ad 
4 
.. 
; 
, 
PHYSICAL ann LITERARY. 326 
of a fixt alcaline falt, we may again difen- 
. gage the volatile falt or fpirit from the acid. 
BuT it may be of more importance to dif- 
cover what kind of acid is joined to the vola- 
tile alcali in the common or crude fal-ammo- 
niac: for this purpofe I made the following 
experiment. When all the volatile falt and 
‘fpirit are drawn off from crude fal-ammoniac 
by the addition of a fixt alcaline falt and wa- 
ter, there remains a faline mafs; which, 
when diffolved in warm water, the folution 
{trained and evaporated, the chryftals very 
much refemble thofe of fea falt, in fhape, 
tafte, and other diftinguifhing charaéters of 
that falt, efpecially when it is well depurated 
and carefully chryftallized. This falt, how- 
- ever, has been dignified with the title of 
fal febrifugum Sylvit. I put three ounces of 
_ it into a retort, and poured in one ounce of 
oil of vitriol, and as much water. In the 
diftillation, the receiver was filled with white 
_ fumes, which condenfed into a liquor of a 
| pale colour, fomewhat turbid at firft, of 
_ which I had near three ounces. The liquor 
_had all the appearances of the fpirit diftilled 
in Glauber’s manner, from common fea {alt . 
and when fome of it was dropt into the folu- 
Sti tions 
