OEGANIC POISONS AND DEUGS 117 



recognition of meconic acid is usually taken as satisfactory 

 evidence of the presence of opium. 



COCAINE. 



OccuFPence. — Cocaine is the active alkaloid of the coca 

 plant, Erythroxylon coca indigenous to South America. In 

 small doses it is a powerful stimulant, causing exhilaration 

 and enhanced muscular activity, for which reasons it is 

 used by the natives when performing long journeys without 

 food. On the same grounds horses are sometimes ' doped ' 

 with cocaine, or cocaine preparations, such as powders 

 containing 90 per cent, cocaine and 10 per cent, strychnine. 

 Cocaine is valuable as a powerful local anaesthetic, especially 

 In eye diseases. For local anaesthesia in dogs Wooldridge 

 uses xir grain per pound body weight, with a maximum dose 

 of 2 grains. 



Poisoning" may result from accident or from excessive 

 ' doping ' and depends on the general action of cocaine as a 

 Qonvulsant, producing spasms, which may be confounded 

 with those due to strychnine. 



In the horse toxic doses (60 to 100 grains) produce rest- 

 lessness and excitement, salivation, dilatation of the pupil, 

 acute mania, and intense excitement. In the dog there 

 is first observed anxiety and fear, then exhilaration, followed 

 by weakness, muscular twitching, rhythmical movements, 

 convulsions and stupor, dyspnoea, feeble pulse, and weakened 

 respiration. The respirations diminish in amplitude but 

 increase in frequency, and cease from 20 to 25 seconds 

 before the heart. 



Examples of cocaine poisoning are rare, not at all likely 

 to occur with the horse or ox, and not often with the dog. 



At the present time cocaine is often replaced by the 

 substitutes such as novocaine and eucaine, or conjoined 

 with adrenaline. This acts by causing anaemia of the part 

 injected, and thus preventing the carriage of the cocaine to 

 the vital organs (Wallis Hoare). 



