[ 23 ] 
m the yellow ley mixed with the Glauber fait. 
Having accidentally added a folution of cauftic alkali 
to this mixture ol the yellow matter, and vitriolic 
acid, it emitted immediately a ftrong fmell of hepar 
fulphuris. This yellow matter I take to be com- 
poled of a Glauber fait, and a yellow oily matter 
common to almoft every water, though perhaps in. 
larger proportion in this than in many others ; but 
whether it contains a pittance of fea fait, I think is 
doubtful ; and what makes me ftill doubt the more,, 
is my having fince evaporated 44 ounces of the water, 
from which I obtained gr. x. of reiiduum, when the 
water was at laft evaporated to drynefs, which I threw 
likewife into diftilled water, and the moll of it paiTed 
the filtre, and concreted into pure cryftals, refem- 
bling thofe of Glauber fait, leaving: but a verv 
fmall pittance of a yellow oily matter behind. How- 
ever, it will be neceffary to have a pretty large quan- 
tity of this laft reiiduum, to determine with precifion 
the nature of every ingredient in its compoiition, and 
the exadt proportion of each. 
Having tried as many experiments as I could, with 
the fmall quantity of this yellow matter I had, I laft 
of all examined the coffin through which the falts 
and it had paffed. After it was dry, 1 found that it 
had increafed gr. ii. in weight, and that it was co- 
vered in the infide, with a yellowifh powder. When., 
part of the paper, with this powder, was lighted with 
a candle, and the fame extinguifhed, it fmelt flrong 
of fulphur ; and, on rubbing a fhilling with another 
bit of the paper, it immediately tinged it yellow, as 
purer fulphur would have done. From- whence, I 
think, we have reafon to conclude, that this powder 
