136 



ESSAY VI. 



SECTION XXXVI. UPON EEGULUS OF ARSENIC. 



(a) The regulus of arsenic digested with acid of arsenic 

 was covered with a white powder, which proved to be 

 arsenic, (b) One part of the regulus was mixed with two 

 parts of dry acid of arsenic, and distilled. The regulus rose 

 into the neck, and the acid entered into fusion, (c) If small 

 pieces of regulus of arsenic be put, one after another, into a 

 retort where the acid of arsenic is in a state of fusion, an 

 inflammation takes place, and arsenic is sublimed, (d) The 

 regulus of arsenic is dissolved by unctuous oils in a boiling 

 heat ; the solution is black, and, after it grows cold, of the 

 consistence of salve. 



