Experiments en the Soaps of Fijh and of Wool, 1 17 



Accordingly my father found that this aflertion of Sir John Dalrymple, was without 

 foundation. 



In the 6th volume of the tranfaftions of the London Society of Arts, mention Is made of 

 2 foap, niinufaclured in India, which is faid to wafh with fea water. It would be very inte- 

 reftina: to have the truth of this afcertained. 



5. Chaptal, iii the 2 iff volume of the Annales de Chimie, has defcribed a method of making 

 foap from wool, and he remarks towards the coHclufion of his paper " This foap has been 

 employed in every manner, and under every form, in my manufactory for dying cottons; 

 and I am at prefent convinced that it may be fubftituted inftead of the faponaceous liquor 

 we make from lixivium of foda and oil, to prepare the cottons. I have conftantly obfarvedy 

 that by diflblving a fufficient quantity of this foap in cold water to render the fluid milky, 

 and by working the cotton with the apparatus, which is well known, it is fufficient to pafs the 

 cotton three times through, drying it each time, in order that it may be as well difpofed to 

 receive the dye, as th^t which has been pafled feven times through the ordinary folution of 

 foap. This will not appear furprifing, when it is confidered that animal matters are very 

 proper to difpofe thread and cotton to receive the dye, and fome of the operations of our dye 

 works confift fimply in impregnating them with thefe fubftances *." In feveral trials which I 

 have made with this fifli foap, I find that it gives a greyifli or brownifli tinge to cotton cloth, 

 which remains after repeated wafh ing with common foft foap.. If this be found, to hold true 

 in other trials, it is not improbable that this fifli foap may be ufed in place of wool foap, 

 in the procefTes mentioned by Chaptal. Several preliminary trials muft be made, to determine 

 whether the Gallic acid decompofes this compound, and if the aftringent principlewill combine 

 with the fifliy matter j at leaft, this is ncceffary in the procefs for dying cotton red. (See 

 Chaptal's paper, Annales de Chimie, vol. 26th. j 



TFool Soap with Tallow^. 



Having obferved from the preceding experiments, that the mufcular fibre of fifhdoes not 

 unite with tallow in making hard foap, I imagined that other animal fubftances might poflefs 

 the fame property. Accordingly I made feveral experiments, with the view of uniting the 

 woolly matter with tallow. 



Experiment i. A quantity of white woollen cloth was- diflblved in cauftic potafli, then a 

 confiderable portion of tallow was added, and the whole boiled (with a frefli addition of ley) 

 until a brownifb- coloured foap was formed. 



2. A quantity of wool foap which had been, made about a year before,. and ftill retainei a 

 ililagreeable fmell, was boiled with tallow, and formed a foap. 



3. A quantity of wool (bap was boiled with whale oil, and afforded a foap^ 



4. A quantity of foap made with wool and tallow was boiled with water; lea fait was 

 then added, and the boiling continued for fome time ; the tallow foon feparated, and rofc to the 



* Ehilof. Journal, I. 43.^ 



togj, 



