the pound, on a width of 
 one ell. I have before ftated, that each pneu- 
 matic veffel is fufficient for the immerfion of 
 eighty or ninety pounds of thread, for the firft 
 working, and ioo for the fecond. I will, there- 
 fore, take only ninety for the middle term. I 
 have alfo ftated, that no more than three im- 
 merfions, at moft, were required to bleach 
 cotton, one of which mould be in the muriatic 
 acid without fmell, and the others in the odo- 
 rant acid, befides three lixiviations. I will 
 fuppofe that neither the acid nor the lees have 
 been ufed before. My piece of cloth mall be 
 ailumed at 180 ells, or two pieces of ninety 
 
 ells 
 
I 
 
 4 
 
 
 
 I 
 
 
 
 e 
 
 32 
 
 8 
 
 6 
 
 Cot Ions, Thread, &c% 201 
 
 ells each, and the quantity of thread equiva- 
 lent to this {hall be ftated at oo"pounds \ whence 
 it will follow : 
 
 LlV. S. d, 
 
 Firft immerfion in new muriatic acid, without 
 
 fmell 716 
 
 Two other new immerfions in the odorant mu- 
 riatic acid - - - - - -1130 
 
 Three new lixiviations in one of double propor- 
 tion with regard to the mafs to be lixiviated - 12 o o 
 
 Three facks of turf, on account of the double 
 lixiviations - - 
 
 One day's work _----. 
 
 Total 
 
 This computation fettles the pound of cotton 
 thread at about 7 fols 6 deniers, and confe- 
 quently the cloth at 3 fols 9 deniers the ell. It 
 is to be obferved, that cotton, being more loofe 
 and fpongy, and more fubjeel: to rife up in 
 the boiler by the aftion of heat, requires near 
 double the quantity of lees than for thread, and 
 confequently more fire in the fame proportion to 
 heat it, fuppofing the fame boiler to be ufed. 
 The fame remark is, in part, applicable to the 
 muriatic acid ; but as this may be ufed rather 
 weaker for cotton than for thread, the liberty of 
 diluting it with water may be taken. 
 
 If the bleacher, according to this new me- 
 thod 
 
202 The Art of Bleaching 
 
 thod, {hall therefore fix the price of bleaching 
 cotton thread at 8 fols 6 deniers the pound, and 
 of cloth entirely of cotton at 6 fols the fquare 
 ell, of every kind coarfe or fine, he may derive 
 confiderable advantage, and the public will 
 have no reafon to complain, fince cotton threads 
 in genera], and likewife muflins, require much 
 care and attention, on account of the delicacy 
 of their texture and the flight tenacity of the 
 fibres, the fhort ftaple of which, as is very well 
 known, will fcarcely permit it to be turned on 
 the reel without great care. 
 
 It now remains to be fhewn what price ought 
 to be fixed for the bleaching of ftockings of linen 
 or cotton per pair. 1 fliall begin with plain thread 
 ftockings of men's fize, from which an eftimate 
 may be made for fmaller articles of the fame 
 kind, as well as all other knit or ftocking-wove 
 goods. I fliall likewife aflume that one pair of 
 men's ftockings contains half a pound of thread, 
 and confequently 6 pounds will be contained in 
 one dozen pair. My calculation will be for :2 
 dozen or 72 pounds of thread. I fliall likewife 
 aflume that one pound of green foap will be re- 
 quired for the firft wafliing of fix dozen pair of 
 men's ftockings, and one pound of white foap 
 for the fecond and laft wafliing of the fame fix 
 dozen. And accordingly I fliall add to the fum 
 
 before 
 
s. d. 
 
 Co/tons, Thread, £3c. 203 
 
 before deduced, for the mere and fimple bleach- 
 ing of 72 pounds of linen, of which the detail 
 has been given, the furplus in lixiviations, im- 
 merfions, and wafliing with foap, which (lock- 
 ings require. This amounts to two lixiviations, 
 and the fame number of immerfions as I have 
 fhewn at chapter X. 
 
 Therefore firft fet down the fimple price of 
 
 bleaching 70 pounds of thread, namely - 
 To which add two additional lixiviations 
 Two immerfions in the odorant muriatic acid 
 Two pounds of green foap for the firft warning 
 Two pounds of white foap for the fecond wafiiing 
 Half a fack of turf to heat the folutions of foap 
 A woman one day for the warning 
 
 Total 
 
 This account gives 8 fols 3 deniers for each 
 pair of men's dockings ; and if 12 fols be taken 
 for this article, I am of opinion that there will 
 not be many bleachers envious of the advantage 
 of rendering them milk-white at this price, on 
 account of the difficulties they prefent, which 
 require them to be turned from time to time to 
 open the texture, which would otherwife become 
 clofe and impenetrable to the muriatic acid: and 
 if the ftockings be ribbed, or have clocks, it will 
 not be too much to charge 14 fols the pair, on 
 
 account 
 
 39 
 
 2 
 
 
 
 6 
 
 8 
 
 
 
 11 
 
 3 
 
 
 
 
 
 16 
 
 
 
 1 
 
 4 
 
 
 
 
 
 4 
 
 
 
 
 
 IS 
 
 
 
 59 
 
 12 
 
 
 
204 The Art of Bleaching 
 
 account of the particular care required for thefe 
 kind of goods, the ribs of which being difpofed 
 to fhrink up, are very apt to prevent the intire 
 action of the acid. 
 
 With regard to women's and boys' (lockings, 
 10 fols per pair may be charged, and for fmaller 
 articles 8 fols; at which laft price gloves ought to 
 be charged, becaufe the fingers being clofer than 
 the other parts, require to be turned from time 
 to time to produce an even colour. Mittens 
 may be charged at 5 fols the pair. Articles of 
 the fame kind of thread and cotton, mixed, de- 
 ferve nearly the fame price on account of the 
 thread which retards the bleaching. 
 
 We muft now inquire the price of bleaching 
 the fame articles in cotton. Here likewife I 
 mall ground my comparifon on plain ftockings 
 for men, admitting that 6 ounces of cotton will 
 make one pair of this fize, which will amount to 
 41 pounds the dozen pair, or 90 pounds of thread 
 for 22 dozen pair. To this laft quantity we 
 fhall direct our inquiries, in which I fhall con- 
 fine myfelf to add to the former determination 
 with regard to 90 pounds of cotton thread of 
 like quality, the extraordinary lixiviations and 
 immersions which knit or itocking-wove articles 
 require. This excefs, as fhown at chapter X. is 
 
 half 
 
Cottons, Thread, &c. 205 
 
 half a lixiviation and one immerfion in the odo- 
 rant muriatic acid. 
 
 Liv. s. d. 
 I (hall therefore reckon for the mere bleaching of 
 
 90 pounds of cotton thread as before ftated - 32 8 6 
 
 To which add half a lixiviation in a double dofe 340 
 
 One immerfion in the odorant muriatic acid - 5 ix 6 
 One fack of turf for heating the double quantity 
 
 of lees - - - 080 
 
 Four pounds of green foap for the fin! warning 112 o 
 Four pounds of white foap for the fecond and 
 
 laft wafhing - -- - - 280 
 
 One fack of turf for heating the folutions of foap 080 
 
 Two days' work of a woman to wafh - 1 10 o 
 
 Total 47 10 o 
 
 Whence we fee that the coft for 1 pair of 
 men's plain cotton (lockings is about 4 fols, and 
 if the charge be fettled at 5 fols for men and 4 
 for women, or 4 fols 6 deniers one with another, 
 there can be no caufe of complaint. Ribbed 
 ftockings mull:, however, be excepted. Thefe 
 deferve at lead an addition of 1 fol per pair for 
 the extra attentions, which have been before 
 mentioned. 
 
 Nightcaps may be charged, one with another, 
 at 2 fols 6 deniers : gloves, on account of the 
 fingers, mull: be charged at 3 fols the pair, and 
 mittens, and children's ftockings, at 2' fols. 
 
 Xh< " 
 
icS The Art of Bleaching 
 
 The foregoing are, in general, the articles 
 which are ufually bleached at the proper works 
 for that purpofe. With regard to the prices I 
 have affi^ncd for bleaching; each article without 
 any kind of dreiiing, they are fuch as I have, from 
 my own experience, thought fit to advife to thofe 
 perfons to whom 1 have had the pleafure of 
 teaching this new and important art of bleach- 
 ing. They are capable of being confiderably 
 diminiihed bv turning to advantage the lees and 
 acid which have been ufed as I have advifed in 
 the proper place. But I have chofen in my 
 eftimates to confider them as new, in order that I 
 might be fubjeft to no reproach for diminifhing 
 the charges which I have, on the contrary, ftated 
 at the higheft, as every operator may convince 
 himfelf. If to thefe firft favings of lees of mu- 
 riatic acid, and of the other collateral and de- 
 pendent objects, we add the advantage which 
 may be derived from the old lees, as I have 
 fhewn, as well as from the exhaufted bleaching 
 liquor, the refidues of the retorts, &c. there can be 
 no doubt but that all thefe different prices may 
 be confiderably abated ; even though we might 
 not venture to affirm that the expence would be 
 entirely compenfated by the profit arifing from 
 an intelligent application of thefe matters, which 
 have heretofore been thrown away as ufelefs. 
 
 CHAP. 
 
Cottons, Thread, &c. 207 
 
 CHAP. XVIII. 
 
 The Method of bleaching yellow Wax, Nankeen 
 Stockings, and other Articles which have acquired 
 a dark Colour by keeping ; Linen Jlained by Damp- 
 nefsy and the Madder Grounds of printed Gcods. 
 
 JL HE bleaching of yellow wax may be ef- 
 fected by means of the bleaching liquor, with 
 fmell, as well as with that which has no fmell. 
 For which purpofe a fingle immerfion, or, at 
 mod, two, with the fame number of intermedi- 
 ate fufions, are necefTary. The operation, never- 
 theless, fucceeds more fpeedjly with the odorant 
 muriatic acid, becaufe the wax bleaches as well 
 above as below; which facility it acquires by 
 its property of fwimming, and prefenting a 
 greater furface, as well to the gas which rifes 
 in the liquor, and bleaches in its paffage, as 
 to that which efcapes above the ribbons of wax, 
 which, being retained by the covers of the vef- 
 fels, is forced to a£t upon the furface expofed 
 to its a£lion by falling in a kind of dew. Thefe 
 ribbons of wax mull be very thin. 
 
 It is more convenient, however, to ufe only 
 the vapour of the oxygenated muriatic acid, 
 
 as 
 
2oS Tie Art of Bleaching 
 
 3.s Berthollet informs us from the experiment of 
 T-andriani. This laft method is, as I likewife find 
 by experiment, much more effectual. To prove 
 this truth, nothing more is neceflary to be done 
 than to expofe wax rafped or fcraped into very 
 thin leaves, under the cover of a pneumatic 
 veffel, above the furface of the liquor. I am 
 even difpofed to think that this experiment may 
 point out the invention of a bleaching procefs 
 in appropriate veffels furnifhed with different 
 ftages of frame-work covered with coarfe cloths. 
 The goods being fufpended through the whole 
 height of the veffel thus conftrucled, or elfe in a 
 chamber difpofed and appropriated to the fame 
 effect, that is to fay, that it fhall be provided 
 \rith fhelves, or poles, fo difpofed all round 
 within its capacity, upon which the acid va- 
 pour, directly conveyed from the neck of the 
 retort, or admitted through the fides of the 
 chamber, may thus act with great freedom and 
 promptnefs, in the fame manner as the volatile 
 fulphureous acid a£ts upon goods which are re- 
 quired to be bleached by its means. I have 
 alfo remarked, that the mafs of wax, with which 
 the ends of 'the leaden tubes, plunged in the 
 intermediate veffel when I ufed this apparatus, 
 was rendered of a beautiful white through its. 
 whole thicknefs, which was nearly half a line, 
 
 and 
 
CottonSy Thread, &V. 209 
 
 and this by no more than two hours expofure to 
 the action of the vapour. 
 
 1 The true nankeen is bleached or deprived of 
 its colour with fome difficulty. It is firft to be 
 wetted and wrung ; after which it i9 fubjee~red to 
 a firft immerfion in the bleaching liquor, which 
 deprives it of a large portion of its colour. It 
 is then to be properly rinfed, and agitated in a 
 good folution of lbap, which is preferable to 
 lees, becaufe it caufes the colour, which had 
 merely difappeared, to (hew itfelf again more 
 effectually. The piece of nankeen is then to 
 be well rinfed, and fubjected to a new immer- 
 fion. The number of immerfions varies accord- 
 ing to the ihade of the colour ; but this article 
 feldom requires more than three immerfions, 
 with intermediate warnings with foap< The 
 finifh is given in a bath of fulphuric acid, after 
 which it is to be rinfed in a large quantity of 
 water, and then wrung and dried. This pro- 
 cefs may be performed indifferently with either 
 of the two acids, the odorant, or that without 
 fmell ; neverthelefs the latter ought always to 
 be preferred, particularly for the firft immer- 
 fion, becaufe it more fpeedily and equally de- 
 ftroys that kind of flefh colour which is peculiar 
 to the true nankeen. Neverthelefs, though the 
 oxygenated muriatic acid acts fo ftrongly on this 
 
 f colour, 
 
a I o The Art of Bleaching 
 
 colour, I never have been able to bring nan- 
 keens to a white of the fame beauty as is ac- 
 quired by cotton, thread, and piece goods 
 bleached by this procefs. 
 
 Stockings and other goods bleached by the old 
 procefs, but which have acquired a ruddy co- 
 lour, at the extremity of the folds, by remaining 
 in the fhop or warehoufe, partly uncovered either 
 from want of care or for fliew, require only a 
 fingle immerfion without preliminary foaping 
 or lixiviation. The ink marks which retailers 
 are in the habit of making to afcertain either 
 the number, price, or quality of their goods, 
 partly difappear in this immerfion, and totally 
 in the bath of fulphuric acid, in which they are 
 afterwards plunged. Thefe goods are to have 
 all the fubfequent dreflings, of which I have given 
 an account, if the proprietor expects or re- 
 quires it. 
 
 It is a peculiar property of the oxygenated 
 muriatic acid, to difcharge thofe black fpots 
 which are feen on foul linen, particularly when 
 they rife from perfpiration or moifture. The 
 places moft fubjec~t to thefe flains, are where the 
 linen is applied to the back or beneath the 
 arm pits. This procefs is to be commenced 
 with a lixiviation or boiling, which is to be 
 fucceeded by^n immerfion, and afterwards by a 
 
 bath 
 
Cottons, Thread, &c. m 
 
 bath of fulpburic acid. However ftrong the 
 fpots may be, they never refill thefe feveral 
 operations. 
 
 Spots of brandy likewife difappear by the 
 fame procefs. 
 
 With regard to the madder ground of paint- 
 ed or printed goods, it is eafily difcharged by 
 either of the oxygenated muriatic acids, a 
 fingle bath ufually being fufficient for that pur. 
 pofe. 
 
 For greater convenience, it is advifeable to 
 ufe the acid without fmel], becaufe the operator 
 may, with more eafe, follow and conclude at 
 a proper time the immerfion of the piece as foon 
 as, while paffing it over the reel, he obferves 
 that the ground is fufficiently white and clear. 
 The bleaching liquor, which is partly exhaufted, 
 may be ufed to advantage in this procefs. Be- 
 fore the immerfion is made, care muft be taken 
 to plunge the piece in water and wring it out 
 fo far as to leave it merely humid or moift. 
 After the immerfion it muft be well rince4 
 and dried either in the fun or in the fhade, turn- 
 ing the coloured furface from the fun. 
 
 It may be remarked that the deep reds are capa- 
 ble of being again brought out, or rendered flightly 
 red, by the fun's light, and the other (hades ad- 
 vanced in proportion 5 this would happen in the 
 eommon method of bleaching, if the printed 
 * 2 part 
 
2t2 The Art of Bleaching 
 
 part were not always turned to the grafs. I 
 fhall proceed to mention fome circumftances 
 with refpecl to this method of difcolouring or 
 bleaching, which may be of ufe to thofe who 
 are interefted in applying it to practice. 
 
 Goods printed in fait colours (bon tei?itj t for 
 thofe with chemical colours (-petit teint) are too 
 difficult to be treated by this method, intended 
 to be bleached by the oxygenated muriatic acid, 
 inftead of the ufual expofure in the field, ought 
 to have their den^iis much more charged with 
 colour, than fuch as are intended limply to be 
 fubje&ed to the action of the air ; in order that 
 while the acid exercifes its action on that part 
 of the ground which is maddered without mor- 
 dant, the fame action which is alfo exerted on the 
 part where the madder is combined with the mor- 
 dant, may not deftroy in the laft part any more 
 of the colour than that quantity in excefs, be- 
 yond what the piece ought to preferve to pro- 
 duce the intended e fleet, and, confequently, 
 that it fliould not, after the procefs, appear 
 more fenfibly altered than it would have been 
 after the ufual expofure in the field : this pre- 
 caution ought to be attended to more particu- 
 larly with regard to the ordinary violets, blacks, 
 and browns. They are much more eafily de- 
 graded than the red, or rofe-colours, and the 
 deep browns. 
 
 One 
 
Cottons, Thread, Z3c. 912 
 
 One leading objecl, which is effential to the 
 prefervation of the colour, and contributes in- 
 finitely to the unmaddering, is to give the pieces 
 pne or two boilings in bran and water, which 
 may follow a boiling in a folution of foap. If 
 thefe three boilings are properly managed, the 
 ground of the piece goods will be brightened 
 at lead three quarters. One or two immer- 
 iions in the bleaching liquor will remove the 
 fmall portion of colour which remains. Be- 
 tween the two immerfions attention muft be 
 paid to plunge the goods in bran and water. 
 This ought to be done after the laft immeriioi), 
 for it raifes and relieves trje tone of the colours 
 which may have been flightly weakened. 
 
 I have feveral times found, that when the 
 preparatory baths have been well proportioned 
 to the grounds intended to be coloured, it is 
 unnecefTary to apply the bleaching liquor. &. 
 few days expofure in the field are fufficient 
 afterwards to complete the bleaching. 
 
 The proportions which I followed for the 
 bath of bran and water, were three ounces and 
 an half of wheat bran, and three pounds and 
 an half of river water. Thofe for the folution 
 of foap were two ounces of foap to four or five 
 pounds of water; the weight of the goods to 
 which thefe dofes were adopted were 10 gros. 
 ? $ More, 
 
214 Me Art of Bleaching 
 
 Moreover, it is practicable, according to the 
 depth of the tints, and the experience the ope- 
 rator may have acquired, to diminifh the force 
 of the oxygenated liquor to that point which 
 may infure him againft a too perceptible de- 
 struction of thofe parts which ought to pre- 
 ferve their brightnefs. But, in this practice, the 
 procefs is too flow, and the great advantage of 
 ufing this method with regard to fuch kind of 
 goods would thus be loft. 
 
 In a confiderable manufactory, where the 
 operations of printing and bleaching fucceed 
 each other with rapidity, it might, perhaps, be 
 more advantageous to clear off no more than 
 three-fourths of the ground of the cloth which 
 has received the madder without mordant, by 
 fubjecting it to the boilings with bran, wa- 
 ter, foap, and a flight immerfion in the liquor, 
 as has been prefcribed, and afterwards to ex- 
 pofe it to the action of the air in the fieid. 
 This method of operating feems preferable, 
 and would be no lefs expeditious, whether in 
 fummer or in winter. And in the cafe only of 
 the goods being in great hafte, the complete 
 bleaching with the oxygenated acid might be 
 advifcable, taking care to ufe all the precau- 
 tions which have already been pointed out. 
 
 In order to avoid expofing the goods to too 
 
 con- 
 
Cottons 3 Thread, &c. 215 
 
 confiderable alteration, it is more convenient to 
 pafs only one or two pieces through at a time, 
 with the attention that they fhould be of the 
 fame degree of intenfity in their colours, in 
 order that if it mould be neceffary to ftop fud- 
 denly the effea of the liquor, it may, in fome 
 meafure, be done inftantly. This could not be 
 eafily accomplifhed, if eight or ten pieces were 
 fewed together as foon as foaped. For it is 
 eafy to imagine, that while one piece was 
 drawn out, the others remaining in the liquor 
 too long a time, would be expofed to have 
 their colours weakened, at lead in the propor- 
 tion of the longer time they remained in the 
 liquor. If it were thought an objea of fuf- 
 ficient importance, this laft inconvenience, 
 however, might be removed, by placing at the 
 bottom of the veflel for immerfion a platform 
 of ftrong balket work, which might be fpeedily 
 raifed by means of a pulley, or other me- 
 chanifm, to remove the goods out of the bath 
 at the inftant it might be found neceffary, and 
 they might afterwards be thrown into a refer- 
 voir of water, or conveyed to the river. 
 
 It would be a very delirable objeft, if the 
 oxygenated muriatic acid could aa only upon 
 the furface oppofite to the printed fide ot the 
 piece. In this way it would operate like the 
 
 P ^ atuio- 
 
2i6 The Art of Blading 
 
 atmofpheric air, without giving caufe to fear 
 the deftru&ion or perceptible alteration of the 
 fbades, whatever might be their depth. The 
 difficulty of fucceeding, and the length of time 
 required for bleaching, may, perhaps, fooner or 
 later, give rife to a method of fixing the co- 
 lour by particular mordants, without the aflift- 
 ance of madder. 
 
 It would alfo be a dcfirable object to difcorer 
 a procefs to prevent too much degradation of 
 the tranfverfal red or blue ftripes, and other or- 
 naments of coloured thread, which are ufually 
 made at each extremity or angle of cotton co- 
 verlids. This procefs might alfo be applicable 
 to the defence of thofe tranfverfal blue or red 
 ftripes which are made in pieces intended for 
 napkins, between one napkin and another, and 
 at the ends of pieces of muflins and the like. 
 The beft method, no doubt, would confift in 
 manufacturing thefe goods entirely of one co- 
 lour, and afterwards making the terminations 
 with coloured thread. As thefe kind of jroods 
 ate capable of being foiled, either by the dref- 
 fing given to their chain, or by the different 
 operations which fucceed or are previous to 
 the weaving, they may be eafily cleanfed by a 
 proper wafhing or foaping. 
 
 The following is the expedient which I have 
 
 thought 
 
Cottons, Thread, &c. 217 
 
 thought proper to ufe to preferve the ftripes in 
 queftion from every action which might be too 
 perceptible. After two good baths in the 
 lixivium, each of the ftripes was covered, on 
 both fides, with one or more coatings of chalk 
 and oil, which was left to dry until the pieces 
 could be handled without fear of fpotting the 
 neighbouring parts. I then fubjecled them to 
 the bleaching liquor, afterwards to a flight lixi- 
 viation, and a folution of foap, &c. and fo on, 
 fuccefhvely, till the ground was as clear as re- 
 quired. After each lixiviation I took care to 
 repair or renew the covering, if neceflary. I 
 afterwards cleared off this covering of chalk and 
 oil, either with a good foaping, or with a flight 
 bath of fulphuric acid, according to the nature 
 of the colour of the bar, and the degree of te- 
 nacity of the paint. If by accident the colour 
 of the bar was fomewhat weakened, it did not 
 fail to be raifed again, by palling it through 
 bran-water at the conclufion of the procefs. I 
 apprehend that this expedient, which I have 
 always ufed with a certain degree of fuccefs, 
 will be acceptable to the'manufacturer. 
 
 CHAP. 
 
2i8 The Art of Bleaching 
 
 CHAP. XIX. 
 
 The Method of df charging the Colour of fainted or 
 fritted Cottons, or Linens, and every Kind of 
 Dye on Cloth cr Thread, before or after it is 
 wrought up, 
 
 -/jLLL the colours of callicocs, or printed 
 goods in fail colours, are deftroyed by either of 
 the oxygenated muriatic acids, without having 
 recourfe to the lixiviations or other previous or 
 intermediate operations before defcribed. The 
 blues, yellows, and blacks, afford an excep- 
 tion with refpect to the bath of fulphuric acid, 
 which muft be fubftituted inftead of the lixi- 
 viation. A fmgle immerfion in the muriatic 
 acid is fufficient to deftroy all other colours, 
 fuch as reds, yellows, auroras, green, &:c. ; but 
 the yellows, properly fo called, and the lemon 
 colour, with which greens are produced, and 
 the blues and blacks, fometimes require, accord- 
 ing to their (hade, three immerlions, and two 
 or three intermediate baths of fulphuric acid. 
 
 It 
 
Cottons, Threads , &c. 219 
 
 It muft not, however, be fuppofed, that the 
 Adrianople reds, when difcharged by the oxy- 
 genated muriatic acid, become perfectly white. 
 There always remains a flight ruddy appear- 
 ance, which arifes from the oily matter which 
 enters into the preparation for this dye.. This 
 tinge of rednefs does not difappear, however 
 numerous the lixiviations and immerfions and 
 baths of fulphuric acid may be. 
 
 There is another thing no lefs worthy of 
 remark with regard to the black colour, which, 
 forms the outline or border of defigns, namely, 
 that if the muflin, or cleared fine piece, upon 
 which the different flowers were deligned 
 which have been difcharged, be folded toge- 
 ther in feveral folds, or placed upon a dark- 
 coloured ground, the effaced outline becomes 
 vifible according to the expofure of the piece 
 under a certain obliquity of the light exhibiting 
 the appearance of a flight trace. The kind of 
 outline which, under thefe circumftances, be- 
 comes vifible, cannot be compared to any thing 
 better than the embroidery of muflins placed 
 on a coloured ground. This trace feen at a cer- 
 tain diftance has the fame effect, and even when 
 clofely obferved, it is impoffible to determine 
 what it is, becaufe it is not vifible, except 
 under a certain reflection of the light ; never- 
 
 thelefs 
 
22* The Art of Bleaching 
 
 thelefs the whole piece appears white, and or a 
 very fuperior quality. I have remarked that this 
 effect does not take place excepting with regard 
 to the old prints of flowered defigns of the 
 true India callicoes imported from that part of 
 the globe. For in the .printed goods of our 
 manufactures, fuch as thofe of Paris, Joly, 
 St. Denis, and Beauvais, all the traces of the 
 defigns completely difappeared, to my great 
 furprize. It mult, therefore, necelTarily be 
 admitted, that the difference in thefe refult* 
 depend on the qualities of the mordants, which 
 are more or lefs oily, or the manner of ftriking 
 the blocks in the aft of printing. 
 
 If this effect were produced by the mordant 
 with the outlines of the defigns in the pieces of 
 printed goods, it might, perhaps, be of advan- 
 tage to take the fame method of obtaining a 
 fubftitute, inftead of the rich expenfive em- 
 broideries with which the fine muffins of India 
 and Switzerland a^e covered. Thcfe defigns 
 Jikewife do not appear in their full effect, but 
 when they are placed upon a tranfparent fluff 
 of a deep colour, which exhibits all the out- 
 line. This method of producing fo rich an 
 effett would be extremely fimple, fingularly 
 permanent, and highly economical. I think, 
 however, that I may add, that, after many trials 
 
 I I 
 
Cottons, Thread, &c. 22 S 
 
 I Lave at laft fucceeded in difcbarging this 
 mordant, fometimes by a bath of fulphuric 
 acid, rather ftronger than ufual, and at other 
 times by foaping the goods before and after the 
 bath. This management is very eflential to be 
 known, in order that the operator may not be 
 cxpofed to the mortification of feeing the fame 
 defigns return again by the fecond action of the 
 madder applied to the fame bleached piece in a 
 fubfequent printing procefs. To obviate every 
 accident of this kind, it will be proper to in- 
 form the owner which of the methods have 
 been ufed to bleach their goods, and in cafe 
 the new method may have been ufed, it would 
 then be prudent to pafs them previoufly through 
 a good Bath of fulphuric acid. 
 
 With regard to chemical colours, as they are 
 called, which are applied on callicoes or other 
 goods, they difappear immediately, and much 
 more fpecdily, than fa ft colours. A fingle im- 
 merlion in the weakeft oxygenated muriatic 
 acid, without any other preparation, is Sufficient 
 to deftroy them, excepting only the outline of 
 the flowers, which, as has already been re- 
 marked, requires particular precautions. 
 
 Among the yellow colours of this defcription 
 there is one, however, in the compofition of 
 which fulphate of copper, fulphate of iron, 
 
 and 
 
222 ¥he Art of Bleaching 
 
 and acetate of lead, are ufed, which is fo far 
 from being deftroyed by the oxygenated mu- 
 riatic acid, that, on the contrary, it is nxed by 
 that means. This colour cannot be difcharged, 
 unlefs the piece be previoufly well rubbed in a 
 good bath of foap, which difpofes it fo far to 
 detach itfelf from the goods, that the immer- 
 fion it afterwards undergoes in the muriatic 
 acid completes its difcharge. 
 
 It is very remarkable, that, after the difco- 
 louring of the printed goods, particularly brown 
 or black, and when the oxygenated muriatic 
 acid has combined with the merchandize, there 
 arifes from the trough a certain gas, which acts 
 upon and irritates the organ of fight only, to 
 fuch a degree, that it is very difficult to fup- 
 port its action for any confiderable time with- 
 out a difcharge of tears *. This effeft, how- 
 ever, is not very perceptible in a trough over 
 which the workman has operated for the whole 
 day, until towards the evening, whence it fol- 
 
 * The effect of this gas upon the human body is very fimi- 
 lar to that which was produced on the 22d Brumaire in the 
 evening, the prefent year, 6th of the republic, by a thick 
 mift, of which the influence was felt, more or lefs, through- 
 out Paris. This action was exerted principally by an irrita 7 
 tion of the throat, a pricking fenfation in the eyes and nofe, 
 and a difcharge from the head. The oxygenated muriatic 
 gas produces the fame effects when it is breathed for any length 
 of time, on which fubject lee chap. vi. of the prefent work. 
 
 lows 
 
Cottons, Thread, &c. 11% 
 
 lows that the acid does not a£t till after a confi- 
 derable time upon the mordants, (o as to pro- 
 duce this peculiar gafeous combination, which 
 is then capable, by its quantity, of irritating the 
 organs of fight. Thefe inconveniences may be 
 avoided, by taking care to work thefe pieces 
 under a glafs cover, exprefsly difpofed for that 
 purpofe, nearly as is reprefented in fig. 1 and 
 2. in plate 1 ; or by making ufe of the covered 
 verTel reprefented in fig. 1 and 2. plate 9. It 
 would be an important acquifition to know the 
 nature of the gas here fpoken of. 
 
 With regard to piece goods dyed before or 
 after the weaving, whether of thread or cotton, 
 all the falfe dyes,-fuch as red, blue, green, flefli- 
 color, orange, grey, black, &c. difappear in an 
 inftant, and almoft conftantly, by a fingle im- 
 merfion, and certainly by one immerfion and one 
 lixiviation ; but it is moft ufual to omit the lixi- 
 viation. 
 
 The fame remark does not apply to the true 
 dyes, or fair, colors, fuch as blues, Indian red, 
 ftrawberry colour, deep brown, &:c. the yellow 
 colour and lemon colour either applied to linen or 
 cotton : thefe are much more difficultly effaced. 
 They fometimes require one lixiviaticn between 
 two immerfions, according to the force of the 
 made. The blue in particular is the molt tena- 
 cious 
 
224 the Art of Bleaching 
 
 cious colour ; it muft be obferved, that a bath of 
 fulphuric acid muft always be given at the con- 
 clufion, particularly with refpeft to the yellows, 
 of the colour of ruft of iron, which does not to- 
 tally difappear but in this laft fluid. 
 
 With regard to goods which have not been 
 maddered, and of which the defigns have been 
 printed in oil, the firft preparation is that of the 
 lees, in which they muft be heated, without rinf- 
 ing or clearing off. After this, while they are 
 yet hot from the lees, they mull be flrongly rub- 
 bed in a good folution of fo?p. Moll of the 
 colours are, by this means, partly difcharged, and 
 their definition may be completed, either by. 
 the oxygenated muriatic acid, or by the fulphuric 
 acid. It is feldom Decenary to repeat this courfe 
 of operations, many of thefe colours being ufu- 
 ally difcharged by the foap. 
 
 It is certainly proper to remark, in this place, 
 that the effect of the oxygenated muriatic acid 
 in deftroying all colours whatever, as well on 
 printed goods, as in fuch as have undergone the 
 procefs of dying, whether in the thread, or in the 
 web, muft afford many perfons the advantage of 
 multiplying, in fome meafure, the changes of 
 their clothes, without going to the expence of 
 new : for if the old or unlafhionable colours of a 
 garment be difcharged, and it be afterwards font 
 
 to 
 
Cottons, Thread, &c. 11$ 
 
 to the printer's to receive a new defign, this fun- 
 pie procefs would enable the wearers to change 
 the faftiion every feafon, if they thought proper. 
 The only expence would be that of difcharging 
 the old colours and printing new, at fo much an 
 ell, for the feveral colours, according to their re- 
 fpe&ive value. It is equally obvious, that dealers 
 in printed goods * might, by this means, vary or 
 enlarge their fpeculations. I muft like wife add, 
 it might be poffible to take advantage of the faid 
 property of the oxygenated muriatic acid, to de- 
 stroy the colours of dyed goods, or to trace any re- 
 quired defign with the pencil, the pen, fimply 
 in the way of outline, and in the manner of 
 goods printed a la referve. I have feveral times 
 attempted to iketch different flight defigns on 
 fuch goods, principally in the muriatic acid 
 without fmell, and I fucceeded perfectly in ob- 
 taining very neat and fine traces. It might be, 
 perhaps, an object of (till greater intereft, to give 
 a rofe or other colour to piece-goods dyed d la 
 referve, becaufe this method has not hitherto 
 been applied but with refpecl to blues, and 
 
 * It feems probable that the wholefale method of operating 
 in England, and the effe£t of the excife laws, would render 
 the practice here dsfcribed not very convenient in the English 
 market, — T. 
 
 €L fometimes 
 
226 I'be Art of Bleaching 
 
 fometimos to orange or olive colour, or a few 
 other light colours of this kind. 
 
 The fame thing might be done with regard 
 to the. particular defigns or things which might 
 be imitated on ftriped goods, the threads of 
 which were dyed before the weaving ; from 
 which it might be poffible, either to take away 
 part of the colour, or to add at pleafure a 
 ftripe of another kind. I have fometimes ac- 
 complished this purpofe on blue and white 
 ftockings, as well as, ftriped and chequed piece- 
 goods, by lightly fprinkling the oxygenated 
 muriatic acid upon them : the different drops 
 of the acid produced a lingular effect by fpot- 
 ting thofe ftockings and ftriped goods. All 
 the goods thus treated may be warned with 
 foap or lees, without danger of effacing the 
 different lingular marks or defigns which have 
 been traced upon them. The obfervation I 
 have made, with refpect to dyed goods, is like- 
 wife applicable with regard to certain patterns 
 of one uniform colour ; it is probable that the 
 prints might be made from a block impregnated 
 with the muriatic acid, combined or amalga- 
 mated in fuch a manner as to work with the 
 fame accuracy as in the common practice of 
 callico printing. 1 fliall hereafter relate an ex- 
 periment 
 
Cottons, Thread, &V. S27 
 
 periment which I have made in fupport of this 
 obfervation . 
 
 I muft not omit the remark, that the oxyge- 
 nated acid is very ufeful to brighten up the 
 white defigns referved in piece-goods printed 
 a la referve. 
 
 It is well known that thefe white fpaces are 
 feldom clear; .either becaufe the compofition 
 being ill applied, or ill made, fuffers a fmall 
 quantity of the colour to pafs through j or from 
 the effect of the fulphuric acid in which they 
 are fteeped to clear off the compofition, when 
 it is made of tobacco-pipe clay, &c. If the 
 piece, when taken out of the boiler, is not well 
 cleared of its colour, this laft will flightly extend 
 itfelf towards the blue, which is uncovered ; con- 
 sequently, by fteeping the piece in a bath of 
 oxygenated muriatic acid, after its immerfion 
 in the fulphuric acid, the colour is not only 
 brightened, but the referved white, in confe- 
 quence of the neat finifh in its outline, is ren- 
 dered much more linking in its effect. 
 
 a. * * CHAP. 
 
228 The Art of Bleaching 
 
 CHAP. XX. 
 
 The Methods of taking cut the Dye from Silk and. 
 Wool. 
 
 J^ILKS dyed in a fimple colour, fuch as indigo- 
 blue, lilac, crimfon, and grey, are capable of 
 lofing their colour, and acquiring a yellow cha- 
 mois colour, by fteeping in a bath of oxygenated 
 muriatic acid, without any previous or inter- 
 mediate lixiviation or preparation. White filk 
 receives the fame yellow colour, if expofed to 
 this acid. But it is poffible to convert this yel- 
 low colour to white, by expofing the filk to the 
 vapour of fulphur or the fulphureous volatile 
 acid. For this purpofe, it is neceffary that they 
 fhould be yet in a moift ftate, to facilitate the 
 equal a£tion of the fulphureous gas. It rauft be 
 obferved alfo, that the goods ought not be ex- 
 pofed too near the flame of the fulphur, becaufe 
 the heat dries them, and retards the aclion of 
 
 the 
 
Cottons, Thready &c. S29 
 
 the volatile acid, and may likewife give them a 
 fcorched or brown colour. 
 
 Compound colours, fuch as browns, violets, 
 greens, and blacks, likewife lofe their colour, 
 and acquire a fimilar tinge of chamois yellow ; 
 but this difcolouring commonly requires two 
 immerfions. The blue of brown violet and 
 puce colours commonly difappears firft, leaving 
 the fhade of red more or leis weakened. The 
 fame gradation takes place with regard to the 
 green and orange colo jrs, of which the yellow 
 gives way firfl:. The blue of the former, and 
 the red of the latter, only remains. It is 
 neceffary that the oxygenated muriatic acid 
 mould be weak (legcre) otherwife it would ac- 
 quire an aurora colour inftead of a rofe colour, 
 when it afterwards came to be fteeped in ful- 
 phuric acid ; for it is to be noted, that it is pro- 
 per to ufe a bath of fulphuric acid, and rinfe 
 off with much water previous to each of the 
 faid immerfions. With regard to black filks, 
 the brown difappears firft, and leaves the blue 
 ground, if this may have been ufed ; or the root 
 ground, fuppofing this lafl: to have been the 
 bafis of the black. 
 
 Thefe obfervations, refpecting filk, hold good 
 alfo with regard to wool dyed grey, orange, green, 
 
 Q. 3 Saxon 
 
a 30 The At of Bleaching 
 
 Saxon blue, apple green, root or fawn colour, 
 brown lemon, and dipped blue. All thefe co- 
 lours difappear more or lefs readily, and become 
 of a chamois yellow, like the filk ; but this laft 
 tint is eafily brought to the original white, by 
 expofure to the volatile fulphureous acid. Two 
 immerfions in the oxygenated muriatic acid are 
 fometimes required, according to the depth of 
 the colour ; and the expofures to fulphuric acid 
 will like wife require to be occasionally repeated. 
 For if the cbamoi.s colour ioes not totally difap- 
 pear at the fir ft expofure, it will at the fecond. 
 
 If we attend, for a moment, to the alterations 
 which woollen and filken goods undergo by ex- 
 pofure to the air, we lhall immediately fee, that 
 the oxygen of the atmofphere is the principle 
 which acls on the colouring matters with which 
 the goods are impregnated, particularly the 
 falfe dyes ; and that the change is of the fame 
 nature as that which is produced by immerfmg 
 thefe goods in a liquid which is, in fome meafure, 
 faturated with that principle. The difference 
 confifts only in the fpeed with which this effect 
 is brought about in the latter cafe. 
 
 The yellowifh colour produced by the oxygen 
 of the air is particularly obfervable in grey 
 woollen with a raifed nap, and loofe hofiery of 
 
 the 
 
Cottons, Thread, Be- 0.3 i 
 
 the fame colour. This mode of fabrication and 
 opennefs of texture probably affords a ftronger 
 hold to the oxygen, from the more extended 
 furface it prefents. 
 
 With regard to dyed filks, thofe of a rofe co- 
 lour, and Saxon blue, as well as the falie blacks, 
 are moft fubjeft to alteration by fimple expofure 
 to the air. 
 
 d 4 CHAP. 
 
2$l The Art of Bleaching 
 
 CHAP. XXL 
 
 Dying by the oxygenated muriatic Acid. 
 
 I 
 
 HAVE little to fay, with regard to the dyes, 
 in which the concurrence of the oxygenated 
 muriatic acid is of advantage, after thofe of the 
 nankeen and lemon yellow, of which I had oc- 
 cafion to fpeak in the fifteenth chapter. I fhall 
 here fpeak only of the different tinges of grey, 
 which are obtained by plunging white wool or 
 iilk in a folution of fulphate of copper, and after- 
 wards taking them out and immerfing them in 
 a bath of the oxygenated muriatic acid, either 
 with or without fmell. By this treatment the 
 operator will obferve the gradual appearance of 
 a fine grey colour, more or lefs dark, and varying 
 in its tinge, accordingly as the folution of the 
 fulplate, or of the oxygenated acid, may have 
 been concentrated. This dye appeared to me 
 to be folid > for I perceived no alteration in its 
 fhade after expofing it for feveral days to the 
 fun, and to a ftrong folution of foap. 
 
 It may be proper, in this place, to fpeak of a 
 black or grey dye varying in its fhade, which I 
 have feveral times feen fuccefsfully made, in 
 
 thofe 
 
Cottons, Thread, &c. 233 
 
 thofe glafs-houfes where the mineral alcali, with 
 the crude foda, or the purified fait, is ufed. I here 
 fpeak only of the Spanim foda, which is well 
 known to contain a certain quantity of the mu- 
 riate of foda, the prefence of which is indicated 
 at the moment of the fufion of the glafs : for 
 at this period more efpecially, as well as during 
 the whitening of the frit, there exhales from the 
 pots, for about half an hour, a thick white fume 
 of muriatic acid, which afts on the nofes and 
 mouths of the workmen, and caufes them to 
 cough and fneeze : its prefence is likewife ma- 
 nifested by the ruft which immediately covers 
 the pipes and other iron implements, placed 
 within its reach, which the workmen are obliged 
 to brighten, whenever they ufe them. I have con- 
 cluded that the dye, of which I mail here give 
 a concife account, was the more evidently pro- 
 duced by the action of the oxygenated muriatic 
 acid, becaufe a confiderable quantity of man- 
 ganefe is ufed in the glafs-works in which it is 
 praclifed. The quantity ufed is fuch that the 
 cadmia fornicorum of thefe works are of a perfeft 
 violet colour. 
 
 The following is the procefs I have feen in 
 pra£iice, at the glafs-works of St. Gobin, in the 
 department of Aifne, as well as in that of Tour- 
 la-ville, in the department oflaManche. The 
 
 former 
 
234 The Art of Bleaching 
 
 former of thefe eftablifhments ufe wood for 
 fue], and the purified fait of the foda of Alicant; 
 the other burns pit-coal, and ufes the fame foda 
 in the crude ftate. 
 
 The fkems of thread being previoufly warned 
 in lees, or cleaned and afterwards rinfed and 
 dried, are fteeped in a folution of alum, in river- 
 water. When they are well foaked in this fo- 
 lution, they are dallied ftrongly upon a kind of 
 blackiih foot, which is fixed along with the fa- 
 line vapours by the internal projection of the fur- 
 nace above the glafs pot or crucible. After 
 having repeated this a number of times, in order 
 that the thread may become more or lefs loaded 
 with the foot, it is agitated or rinfed in the 
 fame alum water, and again dafhed againft the 
 foot, until it is thought to have acquired a colour 
 fufficiently equal and deep. Laft of all, they are 
 rinfed in the fame water, in which they become 
 deprived of the excefs of faline and colouring 
 matter ; after which they are flightly rung out, 
 and dried, either in the fun, or in the made. This 
 black or grey colour, which the thread has thus 
 acquired, is fingularly tenacious. I have neck- 
 ings of thread, thus dyed ten or twelve years ago, 
 which have been warned in lees upwards of forty 
 times, and have loft not the leaft portion of the 
 intenfity of their colour. It is to be remarked, 
 
 that 
 
Cottons, Thread, &c. 235 
 
 that linen and cotton piece-goods are dyed by 
 the fame procefs. There is no doubt but it 
 would be poffible to imitate this dye, with pro- 
 fit and advantage, by fome direct manufacturing 
 procefs. I have made fome trials which have 
 fucceeded, to a certain degree, by putting the 
 foot of pit-coal into alum-water, in which I 
 fteeped thread, which acquired a fhade, and 
 was afterwards put into a bath of oxygenated 
 muriatic acid. I repeated this alternation feve- 
 ral times, which appeared to communicate an 
 equal dye, and this dye was very flightly altered 
 by foap. 
 
 I We may likewife give the fame grey or black 
 fhade to cotton, by boiling it for fome time in a 
 certain quantity of the faline foot of the glafs- 
 works, ufually difFufed in water, in which mix- 
 ture the thread is (imply turned and worked for 
 a number of times, without any previous or 
 fubfequent operation, excepting that of wafhing 
 or rinfing, which is always indifpenfable. I have, 
 in this manner, dyed white thread (lockings of 
 a violet grey colour (grifdelin). This (hade be- 
 came fome what pale after repeated warnings. 
 
 CHAP. 
 
i$6 The Art of Bleaching 
 
 CHAP. XXII. 
 
 Various Properties cf the oxygenated muriatic 
 Acid. 
 
 Ti 
 
 HE power of difcharging every kind of co- 
 lour from painted or printed goods, mud render 
 the difcovery of the oxygenated muriatic acid 
 of the higheft value to manufacturers of 
 paper, who may very profitably avail them- 
 felves of the acid to form white paper out of 
 coloured rags. It, in fome meafure, affords them 
 an additional refource to fupply their manu- 
 factories with raw materials, and to avoid any 
 particular forting. They may, even in this re- 
 fpett, extend their fpeculations to cordage, 
 oakum, old fails, and other articles, which 
 they may bleach as fpeedily, and in as large a 
 quantity, as they pleafe, without giving them- 
 felves any concern about the fcarcity of rags. 
 It may alfo be queftioned, why the bleaching 
 property of the oxygenated muriatic acid mould 
 not be ufed to whiten paper which has been 
 
 written 
 
Cottons, Thread, &c. 237 
 
 Written upon, and is become wafte. This 
 paper may afterwards be fized again, like any 
 other fort, by which means the product and 
 activity of this manufactory may be inftanta- 
 neoufly augmented. This laft object is fo much 
 the more eafy to be attained, becaufe the leaves 
 of paper, containing writing, require to be 
 fteeped only one fmgle time in the oxygenated 
 muriatic acid without fmell. The work is, 
 therefore, of the greateft facility. This firft 
 operation may be made on a number of leaves 
 together, difpofed in fuch a manner that the 
 oxygenated muriatic acid may furround and pe- 
 netrate each leaf fufpended in the fluid. It 
 mull be followed by a bath of fulphuric acid, of 
 the fame ftrength as has already been prefcribed 
 for the dreffings. This bath is effentially ne- 
 ceflary, however clearly the ink may appear to 
 have been discharged when the paper comes 
 out of the muriatic acid. The fulphuric acid is 
 required to take up the iron, which, as is well 
 known, compofes a great part of every writing 
 ink. Care mult be taken to wafh the paper, 
 when it comes out of this laft bath, in clean and 
 limpid water, in order to carry off the fulphuric 
 acid, after which the paper may be fized, if ne- 
 ceflary, and then left to dry. Such paper as 
 has been lized before it has undergone this ope- 
 ration. 
 
2j 3 The Art cf Bleaching 
 
 ration, will not require fizing again, or at leaft 
 this is very fcklom the cafe, unlefs it has re- 
 mained too Jong in the rinfing water. The 
 paper, when dried, muft be afterwards treated 
 exactly in the fame manner as if it had been 
 newly manufactured. This method of bleach- 
 ing written paper may alfo be of the greateft 
 ufe to men of bufinefs of every defcription, 
 merchants, and others, who ufe many books. 
 When thefe have become ufelefs, and out of 
 date, they may, by the method here directed, 
 be eafily cleared of their writing, and ren- 
 dered ufeful a fecond time *. When we re- 
 flect on the property of the oxygenated muriatic 
 acid to difcharge ink from paper, we obferve, 
 in the action of this liquor, a kind of analogy 
 with that action which takes place, in the 
 courfe of time, with refpeft to ancient writings. 
 There is reafon to think, that, in this lair cafe, 
 the air, by virtue of the oxygen which it 
 contains, is acted upon in the fame manner as 
 the oxygenated muriatic acid ; for old writings 
 
 * Since thefe experiments I have had occafioa to make 
 others, as well on the bleaching of the pafte of paper, as on dif 
 charging the colour of written or printed papers. I have, 
 therefore, thought it ufeful to infert, at the end of this work, 
 the feries of particular proceffes which I have made ufe of* 
 and which I addrefled to the different committees of the .Na- 
 tional Convention, in the year Ii. of the republic. 
 
 are 
 
Colt ens y Thread, &c. j^o 
 
 are fo confiderably altered, that a fingk flirht 
 bath of fulphuric acid is often fufficient to dif- 
 charge them entirely, and in cafe this bath 
 fhould not have been fufficient, they do not 
 refill a very flight immerfion in the muriatic 
 acid. 
 
 The fame obfervation may be made with re- 
 gard to fnow and dew; both thefe fubftances 
 difcolour and foon render the foles of fhoes 
 yellow when expofed to their a&ion. This ob- 
 fervation may very eafily be made after walking 
 out on the fnow or grafs embibed with dew. 
 
 On the fame principle it is in the mountainous 
 country, in the department of La Somme, the 
 country people clear their linens limply by ex- 
 pofmg them in the winter to the a&iori of the 
 fnow, the dew, and the mills, without giving 
 them any other preparation; except that they 
 are careful to turn them from time to time on 
 the ground, for about fifteen or twenty days, dur- 
 ing which time this vegetable fubftance is expofed 
 to the influence of the air and the a'tmofphere. 
 
 A folution of fulphate of foda, and the re- 
 fidue of the dialling veflels, is fometimes fuf„ 
 fkient to difcharge thefe ancient writings, which 
 are already in part effaced by the oxygen of the 
 atmofpheric air in the courfe of time. 
 
 I muft here mention an obfervation I have 
 
 had 
 
240 The Art of Bleaching 
 
 had occafion to make in the courfe of my ope* 
 rations on the bleaching of threads and cloths. 
 The waters which had ferved to rinfe the fingle, 
 double, and twilled threads, when taken out of 
 the lees, were very foon covered in the veffels, 
 where this rinfing was then performed with a 
 kind of lather, more or lefs white, accordingly 
 as the thread was more or lefs advanced in its 
 bleaching. This froth, which rofe to the top 
 of the water, wasfometimes more than an inch 
 in thicknefs, according to the quantity of thread 
 or cloth which was rinfed or cleared, and forms* 
 an excellent parte for the immediate manufacture 
 of paper. It may, in fact, be . eafily underftood 
 that this fubftance is of the fame -nature to that 
 which is ufually formed by the decompofed rags 
 in the paper-mills, and is, in the prefenf cafe, form- 
 ed of an affemblage of the filaments of thread or 
 cloth detached by the lees or the acid, but more 
 particularly by the former, and more fpeedily and 
 effectually feparated by the rinfing. I can alfo 
 affert, that the famples of paper which I- have 
 attempted to make with this material, were very 
 beautiful and fine. The bleachers may, there- 
 fore, referve this produce, and fell it to the 
 paper manufacturer at a price which muft necef- 
 farily vary according to its colour and quality." 
 The fame remark is applicable to the inner 
 
 part 
 
Cottons ', Thread, &V. 94 1 
 
 part of the fides of the veffels or tubes which is 
 direclly bleached by the action of the oxyge- 
 nated acid, which, in procefs of time, renders 
 it of a very fine white colour. This ligneous 
 fubftance, when collected, is alfo very proper 
 to form paper, after it has undergone the pre • 
 vious action of the mallets or cylinders of the 
 paper-mill, and is afterwards properly diluted 
 with water, according to the practice of the 
 paper-makers ; a very confiderable quantity of 
 this pafte may even be collected in a fliort time. 
 Nothing is more neceflary for this object than 
 to difpofe the wood in the veffels defiined for 
 this purpofe in fuch a manner, that it may pre- 
 fent alternately to the acid and the fait of the 
 intermediate lees the greateft quantity of furface 
 poffible. Two lixiviations, and two immerfions, 
 are fufHcient to alter the wood fo far that it may 
 be rafped off with advantage. This very eco- 
 nomical method may, with much profit, be ufed 
 to fupply certain paftes, which will afford very 
 fine and good paper, according to its beauty* 
 its whitenefs, and the proportionate mixture of 
 other paftes formed from rags. I have in this 
 manner fabricated fmall famples of paper, 
 which I mewed, at the beginning of 1789, to 
 the adminiftration of commerce, announcing 
 this particular method, as well as that of mak* 
 
 mg 
 
$4 2 The Art of Bleaching 
 
 ing a kind of grey paper with the tufts of the 
 typha paluftris. Thefe paftes are not to be re- 
 jected, even fuppofing they could only be ufed 
 for the white-brown or common paper, or for 
 pafleboard ; as they would always contribute to 
 render the fine rags more abundant for the ma- 
 nufacture of white papers, to which ufe they 
 might be entirely referved, if it fhould not be 
 found advantageous to mix them with the other 
 materials to produce the intermediate kinds of 
 paper. 
 
 Olive oil, expofed in the uppermoft falfe 
 bottom of the pneumatic veffel to the gas or 
 vapour of the oxygenated muriatic acid, pall- 
 ed through water loaded with potafh in the 
 proportion I have pointed out, became changed 
 to the confidence of foft foap, or very white 
 greafe, without tafte, nearly mifcible with wa- 
 ter, not foluble in the fpirit of wine, nor fub- 
 je£f. to any perceptible change by the ordinary 
 muriatic or nitric acids. Rectified fulphuric 
 acid alone decompofes it almoft as foon as 
 poured on. The muriatic acid, with which the 
 oil was combined, flies off, and the fulphuric 
 acid changes the white and foapy colour of the 
 oil into a brown mafs, which very foon after- 
 wards became blackiih. Does not this expe- 
 riment lead to a prefumption that it might be 
 
 poffible 
 
Cottons, Thread, &V. 243 
 
 foflible to form a kind of muriatic foap in the 
 foft or hard form, which mould have the pro- 
 perty of bleaching ? Thus much is certain, 
 that from this notion I have attempted to com- 
 bine olive oil with potafh, partly neutralized 
 by the oxygenated acid ; and a fample of thread, 
 which I bleached and foaped with this kind of 
 foap, appeared to me to become white to a 
 higher degree, and much more fpeedily, than 
 by the method above defcribed. This new 
 method would be of infinite utility in every 
 refpe£t. 
 
 Copper or brafs expofed in the fame manner 
 as the oil above mentioned to the a£tion of the 
 oxygenated acid gas, became, at firft, blackilh, 
 after which it was covered with a firm, dry, 
 pellicle of verdigreafe, as well above as be- 
 neath : this verdigreafe was of a very fine colour. 
 When warned and ground, it is abfolutely equal 
 in colour to that fine Englifh green fo highly 
 efteemed, with which the fafhionable papery 
 hangings are printed. It might be poflible to 
 obtain this matter, in great quantities of it, at a 
 low price, by conftru&ing an apparatus for this 
 purpofe. I have obtained this kind of verdi- 
 greafe by putting copperplates into the waters 
 obtained from the refidue of the diitilling veffels. 
 I have had occafion to remark on this fubjecr, 
 r 2 that 
 
244 "ft* 6 drt of Bleaching 
 
 that the fluid was, in the courfe of time, covered 
 with a pellicle fimilar to that which rifes upon 
 milk when fet to boil, but of a green colour. 
 
 Water, impregnated with the gas, has no 
 action upon the copper, except in the courfe of 
 a long time ; but the gas itfelf acts inftantly 
 either upon copper or brafs. 
 
 This kind of verdigreafe may alfo be ufefully 
 employed in dying, and, in many inftances, fup- 
 ply the place of that which is made with the 
 refufe of grapes in the fouthern provinces. 
 
 Tin vefTels (pewter) are totally diffolved or 
 corroded by the oxygenated muriatic gas, and 
 aflume a grey colour. 
 
 Malacca tin is corroded in like manner, but 
 it affumes a whitifh colour. From this experi- 
 ment it is that we have thought proper to con- 
 clude, that the folder of leaden tubes cannot 
 long refift the aftion of the gas or liquor which 
 is impregnated with our acid, and that it is par- 
 ticularly neceflary, when tubes of this metal 
 are to be ufed, that they mould be caft entire, 
 or without folder *. 
 
 * As the muriatic acid, whether oxygenated or not, when 
 in the expanded or vapourous ftate, attacks, and fpeedily 
 f ults copper, iron, and tin, it is improper to have in the, 
 place of diftillation, any vtflel or inftrument made of thofe 
 metals, becaufe they would fpeedily be deftroyed. 
 
 Sheet 
 
Cottons, Thready &c. 84$ 
 
 Sheet lead did not all, or fcarcely at all, change 
 its colour or properties by this expofure. It 
 merely acquired a flight brown tinge. It was 
 in confequence of this experiment that I de- 
 termined to fubftitute tubes and adopters of 
 lead inftead of thofe of glafs, and to recom- 
 mend that the pneumatic veffels to be made of 
 common wood, and that thefe, as well as the 
 veffels for immerfion, mould be defended with 
 meet lead. 
 
 Litharge of gold, or yellow litharge, remains 
 dry, and undergoes no other effect than to ac- 
 quire a violet colour. 
 
 The directions or addrefs on the outfide of 
 letters difappear entirely, without leaving any 
 trace or alteration in the paper. This experi- 
 ment, added to that of taking out the ink- 
 marks made by the proprietors of (lockings, 
 gave me the firft hint to apply this method of 
 bleaching to written paper, which I have men- 
 tioned in this chapter. 
 
 Red fealing-wax became of a pale rofe- colour, 
 and was reduced into a kind of moid or foft wax. 
 
 Indigo, in fmall fragments expofed in the 
 fame manner to the oxygenated muriatic acid 
 o-as, changed its colour from a deep blue to the 
 yellow colour of dead leaves. Black pitch merely 
 became red at its furface. Hair, and feathers 
 
 r 3 cf 
 
246 The Art cf Bleaching 
 
 of a black colour, were changed, the firft grey, 
 and the latter to an aurora colour. Green oil- 
 cloth (tcih die.'), fpotted with black, became 
 very white, and fpotted with brown fpots. 
 
 Fluid vegetable alkali, being the foluio^ of 
 blue potafh expofed to the fimple contact of 
 the oxygenated muriatic acid, acquired the 
 property of bleaching like the true water of 
 Javelle, but, inftead of the clear yellow colour 
 it at firft poflefTed, it became white and limpid, 
 The bottom of the faucer made ufe of was lined 
 with an infinite variety of very white cryftals, 
 in thin brilliant plates, of a dry appearance, like 
 talc or mica -, having the appearance of fo many 
 factions of the cryftals of fulphate of potafh, 
 through the whole length of the prifms, termi- 
 nating in their pyramids. Thefe cryftals might 
 be one line and an half in length, one in breadth, 
 and near a quarter of a line thick. This expe- 
 riment, and another mentioned in the following 
 chapter, feemed to prove that the violet colour 
 of the lees, diitinguiihed by . the name of ja- 
 velle, is, as Berthollet has obferved, more par- 
 ticularly owing to manganefe, of which the co- 
 louring matter is carried off with the gas that 
 efcapes. 
 
 The folution of mineral alkali, extracted from 
 the foda of Alicant, and of an amber colour, 
 
 being 
 
Cottons, Thread 3 &c. 247 
 
 being expofed in the fame manner as that of the 
 vegetable alkali, acquired the fame property of 
 bleaching, without, however, entirely lofing its 
 own colour, or prefenting any cryftalization. 
 
 Pure water, expofed in the fame manner, ob- 
 tained the fame property of bleaching, preferv- 
 ing its natural colour, without exhibiting any 
 obfervable peculiarity. 
 
 Thefe three different fluids, by becoming thus 
 impregnated by the muriatic acid gas, feem to 
 prove that it is not abfolutely neceffary to agi- 
 tate the water of the veffels to concentrate the 
 gas. An experiment with the intermediate 
 tubulated veffels of the old apparatus, in which 
 I have obtained pure folutions of this gas, co- 
 loured yellow or greenifh, and marked from ten 
 to twelve degrees of concentration, appear like- 
 wife to fliew that agitation of the water is not, 
 in ftrictnefs, abfolutely neceffary. 
 
 Thread, which had been fubjecled to the 
 lees, and was merely moift, or (lightly humid, 
 with the lixivial folution, being limply expofed 
 to the vapour or oxygenated acid gas, acquired 
 a ruddy white colour fimilar to that of the 
 third immerfion, and without any kind of altera- 
 tion. 
 
 Coarfe thread, macerated feveral days in a 
 
 \veak folution of fulphate of potafh, became 
 
 r 4 three- 
 
%±3 "The Art of Bleaching 
 
 three fourths bleached, and with much uni- 
 formity or evennefs of colour. 
 
 Flax macerated in the fame manner likewife 
 obtained a very fine white. 
 
 Flax, macerated for feveral days in the folu- 
 tion of potafh, one degree below zero, and ex- 
 pofed, like the objects above mentioned, to the 
 oxygenated muriatic acid gas, became of th 
 moft beautiful white. 
 
 All thefe different articles were fubjeft to no 
 alteration. It is true, that, being apprehenfive 
 left the gas, with which they were impregnated, 
 mould alter their texture in confequence of its 
 concentration when they ihould become dry, J 
 was careful to wafli them out in a large quan* 
 tity of water. 
 
 May we not infer from thefe various trials, 
 which were all made during the winter of 1790, 
 that it is highly probable that threads and piece- 
 goods might be advantageoufly bleached by 
 fimple expofure to the vapour of the oxyge- 
 nated muriatic acid. For this purpofe it ap- 
 pears to me, that the various articles, flightly 
 moiftened with water or with lees, would re- 
 quire to be hung up in a very clofe chamber, 
 like that which is ufed for expofmg goods to the 
 vapour of fulphur, into which room the extre- 
 mity of the diftilling veffels mull be introduced, 
 
 to 
 
Cottons, Thread, &c. 249 
 
 to convey the gas in proportion as it mould bo 
 difengaged. An experiment of this nature 
 would require peculiar management, and its 
 fuccefs would be of the greateft importance to 
 the manufacturer. 
 
 CHAP. 
 
2 50 The Art of Bleaching 
 
 CHAP. XXIII. 
 
 On the Pojjibility of applying the Refidues to Profit, 
 
 T 
 
 JL HE refidues to which the attention of the 
 operator may be directed, in order to derive 
 advantage, are : 1. Thofe of the retorts, bottles, 
 or other diftillinar veflfels : 2. Thofe of the im- 
 merfions, or bleaching liquors: 3. Thofe of the 
 alkaline lees, or foap : and, 4. Thofe of the 
 baths of fulphuric acid. 
 
 The refidues of the retorts, bottles, or other 
 diftilling veflels, are reducible to the following : 
 1. Manganefe not difcoloured, and the common 
 muriatic acid coloured by manganefe, if the 
 muriatic acid has been ufed inilead of the mu- 
 riate of foda : 2. Sulphate of foda, and a fmall 
 portion of muriate of foda not decompofed, if 
 this laft has been made ufe of: 3. Sulphate of 
 potafh, if lees have been ufed to extinguish the 
 fuffocating odour of the refidue of the folution, 
 which is always more or lefs impregnated with 
 oxvjrenated muriatic acid. 
 
 Though 
 
Cottons, Thread, &?£ z$t 
 
 Though I have reduced the proportions o£ 
 manganefe to one-fixth lefs than directed by 
 Berthollet, it is not,neverthelefs, difcoloured after 
 the operation, or rather, it is only difcoloured very 
 flightly, and in few places. In this ftate it ftill 
 prefer ves fufficient virtue, that is to fay, enough 
 of vital air to be mixed with about one-third of 
 new manganefe of the fame quality. This pro- 
 perty, or ftrength, cannot, however, be afcribed 
 to manganefe in lumps, or interfperfed with 
 quartz, though well cleared of foreign matter. 
 The manganefe cryftallifed in needles, fuch as 
 is fold by Lapelletier, has alone afforded me this. 
 very perceptible difference *. Every other man- 
 ganefe, on the contrary, that is to fay, the fpe- 
 cimens in lumps, afford a much lefs quantity of 
 gas, and render the bleaching liquor lefs ftrong. 
 This laft kind of manganefe is alfo harder and 
 more troublefome to pulverife. 
 
 The manganefe taken out of the retort, 
 after the firft diftillation, preferves almoft the 
 whole of its metallic brilliancy, and foils the 
 hands as before, and may be ufed to purify 
 glafs. It is true, that in this ftate it feems to 
 have increafed in bulk. Manganefe entirely 
 decompofed is known by the whitifh or pale 
 
 * This manganefe is brought from Hambourn;, in the 
 duchy of Deuxponts. 
 
 purple 
 
25ft The Art of Bleaching 
 
 purple colour, which the ftrong impreffion of 
 the fire has given it. 
 
 The fbmrion of the refidue of the diftilling 
 veffels diluted with water, the evening after the 
 dilliilation, is found on the following day, if the 
 veffels have been clofed, to be of a fine red, in- 
 clining to violet or purple, accordingly as the 
 foiutionhas been more oi' lefs diluted; but this 
 colour does not fail to disappear by expefure to 
 the open air, or by the heat employed to eva- 
 porate it. In either cafe, the violet colour of 
 the foluticn is changed for a iliade inclining to 
 apple-green. 
 
 It feldom happens that the water which holds 
 the refidue of the retort or bottle in folution, is 
 not fufficiently concentrated to afford, after re- 
 maining for a day or two in the receiving vef- 
 fels, cryllals of the fulphate of foda ; but thefe 
 cryftals, which are of different fizes, are covered 
 with manganefe, from which it is neceiTary to 
 clear them. This is eafily done, by putting a 
 fmall quantity of thefe refidues into a veffeJ, 
 and pouring a little clean water upon them, 
 which, after brifo agitation, mull be imme- 
 diately poured off, before the manganefe fub- 
 fktes, into a proper veffel intended to receive 
 this laft fubftance. This manoeuvre is to be re- 
 peated 
 
Cottons, Thread, trie 2$$ 
 
 peated four or five times as quic^'y as poflible, 
 in order that lefs of the fait may be diflblved. 
 
 This trouble of warning may be avoided, if 
 the violet-coloured water, which covers the re- 
 fidue of the diftilling veflels, be carefully de- 
 canted off into wooden or leaden receptacles 
 appropriated to this purpofe. The cryftals, 
 which are foon afterwards formed in this water, 
 are neat and clear as they ought to be. But it is 
 neceflary, after having decanted this violet- 
 coloured fluid, that common water mould be 
 poured into the retorts or bottles, for the pur- 
 pofe of facilitating the extraction of what re- 
 mains. This, together with the water, muft be 
 referved by itfelf. If it be propofed to fepa- 
 rate the manganefe, for the purpofe of ufing it 
 again, as I have before mentioned, the follow- 
 ing method mull be recurred to. The refidue 
 muft be warned repeatedly with a large quan- 
 tity of water till it gives no perceptible faline or 
 acid indication. The refidue muft then be 
 dried, and afterwards mixed with new manga- 
 nefe, in the proportions before directed. If the 
 waters of the wafhing be fufficiently impreg- 
 nated to render it proper to mix them with the 
 violet water, in order to increafe the producl of 
 cryftals, whether by infeniible evaporation, or 
 by the affiftance of heat, this muft be done, 
 
 taking 
 
£54 &>* Art of Bleaching 
 
 taking care only, that in the latter procefs leaden 
 veffels mud be ufed, becaufe copper, iron, and 
 mod other metals would be fpeedily corroded 
 and deftroyed. 
 
 The fulphates of foda and of potafh, which 
 are obtained from the wafhings of the refidue of 
 the diftilling veffels, have not hitherto been ap- 
 plied to any ufe in the arts. It is poffible, as I 
 have before remarked, to employ them for dif- 
 colouring certain ribbands, and effacing writing 
 from paper or parchment, as well as for fcour- 
 ing copper and iron for braziers, &c. Both thefe 
 falts are likewife ufed in medicine when puri- 
 fied -, but it may be doubted whether the apo- 
 thecaries would purchafe them, becaufe the 
 very fmall quantity they confume is afforded 
 very cheap from the falt-works of Lorraine and 
 other places. 
 
 It would, therefore, be much more interefting 
 to decompofe thefe falts, and obtain the alkalis, 
 in a difengaged ftate, which might, in that 
 cafe, be ufed, to make the lees in the fubfe- 
 quent operations. Berthollet, in the firft vo- 
 lume of the Annales de Chimie, informs us, 
 that feveral perfons have communicated different 
 recipes to him for effecting this purpofe ; it were 
 much to be wifhed that the authors would 
 benefit the public by a more liberal communi- 
 cation. 
 
Cottons, Thread, cjrV; ac; .? 
 
 Cation. In the mean time I mail here remark, 
 that it is very poffible to decompofe thefe neu- 
 tral falts by means of liberal fulphur and the 
 muriate of foda, by the fulphuric acid, and 
 more efpecially by certain metallic oxydes, par- 
 ticularly that of lead. I have fuccefsfully tried 
 this 1 alt method in 1784, which was indicated 
 by Scheele. The alkali which is obtained by 
 thefe different proceffes is of the pureft kind, 
 and I have had reafon to be affured, that, with 
 proper treatment, it affords glafs equal in beauty 
 to flint or cryftal glafs * 
 
 The fecond refidue, which may be applied 
 to ufe, is that of the exhaufted liquor of im- 
 merfion. After the vital air, or oxygen, has 
 been exhaufted, the odorant liquor contains 
 nothing but muriatic acid and water; the liquor 
 without fmell likewife contains muriate of pot- 
 afh. This fait, as well as the neutral falts, w r ith 
 
 * The Committee of Public Safety published, in the fe- 
 cond republican year, the various procefTes for decompofing 
 muriate of foda, which it had received from the different au- 
 thors or inventors. Eftablifhments may, therefore, be made 
 for fupplying the national commerce with the alkaline fait 
 of foda, the ufe of which is indifpenlible in different works, 
 fuch as thofe of glafs, foap, dyeing, bleaching, &c. for the 
 fupply of which feveral millions are annually expended among 
 foreigners. Note of the Slather, 
 
 A copy of this report may be feen in the Annales de 
 Chimie.— 7*. 
 
 a fixed 
 
2 $6 fhe Art of Bleaching 
 
 a fixed alkaline bafe, is of fome ufe in medi-> 
 cine, but it is not worth while to extract any 
 thing but the fulphate of foda. This may be 
 decompofed for the fake of the alkali, if the 
 refulf mould be attended with fufncient profit, 
 I mall fimply remark in this place, that thefe 
 exhaufted bleaching liquors may be effectually 
 ufed in making fill ammoniac. The different 
 trials I have made on this fubjecl, by combining 
 them with the volatile alkali of putrified urine 
 or rotten vegetables, have conftantly tended to 
 confirm my opinion. Laftly, if it fhould be 
 found advantageous to reduce the pure bleach- 
 ing liquor without potaih to the merchantable 
 ftrength, it may be ufed for the fubfequent 
 diftillations, in the fame manner as other mu- 
 riatic acid, inftead of the muriate of foda and 
 fulphuric acid j unlcfs, indeed, it ihould be 
 thought more advantageous to ufe it for making 
 white lead or verdigris, both which combi- 
 nations I have made and ufed in painting with 
 fuccefs. The verdigris might alfo be ufed in 
 dyeing. 
 
 I have alfo occafionally ufed thefe waters of 
 immerfion of the muriatic acid without fmell, to 
 make the fecond lees for piece-goods and 
 threads. This fluid becomes as highly charged 
 as if the lees had been pure. The exhaufted 
 
 bleaclr 
 
Cottons, Thread, &c. 257 
 
 bleaching liquor may likewife be ufefully em- 
 ployed in the firft maceration of goods ; for 
 which purpofe, when it is not highly charged 
 with colouring matter, it is no lefs valuable than 
 the new liquor from the pneumatic veffels. 
 
 There is another property of the exhaufted 
 bleaching liquor, which is, perhaps, of conlider- 
 able importance, namely, that of accelerating 
 the vegetation of plants ; from repeated trials 
 I can affirm that it pofleffes peculiar properties 
 in this refpecl. I have at different times ufed 
 it, inftead of common water, on cauliflowers, 
 chervil, peas, cabbages, leeks, &c : and thefe 
 various plants have not only grown more quickly 
 than others of the fame kind planted in the 
 fame bed, and watered with river water, but 
 have likewife acquired double the fize. 
 
 Befides the property of accelerating vegeta- 
 tion, thefe waters have likewife the property to 
 drive away, at the inftant of pouring on the 
 ground, the fpiders, ants, worms, fnails, and 
 other reptiles of this kind, which are noxious 
 to plants and feeds. A gardener, near the la- 
 boratory where I made the muriatic acid for 
 bleaching, was fo fully convinced of the advan- 
 tage of thefe waters, from his own experience, 
 that he requefted, as a favour, that I would re- 
 serve them for his ufe; and was continually 
 
 s fpeak- 
 
258 The Art of Bleaching 
 
 fpeaking in praife of the good effects it produced 
 on the plants in his garden. 
 
 But in proportion as the fmall quantity of 
 oxygenated muriatic acid, diffufed through' the 
 exhaufted water, is of advantage to vegetation, 
 fo much more noxious it is to plants when in 
 the form of gas or vapour. Plants expofed to 
 this elaftic fluid infrantly fade and perifli. I 
 have frequently feen this effect on the plant 
 monk's-hood, and even on vines, the leaves of 
 which foon became vellow, and the ftems, after 
 having languished for a certain time, partly died. 
 
 With regard to the third refidue, of which 
 the waters of lixiviation form a part, I think I 
 have faid all that is neceffary in the chapter 
 upon lixiviums. I (hall here only add, that if 
 there were an opportunity of difpofing of them 
 to advantage to a faltpetre-work, it would pro- 
 bably be more advantageous than to reduce 
 them by evaporation. There is, however, rea- 
 fon to think, that the old lees might be re- 
 stored to a certain point by boiling them a long 
 time with lime j this earth, having the property 
 ct dcftroying the vegetable parts which cover 
 and weaken the alkalis, might, perhaps, produce 
 the fame effect as reducing the folution to the 
 iblid confidence. 
 
 The following is likewife an economical me- 
 thod 
 
Cottons, Thread, &c. 259 
 
 thod of constantly applying the fame lees to ufe, 
 which I have often employed with the greateft 
 fuccefs. It confifts fimply in throwing the afbes, 
 from which they have been extracted, into the 
 fires ufed for domeftic purpofes in the houfe, 
 fufFering them to dry, and afterwards wetting 
 them with the exhaufted lees from time to time, 
 which are to be referved for this purpofe. The 
 flame of the wood, burned in the chimney 
 (for thefe obfervations are only applicable to a 
 wood fire), and the heat of the hearth, foon 
 burn the impurities, which coloured the alkali, 
 and the afhes fpeedily become proper for lixi- 
 viation as before. This operation, which de- 
 mands very little care, may be of great ufe, 
 ^even in the domeftic concerns of a houfe where 
 alkaline lees are ufed. 
 
 The foap-waters likewife are not to be 
 neglected. It would be poffible to decompofe 
 them, either by means of the waters which 
 have ferved for the baths of fulphuric acid, or 
 with thofe of the exhaufted bleaching liquor ; but 
 the beft ufe would be for the manufacture of falt- 
 petre, for which purpofe the alkali mult be ex- 
 tracted by calcination. In the laft cafe the procefs 
 is nearly the fame as with the lees - 3 that is to fay, 
 when the foap-water is reduced to the con- 
 fidence of extract, and nearly dry, the oil mutt 
 s 2 be 
 
260 The Art of Bleaching 
 
 be burned off in an open fire, which will leave 
 the alkali foluble in water, and ready for ufe, 
 in the diftillations and lixiviations, in the fame 
 manner as new potafh. I have pra&ifed this 
 method, and muft here remark, that new foap- 
 water rifes in froth above the veffel when it 
 boils, whereas that which has been ufed does 
 not exhibit the fame propertv. 
 
 With regard to the baths of fulphuric acid, 
 which compofe the fqurth refidue, when they 
 are too much diluted with water, from the im- 
 merfion of wet articles, the fhorteft method is 
 to add more acid, or elfe to concentrate the 
 fluid in the fame manner as I have obferved 
 with regard to the fulphate of foda, and other 
 falts. For this purpofe it may be concentrated 
 to fuch a degree as to be ufed again infread of 
 common fulphuric acid, or it may be ufed tor 
 making alum or fulphate of ammoniac, by com- 
 bination with the alkali of urine or putrefying 
 vegetables. 
 
 CHAP. 
 
Cottons, Thread, (3 c. 261 
 
 CHAP. XXIV. 
 
 'The Method of bleaching Hemp and Flax in the 
 unmanufactured State, as well as Thread and 
 Piece-goods, by the Affifiance of Water only. 
 
 I 
 
 HAVE long remarked, that the rags or 
 pieces of unbleached cloth, which have been 
 fet to ferment in order to make blotting-paper, 
 became white to a certain point, in confequence 
 of being wafhed or foaked, either in heaps or 
 under the mallets, for the purpofe of deftroying 
 their texture. The wafhing, in thefe circum- 
 ftances, becomes more eafy on account of the 
 fermentation, which opens the threads of the 
 cloth, and the mechanical procefs of the cy- 
 linder, or mallet, which renders the colouring 
 parts more eafily detached, and in a certain 
 degree diflblved. I attempted to imitate this 
 fermentation, and folution of the colouring part 
 of the thread, by warning in a large quan- 
 tity of water. I made my experiment in pre- 
 ference upon flax. - I firft. macerated it in pure 
 fiver water, in a veifel, where I fufFered it to 
 s 3 remain 
 
262 The Art of Bleachir,? 
 
 remain till the furface of the fluid was covered 
 with numerous bubbles. In this ftage I turned 
 it, and faw, with pleafure, that its grey colour 
 was changed to a light yellow. I then changed 
 the water, firft warning out the flax, and left it 
 till other bubbles appeared, when I warned it 
 again. At the fecond wafhing, I obferved fe- 
 veral parts which were whiter than the reft, 
 and at the fame time obferved a confiderable 
 quantity of fmall portions of grey and yellowifla 
 impurities, which detached themfelves from the 
 filaments of the flax. I then warned it with rub- 
 bing, and was not a little furprifed to obferve the 
 quantity of impurity increafe, and the flax become 
 whiter in proportion. Encouraged by the fuccefs 
 of this wafhing, I then plunged the fame flax into 
 warm water, to haften the folution of the other 
 colouring parts, which had immediately fixed 
 themfelves on the flax, as foon as it had dried, 
 after taking out of the vefTel. I then prefTed it 
 in the water, which difengaged an additional 
 quantity of colouring parts, and the flax appear- 
 ed much more beautiful. I did not carry this 
 experiment further, becaufe the flax appeared 
 clear and white, to as great a degree as 1 fup- 
 pofed it would arrive at by this method, for no 
 more impurities were detached. Though it ap- 
 peared to be white, when in the ftate oi divi- 
 sion. 
 
Cottons, ttrecd, (3c. 2.63 
 
 (ion, yet in the mafs it dill preferved a flight 
 (hade of yellow, which with a fimple bath of 
 oxygenated muriatic acid totally difappeared, 
 without the ufe of lees, or any other particular 
 preparation. 
 
 This experiment perfectly agrees with an ob- 
 fervation which may be daily made upon pieces 
 of cloth which are fubje£ted to the fulling-flock. 
 Some of thefe pieces have holes in them ; and 
 jn order that thefe damaged parts may not be 
 enlarged by the procefs of fulling, it is ufual to 
 fecure them by fewing on a piece of brown 
 linen cloth. I have remarked, not without 
 aftonilhment, that thefe pieces of unbleached 
 linen, after having remained in the water for 
 two or three days, with the cloths to which 
 they were fixed, and which were thus expofed 
 in order to clear them, either from the folution 
 of foap, the urine, or the fullers' earth, became 
 as white as if they had been palled through the 
 lees, and expofed alternately in -the field foj 
 feveral months, or the ufual time employed in 
 bleaching. 
 
 This refult likewife agrees with the method 
 in ufe in India, where, according to the rela* 
 tion of travellers, the natives bleach their fine 
 cottons, which we receive from them, in no 
 other way than by wetting and evaporation by 
 s 4 the. 
 
264 The Art cf Bleaching 
 
 the fun, and expofure to the dew, without the 
 ufe of lees, or any other preparation. 
 
 All thefe experiments prove, therefore, that 
 it would be very poffible to bleach with water 
 alone, if not piece-goods, at leaft flax, in as ex- 
 peditious a manner as can be defired. This has, 
 to a certain extent, been put in practice by a 
 certain induftrious individual in the town of 
 Amiens, named Bade. Without any know- 
 ledge of this man, or his method, but from the 
 fimple recital of his difcovery, that he had 
 bleached hemp in the ftalk by water alone, I 
 was tempted to make the trial. In confequence 
 I fet to macerate in water, during for about a 
 fortnight, a certain quantity of hemp ftalks, which 
 had been gathered about five or fix months, and 
 afterwards dried in a barn, without undergoing 
 the procefs of rotting. At the end of fifteen 
 days the hemp had recovered its original ver- 
 dure, that is to fay, the appearance it had when 
 rirft gathered. I rubbed them much under 
 water, which difperfed the green matter which 
 appeared on the bark, and difcovered the fibrous 
 part, which had a pretty good appearance. I 
 feparated this, and left it to fteep for feveral 
 fucceflive days in frefn water, after which I gave 
 it another rubbing, and immerfed it for a fecond 
 time. It then appeared of a very beautiful 
 
 white, 
 
Cottons, Thread, &c, 265 
 
 white, nearly the fame as thread acquires by the 
 old method of bleaching in the field, or the new 
 procefs with the oxygenated muriatic acid. 
 This flax retained only a very flight tinge of a 
 pale ruddy colour. 
 
 Thefe various experiments evince how import- 
 ant it would be to bring the fteeping of hemp 
 and flax to perfe£tion, particularly of the latter 
 article, which in the department of La Somme, 
 whence it is watered only on the grafs ; but the 
 deiire of gain, which attends to the weight only, 
 and not the quality, will fcarcely permit the 
 old method to be laid afide. On the other 
 hand, the bleacher, who is accuftomed to ufe 
 lime in folution, and even in fubftance — an in- 
 gredient which is, in fome refpecls,, rendered 
 neceflary by his intereft, and the black tenacious 
 colour of flax thus watered — might alfo, per- 
 haps, be unwilling to abandon this praclice. 
 For the cheap price, which the ufe of this me- 
 thod enables him to offer, namely, 3 fols an 
 ell, without regard to the breadth, may fecure 
 employ, which would, perhaps, leave him, if he 
 were to ufe another method, fomewhat more 
 coftly, though at the fame time in every refpect 
 beneficial for the merchandize and the pro- 
 prietor. 
 
 CHAP, 
 
a 6 6 The Art ef Bleaebin* 
 
 CHAP. XXV. 
 
 The Method cf Bleaching written or print e J paper} 
 and Rags, whether unbleached, dyed, or cc loured. 
 
 HE following proceffes are extracted from 
 different memoirs addreffed to the Committee of 
 Commerce of the French National Convention ; 
 alfo to the Commiflion of Sublicences and Pro- 
 yifions, on the 24th Frimaire, the 15th Plu- 
 viofe, and the 9th, 14th, and 21ft of Germinal, 
 an the fecond year of the French republic. 
 
 Bleaching cf old pointed Papers, to be "jxrked up 
 again. 
 
 1. Boil your printed paper for an inftant in 
 folution of foda rendered cauftic by potaih. The 
 foda of varech is good. 
 
 2. Steep them in foap-water, and then wafh 
 them, after which the material may be decom- 
 pofed, or reduced to apulp, by the machinery 
 of the paper-mill. The wafhing with foap may 
 be omitted without any great inconvenience. 
 
 Bleaching 
 
Cottons, Thread, tsfo 267 
 
 Bleaching of old written Papers, to be worked up. 
 again. 
 
 Steep your paper in a cold folution of ful- 
 phuric acid in water, after which waih them 
 before they are taken to the mill. If the acidu- 
 lated water be heated, it will be fo much the 
 more effe&ual. 
 
 Bleaching of printed Papers without deflroying the 
 'Texture of the Leaves. 
 
 i. Steep the leaves in a cauftic folution of 
 foda, either hot or cold. 2. And in a folution 
 offoap. 3. Arrange the meets alternately be* 
 tween cloths, in the fame manner as the paper- 
 makers difpof e thin meets of paper when deli- 
 vered from the form. 4. Subje£t the leaves to 
 the prefs, and they will become whiter, unlefs 
 they were originally loaded with fize and prin- 
 ters' ink. If the leaves mould not be entirely 
 white by this firft operation, repeat the pro- 
 cefs a fecond, and, if neceffary, a third time. 
 The bleached leaves, when dried and preffed, 
 may be ufed again for the fame purpofes as 
 before. 
 
 Bleaching 
 
268 The Art of Bleaching 
 
 Bleaching of old written Tapers without deft r eying 
 the Texture of the Leaves. 
 
 i. Steep the paper in water acidulated with 
 fulphuric acid, either hot or cold. 2. And in the 
 folution of oxygenated muriatic acid. Thefe 
 papers, when preffed and dyed, will be fit for 
 ufe as before. 
 
 The Method of bleaching Rags of the natural brown 
 Colour for the Manufaclory of white Paper. 
 
 1. Let the rags be opened or feparated from 
 each other, after previous foaking or macera- 
 tion for a longer or a fhorter time, according to 
 their texture and quantity. 2. Give a lixivia- 
 tion in cauftic, vegetable, or muriatic alkali. 
 
 3. P2fs them through the oxv<renated muriatic 
 acid, more or lefs concentrated with alkali. 
 
 4. Let the mafs be then worked for a fufheient 
 time in the apparatus of the paper-mill, and it 
 may be advantageouilv fubftituted inftead of that 
 which is afforded by white rags. 
 
 The white colour will be ftill better, if, aficr 
 ihe maceration, the rags be opened and fub- 
 jecled, asufual, to the aclion of the mill ; after 
 which the pafte itfelf muft be fubjecled to on? 
 lixiviation, one immernon, and a bath of ful- 
 phuric acid. The mafs being then well wnfhed 
 
 and 
 
Cottons, Thread, 13 c. 269 
 
 and preffed out, may be thrown into a trough 
 to be manufactured. 
 
 Method of bleaching Rags, of all Colours whatever, 
 in order to make white Paper. 
 
 1. Let the rags be opened, as before. 1. Steep 
 them in the oxygenated muriatic acid. 3. If, as 
 it commonly happens, the colour is difcharged 
 by this firft immerfion, let thefe bleached and 
 decompofed rags be immerfed in water acidu- 
 lated with fulphuric acid. 4. Complete the dif- 
 organization by the mallets or cylinders of the 
 mill, after having previoufly well warned them. 
 
 If the colour fhould not be fufficiently dif- 
 charged by the firft immerfion in the oxygenated 
 muriatic acid, which is very feldom the cafe, 
 give them another alkaline lixiviation, and after 
 that a fecond immerfion in the oxvgenated mu- 
 riatic acid ; after which deep them in water 
 acidulated with fulphuric acid, either hot or 
 cold, the latter of which is the moil aclive and 
 effectual; and, laftly, let them be fubjecled to 
 the action of the mallets or cylinders. 
 
 Red and blue colours are moft tenacious. 
 With regard to black, it will be fufficient if 
 they be fteeped after opening their texture, 
 
 1. In a diluted folution of fulphuric acid ; and, 
 
 2. In a folution of the oxygenated muriatic acid. 
 
 If 
 
tyo Tht Art of 'Bleaching 
 
 If the operator could know that thefe rags 
 had been dyed in the raw ftate, a ftill more bril- 
 liant white might be obtained by following the 
 fecond method defcribed in the preceding ar- 
 ticle. But it very feldom happens that coloured 
 lags have not been bleached before they were 
 dyed. The manipulations may be performed 
 with fufficient fpeed to bleach at lead three 
 thoufand pounds weight in the courfe of the day, 
 without appropriating any extraordinary edi- 
 fice or workfhop to this purpofe. 
 
 Thefe new methods, if adopted in the prefent 
 circumftances (of France), will greatly contri- 
 bute to prevent the Avant or dearnefs of paper 
 or rags. The quantities of the refpective ma- 
 terials cannot be precifely directed on account 
 of the difference of the veffels, the papers, and 
 the colours; but practice and attention have 
 foon regulated thefe matters. In the applica- 
 tions of thefe principles, the republic of France 
 have obtained two valuable advantages. On 
 the one hand, a greater quantity of linen has 
 been faved for the ufe of the hofpitals ; and, on 
 the other hand, it has been more eafy to referve 
 the rags of fuperior quality for paper-money 
 and the purpofes of trade, which require pecu- 
 
 liar flrength to undergo the circulation. 
 
 CHAP. 
 
Cottons, Thread, &c. 271 
 
 CHAP. XXVI. 
 
 X HE valuable product of vegetable alkali, 
 which may be expected from the incineration of 
 the marc or refidue of grapes*, in order to mew 
 the considerable magnitude of the advantage 
 which this hitherto neglected material may af- 
 ford, which in fome vineyards is ufed as fuel, 
 and in others as manure, I fhall (imply remark, 
 that, after direct experiments, 1 find that five 
 hundred pounds of the refidue of this marc, 
 dried after diftillation (a purpofe to which they 
 are in fome provinces applied to obtain brandy), 
 and afterwards burned, have conftantly afforded 
 me one hundred pounds, or thereabouts, of afhes, 
 which produced ten pounds of fixed vegetable 
 alkali or potafh, reduced to the confidence of 
 faline of a blackifh brown colour. 
 
 It is eafy to perceive what an immenfe pro- 
 vifion of this article one might annually obtain 
 •in countries where the marc is ufed only as 
 
 * The following account is extracted from a memoir on the 
 fame fubjec% which was addreffed on the 18th Thermidor to 
 t he CommuTion for Provifions and Ammunition to the armies 
 of France, 
 
 manure. 
 
2^2 The Art of Bleaching 
 
 manure. Nothing more would be required 
 than to collect the aflies of this marc, burned 
 after it is taken from the prefs, or fubfequent to 
 the time of attaining the fmall vines, or, laftly, 
 after diftillation in thofe places where they are 
 ufed to make brandy. 
 
 The refidue of grapes is not eafily burned, 
 becaufe the feeds become difengaged. It may, 
 neverthelefs, be burned with a certain decree 
 of fpeed, by means of a grate, having intervals 
 of one inch, or half an inch wide, raifed above 
 an afh-hole or hearth to the height of 11 or 15 
 inches. The hulks intended to be burned are 
 to be difpofed all round, becaufe the previous 
 drying is of advantage to haften the combuftion. 
 The feeds which fall through muft be thrown 
 up, from time to time, with a (hovel, until they 
 are entirely red hot, in which ftate they are to 
 be taken out and thrown in a heap in fome 
 convenient "place near the furnace, where the 
 combuftion may be completed by turning them 
 over from time to time, and expofing them to 
 a current of air. The larger this heap is made, 
 the more fpeedy and perfect will be the com- 
 buftion, and the more abundant will be the 
 alkaline produce. The heat remains a long 
 time. I have feen inftances in which the mafs 
 remained very red after having burned for a 
 
 month 
 
Co/ tens, Thread, 6sJV. 273 
 
 month with frequent ftirring and expofure to 
 the air. It is proper to remark, that whatever 
 care is taken to burn the feeds, there will, 
 fieverthelefs, remain near one-tenth part not 
 entirely confumed, which may be eafily feparat- 
 ed from the red with a fieve. Thefe may after- 
 wards be burned with the hulks, or feparately, 
 as may be mod convenient. The rain does not 
 perceptibly injure the allies of thefe heaps, if 
 they be covered with other hulks, either dry of 
 flightly moift. If the marc be burned in this 
 lair, fiate, it produces a cinder, which is difpofed 
 to agglutinate together in a ftony form. 
 
 When the fire is once kindled upon the grate, 
 it is afterwards kept up without intermiffion, by 
 charging it with dry hulks in proportion as the 
 combuftion proceeds. Thefe may be put on to 
 the depth of (ix inches. When the fire is well 
 lighted, and urged by a ftrong wind, the moift 
 hulks and ftalks burn almoft as fpeedily as thofe 
 which are dry. 
 
 It is of elfential confequence, that the grates 
 fliould be fixed in a fpacious airy place, where 
 there is no danger from fire. The relidue of 
 grapes emits during its combuftion a white 
 and very thick fmoke, which would incommode 
 the neighbourhood. 
 
 t Two 
 
274 The Art of Bleaching 
 
 Two grates of iron wire, about three quarters 
 of an inch in the meihes, or holes, twelve feet 
 n length, and four and an half or five feet wide, 
 properly attended by one man, will burn in a 
 clay, by a frelh wind, five thoufand pounds of 
 this dry refidue, which afford nearly one thoufand 
 pounds of allies, and from the lixiviation of thefe 
 alhes a product of one hundred or one hundred 
 and ten pounds of well dried falin or vegeta- 
 ble aikaii is attained. 
 
 The relidue of grapes may alfo be made up 
 in the torm of peat, and dried in the open air, 
 or under a fhed. Thefe are moulded in the 
 lame manner as the relidue of the tanners. Af- 
 ter drying for three days, they are fufficiently 
 firm to be burned on a grate of bars one inch 
 iquare, and an inch afunder, which form a kind 
 cf turnace either in the open air, or beneath a 
 chimney. A furnace 8 feet long, 20 inches wide, 
 and 18 inches deep, may confume four thoufand 
 cf thefe dry pieces, each weighing about one 
 pound and a half, and meafuring in diameter 
 rive inches, and from an inch and a half to two 
 inches thick. A woman, or a boy of fifteen 
 years old, can make fifteen hundred of thefe cakes 
 in a day with eafe. This was the procefs I 
 uled in Meflidor, in the year two, in order to 
 
 afford 
 
Cottons, Thread, &c. 27$ 
 
 afford a fpeedy fupply of vegetable alkali to a 
 manufactory of faltpetre, which I directed that 
 year in the department of La Cote d'Or. 
 
 It may alfo be remarked, that advantage may 
 very ealily be derived from the heat of the fire, 
 neceffarily made of this procefs, whether for the 
 purpofe of lixiviation of the allies, or drying the 
 alkali. 
 
 The mod effential facl, however, which re- 
 quires to be known, is, that a very fpeedy and 
 abundant product of vegetable alkali, for the 
 manufattory of faltpetre, or for other arts and 
 manufactories, may be obtained by the fimple 
 means here pointed out. 
 
 t z CHAP. 
 
G.j G The Art cf Bleaching 
 
 CHAP. XXVII. 
 
 Fabrication of crude Alkali [cendres Gravelees), with 
 the Lees cf IVine *. 
 
 U NDER the mantle of a kitchen, or a bake- 
 houfe chimney, from one wall to the other, at 
 the diftance of 18 or 20 inches from the back, 
 according to the opening of the flue, let a grate 
 be fixed of bars of one inch fquare, at the diftance 
 of about one inch and a half afunder. This grate 
 is to be raifed at leaft 18 inches above the 
 hearth, and defended in front with a wall one 
 brick thick, having perforations nearly refembling 
 thofe of a pigeon- houfe. Or, inftead of the 
 wall, a grate may be fubftituted fimilar to that 
 of the bottom. This wall, or grate, may be 24 
 inches high. The interior fpace of this kind 
 of furnace, is then to be rilled with the lees 
 of wine preffed dry or green. The latter are to 
 
 * The following is extra&ed from a memoir prefented 
 on the 22d Vendemiaire, in the year two, to the Committees of 
 Commerce and Provifions, and to the Commiffion of Agricul- 
 ture and of Arts. 
 
 be 
 
Cottons, Thread, &c. 277 
 
 be preferred, becaufe the alkali they afford is 
 much finer. The whole is to be fet on fire by 
 means of ftraw or fmall wood, previoufly difpof- 
 ed under the lees. The fire foon penetrates thp 
 whole mafs, and in lefs than a quarter of an 
 hour the flame fpeedily reaches the upper ftrata, 
 which muff be regularly fupplied with new 
 lees, in proportion as the mafs finks down by the 
 combuftion. That portion which falls through 
 the grate, and may appear from its brown or 
 blackifh fracture to be not entirely confumed, 
 muft be returned again to the fire. The grate 
 muft be cleared from time to time with a hook, 
 in order to facilitate the combuftion. 
 
 Inftead of burning the lees in a furnace of this 
 kind, another furnace may be ufed with equal 
 advantage, entirely of brick, in the form of a 
 hollow tower, at the bottom of which fome fag- 
 gots of wood are to be placed, which are to be 
 lighted after having filled part of the capacity 
 of the furnace with frefh lees, mixed with dry, or 
 with frefh lees only; for thofe which are too dry 
 muft be fteeped a day beforehand, in order that 
 they may be perceptibly moift. Thofe lees are 
 then fucceftively thrown in at the top of the fur- 
 nace, in which manner the procefs is to be con- 
 tinued until the whole of the lees are confumed. 
 After continuing this procefs for feveral days, the 
 
 t 3 furnace 
 
278 "The Art of Bleaching 
 
 furnace is fuffered to cool, and the allies taken 
 out through a door at the bottom. 
 
 It is proper again to remark, that thefe fur- 
 naces ought to be conftrucled in a fpacious 
 place, on account of the dangers of fire, and 
 the inconvenience of the fmoke, wliich is very 
 conflderable. 
 
 The lees, thus burned, emit a light very long 
 flame tinged with different colours. It may 
 be advantageoufly ufed in furnaces inftead of 
 wood, either alone, or mixed with that combuf- 
 tible. 
 
 One barrel or piece and a half of cendres 
 gravelces, weighing about 260 Paris pounds, 
 is the product per day by one man's work of 
 the combuftion of 6 or 7 barrels or pieces of 
 wine lees, well dried in a furnace conftrucled 
 under a chimney 20 or 24 inches deep, 18 inphes 
 wide, and 8 feet in length. This was filled 
 four times during the day, taking care each time 
 in the fir ft place to llir the lees at top and in 
 front with an iron fork, and to clear the grate 
 beneath with a hook, which is abfolutely necef- 
 fary to be done, in order to prevent the mafs 
 from coagulating, and to favour the action of the 
 air. With proper attention 50 or 60 barrels 
 may be burned in fix days, without being oblig- 
 ed to employ the night j the fame quantity may 
 
 be 
 
Cottons, Thread, &c. 279 
 
 be burned in three days and two nights in the 
 round furnace above defcribed, if conftru&ed of 
 a diameter of 5 feet. 
 
 The good cendrcs gravels s, or that which is 
 afforded by the red lees, contains at leaft 70 cr So 
 pounds of vegetable alkali in the hundred, when it 
 has been carefully burned. That which is made 
 with white lees, though well pounded and difr 
 folved in hot water, does not afford more than 
 45 or 50 pounds of alkali. In general, when 
 the cinders have acquired a green or blue colour 
 in the fire, and are light and fonorous, the qua^ 
 lity is good j but it feldom happens that the 
 whole product is of the fame colour. That 
 which is too much burned and refembles the 
 fcoria of iron, mult be rejected, not only becaufe 
 it is very difficult to pound, but likewife infolu- 
 ble and earthy. The faltpetre-makers, dyers, 
 bleachers, potters, leather-ftainers, glafs-makers, 
 and others who ufe this faline fubftance, are 
 particular in their choice of that which is light, 
 fpongy, and of a greeniih or bluifh colour, which 
 fhews no fign of vitrification in its fra&ure, the 
 undoubted fign of too ftrong a fire. 
 
 T4 
 
 CHAP. 
 
2 So ?ht Art of Bleaching 
 
 CHAP. XXVIIL 
 
 The Method of Bleaching U r ooL 
 
 Jl lECE-gocds formed of thread and wool, 
 wool and cotton, being at prefent very much in 
 fafhion (in France), it may probably be an inte- 
 resting object to manufacturers in this branch, 
 to fee an account of the method of bleaching 
 wool in this place by the ordinary procefs, 
 though well known. I fhall in the firft place 
 fpeak of carded wool, which is ufed for broad- 
 cloths, and wool proper for combing, which is 
 ufed for the manufacture of (luffs *. 
 
 Wool for carding for the mawfafture cf broad- 
 cloths, &c, — This kind of wool, as it is ufually 
 found in the market, has already been fubjected 
 in the hands of the grower or dealer to a cleanf- 
 ing, which has deprived it of 50 or 60 per cent. 
 But the wools forwarded to the manufactories 
 are (till loaded with a portion of the unctuous or 
 
 * The following is, in great part, extracted from different me- 
 moirs of Roland Laplatiere, and Allard, formerly infpeftors of 
 manufa&ures. 
 
 sre afv 
 
Cottcvs, Thread, &c. i8i 
 
 greafy matter, wh'ch it isneceffary to clear them 
 of. Experience has (hewn, that thisfmall quan- 
 tity of natural greafe is neceffary to preferve 
 them from worms, during the carriage, as well 
 as the time of keeping, before they are a pplied 
 to ufe. 
 
 The manufacturer's method of cleanfing his 
 wool, is ufually performed as follows : — To a 
 given quantity of water poured into a boiler, 
 for example, five-and-twenty pails, an addition 
 is made of five of old putrified urine, which is 
 boiled for a fhort time. The mixture is then pro- 
 per to dilTolve the greafe of the wool. Three or 
 four pails of this liquid are then poured into a 
 yeffel at the heat which will admit the workman 
 to hold his hand in it. About %o pounds of 
 wool are then thrown in, which, after fteeping 
 a very fhort time, are- continually rlirred with a 
 flick for a quarter of an hour, after which it is 
 taken out and drained for a few moments in a 
 bafldet over the veffel, into which the drainage 
 liquor returns. The wool is then carried to 
 the river and repeatedly warned in large open 
 batkets, by ftirring it about with long poles or 
 rakes, till the water comes off very clear. In the 
 mean time another workman puts a like quan- 
 tity of wool into the verTel, and the fame opera- 
 tion is repeated, &c. 
 
 Several 
 
582 The Art of Bleaching 
 
 Several eflential matters are required to be 
 obferved during this operation, i. The bath 
 in the boiler, as well as in the ether veflel, muft 
 be refrefhed * from time to time, when its force 
 is found to be diminished, for it lofes much 
 of its ftrength, in confequence of the various 
 changes of the wool, as well as from evaporation. 
 2. It he fliould think the addition of urine un- 
 neceflary, by way of reftoring the bath, he muft 
 raife its temperature, in order to give it the 
 requifite power for the wafhing. 3. But the 
 heat muft be carefully prevented horn increafing 
 beyond the proper degree, as determined by 
 experience, for it is found that too much heat 
 hardens the un£hiou^ matter, infeead of diflblving 
 it, and that too great a quantity of urine changes 
 the wool, and renders it harfh. 4. When the 
 bath has become too foul for the warning, k 
 muft be entirely changed : it may eafily be ima- 
 gined, that this work requires a very intelligent 
 workman ; but practice renders the bufmefs 
 very eafy. 
 
 The fuccefs of this operation is afeertained 
 from the appearance of the wool, which becomes 
 
 * It i> more advifable. to refrefti than to renew the hatl^ 
 becaufe the greafy impurity of the wool, which is dilengaged 
 by warning, becomes a leaven which dilengages the greale from 
 the other wool, plunged in the bath. 
 
 white. 
 
Cottons, Thread, &c. £83 
 
 white, foft, elaftic, and open, dilating or fwelr 
 ling when touched, inftead of being hard, greafy, 
 and clofe, as it was at firft. The qualities it 
 acquires in the bath do, therefore, fufficiently 
 ihew the neceffity and utility of this fecond 
 cleanfmg, by which it lofes 10 or 12 per cent 
 more. This laft lofs, added to the former, gives 
 a total of about 60 or 70 per cent; that is to fay, 
 100 pounds of raw wool produce fcarcely more 
 than 30 or 40 pounds in a very clear date, fit 
 for the manufacturer. 
 
 Wool fir combing for the manufafture of Stuffs. 
 
 This wool, in the market, is broken or 
 
 Ported by the clothier, and fent before or after the 
 dying (if this be intended) to the combers in 
 parcels of about fix pounds and a half each. 
 '1 he quantity is fir ft warned in a velTel filled with 
 hot water, taken out of a fmall boiler in which 
 two or two and a half pounds of green or black 
 foap has been diflblved, for the faid quantity 
 of wool, which accordingly as it is thought to 
 be more or lefs foul, is well preffed and after- 
 wards wrung on the hook, and then dried in the 
 fun, or in the open air. Before it is combed, it 
 is again fubjeded to a fecond bath of the fame 
 kind. Thefe two clearings are fufficient to 
 deprive it of all the natural greafe which remains, 
 
 and 
 
1 84 The Art of Bleachm* 
 
 and of fuch impurities as might be an impedi- 
 ment to the combing procefs. 
 
 It muft be remarked, that thefe fix pounds 
 and a half of wool are wafhed in fuccefiive 
 fmalJ portions at a time. The water of the 
 wafhing-tub is renewed as the work goes on, in 
 order to detach the greafe and other impurities 
 from the wool - 3 there are two hooks fixed within 
 the vefTel, one at each end, one of which can be 
 turned round by a handle. The workman, after 
 having well wafhed and preffed with his hands 
 the feveral parts of the w r ool, wraps them round 
 the tw r o hooks, and by wringing it out, he ex- 
 prefles the dirty water, which carries with it ali 
 the greafe detached by virtue of this ftrong 
 preffure. After this fecond warning, the wool 
 is dried carefully to prevent its being accident- 
 ally foiled. 
 
 In this ftate it is, that the wool is combed. 
 It muft be rather moift for this operation, in 
 order to facilitate the prolongation of its fila- 
 ments, of which, when the wool is well cleanfed, 
 the comber ought always to form lengths of 
 three or four feet each. It is, therefore, eflenti- 
 ally neceflary, that this operation mould be well 
 managed, not only for the good effect it pro- 
 duces in the opening, but, likewife, becaufe the 
 
 colour 
 
Cot tens, Thread, &c. 1%$ 
 
 co our and clearnefs of the fluff depends much 
 more upon this firft operation, than it is generally- 
 imagined. 
 
 In many manufactories, after the wools are 
 combed, and according to the kind of ftuff in- 
 tended to be made, it is ufual, in order to difpofe 
 them to fpin well, to give them a third wafliing 
 in the fame veiTel with hot water and foap* 
 The wool is afterwards carefully dried, and in 
 this (late delivered to the fpinner, if it be intend- 
 ed for the chain or weft ; but that which is 
 intended for weft is returned to the comber, 
 and after coming out of his hands it is warned 
 a fourth time as before. But this fourth and 
 laft warning is not given except to wools of 
 the firft quality, manufactured of a white colour, 
 or intended to receive any clear and brilliant 
 dyes. 
 
 Wool, which is well cleared of the greafe, 
 ought to have its filaments flender, long, even, 
 and not connected with each other, hefides which 
 it ought to be tenacious, white, and difengaged 
 from every foreign fubftance. The wool from 
 Holland is remarkable for this laft quality. That 
 of England, is harfher and much fouler. The 
 German wool is ftill harfher, but equal to this 
 in length. It approaches the French wool, 
 
 which 
 
1 8 6 The Art of Bleaching 
 
 which is the word kind of any, with regard to 
 its length and fitnefs for combing;. 
 
 The lofs fuflained by cleanfing, is fomewhat 
 lefs than one-fourth in the Dutch wools, and 
 about a fourth in thoie of England. The Ger- 
 man wools, and fchofe of France, undergo a iliil 
 more confiderable lofs, on account of their infe- 
 rior quality. Some of the latter lofe more than 
 one-third. 
 
 Sulphuring. Wool, fluffs, (lockings, and other 
 articles of the fame nature which are foiled by 
 dreffing or ufe, are expofed to the vapours of 
 fulphur. By this procefs thefe goods receive a 
 clearer white than that which is natural to the 
 wool after the ufual warning and cleanfing. 
 
 This operation is ufually commenced by wafh- 
 ing or fulling the piece, For this purpofe it is re- 
 quifite that the fulling rammers mould be made 
 lighter than ufual. When the convenience of a 
 ftream is not to be had for moving them, it will 
 be fufRcient if a frame of 15 or 20 inches wide 
 be made with two beams three or four inches 
 thick, fupportcd by crofs-pieces, and terminat- 
 ing below in a crofs-piece fomewhat longer, 
 ftronger, and vertically fufpended to a plank 
 or poles placed between the timbers of the 
 loof, and forming a fpring. A wooden trough 
 
 ft 
 
Cottons, Thread, &f& 287 
 
 is placed underneath, in which a workman may 
 move the fpringing peflle up and down with 
 his hand with great facility, and by inclining 
 the trough the fame effect of turning the (luff 
 may be produced as in the common fulling 
 apparatus. 
 
 Inflead of a machine of this kind, the ma- 
 nufacturer may ufe the mallet, or which is ft 111 
 better, the goods may be worked with the feet, 
 in a place properly difpofed for this effect, as 
 has been recommended for piece-goods and 
 (lockings. 
 
 When the piece is well cieanfed and rinfed 
 in a dream, it is dried and fmged, or fent to the 
 dye-houfe ; if, on the contrary, it is intended for 
 a clear white, it muft be finged before the 
 fcouring ?. For the fine white, a fecand (light 
 warning is given in a folution of foap, in which 
 the (luff is left for a certain time, then vvaflied 
 well, rinfed in running water, and left to drain 
 tor an hour on the horfe, after which it is ex- 
 pofed to the vapours of fulphur for five or fix 
 hours, or longer, as far as 24 hours, according to 
 the bulk of the piece. 
 
 After this operation, it is again waihed, and 
 
 * The method of tinging muflins. i? equally applicable to 
 Woollen goods which require this treatment. 
 
 its 
 
28B The Art of 'Bleaching 
 
 its colour heightened with fine whiting and blue, 
 which are difFufed in clear water j it is then 
 fulphured a fecond time, waflied in a flight 
 folution of foap, dried, patted through the 
 flretching machine, calendered, or prelTed, ac- 
 cording to its nature. 
 
 The following is the method of treating a 
 piece of cloth of 40 or 4c ells, with the whiting 
 and blue. Seven or eight pounds of fine whit- 
 ing (blanc d'FJpagne) are pounded and mixed 
 up with water in a pail. This mixture, except 
 the coarfe particles at the bottom, is poured 
 into a fmall trough of- clear water. The bath 
 being well mixed, the piece is patted rapidly 
 through it upon the reel for a quarter of an hour, 
 after which it is raifed out of the bath upon the 
 reel, and a pail of water is added, in which an 
 ounce and a half of the finell indigo, or Pruiiian 
 blue, has been dittufed by the ufual method 
 of pounding, lifting, and wrapping it in a bag. 
 The bath being again well ftirred, the piece is 
 immediately returned through the fluid again 
 by means of the reel. After this treatment, it 
 is laid on a packing-cloth, and carried to the 
 workfhop, where the nap is laid by the fullers' 
 thiftle, during which the furface is wetted with 
 the fluid of the bath, and when the piece is dry, 
 
 it 
 
Cottons, Thread, &c. 289 
 
 it is beaten with twigs to clear it of the white 
 powder it received in the foregoing procefs. 
 
 It is proper to obferve, that bad fmells, and 
 even the offenfive breath of individuals, will fome- 
 tiiries produce a change in the bath of blue and 
 white, in which woollen goods are deeped ; or, 
 at lead, this is what very refpe£table manufac- 
 turers affirm to be the cafe. When this happens, 
 the operator is obliged to plunge his piece in a 
 bath of hot water, to warn out the white and the 
 blue, which have fixed themfelves irregularly 
 in a kind of vegetation, after which the opera- 
 tion muft be repeated. With regard to woollen 
 fliirts, flannels, and other articles intended to 
 be worn next the (kin, neither fulphur nor foap 
 are in any refpecl fuitable to them. It is fuffici- 
 ent if thefe be well fcoured in bran and water, 
 and afterwards well warned in clear water. The 
 colour is of no particular confequence, as the 
 main objeft is to render it as abforbent as poili- 
 ble, to which quality the foap itfelf is a great 
 impediment. 
 
 The preference is often given to leave dock- 
 ings on the leg with waihing or fulphuring 
 them. 
 
 The place in which the operation of fulphur- 
 ing is performed, is merely a very clofe chamber, 
 in which the goods are fufpended on poles of 
 
 v white 
 
290 Tbt Art of Bleaching 
 
 white deal, fo as to hang down in folds, which 
 neither touch each other, nor the floor or wall. It is 
 ftill more particularly neceflary, that they fhould 
 not touch any iron, which becomes oxyded by 
 the muriatic and the volatile fulphureous acid 
 afforded by the fulphur which burns in a veffel on 
 the floor, and would certainly fpot it, Inftead of 
 pafling thefe pieces over the poles, it might, per- 
 haps, be more advifeable to faflen them beneath 
 the fame poles, by means of hooks pafling either 
 through the lifts themfelves, or through loops 
 of twine attached to the lifts. 
 
 It is neceflary to be aware, that a cloth which 
 has undergone the operation of fulphuring, fhould 
 not be immediately laid upon wood before it is 
 purged of the fulphureous acid, which would 
 diflblve the refinous or gummy parts, and fpot 
 the goods. 
 
 The fulphuring not only communicates a dif- 
 . agreeable fmell to the cloth, but likewife gives 
 it a harfh feel. A bath of foap which is given 
 after this operation reftores its foftnefs, and that 
 in a degree which is more effe&ual the longer 
 the cloth is worked in it. 
 
 CHAP. 
 
Cottons, Thread, (2c. *9 X 
 
 CHAP. XXIX. 
 
 The Bleaching of Silk. 
 
 Th E fame reafons which have led me to in- 
 fer! the procefs of bleaching wool in the forego- 
 in. chapter, with the account of the goods which 
 are wholly or in part made of that material, in- 
 duced me likewife to infert the proceffes for 
 
 bleaching filk. . 
 
 There are two methods of performing thi?, 
 either by ungummhg it, or leaving the gum m 
 its texture. I mall treat of both, beginning 
 with that in which the filk is ungummed and 
 
 boiled*. „ _._. , ? 
 
 This procefs is managed as follows: D.ffolve, 
 in a fufficient quantity of water, in a bo.le. -over 
 the fire, JO pounds of white foap of Marseilles 
 for every 100 pounds of filk. After the fo luhon 
 has boiled, lower its heat by an addition of cold 
 water. Extinguilh or flacken the fire, but take 
 
 . Here, as in the foregoing chapter, I recur to the Memoirs 
 
 of Roland Laplatiere. 
 
 o 2 care, 
 
2 2 2 The Art of Bleaching 
 
 care, neverthelefs, to keep the bath at a confi- 
 derable heat. Steep therein the filks, hung on 
 rods, in which ftate. leave them till their white- 
 nefs and flexibility fhevvs that the gum is diffolv- 
 ed and feparated. Spread out the filk on the 
 rods, and turn them, in order that the parts out of 
 the bath may be ftet-ped in their turn, and when 
 each hank is perfectly ungummed, wring them on 
 the pin to exprefs the foap ; make them, and put 
 them in bags of coarfe cloth, containing 20 or 
 30 pounds each. 
 
 Make a new bath in the fame proportion, and 
 in the fame manner, as the former. Throw the 
 bajjs therein, and boil them for an hour and a 
 half, ftirring them from time to time in the 
 boiler. The ungumming and boiling of filk 
 deprives it of 25 per cent of its weight. 
 
 If the filk be intended to be dyed, the ungum- 
 ming and boiling are performed in the fame 
 bath, which is boiled for 3 or 4 hours, making 
 ufe of a quantity of foap proportioned to the 
 finenefsof the colour, or rather the white ground 
 which it requires j 25 or 30 pounds are fufficient: 
 for common colours, and as much as 50 for thofe 
 with faffranum, and poppy red, cherry colour, 
 &c. 
 
 But when it is intended that the filk mould 
 be white, and, confequently, to bleach it, the 
 
 basrs 
 
 a 
 
Cottons, Thread, erV. 293 
 
 bags are carried to the river, when they are 
 taken out of the boiler, and the filk being taken 
 out, is extended upon cords floating on the 
 water and well wafhed. 
 
 A new bath, containing a pound and a half 
 of foap to 30 pails of water (of about three 
 Englifli gallons each), in which a fmall quantity 
 of litmus, with a portion of powder-blue or in- 
 digo, isdiffufed, according to the nature of the 
 made intended to be given. The boiler is filled, 
 the bath heated, but never to boiling, and the 
 filk is paffed through it over the rods, until it 
 has uniformly acquired the requifite made. It 
 is then wrung dry, and hung out, or elfe carried 
 to the fulphuring room. 
 
 All the filks made ufe of in the white, in any 
 manufacture whatever, require to be fulphured 
 in order to bleach them more perfectly. One 
 pound and a half or two pounds of fulphur 
 are fufficient for one hundred pounds of filk. 
 At the expiration of 24 hours, the room is ven- 
 tilated, and muff, not be entered until the vapour 
 of the fulphur is ditfipated. The air which 
 enters in Cummer is fufficient to complete the 
 drying of the filk, but in winter this is performed 
 by a chafing-dim or ffove put into the room. 
 
 If the white or fulphured filk fhould not prove 
 
 blue enough, a new (hade is given with clear 
 
 u 3 watery 
 
194 The Art of Bleaching 
 
 water ; the hardeft water is beft, after which it 
 is fulphured a fecond time. 
 
 With regard to filks intended for gauzes and 
 blonds (one of the principal qualities of which 
 is derived from the natural rigidity of the filk), 
 they ought not to be either ungummed or boiled. 
 The whiteft natural filks are chofen in prefe- 
 ence, which are fteeped and opened in a bath 
 of clear hot water, or foap and water In the 
 firft cafe, they are wrung, and afterwards fulphur- 
 ed. The fine filks of Nankin, which are of a 
 beautiful white, have no need of this operation. 
 
 The following is the method publifhed by 
 Rigaud in 1778, for bleaching filks without 
 ungumming them *. 
 
 The filk, intended to be bleached, is put into 
 a glafs veffel containing a mixture of fpirit of 
 wine and muriatic acid, in the proportion of 
 a pound of the former to half an ounce of the 
 
 * This method differs a little from that publifhed in 1793, 
 by Baume. See this laft, Journal de Phyfique of the fame year 
 may be confulted, and for that of Rigaud, the Gazette du 
 Commerce of the 7 Ncvembre, 1778. Kate of the Author. 
 
 This method requires many precautions, and would be 
 much too expenfive if the materials were not afterwards re- 
 covered. An abridgement of Baumt's paper, which contains 
 a detail of thefe obje«£b, may be feen in Nicholfon's Philoso- 
 phical Journal, I. », 32. — N. 
 
 latter, 
 
Cottons, Thread, fcfa 295 
 
 latter, and, in quantity, fufficient to float the 
 filk. The veffel is then clofed with wet parch- 
 ment, and expofed for 12 hours to the fun, or 
 othervvife it may be left 24 hours in the (hade, 
 at a temperature between 15 and 20 degrees of 
 Reaumur. The filk is then taken out and preffed, 
 and again macerated for the fame time, and un- 
 der the fame circumftances, in frefh acidulated 
 fpirit of wine, in another fimilar veffel clofed as 
 before. The filk is then taken out, preffed, and 
 walhed for four or five minutes in pure fpirit of 
 wine. In the next place, it is kept for 24 hours 
 in the fun, or 36 in the fhade, in a third veffel, 
 containing pure fpirit of wine, which is to be 
 renewed at intervals, after which the filk is t<J 
 be taken out, preffed, and warned two or three 
 times in clear water, which is to be changed 
 at each warning. Laftly, the filk is expofed 
 to dry upon a frame fo contrived as to ftretch 
 it with considerable force, and prevent its curl- 
 ing up as it dries. 
 
 v 4 EXPLA- 
 
t *9 6 3 
 
 EXPLANATION OF ftiE PLATES. 
 
 The fame Letters denote the fame Things in the eorref- 
 fondent Figures of Plans, Elevations, Seflions, and 
 Profiles, 
 
 PI,ATE THE FIRST. * 
 
 FIGURES i, i. 10, ii. The plan, fedion, 
 profile, and detail of a diftilling apparatus, en,, 
 tirely mounted and ready for fervice. It ma ybe 
 formed either with a fingle or double apparatus, as 
 is fhewn in the figures. Each apparatus is com- 
 pofed of two feparate furnaces, which are, never- 
 thelefs, fupportedon the fame ftru&ure, with two 
 diftilling-veflels, one pneumatic veffel, and a 
 veffel for immerfing the goods. 
 
 A. A ftru&ure of light wood-work, which fup- 
 ports the furnaces cr their mafonry in brick or 
 plaifter. 
 
 B. Platform of brick or tile, ferves as a 
 hearth to the alh-holes, C, of the furnaces. 
 
 D. A bed of clay, on which the brick plaU- 
 form is fupported. 
 
 E. The wood-work, or planks of the veffels in 
 which the bed of clay is placed. 
 
 F. A vacant {'pace, in which the mixtures of 
 muriate of foda and manganefe, in the proper 
 dofesf or changing each diftilling veffel, are 
 
 kept 
 
Explanation of the Plates. 297 
 
 kept dry, for the purpofe of procuring the oxyge- 
 nated muriatic acid by the muriate of foda, in- 
 ftead of directly ufing the common muriatic acid 
 at 25 degrees of concentration of the areometer of 
 Molly. 
 
 G. The door of each of thefe receptacles. 
 H. The drying pans. Thefe are a kind of 
 troughs or capfules of plate-iron of a fquare form, 
 in which the muriate of foda is put to dry, either 
 before or after pounding and fifting. 
 
 T. T he ventsor chimnies through which the 
 fmoke or fumes of the coal efcapes, which is ufed 
 in heating the diftilling veflels. 
 
 J. The chimney of the furnace, leading under 
 the drying place. 
 
 K. Acapfuleorveffel of plate-iron, either fquare 
 or cylindrical, for the purpofe of fupporting the 
 diftilling veflels and the fand-bath in which they 
 are placed. It is moft advifeable to form this 
 veffel cylindrical, becaufe the flame, in that cafe, 
 applies better to its external furface, and a lef* 
 quantity of fand would be required to be heated. 
 L. The door of the furnace. 
 M. A ledge or ftep, fixed to the frame of the 
 furnace, in order that the operator may raife 
 himfelf upon it fufficiently high to pour the mix- 
 tures into the diftilling veffels, or for any other 
 operation relative to the furnaces. 
 
 N. The 
 
ipS Explanation of the Plates. 
 
 N. The diftilling vcffel, or retort, having its 
 neck O, and its adopter P, which lad may be of 
 glafs,feparatefrom the retort, or elfe apart or pro- 
 longation of the fame, fuppofing the glafs-men 
 to be fufficiently fkilful to give it this figure. In 
 order to obviate the accidents of fractures, it 
 may be made of (tone ware, porcelain, or, which 
 is ftill better, of lead, as is fhewn in the figure, 
 
 O. A welt or projection of lute which fixes the 
 adopter to the retort. Inftead of the retort, the 
 operator may ufe, with ftill greater advantage, 
 balloons, or tubulated veffels, fuch as are defcrib- 
 ed in plate 9, fig. 1 and 2. I prefer thefe laft 
 veffels becaufe lefs expenfive, more common, 
 more generally ufeful, and, in particular, more 
 convenient. Q. 1, a pipe of glafs, ftone-ware 
 porcelain, or lead, the latter of which is prefer- 
 able; its"extremity, Q 2, is fitted to the adopter - 3 
 and its other extremity, Q j, fuffers the 
 oxygenated muriatic acid to efcape in the form 
 of bubbles into the pneumatic veftel. 
 
 R. The pneumatic vefTel, placed on its three- 
 legged fupport S. 
 
 T. The arbour of the agitator. U its fans, or 
 arms. V. Handle for turning it. X. Diaphragms 
 or falfe bo:toms, beneath which the oxygenated 
 muriatic acid gas is concentrated and abf>rbed; 
 they are fupported on one fide by the regular in- 
 clination 
 
Explanation of tfot Plates. 299 
 
 clination of the ftaves of the veffel, and on the 
 other by the pegs of wood Y : thefe falfe bottoms 
 divide the pneumatic veflel into a number of fe- 
 parate receptacles. 
 
 Z. The pipe through which the gas pafTes from 
 one cavity to the other ; its prolongation pre- 
 vents the gas from immediately efcaping into 
 the upper-chamber; the gas being by this means 
 forced to remain for a time in the inferior cham- 
 ber, where it is frequently agitated by the arms of 
 the apparatus, becomes abforbed in the water to 
 a certain degree. &, a funnel of wood to facilitate 
 the pouring of water into the pneumatic veffel, 
 when its cover is fixed on, pinned faft, and the 
 places fecured by paper palled on. 
 
 a. Spigot, or cock, to draw off the acidulat- 
 ed water for trial of its ftrength, by the known 
 re-agents, indigo or cochineal, as mentioned in 
 chap. 14. This cock may be formed of glafs, or 
 lead, or even copper ; but this laft metal muft be 
 covered with a coating or two of white lead paint, 
 to prevent its being rutted, or oxyded by the 
 vapour of the gas, and its confequent fpotting 
 the various goods which may come into contact 
 with it, or may be foiled by the falling of parti- 
 cles of verdigreafe with which it would become 
 covered. 
 
 b. The cocks, for emptj ing the bleaching li- 
 quor 
 
300 Explanation of the Plates. 
 
 quor into the veffels of immerfion : they ought 
 to be of wood, clofed either with a cork, or with 
 a turned pin, fecured with flax ; they mud like- 
 wife be firmly fixed in the pneumatic veffel, and 
 well defended with fat lute, within and without. 
 
 c. A tube of glafs, of the fize of barometer 
 tubes ; that is to fay, 2 or 3 lines in diameter : it 
 ferves to fhew the height of the liquor which re- 
 mains in the veffd, when a portion has been drawn 
 off for particular immerfions; and it likewife in- 
 dicates the greater or lefs a£tion of the diftilla- 
 tion, by the frequency with which the liquor 
 ofcillates up and down without. This laft indi- 
 cation is particularly ufeful toward the end of 
 the operation, when the flownefs and weaknefs 
 with which the bubbles efcape, produce fcarcely 
 the leaft found in the veffel, even though the 
 car be applied to its fides. 
 
 This tube is fixed at the diftance of about an 
 inch from the bottom of the pneumatic veffel ; 
 its place of junction is well fecured with fat lute, 
 within and without ; its upper extremity is fe- 
 cured in its place, by a fmall piece of wood, d t 
 pinned to the pneumatic veffel. 
 
 e. A fhort tube, of about the length of two 
 inches, below each inferior falfe bottom ; it does 
 not fuffer any gas to efcape from one cavity to the 
 other, excepting that portion which cannot in- 
 corporate 
 
Explanation of the Plates. 301 
 
 corporate with the water, either becaufe it may 
 already be nearly faturated, or becaufe too large 
 a quantity may be collected in the upper part of 
 each cavity, refpectively, for want of the agitator 
 being worked with fufficient frequency. 
 
 /. Pipes of lead, or ftone-ware ; they may 
 likewife be made of wood ; one of them paffes 
 through all the falfe bottoms, the other paffes 
 only through the uppermoft ; they ferve to intro- 
 duce, upon the bottom of each cavity, either 
 the quantity of potafh neceffary to fix the odour 
 of the muriatic acid, or that which may be necef- 
 fary to form the liquor, known under the deno- 
 mination of the oxygenated muriate of potafh. 
 Thefe two pipes are clofed during the distil- 
 lation, with a ftopper of cork ; their upper extre-, 
 mity, being formed fomewhat in the fhape of a 
 funnel, facilitates their fufpenfion and fupport ; 
 they mud be well fecured with fat lute, at the 
 place of contact, with the partition through which 
 they pafs. 
 
 g. The cover of the pneumatic veffel. It muft 
 be kept in its place by good pins of oak formed 
 with heads, and its joints all round muft be clofed 
 with ftrips of paper patted on The joints of the 
 feveral pieces or planks which compofe it, though 
 tongued together, are likewife covered with pa- 
 per: by means of thefe precautions, no fmell of 
 
 the 
 
302 Explanation of the Pla'i;. 
 
 the oxygenated acid exhales. In order likewife 
 that this vapour ihould not efcape through the 
 fmall fpace between the cover and the arbour of 
 the agitator, this laft is furrounded with a fmall 
 quantity of flax, or piece of rag, wetted, either 
 with common water, or a folution of pot-afh. 
 When the diftillation is begun, the opening 
 of the aperture of the funnel / muft be clofed 
 with a cork. 
 
 h. Supports of the adopter of the retort : 
 they reft on the cover of the pneumatic vef. 
 fel, and receive the upper extremity of the 
 tube, communicating with the internal part near 
 the bottomof the veflel ; this extremity is difpof- 
 ed in the form of a funnel ; i. To receive the 
 beak of the ad. pter; 2. To facilitate the applica r 
 tion of the lute. The two parts which compofe 
 the fupport are connected together, either with 
 Iron-wires, or pack-thread, or elfe by means of 
 hooks, i a hole to fuffer the air to efcape out 
 of the pneumatic velfcl when the water is pour- 
 ed in. 
 
 /. The veffel for immerfions, mounted on its 
 rollers J. m the reel to move the piece-goods 
 in the liquor, n its handle. the piece, or 
 good . pafiing over the reel, p the dotted lines, 
 reprefenting the cover. It may confifl either 
 of a cloth, thrown over the veflel after the 
 liquor has been poured in, or it may be much 
 
 more 
 
Explanation of the Plates. Tp$ 
 
 more fuitably and conveniently formed, by means 
 of two frames of light wood, with panes of glafs, 
 which open on the oppofite faces, and clofe to- 
 wards the upper part of the triangle, which they 
 form by their junction. In order that the odour 
 of the liquor may not be inconvenient to the 
 workman, at the time it is poured into the vefTels, 
 in thofe cafes, where it is not thought proper to 
 extinguish it; either by a certain dofe of fifted 
 chalk, or a proper addition of folution of pot-afh 
 in water,one of thefe frames has a proper opening 
 to fuffer the difcharging cocks to pafs through; 
 and thofe parts of this opening, which are not ac- 
 curately clofed, are afterwards fecured by means 
 of cloths tied round the cock itfelf. In order, 
 moreover, to avoid all fmell from the pipes, 
 communicating from the bottom of the pneumatic 
 vefTels to the veffels of immerfion, thefe may be 
 fo difpofed, as to convey the bleaching liquor 
 to the bottom of this laft, and caufe it to rife gra- 
 dually, inftead of pouring it in with agitation. 
 
 Fig. 3. — Perpendicular view of the grate, or 
 chafing-difh, upon which the coal and charcoal 
 a, which heats the capfules and retorts, is placed. 
 They may be raifed higher or lower by placing 
 them on one or more bricks. It is likev, ife very 
 eafy to take them out of the furnace by means of 
 the handle B, when it is required, from any caufi 
 
 whatever. 
 
304 Explanation of the Plates. 
 
 whatever, that the diftillation fliould fpeedily be 
 checked. 
 
 Fig. 4. — The elevation in pcrfpective of this 
 
 grate. 
 
 Fig. 5. — Plate of iron, which ferves as a door 
 to the furnaces. 
 
 Fig. 6. — The fame plate, or door, feen in pro- 
 file; a t a projection which ferves to raife it, or 
 place it ; b y borders, by means of which it refts 
 on the joints, formed by the upper bricks of the 
 furnace, which, at the time of its construction, 
 are left open for this purpofe. 
 
 Fig. 7. — Supports which furround the upper 
 extremity of the tube of lead, which receives the 
 beak of the adopter of the retort, or the retort 
 only, if the glafsman have made it all of one 
 piece. 
 
 Fig. 3. — Elevation, in perfpeclive,of the iron- 
 trough, which contains the mixture of muriate of 
 foda and manganefe, which is fet to dry, as 
 before defcribed, between the furnaces, under 
 the drying place, during the time of diftillation, 
 in order that it may be ready for the fubfequent 
 procefs. 
 
 Fig. 9. — Plan of the fame trough. 
 
 Plate the second. 
 Fig. 1. — A machine for grinding the glafs 
 
 (toppers of veffels and bottles, which are requir- 
 ed to be clofed, as it were, hermetically. 
 
Explanation of tie Plates, 30c 
 
 A^. A bottle with three necks. 
 
 B, The ftopper fitted to clofe the middle 
 neck. 
 
 C. A kind of brace, one extremity of which 
 has its centre of motion in the wooden Aider E, 
 and the other extremity F receives in its focket 
 G, the ftem H, of the prefs I, the two jaws of 
 which, I, K, hold faft the knob of the ftopper, re- 
 quired to be ground in. The Aider of wood E is 
 not fixed, but muft rife or fall according to the 
 wear of the ftopper in the neck of the bottle, in 
 which it is intended to be fitted. 
 
 Fig. 2 and 3.— Plan and profile of a veflel, for 
 immerfing thread ftockings, or other pieces of 
 frame-work knitting ; if, inftead of the round 
 figure, this veflel had been made fquare, the 
 goods might have been ftowed in a more advan- 
 tageous manner. Three bafoets of white wicker- 
 work may be placed one upon the other, as is 
 fhewn in figure 2, each upper bafket reding on the 
 handles of that beneath. B, a bundle, or hank, 
 of flcains of thread fpread out in the bath : there 
 muft not be more than three or four ofthefe con- 
 nected together in the fame bundle, as,other- 
 wife, they would be lefs conveniently expofed to 
 the action of the bleaching liquor, and lefs eafily 
 wrung orcleared out. In order that no dirt may 
 fall into the veflel, and to prevent any oppreflive 
 
 x vapour 
 
306 Explanation of the Plates, 
 
 vapour from incommoding the workmen, the> 
 whole is covered with a piece of cloth, deftgned 
 for this purpofe; or, rather, with a light cover- 
 ing of wood, cut into two pieces, to facilitate 
 the management. 
 
 Fig. 4 and 5. — Plan and elevation of a fmal] 
 portable boiler for the purpofe of immediately 
 Doiling the thread in. alkaline lees, or any other 
 fmall articles, which either cannot with conveni- 
 ence, in point of time, or otherwife, be put into 
 the large boiler with piece-goods, or other articles, 
 whether on account of their finenefs, their fmall 
 quantity, the fpeed required, or their being the 
 obje£t of fome particular experiments. 
 
 a. The boiler, placed on its tripod, £, under 
 the mantle of the chimney ; c its cover, which 
 muft never be neglected to be put on, not only 
 becaufe the heat is more fpeedily produced, but 
 likewife for the purpofe of defending goods from 
 foot, which may fall down the chimney, and 
 would produce fpots not eafily discharged, as has 
 been mentioned in chap. 15. This boiler may 
 be heated by means of wood, or turf, or pit-coal, 
 if a proper grate may be made ufe of. 
 
 Fig. 6. — The method of fufpending, by means 
 of an arbor D, the bafket, containing the articles 
 taken out of the boiler, and draining over it. In 
 order that no impurities may fall either into the 
 
 lees, 
 
Explanation cf the Plates. 307 
 
 lees, or upon the goods, during this operation, 
 it will be proper that a clofe cloth, or frame of 
 light wood, fhould be fupported in that part of 
 the pipe of the chimney which is immediately 
 over them. 
 
 e. The bafket, or plat form, of ofier, fupporting 
 the goods ; this plat-form may likewife be made 
 of iron, covered with linen rags : if a bafket be 
 ufed, it muft be perfectly cleared of its bark, for 
 fear of fpotting the goods. 
 
 The four cords f t which fupport the bafket, 
 are united in pairs, on each fide, at the knot g t 
 to the cord h, which winds on the arbor. 
 
 j. Supports, between which the arbor turns. - 
 k y a clump fattened on the arbor, to prevent its 
 recoiling from the fupport i, in confequence 
 of the fri&ion upon m. n> the handle of the 
 arbor. 
 
 Fig. *j. — Rollers, for the purpofe of folding 
 piece-goods into lengths, after they have received 
 the dreflings. 
 
 a. Cords, one extremity of which is attached 
 to the ring b> fixed to the cieling, and the other 
 extremity bears the two gudgeons of the 
 wooden roller d. 
 
 e. Part of the piece of cloth, to be folded in 
 two. 
 
 /. Part pf the cloth already folded. In this 
 x 2 operation, 
 
3^8 Explanation of the Plates. 
 
 operation, which is very fpeedy, the cloth is 
 fupported by holding one part, /, in one hand, 
 and the other part, e, in the other, taking care to 
 bring the edges together by raiting this part of 
 the cloth thus joined a little, the weight of the 
 folded part, foon draws over that part to the 
 other fide of the roller, a new portion is fuccef- 
 iively folded, and is thus fubjected to the fame 
 manipulation. 
 
 Fig. 8, 9. — Plan and profile of a machine for 
 folding cloths in equal folds, whether it be re- 
 quired that the folds mould be in the whole length, 
 or that they mould be folded in two, as has al- 
 ready been obferved. 
 
 a. Uprights of iron, placed oppofite each 
 other, in the holes b, in the brafs c, fixed on 
 each fide of the table d. 
 
 e. Reds of iron, or wood, placed in each fold 
 of the cloth behind the two uprights. 
 
 /. Another rod, which raifes from the heap 
 of cloth, g, that part which is to be carried be- 
 hind the upright, over the rods. In proportion 
 as the folding advances, the lower rods are drawn 
 out to be ufed in the progrefs of the work. By 
 this means the operation may be performed with 
 a dozen rods. The ufe of thefe rods, and the 
 regularity which they afford in this method of 
 folding, which is very expeditious, has caufed it 
 
 to 
 
• Explanation of the Plates: 309 
 
 to be named folding by the rod, in the fame 
 manner as that defcribed in figure 7 is named 
 folding by the roller. 
 
 Fie. 10. — End view of the manner in which 
 the pieces are folded together after they are 
 taken from the machine, fig. 9 : the round fold, 
 which is given to the piece, is fecured by means 
 of firings, more or lefs fine, a a t according to 
 the quality of the merchandize. Thefe cords, 
 firings, or twift of filk, or flax, pafs from the up- 
 per felvedge to the lower ; they are faftened to- 
 gether with a knot, which is, la ft of all, covered 
 with a taffel, b, of coloured thread, of filk, or 
 linen, or thread, according to the beauty and 
 flnenefs of the piece. Coarfe goods are likewife 
 faftened in front, as is (hewn by the letter C. ' 
 
 Fig. 11.— Hanks of linen or cotton thread; 
 the union of feveral fkains, that is to fay, frve or 
 fix by a fingle firing, a, forms what is called a 
 hank : by the number of knots, b, made in 
 one or other of the two ends of the firing, 
 the bleacher diftinguiihes the merchant to 
 whom the article belongs. For this purpofe 
 the diftinclive figns are entered in a book, oppo- 
 fite the name of the proprietor. With regard to 
 other articles, fuch as piece-goods, ftockings, 
 &c. they may be diftinguiflied by one or more 
 coarfe threads fewed to them, upon which any 
 x 3 number 
 
3 » o Explanation of the Plates. 
 
 number of knots at pleafure maybe made. This 
 method of marking goods appears to be much pre- 
 ferable to the different marks with crayons, red 
 oaker, &c. which always, more or lefs, fpot and 
 foil the goods. 
 
 Fig. 12. — Shews the method of rinfing the fkairt 
 on the pin to clear it of water, lees, or any other 
 fluid it may contain. As the part which is near- 
 eft the pin is not fo effectually wrung as that 
 which lies near the middle, care mud be taken 
 in opening the fkain, c, to icpkce it in fuch a 
 manner that the part which was upon the pin, 
 a, fhall be near the middle at the time of the 
 fecond wringing. After this fecond wringing, 
 the thread is, for the mofl part, dry enough, and 
 may be ftraitened out -, which is done by palling 
 it over the hand, and ftrongly jirking or mak- 
 ing it by drawing out ; or the operation may 
 be performed with the wringing-pin inftead of 
 the hand. 
 
 Fig. 13.— The method of difpofing the fkains, 
 fo that they may not intermingle too much 
 with each other, particularly thofe of fewing 
 thread, which, inftead of being wrung on the 
 pin, are worked under the lower part of a kind 
 of rammer or ftirrer. The four faftenings, a, pre- 
 vent the fkains from becoming intermingled dur- 
 ing this kind of fulling procefs. A tub or pail may- 
 be 
 
Explanation of the Plates. % 1 * 
 
 be ufed for this operation, according to the quan- 
 tity of the article, intended to be cleared in this 
 manner. A man or woman may work them 
 with the inftrument, fig. 14, without much dif- 
 ficulty : a certain degree of (kill and intelligence 
 is required to do the bufinefs in the molt effec- 
 tual manner. 
 
 a. Reprefents the handle of this inftrument, 
 and b, the lower part, which is made of beech 
 cut into fteps or notches, c, on each fide, in order 
 that it may take a flight hold of the goods, and 
 afford a facility in turning them. Thefe indenta- 
 tions muft be rounded at the edges and corners. 
 
 Fig. 15, 16. — Plan and elevation of a warn- 
 ing implement, with which {lockings, thread, 
 and other fmall and fine articles, may be cleaned 
 or rinfed in a tub or pail, a, exhibit the teeth 
 or feet, between which the different goods dif- 
 pofe themfelves, and are agitated againft each 
 other, for the purpofe of clearing them of the 
 different liquids, with which they are fucceffive- 
 ]y penetrated during the courfe of the bleaching. 
 b, is a double handle, by the affiftance of which 
 this fmall inftrument is moved. 
 
 Plate 3. Fig. 1. — a* Birds-eye view of the great 
 boiler, in which piece-goods are heated in the 
 alkaline folution or lees. 
 
 % 4 Fi 
 
 a* 
 
312 Explanation of the Plates. 
 
 Fig. 2. — Se&ion of the fame boiler through 
 the line A, B. 
 
 a. Floor of the (hop. 
 
 b. The mafonry, in which, the copper C is fet' 
 
 d, the wooden cover, formed of two or more part?. 
 
 e, crofs pieces which pafs under the cramps/, fix- 
 ed to the boiler itfelf, which keep down the co- 
 vering and prevent it from rifing by the force of 
 the ftream, which lad is, by thefe means, com- 
 pelled to re-aft on the pieces of cloth, or other 
 articles placed in the boiler. 
 
 g. A cavity or gutter furrounding the copper, 
 and ufed for evaporating without any other heat 
 than that which it receives from the boiler itfelf, 
 the old lees, which are referved after they have 
 been applied to every ufe, which can be made 
 of them, in order to recover the alkali. 
 
 h. A fmall boiler, heated by the heat which 
 efcapes from the great boiler, before it pafles 
 into the chimney. In this fmall boiler is kept 
 a quantity of lees, ready prepared, of the proper 
 flrensth. It here receives an increafe of tern- 
 perature, which prevents its fenfibly retarding 
 the boiling of the great boiler, when it is ne- 
 cefTary to convey a certain quantity into this 
 laft velfel. 
 
 i. A cock, by which the pure folution of al- 
 kali is drawn off, and may be conducted to 
 
 the 
 
Explanation of the Plates. 313 
 
 the great boiler, by a channel of tin or wood, 
 &c. &c. 
 
 j. The fire-place under the boiler. Inftead of 
 the iron-bars, or a grate, which, on account of 
 this diftance between them, fuffer too much air 
 to pafs, for the confumption of wood, and by 
 thefe means wafte much of that fuel, I have 
 preferred an arch of brick-work, with openings 
 of a fufficient fize. This arch, w T hile it faves 
 the wood, likewife preferves the heat, on ac- 
 count of the fpace between the vents, upon 
 which the burning fuel remains for a longer 
 time. It might perhaps be poffible to diminiOi 
 the expence ftill further, by having no apertures 
 at all through the arch. Thefe apertures are alfo 
 liable to be worn or broken, and require to be 
 defended at their edges with iron. 
 
 k. The afh-hole. 
 
 /. The chimney, proceeding from the fire- 
 place, immediately beneath the fmall boiler. 
 
 n. Stairs afcending from the floor, to the brick- 
 work of the floor. 
 
 0. Another fet of (lairs, leading to the plat- 
 form p. 
 
 q. A regifter for regulating the heat of both 
 boilers. 
 
 r. Flue of the chimnev. 
 
514 Explanation of the Plates, 
 
 Fig. 2' — Se&ion of figure 1, along the line 
 c d. a, the floor. b> the mafonry in which the 
 copper is fct. c t mouth of the fire-place of the 
 great boiler, d, lower part of the chimney, 
 e, afh-hole. /, regifter, to regulate the heat of 
 the fmall boiler, g, the flairs from the platform 
 of the mafonry to the floor of the work-fhop. 
 b, ftairs leading to the upper part of the ma-» 
 fonry. 
 
 Fig. 4. — A crane, moveable on its axis, pro- 
 vided with tooth and pinion-work, by means of 
 which the charge of the boiler, confifting of 
 piece-goods, or other articles, may be raifed. 
 a, the (haft, b, the pivot, c, the arm. d, 
 bracket, or fupport. e, a ratchet wheel, worked 
 by a pinion with a double lever: round the 
 barrel of this wheel is wound the chain, at 
 the other end of which are three or four hooks, 
 in which the chains h are held. Thefe laft are 
 covered with cloth or cord, to prevent the ef- 
 fect of ruft. The intermediate part between 
 the two concentric circles, which form the 
 veflel, or fufpended apparatus, is likewife de- 
 fended by fmall cords, in order that the various 
 articles difpofed therein may not efcape ; this 
 (lage, charged with the different articles which 
 have undergone lixiviation, is, by means of the 
 
 crane, 
 
Explanation of the Plates. 315 
 
 crane, conveyed over other veffels, where it is 
 lowered down upon crofs pieces, in order that 
 the drainage may be completed. 
 
 Fig. 5, 6, 7. — Plan, feclion, and elevation, 
 of an oven for calcining crude alkali, in order 
 to convert it into potafh. a 9 flairs, which lead 
 to the back part of the oven, where there arc 
 placed two boilers of caft-iron, b b, in which 
 the alkali is dried, after having been concen- 
 trated to a certain degree in the cavity furround- 
 ing the great boiler. See Fig. 1, 2. Thefe 
 two boilers may be appropriated alternately to 
 dry the alkali entirely, whence it is to be con- 
 veyed into the calcining oven ; and afterwards 
 to complete the reduction of the concentrated 
 alkalies to the confidence of extract ; and may 
 Jikewife be difpofed in fuch a manner that 
 the flame which they receive from the fire- 
 place of the oven, before it palTes into the 
 Jower part of the chimney, may heat a third 
 boiler of caft-iron, -of copper, or even of lead, 
 which may be ufed to evaporate the old lees, 
 or folutions of foap: for thefe lad: require the 
 fame management in order to obtain their at- 
 knli. 
 
 This concentrated alkaline folution from the 
 tipper boiler, may be fuffered to fall, drop by 
 drop, into the lower, in order that the evapora- 
 tion, 
 
3 1 6 Explanation of the Plates. 
 
 tion, or complete drying, may not be impeded 
 by too much water being fuddenly poured in. 
 
 c. Paflage from the fire-place to the fpace 
 beneath the caft-iron boilers. It conveys a 
 ftream of flame, which is more than fufficient, 
 and may be governed by means of regifters. As 
 this paflage is conftructed on a flope, which, 
 for that reafon, is not eafy to be made in the 
 mafonry, a contrivance was ufed during the 
 building of the roof of the fire-place, to fix in 
 the proper place a roller of wood, upon which 
 the bricks in part refted which were intended 
 to form this paflage ; it may eafily be imagined 
 that this wooden roller could not be taken out 
 after the conftruction was fini fried ; it was, 
 therefore, intended that it mould be burnt out. 
 To accelerate the combuflion at that time, and 
 during the heating of the oven, a hole of two 
 or three inches in diameter was bored through it. 
 This piece of wood may be of white deal, or any 
 other material which is mod readily confumed. 
 The heat conveyed by this paflage, of which I 
 have afcertained the good effect by experiment, 
 is very well regulated by means of a regifter 
 made at the bottom of the fpace immediately 
 beneath the boiler. This regifter is entirely 
 fhut when the boilers are not intended to be 
 ufed. 
 
 When 
 
Explanation of the Plates. 317 
 
 When the calcining oven is not ufed, but 
 the boilers are wanted to dry alkaline folutions, 
 thefe laft may be feparately heated by a fire 
 between both. 
 
 d. An aperture in the roof of the oven, through 
 which the dried alkali is conveyed into the 
 oven. 
 
 e. The calcining oven. In order that the 
 alkali may be eafily difengaged from the edges 
 or angles of the floor where the walls take their 
 rife, at which place it readily fixes itfelf by the 
 aqueous fufion, it is advifeable that this part 
 fhould be defended by a plate of iron, four or 
 five inches high, and about half an inch thick. 
 By this means the fait is more eafily feparated 
 by the rake. 
 
 /. The ftoke-hole for fupplying the fuel. It 
 is conftru£ted in the fame manner, and for the 
 fame ufes, as that of the boiler for lixiviation. 
 
 g. A flight piece of brick-work, between 
 the fire-place and the hearth of the oven, which 
 prevents the fuel and the faline matter from 
 communicating or mixing with each other. 
 
 h. A done or cafl-iron trough, into which the 
 red hot calcined alkali is thrown when taken 
 out of the oven. In this veflel it is left to cool 
 before it is packed up in calks, in which laft 
 veflels it mud be prefled as clofely as poffible, in 
 
 order 
 
3 1 8 Explanation cf the Plates. 
 
 order that it may be lefs liable to attract moiflure 
 from the air. 
 
 /. The mouth of the oven. It has two iron 
 uprights, j j, forked at top, in which the ends 
 of a racked bar k are placed. The handle of the 
 rake, with which the alkali is ftirred, is refted 
 between the notches of this bar. The mouth 
 of the oven is alfo provided with an iron plate, 
 to be ufed either for clofing it entirely, or more 
 or lefs, as occafion may demand. 
 
 Inftead of fufFering the heat, which ifiues 
 from the mouth of the furnace, to be loft, it 
 may be very advantageoufly directed by a pipe 
 rifing under the boilers of call-iron, or thofe 
 which are placed above, for preparatory eva- 
 poration. None of thefe means ought to be 
 neglected of employing the heat, which in al- 
 mod every conilruclion of this kind has been 
 hitherto loft, for want of a proper degree of 
 fkill in the proprietors, or thofe who undertake 
 to erecl them. 
 
 Fig. 8. — Reprefentspart of the chain, which is 
 wound upon the drum of the ratchet-wheel of 
 Fig. 4. It may be obferved, that it is con- 
 ftrucled on the fame principles as the chains of 
 pocket watches. 
 
 Fig. 9, 10, and n.— Details relative to the 
 
 racked 
 
Explanation of the Plates, 3T9 
 
 tacked bar placed acrofs the mouth of the cal- 
 cining oven. 
 
 a. The teeth, between which the handle of 
 the rake is moved, b, an elbow, which pre- 
 vents the rake from moving the bar fide-ways 
 when once duly placed, r, crampons, or iron 
 fixed pieces, whieh receive and {ready the up- 
 rights, d, the mafonry of the oven in which 
 they are placed, c, the rake feen fide-ways, 
 /, its claw placed on the floor of the oven, g, its 
 iron handle, h, the external part of its handle, 
 which is made of wood, becaufe the iron would 
 communicate the heat too readily to the hand of 
 the workman. Fig. 11. the claw of the rake 
 feen in face. Fig. 12. an hook, by means of 
 which the rake is lifted up or changed for an- 
 other, either on account of its being too hot to 
 be touched, or in danger of bending, a, the 
 hook, b 3 its handle. In order that the iron 
 handle of the rake may Hide more readily be- 
 tween the teeth of the crofs-bar, it is occafion- 
 ally rubbed with a piece of bacon nailed to a 
 fmall piece of wood. 
 
 PLATE THE FOURTH, 
 
 Fig. 1.— Elevation of a miH proper to cleanfe 
 piece-goods and other articles, which are more 
 
 or 
 
3 20 Explanation of the Plates. 
 
 or lefs bulky. It is moved by a horfe ; or its 
 mechanifm may be fet in motion by wind, wa- 
 ter, or other powers, by making fuitable ar- 
 rangements for that purpofe. 
 
 A, the principal thaft. B, the bar, to which 
 the horfe is attached. C, the wheel. D, lan- 
 tern. E, the arbor, which gives motion to 
 the flocks or peftles E, by means of certain 
 tripping pieces. See Fig. i. and 2, Plate V. 
 F, mortices, in which the tripping pieces move 
 to raife the peftles. It is advifeable that the 
 part which is a£ted upon by the tripping piece 
 ihould be defended, either by a plate or roller 
 of copper. G, crofs-pieces, between which 
 the peftles rife and fall. H, the box or recep- 
 tacle, in which the goods are placed. The 
 figure reprefents the internal part, in confe- 
 quence of a portion of the wood-work in front 
 being removed. One of the fpaces is larger 
 than the other, for the purpofe of fubdividing 
 the different kinds of work. The receptacle is 
 commonly made of elm, and the rammers of 
 beech. I, holes made at different heights, to 
 draw off the water. J, a door, which may be 
 taken down or put up at pleafure by means of 
 buttons. It mult always be up during the time 
 of work. K, a pipe, which fupplies the work 
 with water. Out of this proceed a number of 
 
 fliort 
 
Explanation of the Plates. 321 
 
 jhort pipes anfwerable to the refpective cham- 
 bers. L, a ftop, to prevent the peftle from 
 defcending too low, and injuring itfelf. M, a 
 lever fixed to a crofs-piece, N, behind the 
 four uprights, O. By means of the pin P, and 
 the firing Q, the fulling rammer may be raifed 
 fo high, that the tripping pieces cannot reach 
 it. While it remains thus fixed, the goods 
 may be examined or taken out, as occafion may 
 require. 
 
 Fig. 1 and 3 A fucking-pump, which fur- 
 
 nilhes the water to the work. Fig. 2, fhews the 
 fame in profile, and Fig. 3, the front view. 
 
 A is the extremity of the arbor which works 
 the fulling apparatus. B, prolongation of the 
 axis or pivot of this arbor. It turns on the 
 brafs bed C ; and its extreme part D is bended 
 into a handle, which gives motion to the pump, 
 rods E F. The latter is attached to the ftem of 
 the pifton which moves in the body of the pump. 
 H. I, the pipe, which fupplies the refervoir J 
 with water. K, the pipe which conveys the 
 water to the fulling works. 
 
 PLATE THE FIFTH, 
 
 Plan and elevation of the fame machine for 
 wafhing and cleanfing piece-goods. A, the 
 
 y turning 
 
322 Explanation of the Plates. 
 
 turning arbor, with its tripping pieces B. C, the 
 mortices, in which the tripping pieces enter to 
 raife the hammers. D, holes, through which 
 the rammers traverfe. E, bolts, which hold 
 together the lateral partitions, and connect them 
 with the uprights F. G, the fulling rammer, 
 refting on its ftop H. I, the lever, to throw 
 the fulling rammers in or out of work. The 
 dotted lines J denote the pofition of the levers 
 when the work is flopped. The cord K being 
 fattened to the hook L, keeps the lever in this 
 pofition; but when M is fixed to the fame 
 hook, it keeps the lever clear of the working 
 bar. N, the infide of the receptacle for the 
 goods. O, holes for drawing off the water. 
 F, the door. Q, the pipe which brings water 
 to the work. R, a table, on which the goods 
 are laid before or after they have been put into 
 the engine. T, a board to defend the work- 
 man frOm being wetted. 
 
 Fig- 1. — A, the principal arbor, with its 
 tripping pieces B. This figure fhews in what 
 manner they are difpofed in order to produce 
 their alternate effects on the rammers. 
 
 Fig. 3«— Plan of the wheel fixed on the up- 
 right (haft, which ferves to fhew the manner 
 of its conftruclion. 
 
 Fig. 4. — The lantern which moves the arbor. 
 
 A, reprc- 
 
Explanation of the Plates. 323 
 
 A, reprefents the arbor itfelf, upon which the 
 lantern it folidly fixed. The bolts B connect 
 the two drum-heads. 
 
 Fig. 5, (hews the method of difpofing the 
 goods in the trough of Fig. 1, when it is more 
 particularly intended to work them acrofs their 
 length. Fig. 6. The method of difpofing them 
 when, on the contrary, it is intended to work 
 them in the direction of their length. 
 
 PLATE THE SIXTH. 
 
 Fig. 1, 2. — Plan and profile of the machine 
 for fquaring and rolling out the pieces after they 
 have received the dreffings. a, the flage on 
 which the goods are placed, b, the piece folded 
 back and forwards. c } the ftretcher, through the 
 mortice of which the cloth pafles. At one of 
 its extremities there is a ratchet-wheel, a 7 , by 
 means of which the neceffary tenfion is given, 
 that the cloth may undergo a flight degree of 
 fricVion againft its rounded edges during its 
 courfe. <?, crofs pieces, at fuch a diftance from 
 each other, that the cloth, by pairing alternately 
 over one and under the other, may be gently 
 rubbed againft their blunted edges. f 9 another 
 ftretcher, through the mortice of which the piece 
 likewife paftes before it arrives at the wooden 
 y 2 cylinder. 
 
3 -4 Explanation of the Plates » 
 
 cylinder. This is likewife provided with a 
 ratchet-wheel, g, for the purpofe of ftretching 
 the cloth more or lefs. As the tenfion is consi- 
 derable in this part, there is a lever, h, fixed 
 on for the purpofe of facilitating the turning, 
 z, a cylinder or roller of wood, upon which the 
 cloth is rolled, and left for a longer or ihorter 
 time, as may be necefiary for it to keep the 
 figure and dimenfions which it has received. 
 The workman, who itands before this roller, 
 takes care for this purpofe to arrange and draw- 
 out the felvedges in fuch a manner that they 
 may apply at every turn upon the fame parts of 
 the cloth which are already rolled, and preferve 
 the fame width throughout. /', a moveable 
 piece, which may be thrown forward, and 
 ferves to keep the roller in its place endways, 
 and when drawn back, leaves it at liberty to be 
 taken out for the purpofe of unrolling the cloth. 
 A. groove is made lengthways in the roller, for 
 the purpofe of fixing the end of the cloth 
 therein, which is firir. wrapped round a wooden 
 rod, and then lodged in the groove. /, brafs 
 rollers, upon which the wooden cylinder turns. 
 m> the fquare, into which the fquare end of the 
 cylinder is lodged. », wheel of the arbor, which 
 carries the fquare. c. the lantern or pinion, 
 hlch gives. motion to the wheel, and is itlelf 
 
 carried 
 
Explanation of the Plates. 325 
 
 carried round by the handle p, worked by one 
 or two men, according to the force or velocity 
 required to be exerted, q, a fly, armed with 
 balls or plates of lead, which ferves as a refer - 
 voir of force, and greatly affifts the workman, 
 j, a trough of plate-iron, in which hot embers 
 are put for the purpofe of drying, or giving a 
 proper degree of firmnefs to certain goods be- 
 fore they are rolled on the cylinder, upon which 
 they preferve the ftate and appearance it is in- 
 tended they mould receive. 
 
 Fig. 3 and 4. — Plan, fection, and profile, of 
 the earthen furnace, made au rue Mazarin, of 
 which mention is made in Chapter II. a, the 
 furnace. I/, the am-hole. c, the door of the 
 afh-hole. d, the fire-place, e, door of the fire- 
 place. /, grate of earthen-ware ; inftead of which, 
 if preferred, a grate of iron may be fubftituted. 
 g, the chimney. h, a protuberance for more 
 ealily removing the furnace, i, the pot. /, fand- 
 bath. m, tubulated bottle, containing the mix- 
 ture for diftillation. Inffcead of the bottle, a 
 tubulated retort may be ufed, which, in that 
 cafe, may be placed in a bath fuited to its figure. 
 n, the neck, to which the tube of lead is to be 
 adapted, for the purpofe of conveying the gas 
 into the pneumatic veflels. 0, the aperture, into 
 which the fulphuric or muriatic acid is to be 
 
 y 3 poured, 
 
326 Explanation of the Plates. 
 
 poured, accordingly as the diftillation is per- 
 formed with or without the muriate of foda. 
 f y a ftand or bafe of ftone, upon which the fur- 
 nace may be raifed, either for the purpofe of 
 giving it a proper elevation, or to prefervc the 
 floor from the danger of fire. 
 
 This kind of furnace is ufually compofed of 
 one fingle piece , but for the facility of remov- 
 ing and fixing them, when conftructed of a cer- 
 tain fize, they ought to be formed of fevcral 
 pieces which may be eafily fixed together by 
 means of indentations made in them before 
 they are baked. 
 
 plate the seventh. 
 
 Fig. t, 2, and 3. — Bird's-eye view, elevation, 
 and profile, of the machine for calendering piece- 
 goods with or without heat. A, a double handle 
 which gives motion to the pinion B. This ma- 
 chine, as well as the one juft defcribed, may 
 eafily be moved by connecting it with the ful- 
 ling mill, in the fame manner as the pump re- 
 ceives its motion, namely, by a branch or tum- 
 bler, which on the one hand is applied to the 
 arbor of the mill, and on the other to the leading 
 axis of th« machine. It is neceflary of colirfe 
 to arrange the workfhops accordingly. The 
 
 pinion 
 
Explanation of the Plates. 327 
 
 pinion drives the toothed wheel C ; on the 
 axis of which is fixed the lantern or pinion P, 
 which moves the great wheel E, to which is 
 adapted the brafs cylinder F, and this in its turn 
 communicates its motion to two cylinders of 
 walnut-tree G. 
 
 H, the ftage upon which the piece I is placed 
 ready for calendering, having previoufly receiv- 
 ed all the other dreffings ; it is folded, as the 
 figure mews, in alternate folds, in order that it 
 may be more eafily delivered. It firft paries 
 between the crofs-pieces J, thence through the 
 mortice K, of the ftretcher L, which is provided 
 with a wheel and click, M, to flretch the piece 
 more or lefs and regulate its courfe. It after- 
 wards paffes back under the brafs cylinder N, 
 over that of walnut-tree, and returns in front 
 under the upper wooden cylinder, which it en- 
 velopes as it paffes over and falls behind O of 
 the machine on the roller P, and againft Q, 
 where it is ranged in alternate folds on the 
 ftage R, whence it is taken to be regularly made 
 up for fale. 
 
 S. The prefling fcrew, by means of which the 
 upper wooden cylinder may be urged more 
 flrongly againft that of brafs, accordingly as it 
 js required that the face of the cloth iliould be 
 niore or lefs acted upon. 
 
 \ r 4 T. Piece 
 
328 Explanation of the Plata. 
 
 T. Piece of caft-iron, which Aides in grooves 
 made in the uprights U, and bears upon the 
 pivot V of the upper cylinder, accordingly as 
 the fcrews prefs upon the crofs- piece X, to 
 which this piece of call-iron is fixed. 
 
 Fig. 4. — The brafs cylinder feen at one end, 
 where it is open to receive the bars of red-hot 
 iron which heat it. 
 
 A. The cylinders of wood to which the brafs 
 cylinder communicates its motion. Inftead of 
 wooden cylinders, others may be fubftituted of 
 card-paper, compofed of the quantity of leaves 
 necefTary to fill the fpace which is determined 
 between the plates of brafs adjufted at the ex- 
 tremity of their axis. They are ftrongly preffed 
 by thefe plates, which are retained in their pofi- 
 tion by powerful fcrews. Cylinders of paper, 
 properly turned, give to fine goods a glaze which 
 they cannot acquire by the wooden cylinders. 
 They have likewife the advantage of retaining 
 their figure, which is not the cafe with wooden 
 cylinders. Thefe lafi: require to be occafionally 
 rectified in the lathe, and at laft become too 
 fmall for ufe. 
 
 The lathe ufed for turning any of thefe cylin- 
 ders ought to be conftru£ted in fuch a manner, 
 as to render it a matter of certainty that the 
 
 diameter 
 
Explanation of tbe Plates. 329 
 
 diameter fhould continue equal from one end 
 to the other. 
 
 B. The cylinder of brafs. 
 
 C. The neck on which it turns in the manner 
 of a pivot. 
 
 D. The aperture through which the bars of 
 red-hot iron are introduced with tongs. The 
 aperture is then clofed with a cover to keep in 
 the heat. 
 
 U. The uprights between which the brafs 
 cylinder moves againft the plates V. 
 
 Fig. 5. — The form of the pieces of caft-iron 
 with which the cylinder is heated. Two are 
 commonly put in, and they are ufually changed 
 every hour, or oftener, according to the nature of 
 the work. 
 
 PLATE THE EIGHTH. 
 
 Fijf. 1 and 2 Plan and fection of a veffel 
 
 particularly defigned for fubmitting fine piece- 
 goods, fuch as muflins, linens, &c. to the ac- 
 tion of the oxygenated muriatic acid. 
 
 a. A frame armed on each fide with fmall 
 leaden points or pins, b, the central parts of 
 which are iron ; they may be altogether of iron, 
 painted with white lead, and well wrapped with 
 ftrips of linen or itring. Thefe points are of 
 
 ufe 
 
33° . Explanation of the Plates. 
 
 ufe to fufpend the piece-goods in a zigzag form, 
 as is fhewn by thefe figures, either immediately 
 by the felvedge of the piece, or by loops of tape 
 fewed to the pieces themfelves. 
 
 c. Rings of lead cad upon rings of iron, which 
 they cover; otherwife rings of iron alone, paint- 
 ed with white lead, and wrapped with cloth 
 or twine to defend them from the mil. The 
 cords e> w T hich are faftened to thefe rings, pafs 
 over hooks at d, fixed to the cord/, which, by 
 means of the pulley £, is ufed to raife or lower 
 the frame. When the latter is entirely plunged 
 in the bleaching liquor, the cords are detached 
 from the hook g, and the veilel is covered to 
 prevent the introduclion of any impurities, as- 
 well as to defend the workmen from any dif- 
 agreeable odour. 
 
 An apparatus of this kind may be ufed, not 
 only for immerfmg of the goods in the oxvge- 
 nated muriatic acid, but likewife for the lees, 
 as well as the bath oi" fulphuric acid, 8cc. 
 
 Fig. 3 and 4. — Elevation and profile of the 
 frame for ftrctching the fkains of thread when 
 taken out of the bleaching veflels. A, upright 
 pieces, in which a number of holes, B, are 
 pierced for the purpofe of fupporting C, the 
 crofs-pieces, over which the fkains of thread, 
 D, pafs fingly. Thefe crofs-pieces have th< ir 
 
 angles 
 
Explanation of the Pla'es. 331 
 
 angles well rounded, and are fet at a greater 
 or lefs diftance, according to the degree of ten- 
 fion to be produced, by means of the iron pins 
 inferted in the holes of the uprights. 
 
 The thread is firft well wrung upon the pin, 
 or with the hand, after which ii is fh-etched 
 upon the pannel, and left to dry. Care muft 
 be taken that thofe Ikains which are put on at 
 any one time fhall all be of the fame length, in 
 order that the tenfion may be equal throughout. 
 
 If thefe threads, when taken out of the 
 bleaching veflels, fhould be fo entangled or 
 mixed as to feem incapable of being cleared 
 without breaking, they may eafily be brought 
 to their original ftate by plunging them in water, 
 and gently finking them with the edge of the 
 hand. This operation may, if thought fit, be 
 repeated at each immerfion, in cafe it fhould 
 be fuppofed that the thread would be too dif- 
 ficult to clear after the entire bleaching-. 
 
 The fkains of thread, thus adjufted and dried, 
 are afterwards twifted together in dozens or 
 fcores, or any other count, according to the 
 cuftom of the market ; or they may be packed 
 in fmall parcels in coloured paper, according 
 to their quality, and the orders of the vender. 
 
 Fig. 5, 6, 9, 10.— Plan, profile, and parts of 
 the machine for fcorching or fingeing muflins, 
 
 and 
 
332 Explanation of the Plates. 
 
 and other piece-goods, which are particularly 
 required to have an even face fimiJar to goods 
 of the fame kind imported from England. 
 
 A, ports fixed in a cavity, B, in the pave- 
 ment y or floor of the workfhop. They are con- 
 nected by the crofs-pieces, C, fixed at their up- 
 per extremities by the bolts or fcrews D. Thefe 
 pofls may be taken up at pleafure, in order to 
 leave more fpace in the workfhop. E, axis of 
 a roller placed between each poll, the pro- 
 longation of which is bended into a handle, F, 
 for regulating the tenfion of the piece by the 
 ratchet-wheel G. A fhort piece of cloth or can- 
 vas, H, is nailed to each of thefe rollers, and to 
 thefe the extremities or ends of the piece to be 
 finged are fixed with the needle or rod of iron, K. 
 One of thefe rollers takes up that part of the 
 piece which is finged, while the other gives off 
 or unfolds a new length to be fubje&ed to the 
 fame operation. 
 
 L, the bended iron, with which the fingeing 
 is performed by palling it over the furface, from 
 one edge to the other, in a light, fpeedy, and 
 dextrous manner. The flat part M being firft 
 made very hot, is well wiped on a cloth or pad, 
 in order that it may not foil or greafe the piece, 
 which laft action would endanger its being 
 burned. This iron is to be pafled two or three 
 
 times 
 
Explanation of the Plates. 333 
 
 times over the extended part of the cloth, in 
 order that it may produce its effect more uni- 
 formly. 
 
 If the piece require to be finged on both 
 fides, it muft be afterwards turned, by chang- 
 ing the rollers M for N. The brown fcorched 
 colour which the piece acquires by this treat- 
 ment fpeedily disappears in the bleaching. 
 
 Fig. 7 and 8 A plate of call-iron, viewed 
 
 in face and edgewife, which is advantageoufly 
 ufed to fmooth or lay the nap of certain piece- 
 goods, fuch as velverets, fuftians, coverlets, &:c. 
 This plate is heated to the proper degree ; and 
 one or two men, according to the weight and 
 dimenfions of the plate, and the nature of the 
 fluff, pafs it along, more or lefs fpeedily, over 
 the piece intended to be thus ironed or fmoothed. 
 The fame care mult be taken to wipe the plate 
 when it comes out of the furnace as was de- 
 fcribed for the fingeing. The handles, B, of the 
 plate, are wrapped round with cloth, in order to 
 defend the hands of the workman. 
 
 Fig. 14. — -A bru(h,with ihort hair, ufed to raife 
 the fibres or nap of the piece-goods intended to 
 be fubje£ted to either of the operations here 
 defcribed. 
 
 Fig. 11,12 and 13. — Plan, elevation, and fec"H- 
 on of a prefs proper for drying or expreffing the 
 
 Water 
 
334 Explanation of the Plates. 
 
 water from piece goods, whether in the courfe 
 of the f veral operations, or at the end of the 
 bleaching procefs. This prefs may like wife be 
 employed to advantage, to give a neat appear- 
 ance to folding goods, or for the clofe packing 
 of bales. 
 
 A. The platform or table of the prefs upon 
 which the goods are placed. This table is hol- 
 lowed out to the depth of one inch, and is in- 
 clined towards the gutter or beak, B, in order 
 that the waters which flow from the goods may 
 be received in a pail placed underneath for that 
 purpofe. 
 
 C. The preffing fcrews which rife and fall be- 
 tween the uprights, D, in order that the whole 
 furface of the table may be left clear. 
 
 PLATE THE NINTH. 
 
 Fig. i and i. — Plan and fecrion of the dif- 
 tilling apparatus mentioned at the commence- 
 ment of this work. 
 
 A. The double furnace with its fixed grate. 
 B a cover of plate-iron of a fquare or round 
 figure with Bat edges, which may be raifed or 
 placed in contact with the furnace. C the fand 
 bath whieh furroands the capfule ; it ought to 
 be verydry> fine and uniform. D, the cylindrical 
 
 bottle 
 
Explanation of the Plates. 335 
 
 bottle with two necks ; one in the middle, E, to 
 receive the ftem, F, of the communication of 
 the pneumatic veffel, and the other for pouring 
 in the fulphuric acid, when muriate of foda is 
 ufed, or the common muriatic acid, if that fait 
 be not applied. Inftead of the cylindrical bottle, 
 a balloon, or globular veffel with a neck on one 
 iide, may be ufed, as is (hewn in figure 2. The 
 choice of thefe veffels will, in a great meafure, 
 depend on the fkill of the workmen, at fuch 
 glafs manufactories as may be in the neighbour- 
 hood of the bleaching works. In ftrictnefs, the 
 neck or tube on one fide may be difpenfed with, 
 and it is here mentioned only becaufe it adds a 
 convenience to the operation. 
 
 From thefe obfervations on balloons, it is eafily 
 feen, that thofe who, in purfuance of the dire£ti- 
 onsin the memoir upon bleaching, in the fecond 
 volume of the Annals of Chemiitry, may have 
 ufed the mattras, the neck of which fooner or 
 later muft break at the termination of the 
 chimney of the dome of the furnace there re- 
 commended, may afterwards ufe thefe globu- 
 lar veffels with advantage. 
 
 J. The door or opening to the fire-place. 
 
 Inftead of glafs bodies, it might probably be 
 of advantage to ufe leaden veffels heated by a 
 water-bath, or in any other manner which would. 
 
 not 
 
336 Explanation of the Plates. 
 
 not endanger the fufion of thofe vefTels. This 
 danger would be lefs to be feared when manga- 
 nefe and the muriatic acid were ufed alone ; 
 but vefTels of this kind would always have the 
 difadvantage of not allowing the operator to fee 
 what paffed within them, as he may with glafs, 
 nor whether the vefTels were well cleaned. Thefe 
 two inconveniences, which can hardly admit of 
 any remedy, unlefs a glafs could be fixed in the 
 upper part, have hitherto prevented me from 
 ufing them, though they might, probably, be at- 
 tended with very confiderable advantages. 
 
 K. The afh-hole ; this is clofed in the fame 
 manner as the aperture of the furnace, by Aiding 
 doors ; or more limply as has been defcribed in 
 the explanation of the furnace exhibited in 
 plate I. 
 
 G. A tube of lead formed all of one piece, 
 without folder, and caft at one Tingle pouring, 
 or feveral fucceffive pourings like water pipes in 
 copper moulds. It may alfo be caft very fhort 
 at one (ingle pouring, provided it be made thick 
 enough to be afterwards drawn out. TheTe 
 fucceffive drawings reduce its thicknefs to a An- 
 gle line, while its internal diameter is kept at 
 feven or eight lines, which proportions are very 
 convenient. This pipe is fixed in the pneumatic 
 veflel in fuch a manner that it may be freely 
 
 raifed 
 
Explanation of the Plates. 337 
 
 raifed and lowered in the groove L, made for 
 this purpofe in the piece which fecures it on 
 each fide in its place, by means of the wooden 
 pins M. 
 
 N. Another tube for a fecond diftilling appa- 
 ratus, if it be thought fit to place one befide 
 that already formed, whether for the purpofe of 
 obtaining a high degree of concentration in the 
 oxygenated acid, or great fpeed in the compofi- 
 tion of the gas, on account of the hafte required 
 in the work. 
 
 O. Arms of the agitator, which may be floped 
 off on both fides. This form agitates the liquor, 
 and facilitates the abforption of the gas more 
 effectually than any other. 
 
 P. A focket applied to the arbor 'Q of the 
 agitator. If the pneumatic veffel be conftrucled 
 according to the reprefentation in the figure, 
 and the explanation given in the chapter IV. the 
 fockets, R, here expreffed become unneceffary, 
 as well as the inverted ftages, whether they be 
 made with hoops, as at S, or conftru£ted of thin 
 wood-like fieves, as at T. They are placed in this 
 drawing only to fhew the manner of difpofing 
 them in cafe they fhould be preferred. The 
 crofs-pieces, U, of the bottoms of thefe kind of 
 veffels, placed upon cleats fixed to the flaves of 
 the veffel,, fhew the manner in which they are 
 
 z to 
 
33 5 Explanation g/ the Plates. 
 
 to be fixed, with wooden pins, that they may 
 not be fubje£t to rife, nor become loofe in any 
 refpect. 
 
 X. The cover of the pneumatic veffel. 
 
 Y. A ftool upon which the veflel itfelf is 
 fupported. 
 
 Fig. 3. — Exhibits the manner in which the 
 hoops of thin wood are joined for the purpofe 
 of forming the inverted veffels, as well at their 
 terminations, where one part overlaps the other, 
 as upon the circumference attached to the bot- 
 tom itfelf. 
 
 a. Wooden nails with heads. Oak is the befl 
 material. The extremities of the hoop of thin 
 wood overlapping each other, and fecured on 
 each fide in the joint of their ligature with 
 wooden wedges. 
 
 b. The extremities of the circle of thin wood 
 lying over each other, and confined on each 
 fide in the joint of their ligature with wooden 
 wedges. 
 
 Fig. 4. — The manner in which the hoops are 
 put on which hold the fmall ftaves of thefecond 
 conftruftion together. The circles a are kept 
 together without binding, merely by a fcarf or 
 notch made in each end. Thefe hoops are 
 {tripped of their bark. 
 
 Cr The 
 
Explanation of the Plates. 339 
 
 c. The flaves. Thefe, as well as the bottoms 
 themfelves, may be made of yellow deal. 
 
 a. The fcarfed ends of the hoops, which are 
 turned inwards. 
 
 Fig. 5. — The method of difpofing the tranf- 
 verfal bars to which the bottoms of the inverted 
 veflels are fixed, a the crofs-bars. b the bottom 
 of the inverted vefTel. c the ftaves. d the fcarfed 
 hoops, e wooden pins which fix the bottom of 
 the inverted veflfcl to the crofs bar. They are 
 rivetted beneath, by fplitting the lower point of 
 the pin, and driving a wedge into the notch. / 
 a fmall block or cleat, fixed to the ftaves of 
 the cafk with wooden pins, g, driven flan t ways 
 above the crofs-bar to keep it fteady in its place. 
 
 Ffsn 6. — The method of fixing the inverted 
 veflels, which have a border of thin wood like a 
 fieve. a the hoop or circle of thin wood pinned 
 to the circumference of the bottom, b heads of 
 the pins which fix the circular part, c boards 
 making part of the bottom, but left of a greater 
 length, in order that they may be fixed down to 
 the fupport d. 
 
 As thefe circles of thin wood are not likely to 
 join exactly to the circumference of the bottom 
 of the vefTel, they mult be made good with putty, 
 after previoufly flopping the larger vacuities 
 with tow driven firmly in. Pitch may be ufed 
 
 z 2 inftcad 
 
34-o Explanation cf the Plates. 
 
 inftead of putty, if it fhould be found more con- 
 venient. 
 
 Fig. 7 and 8. — Section and plan of the veffel 
 for immerfing linen, hempen or cotton thread. 
 It is placed on rollers or trucks, a, for the con- 
 venience of removal. 
 
 A. Ears with the corners rounded off, which 
 are fupported at each end in a notch or mortice, 
 B, in the-crofs piece c. 
 
 d. Skains of thread, feparate or ranged in 
 bundles of two or three only. The pofition ot 
 thefe muft be changed once or twice during the 
 immerfion, in order that the part which refts on 
 the bar may be fubjected in its turn to the 
 action of the oxygenated muriatic acid. 
 
 E. A pipe of lead or wood, through which the 
 veffel is filled from beneath. If the acid were 
 to be poured upon the thread, it would bleach, 
 more fpeedily at the upper part than elfewhere. 
 Inftead of one pipe there may be more, or the 
 diameter may be fufficiently large for the fpeedy 
 filing of this veffel. 
 
 F. A funnel through which the bleaching 
 liquor flows from the pneumatic veffel. In ftricl- 
 nefs it may be fuppreffed, and the apparatus fa 
 difpofed that the cocks from that veffel may 
 difcharge themfelves immediately into the upper 
 part of the pipe, which muft be fixed withinfide 
 
 the 
 
Explanation of the Plates. 341 
 
 the vefTel, in order that it may not impede the 
 covering and uncovering. The cover ought to 
 be corapofed of feveral portions or frames of 
 glafs, as was directed with regard to the vefTel 
 for immerfing piece-goods 3 as by this means 
 facility of management, and fpeed in the procefs, 
 are infured. 
 
 G. A fmall door or Aiding piece, in which a 
 plate of glafs is fet, through which it is eafy to 
 obfer-ve the progrefs of the work. This may be 
 opened from time to time to examine the goods 
 without railing the covers. 
 
 This method of difpofing the fkains of thread 
 in the oxygenated muriatic acid, is likewife ap- 
 plicable to their immerfion in the fulphuric acid 5 
 when either of thefe liquors is exhaufted, it may 
 eafily be drawn off, either by means of fyphons 
 or of a cock placed near the bottom. 
 
 Fig. 9.— Seaion of a vefTel for immerfing 
 piece-goods, to which a pair of hooks is ahixed to 
 wring out the pieces in parts at a time, particu- 
 larly if of considerable magnitude. 
 
 A. uprights, which may be eafily adapted to 
 the two oppofite fides of the vefTel by means of 
 the two clamps, B, which are fixed to the vefTel 
 with a hinge on one fide and a ftaple and pin on 
 the other or by ftaple and pin on each fide, if 
 z 3 intended 
 
542 Explanation- of the Plate t. ' 
 
 intended to be applied to other vefTels. The 
 lower ends of thefe uprights are inferted into 
 holes in the floor or pavement of the workihop. 
 The hook D is fixed and unmoveable. The hook 
 E is capable of revolving upon its fhank, the 
 outer end of which is fixed by plate3 of iron and 
 fcrews to the levers I. 
 
 The ufe of this aparatus for wringing is equal- 
 \y applicable to the bath of oxygenated muriatic 
 acid, or fulphuric acid or lees, or the macera- 
 tions, &c. 
 
 Fig. 10. — A tube of glafs divided into feveral 
 equal parts called degrees, it is of ufe to afeer- 
 tain the ftrength of the oxygenated acid. This 
 tube is eafily made out of any cylindrical bottle 
 or piece of tube, the lower end of which may be 
 (imply flopped with a cork. White glafs is to 
 preferred, and it is convenient that it mould be 
 about an inch in diameter. 
 
 Fig. 1 1 .—A fmall meaiure of glafs, tin, lead, or 
 pottery, which when full contains the quantity 
 of liquor neceffary to form one of the degrees 
 traced on the external furface of the tube with 
 a flint or the edge of a file. The trial is made 
 by pouring one of thefe meafures of the oxyge- 
 nated muriatic acid intended to be proved into 
 the vellel ? fig. 10, and afterwards oblervirig how 
 
 many 
 
Explanation of the Plates* 343 
 
 many of the fame veffels filled with indigo blue, 
 or tincture of cochineal, &c. prepared as direct- 
 ed in Chapter IX — XIV, it will difcolour. .From 
 the refult of the experiment, the liquor is judged 
 to be more or lefs adapted to the bleaching 
 procefs , 
 
 * 4 
 
APPENDIX } 
 
 R, 
 
 SUPPLEMENTARY CHAPTER. 
 
 i. Nomenclature. 
 
 J\t the end of the original work, the author 
 has given a fhort table of fynonimous terms, to 
 which the following is equivalent : 
 
 Scientific Names. 
 
 Marine or muriatic acid 
 Oxygenated muriatic acid 
 
 Nitric acid — 
 
 Sulphuric acid — « 
 Ammoniac — 
 
 Carbonate of ammoniac 
 Aluminc — 
 
 Potato — . 
 
 Carbonate of potalh 
 
 Names in the Market, or 
 common isames. 
 
 Spirit of fait. 
 
 Dephlogifticated marine 
 acid of Scbecle. 
 
 Spirit of nitre; aqua 
 fortis. 
 
 O'l of vitriol. 
 
 Spirit of fal ammoniac 
 with lime. 
 
 Sal volatile. 
 
 Pure clay. 
 
 Pearl afti (which is im- 
 pure). 
 
 Salt of tartar. 
 
 Soda 
 
346 
 
 'Appendix, 
 
 Scientific Names. 
 
 Soda — 
 
 Carbonate of Soda 
 Sulphate of ; otafh 
 
 of foda 
 
 ■ of alumine 
 
 . of iron 
 
 - of copper 
 
 -^— — of zinc 
 
 Acetite of copper 
 
 Muriate of foda 
 Oxide — 
 
 Namtt in the Market, Of 
 common Names, 
 
 Barilla. 
 
 Salt of foda. 
 
 Vitriolated tartar, 
 
 Glauber's fait. 
 
 Alum. 
 
 Copperas ; green vitriol. 
 
 Vitriol ; blue vitriol. 
 
 White vitriol, or cop- 
 peras. 
 
 Verdigris, or diftilled ver- 
 digris (if in cryftak). 
 
 Common fea fait. 
 
 The ruft or calx of a 
 metaL 
 
 2. Meafures and Weights* 
 
 I have not been able to difcover the Jaws of 
 graduation of the areometer of MofTy, which is 
 mentioned in this work. If is much to be re- 
 gretted that all meafures, and inftruments for 
 fpecific gravity, are not reduced to the. ufual 
 numbers, of the tables in which that of water is 
 taken as unity. 
 
 Meafures of Temperature, according to Reaumur's 
 fc ale, are reduced to that of Fahrenheit by this 
 Rule : Multiply the degrees by 9 - y divide thepro- 
 du£t by 4, and to the quotient add 32, if the 
 
 temperature 
 
•dfpendiw 347 
 
 temperature be above the freezing water point ; 
 or otherwife, if below freezing, take the quo- 
 tient from 32. The fum or remainder will be 
 the degree fought. 
 
 Meafures of Length. The old French meafures 
 of length are ufed throughout this treatife. The 
 Paris foot, compared with the Englifh (Philof. 
 Tranf. 1768), is as 1.06575 to t, which anfwers 
 to fomewhat more than 12 inches and three 
 quarters Engliih. The Paris ell (aune) being 
 44 French inches, will therefore meafure 46.89 
 Englifh inches, or rather more than 46 inches 
 and feven eighths. Whence 5 Paris ells are 
 very nearly equal to 6§ Englifh yards, the 
 latter quantity being lefs than half an inch 
 morter. 
 
 Meafures of Capacity. The Paris pint is 2.017 
 Engliih wine pints, or a little more than a quart ; 
 and the muid of wine 280 pints, or very nearlv 
 707 gallons. The feptier or chopine is half a 
 pint. In corn meafure of Paris, 3 buihels make 
 1 minot j 2 minots, 1 mine j 2 mines, 1 fep- 
 tier ; and 12 feptiers, 1 muid. The muid is 
 not quite 52 Winchefter bufhcls. 
 
 Weights. The Paris pound is 7561 Englifh 
 grains, or one pound, one ounce, and 24I 
 grains avoirdupois. 
 
 Money. The livre is commonly reckoned at" 
 
 ten 
 
34^ Appendix, 
 
 ten pence Englifh, and is divided into 20 fob, 
 each confifting of 12 deniers*. 
 
 With regard to the articles made ufe of, the 
 od of vitriol, or fulphuric acid, may be rated 
 at c|d per lb.; fait, at if per lb. ; manga- 
 nefe, about one penny per pound ; pearlafh, 
 6d. per lb. ; foap, 4 1. per cwt. ; coals and other 
 fuel very different in price, according to the 
 fituation of the manufactory. 
 
 3. Obfervations en the Procefs, 
 
 The new method of bleaching, for which wc" 
 are undoubtedly indebted to Berthollet, in his 
 application of the oxygenated acid, firft dif- 
 covered by Scheele, to this ufeful purpofe, was 
 very fpeedily introduced into our manufactories 
 at Glafgow and Manchefter, and has fince been" 
 very generally adopted in Ireland, Germany, and 
 France. Some of our bleachers in Ireland im- 
 merfe one thoufand pieces daily. The obftacles 
 which at firft impeded the progrefs of this new 
 aft arofe from the prejudices of bleachers, their 
 ignorance in chemrftry, and the real difficulties 
 
 * For the new weights, meafures, and money of France, 
 which, however, are not ufed in the foregoing treatife, fee 
 Nicholfon's Fhilof. Journal, I. 199. 
 
 of 
 
Appendix. 349 
 
 of the procefs *, the chief of which, as is very 
 ftrikingly (hewn by our author, confifted in the 
 intolerable exhalations of the oxygenated acid, 
 which rendered it nearly impoffible and highly 
 dangerous for any workman to handle the goods 
 during the immerfion, while it feemed no lefs 
 impracticable to contrive a clofe apparatus, in 
 which the goods ihould be expofed through all 
 their parts to an equal a&ion of the bleaching 
 liquor. Various contrivances were tried with 
 little fuccefs, till it was difcovered that an ad- 
 dition of alkali deprived the liquor of its pun- 
 gent effluvia, but left it in poffeffion of its 
 bleaching power. It feems to have been gene- 
 rally thought that the only inconvenience of 
 this addition was the expence of the alkali ; but 
 Mr. Rupp f, in a lace excellent memoir, has 
 fhewn that the ufual addition of one pound of 
 pearlafli to the liquor for every three pounds 
 of fulphuric acid in the mattras, renders the 
 bleaching upon an average * $ per cent, lefs ef- 
 fectual, which, with the coil of the alkali adds 
 40 per cent, to the coft of the unfaturated liquor. 
 
 * Mr. Watt at Glafgovv, and Mr. Henry and Mr. Cooper 
 at Manchefter, were among the firft by whofe exertions .his 
 art was introduced. 
 
 ) Manchefter Memoirs, v. Parti.; or Nicholibn's Jour- 
 nal, II. s68. 
 
 The 
 
35° Appendix. 
 
 The fame ingenious chemift has propofed a 
 machine for the gradual and regular expofure 
 ofthefurtace of piece-goods to the bleaching 
 liquor in a clofed veffel. It confifts of two rol- 
 lers, upon one of which the cotton is wound, 
 and from which another roller draws it by- 
 means of a winch. Daring this action, the 
 evolved face is expofed to the liquor, and when 
 all the cloth is thus wound off, it is rolled baek 
 again upon the original cylinder, to which the 
 handle is for that purpofe fhifted. It does not, 
 however, appear that the inventor has ever ufed 
 his apparatus, and I very much fear that the 
 piece would run endways upon the cylinders fo 
 as to defeat the operation *. 
 
 Mr. Rupp found the bleaching liquor to be 
 always ftrongeft when the diftillation was car- 
 ried on very flowly, and that this ftrength is 
 much increafed by diluting the fulphuric acid 
 more than is ufually done. The following pro- 
 portions afforded the ftrongeft liquor : three 
 parts manganefe, or more or lefs, according to 
 its quality; eight parts common fait; fix parts 
 oil of vitriol; and twelve parts water. 
 
 The author of the prefent treatife mentions 
 
 * On this fubjecl:, which is the chief difficulty in cylinder 
 printed, fee the Journal kft quoted, I. 33. 
 
 lime 
 
appendix. 25 l 
 
 lime as a fubftitute for alkali in the bleaching 
 liquor, but without particularly infilling upon 
 it as pofTefling fuperior advantages. Our bleach- 
 ers, however, doubtlefs from experience, at 
 leaft in point of cheapnefs, fet'a confiderable 
 value upon it. Mr. Turner, of Darnly, near 
 Glafgow, obtained a patent * in January, 1798, 
 for the fole ufe of this earth in a 11 ate of me- 
 chanical fufpenfion in the bleaching liquor, and 
 has even received premiums or rents from other 
 bleachers for permiihon to ufe his method. But 
 I understand that the validity of this grant is 
 likely to be contefted. 
 
 * See Repertory of Arts, ix. 303. 
 
 THE END, 
 
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 and beautiful edition, to be published in about 216' numbers royal 
 4to. on fine wove paper, the 1st number at Od and all- the othors at 
 6d each, 1 number published weekly. There are 8 numbers al- 
 ready published. 
 24> A Short History of the Anciert Israelites, with an ac- 
 count of their manners, customs, laws, polity, religion, sects, arts, 
 and trades, division of time, wars, captivities, ire. a work 
 
4 Nea Books Published by W. Bayncs. 
 
 F greatest utility to all those who read the Bible, and desire fully fo un- 
 derstand the various customs, maimers, &c. referred to in that sa- 
 cred book, written in French by the Abbe Fleury, and translated 
 by Mr. Farneworth, much enlarged from the apparatus biblicus 
 of Pere Lamy, and corrected and improved throughout by Adam 
 Ci.ab.KE, in 1 vol. crown 8vo. 4s boards. 
 This little took contains a concise phasing) and just account of the maimers, customs, lau-Sf 
 polity, and religion of the Israelites. It is an exccllait introduction to the reading of the Old 
 Testament, cful should be put into the hands of every young person: an elegant English ver- 
 sion of it, by Mr. FarncvLorth, ivas first printed in 1756. 
 
 Vide Bishop Home's Discourses, vol. 1. 
 
 25 A Serious Call to a Devout and Holy Life, adapted to the 
 
 state and condition of all orders of Christians, by W. Law, A.M. 
 The fourteenth edition, corrected ; to which is added some account of 
 the Author, and Three Letters to a Friend, not before published in 
 any of his Works; also Two Letters from Clergymen in the Esta- 
 blished Church, strongly recommending the Serious Call, &c. of the 
 Author, his Character by F. Gibbon, Esq. the historian, and a list 
 of all his works, large print, in 1 vol. Svo. 6s in boards 
 *+* Dr. Johnson says, Law's Serious Cali is the finest piece of horta- 
 
 tory theology in any language. Vide his Life by Bosxccll, Svo. vol. 2. 
 
 This excellent treatise is written in a strong and nervous stile, and 
 abounds with many new and sublimo thoughts; in a word, one may say 
 of this book, as Sir Richard Steele did of a Discourse of Dr. Soulh's, that 
 it has in it whatever wit ami wisdom can put together. 
 
 Vide Clergymen's Letter, Gents. Mug. Nov* I SCO. 
 
 26 Clarke's 'Dr. Samuel) Collection of the Promises of Scrip- 
 
 ture, under their proper heads, recommended by Dr. Watts, a 
 new edition on fine paper, 12mo. 3s, or with the Life of Christ 
 added 3s 6d 
 
 27 Dr. Doddridge's Ten Sermons, on the Power and Grace 
 
 of Christ, and on the Evidences of his Glorious Gospel, a neat 
 edition. 2-lmo. is bound, or on liner paper 2s 6"d 
 
 2S Dr. John Evans's Sermons on the Christian Temper, with 
 his Life by Dr. Erskine of Edinburgh, 2 vols. 12mo. Ss boards 
 
 25 Lev. John Maclaurin's Sermons and Essays, the 3d edition, 
 to which is prefixed the Life and Character of the Author by Dr. 
 Gillies. Glasgow, 12 mo. 3s. fid. boards 
 v i* Maclaurin's Sermons and Essays is a work of uncommon worth, 
 truth, and experience, traced to their genuine principles, a mind 
 equally devour and penetrating, and language highly expressive and 
 
 energetic. -Vide Dr. Williams's Christian Preacher. — For an high 
 
 character sec ttho thr Evangelical and Theological Magazine. 
 
 30 Sermons by J. 13. Massillon, Bishop of Clermont, selected and 
 
 translated by W. Dickson, to which is added the life of the Au- 
 thor, tecond edition in 3 vols. 12mo K's 6"d boards 
 
 31 Rev. John Macgou an' Works, containing Dialogues of Devils, 2 
 
 vols.— Death a Vision — Shaver's Sermon — Arian and Sociuian's 
 Monitor — Looking Glass for the Professors of Religion, and L:fe of 
 Joseph, in j neat pocket volumes with frontispieces, 10s boards 
 
 7/2 the Press, and nill fa shortly published, 
 
 32 The Rev. W. Shrubsole's Christian Memoirs, or a Review of 
 
 present State of Religion in England, in the form of a New Pilgri- 
 grimage to the Heavenl) Jerusalem. The third edition, reused and 
 corrected, with the Life of the Author by his Son, neatly printed in 
 1 large volume Svo. with plates