[22 ] 
though when a folution of the cauftic vegetable alkali 
was added, each drop occaiioned a white cloud. 
Some drops of oil of vitriol, let fall on fome of this 
fait, occaiioned no effervefcence, nor raifed any fumes j. 
and when fome of it was put on a red hot poker, it 
rofe into blifters, and did not crackle. From all 
which I conclude, that this was a true Glauber 
fait. 
After this fait was feparated, the remaining liquor 
was left in the tea-cup, and, at the end of four days, 
it concreted into a yellow cake, which ftill contained 
a good deal of a fait ; it weighed gr. ix. fo that there 
bad been a great increafe of weight, from the water 
the falts had taken up in their cryftallifation. This 
matter was extremely bitter, and had likewife a cool- 
ing faline tafte. Some of it, put on a red-hot poker, 
melted, -and rofe into bidders ; it emitted a little 
fmoak, but did not flame ; and it had fuch a very 
flight fulphureous fmell, that it was doubtful whe- 
ther it proceeded from the yellow matter or the ig- 
nited iron ; it burnt to a black coal, which tailed 
iomewhat faltilh. Some oil of vitriol dropt on fome 
of this matter occaiioned very little effervefcence, 
but raifed a llrong pungent acid fmell, which i at 
firll imagined mull be that of fea fait ; but, from 
tile few marks I have obferved of the exillence of 
this fait in a perledt Hate in thefe waters, I have 
Cnee thought, that it might be that of a volatile vi- 
triolic acid, which had been formed by the union of 
fome of the acid of the Glauber fait, with a ful- 
phureous or oily matter, and diflodged by the addi- 
tion of a fixed acid of the fame kind, though perhaps 
there may be a pittance of a calculareous marine fait 
