39^ ESSAYS AND OBSERVATIONS 



/»• From its tafle becoming more alu-r 

 minous, when part of the water is exha- 

 led, by being expofed to the air for be- 

 tween five and fix weeks (12.). 



y* From its tafte after three fourths of 

 the water was evaporated, which was 

 more harlli and aluminous, than that of 

 the frefli fpaw, or than that which had 

 been fo long expofed to the air (13.) 



"• From the aluminous tafle of the fak 

 (14. 2.y.), 



i. From its fait fwelling and rifing into 

 a blifter on the hot iron (18.). 



C From this fait lofing its aluminous 

 tafle when calcined a fufficient time (17.)? 

 "which alfo happens to alum, when treat- 

 ed in a like manner. 



Th e nitrum murale^ it is true, alfo fwells 

 and rifes in bliflers on the hot iron ; like- 

 ways borax, and the purging laic of Scar- 

 borough water : But the nitrum niurale dif- 

 fers from this fait in tafle, and, when cal- 

 cined, falls down into a loofe powder, 

 like lime ; which this fait did not do, 

 though calcined for a confiderable time 

 in a flrong fire. 



Borax 



