ON ARSENIC 109 



an heavy oil, while the acid of arsenic remains behind in the 

 retort. The acid obtained in this way has precisely the 

 same qualities with that obtained by the former process. 

 It is, however, remarkable that the butter of arsenic does 

 not combine with the muriatic acid when it is somewhat 

 concentrated. 



SECTION IV. 



Before I subjected this acid to my experiments, I was 

 curious to know whether it is as fatal as arsenic itself. I 

 therefore mixed a little of it with honey, and exposed it to 

 the flies, when I found that it killed them in an hour. I 

 gave 8 grs. of the powdered acid, enclosed in a piece of meat, 

 to a cat, which, two hours afterwards, seemed to be at the 

 point of death ; I then gave it some milk, upon which it 

 vomited violently, and afterwards ran away. 



SECTION V. EFFECTS OF THE ACID OF ARSENIC UPON 

 INFLAMMABLE SUBSTANCES. 



(a) If 1 oz. of dry acid of arsenic be exposed by itself 

 in a small glass retort to such a degree of heat that it be- 

 comes nearly red hot, it flows into a clear liquid, which, 

 when cold, is of a milky colour ; but if the heat be increased 

 to such a degree that the retort begins to melt, the acid 

 begins to boil, and a little arsenic rises into the neck of the 

 retort. The longer the boiling is continued, the more arsenic 

 is obtained. After I had kept up this degree of heat for an 

 hour, the retort melted, and the acid ran into the fire. 

 After the whole was cooled, I found that the acid had risen 

 up the side of the retort as high as the neck. (6) The 

 same quantity of dry acid of arsenic, melted in a close 

 crucible in a strong fire, boils violently, and disappears in 



