B L E 



«ns filtered through acoarfecloth, and ihe refiduiim wafficd 

 rcptratcdiy in four sjall'-nis of water, to obtain the whole 

 ftrength of the alkali ; the whole fourteen gallons being 

 then carefully mixed, the ley proved, by very accurate 

 weighing, to contain twelve ounces of cauftic alkaline fait to 

 the gallon. From this, a ley was made from the work, by 

 adding fix parts of water to one of tlie rtiother-ley ; thus each 

 gallon of the working ley contained one ounce, live drachms, 

 and forty-three grairs of cauftic alkali. 



The boiler being charged with this ley, the linen, which 

 had been fpittle waihed, was ftceped in it cold for one hour ; 

 then brought up by a very gentle heat to a llmmering 

 boil, which was continued for three hours ; the ctoth was 

 then well waflied out, and left in ftecp for that night. 



May iSth. Wafhed out the above linen in frefh water; 

 hung it on caids in the open air, watering it fcveral times 

 ia the day. 



May 19th. Finding the cloih not fo well cleared as 

 could be wifhed, the boiler was again charged with one of 

 mother-ley, to four of water, which made the ftrength two 

 ounces> three drachms, twelve grains of cauftic alkali to the 

 jjallon. In this was boiled another piece of linen which 

 had been fpiclle waflicd as the others ; and after it was boiled, 

 it was well waflicd cut. 



May 20th. Steeped the who'eof the linens for fix hours 

 in the liquid prepared with the oxymuriatic acid of the feve- 

 ral claimants ; afterwards wafhed them well out, and left 

 th-;m fteeping in cold water all night. 



May 2 iff. Waflied out all the ybove linens, and when 

 cry, boiled the whole parcel as before in one of the mother- 

 leys, to five of water, containing two ounces of cauftic alka- 

 line fait to che gallon ; wafhed tiiem well out of the ley, and 

 left them to ileep in pure water tiil Monday morning, the 

 a jd iuftant. 



May 24th. Steeped the linens for the fecond time in 

 {he oxygenated muriatic acid for fix hours ; then waflied them 

 out, and left them to fteep all night in cold water. 



May 2 ^th. Having charged the copper with a ley made 

 from one ot mother-ley, to fix of water, containing one 

 ounce, five drachms, and forty-three grains of cauftic alka- 

 fine fait to the gallon, the linens were boiled in this for the 

 third time, with a very penile fimmering heat for three 

 hours ; they were then wafhed out, and left to fteep. 



May 2;;th. Steeped all the linens for the third time fix 

 hours in oxygenated muriatic acid as before j waftied them 

 tint, and left them in water all night. 



May 28th. Immerfed all the linens which had been 

 fteeped ycllcrday in the oxygenated muriatic acid, in a weak 

 vitriolic acid for four hours ; then waihed them out, and 

 left them fteeping in cold water. 



May 29th. Wafhed and dried the linen cloth which had 

 been foured yefterday. 



June lit. Boiled all the linen which had been foured in 

 a ftrong lather of foap. 



June 2d. Soured and wafhed out all the linen which had 

 been boi!ed in a foap lather yefterday. This operation 

 finillied that experiment, in wh'.ch tlie above linens were firft 

 fteepcd in water ; then boiled in ca^Utic alkaline ley, and 

 fteeped in oxygenated muriatic acid alternately four times ; 

 then foured in vitriolic acid, foaped and loured again. 



The above experiments were made, with various others, 

 by Mr. John Arbuthnotj.and Mr. John Clarke ; and on i!ie 

 trials of the diifcrent fpecimens of the oxygenated muriatic 

 acid, t!;e preference was given to that prepared by Mr. 

 Robert Roe, of Bir.g's End, on the principle of the javelle 

 Jicjuor mentioned by Mr. Barthoiles, by adding a folution 

 of alkali in water in the receiver. Mr. Roe'& belt prepaia- 



B L E 



tion, of which was made by adding thirty-eight pounds of 

 quicklime to Ji4lb. of pearl-afh, which made a caullicr 

 ley of about nine pounds weight per gallon ; he found 

 cauftic ley more fufceptible of imbibing the gas and retaining 

 it, than mild ley of equal ftrenglh. 



From the different experiments made to bleach various 

 articles at the above time, the following inferences may 

 be deduced, viz. that allowing cotton or linen, when rave 

 from the the loom, to ferment, by fteeping in warm water a> 

 conliderable time before boiling the cloth in an alkaline ley, 

 is of confiderable fervice. 



That cloth or yarn is not injured by fteeping for fix hours- 

 together in oxygenated muriatic acid. 



That ftrong alkaline leys aufwer better than weak ones^ 

 at the commencement of ufing the leys. 



That the white colour of bleached cloth can be better 

 judged of wet than when dry. 



That very minute attention in excluding light and air i» 

 not abfolutely iieceffary in bleaching with oxygenated mu- 

 riatic acid. 



That purging or cleariiTg yarn or cloth in an alkaline Lyj, 

 previous to fteeping in oxygenated muriatic acid, is abfo- 

 lutely neceff'.ry. 



That the bL-aching liquids made from oxygenated mu- 

 riatic acid, in which alkaline fait is blended in the compofT* 

 tion, require the cloth to be frequenliy fteeped in vitriolic 

 acid ,' and that the oxygenated inu.riatic acid made witk 

 water only, make more frequent boilings of the cloth in al- 

 kaline leys ueceffary. 



That the lofs of the cloth in weight, when bleached by 

 the new method, is only oue fourth, but by the old method- 

 one third. 



That fteeping in warm water is infinitely better to extradl: 

 the fowen and dirt from the raw cloths, than boihng them with, 

 foap or ley immediately as they come from tlie loom. 



The liquors of the oxygenated muriatic acid, and alfo- 

 thofe made from the vitriolic acid, may be repeatedly ufed 

 without detriment, till the whole ftrength is exhauftcd. 



The cloth or linen, in the acid bleaching liquors, fhould' 

 be moved in the liquor every hour, that every part may be 

 equally cleared. 



It is difficult to afcertain the flrength of the leys proper 

 for ufe in bleaching cotton or linen, as the alkalies or afhes- 

 differ fo greatly in purity, and the admixture generally 

 found in them of neutral falts prevents the hydrometer 

 from being a regular tcft. The common allowance for 

 bleaching linens in Ireland, is ftated by Mr. Higgins, in his 

 ingenious memoir in the Tranfatlions of the Dublin Sociefj',. 

 to be for fixty gallons of water, fix pounds of barilla, or four 

 pounds of pot-afh at the Icaft, and moft bleachers ufe mors 

 than this. 



To dilcover adulterated' pot-a(h, Mr. Higgins recommends 

 the following method. The fpecimen of afhes being firffc 

 weighed, is digefled for a few minutes on a fand bath, in 

 twice its weight of water, in a heat of about 212 d-cgrees> 

 and inftantly flirred. It is then removed from the land- 

 bath, and before it is cooled to the temperature of the at- 

 mofphere, it mull be filtered through paper. When all the 

 liquor has palTcd through the filter, a finall quantity of cold 

 water is gradually poured upon the faline refiduum or the 

 filter, in order to wa.'h through the whole of the alkalis 

 The undiffolved fait fulpkate of pot-afh (vitriolated tartar,) 

 remaining on the filter, is afterwards dried and weighed, to 

 afcertain the quantity. 



To determine whether any common fait is fufpended in 

 the liquor which has been filtered, evaporate the clear folu- 

 tion a little 08 a fand-bath, and fet it in a cold place for 24 



houre J 



