282 VETEEINAEY TOXICOLOGY 



the distillation flask is made alkaline with sodium hydroxide ; 

 or if none of the foregoing is present, a fresh portion of 

 original substance is made into a paste with water and 

 alkalised, and again steam distilled. In this case there 

 distil over — volatile bases, ammonia, conine, nicotine, 

 arecoline, and some bases of putrefaction — e.g., trimethyl- 

 amine (from brine), putrescine, and cadaverine (ptomaine). 

 Chloral gives, with alkali, chloroform. These substances 

 must be then detected and estimated by appropriate special 

 methods. 



The results above described may be summarised as 

 follows : 



(Hydrocyanic acid. 

 Phenols. 

 Sulphuretted hydrogen. 

 Sulphur dioxide. 

 Ammonia. 



Poisons distilled from dilute 

 caustic alkali solution only 



Poisons distilled either from 

 acid or alkaline solution 



Conine. 

 Nicotine. 

 Arecoline. 



Certain bases of putrefaction. 

 '^Chloroform (from chloral). 

 Phosphorus (not entirely with- 

 out change). 

 Turpentines. 

 Essential oils. 

 Alcohol. 

 Ether. 

 Chloral. 

 Chloroform. 



GROUP B. 



Group B comprises heavy metals and metalloids — viz., 

 arsenic, antimony, mercury, silver, lead, copper, zinc, 

 chromium, and barium. Other metals which fall into the 

 same category do not possess importance from the stand- 

 point of veterinary toxicology, and are — tin, bismuth, 

 cadmium, iron, manganese, gold, and platinum. Iron is 

 always present, mainly from blood, and the others, if 

 also present, offer no difficulties to the experienced 

 worker. 



