118 VETEEINAEY TOXICOLOGY 



The toxic doses in grains per pound body weight are 

 approximately — 



Horse ... ... ... ... ^ grain 



Ox ^ „ 



Dog Jj „ 



but these are probably too low. 



In the system cocaine is largely oxidised, and only in 

 part excreted by the kidneys, which renders its detection as 

 a dope a matter of some difficulty. 



Treatment of cocaine poisoning requires rapidly acting 

 stimulants, such as nitroglycerin, strychnine or atropine, 

 together with the usual steps towards securing elimination. 



Chemical Diagnosis. — Cocaine is separated in the general 

 alkaloid scheme, and may be recognised by producing local 

 anesthesia on the tongue, and by the characteristic forma- 

 tion of a purple crystalline precipitate with potassium 

 permanganate, a test which fails, however, unless the 

 alkaloid extract is fairly pure. 



ESERINE OR PHYSOSTIGMINE. 



Occurrence. — The alkaloid eserine occurs in the seed of 

 Physostigma venenosum, Calabar bean, chop nut, or ordeal 

 bean, native to West Africa, and used by the natives as a 

 primitive method of trial by ordeal. Eserine is not likely 

 to give rise to poisoning among animals, but is used some- 

 what extensively as a powerful defsecant in obstruction of 

 the bowels. In this capacity caution is needed, as some 

 subjects are very sensitive to the toxic effects. Crude 

 eserine is further liable to be contaminated with calabarine, 

 an alkaloid which causes severe muscular tremors. The 

 dose of eserine as sulphate or salicylate is from 1 to 1^ 

 grains for the horse hypodermically. 



The toxic doses by subcutaneous injection are, according 

 to Kaufmann : 



Dog ... .., ... ... iV to tV grain 



Horse ... ... ... ... 2| grains 



Ox 5 „ 



