fome Mineral Subjlances. 3 1 
other experiments with diftilled vinegar and rectified 
fpirit of wine, gave no marks of neutral fait. The un- 
diffolved part after this operation dried, weighed ^ ij. and 
gr. 1. : this was mixed with oil of vitriol, which caufed a 
ftrong effervefcence, and then calcined, to be deprived of 
its excefs of acid. It was now digefted, at three different 
times, with diftilled water, which diffolved a portion of 
it ; what remained undiffolved after this operation, being 
dried, weighed ^ j. and gr. lii. and was a felenite, as will 
appear by further experiments. The three portions of 
water, with which this matter was digefted, mixed toge- 
ther, then evaporated and cryftaliized, produced ^ ij. and 
gr. xlv. of a white fait, moftly confifting of rhomboidal 
prifms, fome lying flat and fome erected fide Ways. This 
I judged, by its ftyptic tafte, to contain iron, and by its 
white colour to contain a Jal catbarticus amarus , or at 
leaft a new earth, which with the acid of vitriol forms a 
foluble fait. 
EXPERIMENT II. 
This fpar, in its crude ftate, effervefces ftrongly with 
oil of vitriol diluted with water. Three drams of the fpar 
treated in this manner, and afterwards deprived by calci- 
nation of its excefs of acid, and then of its faline part by 
diftilled 
