156 JDr. Elliot’s Obfervations on the Affinities 
To try this 1 took fome diachylum, which had been bought 
at Apothecaries-Hall, and added to it fea fait ; then covered 
them to a fufficient height with fpirit of wine, and fet the 
bottle over the fire. Soon after they had boiled, the decom- 
pofition of the diachylum began to be apparent. When the 
boiling had continued Tome time, I removed the veffel from 
the fire, and after it had flood a few minutes, decanted the 
clear liquor while hot ; then evaporating it, obtained a true 
alkaline foap. The refiduum of courfe contained a quantity of 
calx of lead, combined with marine acid. 
But much of the diachylum remained either wholly or 
partly undecompofed : I therefore added more fea fait and 
fpirit of wine, and obtained a further yield of foap. But 
though much fea fait remained behind, diachylum was ftill 
found in the refiduum. I found, indeed, that if the ingre- 
dients were previoufly freed from their water, the procefs fuc- 
ceeded to fomewhat better advantage. 
From five ounces of diachylum I did not get quite three 
ounces of foap. This foap was likewife foft, and contained a 
portion of oil not combined with a fufficient quantity of alkali. 
The oil, I fuppofe, had exifted in a fimilar ftate in the diachy- 
lum : and I remarked, that as the fpirit evaporated, it gave 
out the true foap firft, the unfaturated oil not till afterwards ; 
fo that the latter might eafily be obtained feparate from the 
former. 
If too much fait was employed, much of it was taken up 
by the liquid, and communicated to the foap, at leaft if the 
ingredients had not been previoufly deprived of their water. 
To feparate this fait I diflblved the foap in hot water. When 
the liquor was cold, the foap floated at top, the fait remaining 
in the water underneath. If too little fait was ufed, this 
inconvenience 
