. 
■ ' , , . ^ , • ' . ■ ; ■ . ■' . ^ v . .V , . / V ( '■ , '■ ' '• ' 
' . I 
74 MINER ALOGICAL 
dered totally blue. With a folution of 
hepar fulphuris made with fixed alkali it 
forms a green, and with that of hepar 
fulphuris volatile a blue colour : the pre¬ 
cipitates of both are blue. 
§ 5 ° 
Half an ounce of the dry acid of wol¬ 
fram was digefied for fome time with z 
ounces of concentrated marine acid ; it 
Cr 
affirmed a dark yefiow fulphur-1 ike co¬ 
lour, and loft i dram of its weight. The 
marine acid feparated by the filtre, and 
the water ufed for edulcorating the yel¬ 
low refiduum were mixed and faturated 
by fixed vegetable alkali: the folution 
became turbid, and formed a jelly-like 
precipitate, which, when dried, weighed 
2 grains. In an open fire it was in part vo¬ 
latile with the fmell of arfenic, and a fco- 
ria containing fome iron was left. This 
fhews that the white acid of wolfram ftill 
contains 
