412 VEGETABLE DRUGS 



aiily produce anaesthesia when introduced under the skin. 

 In the horse, subcutaneous injection of a 5 or 10 per cent, 

 solution may be made to the amount of 2 drachms of the 

 former, or 1 drachm of the latter solution (cocaine, gr.6). 

 Larger doses may induce restlessness, excitement, etc., 

 which, although not indicative of danger, may interfere with 

 operative procedures. When larger quantities are desirable,- 

 2§ drachms of a 4 per cent, solution, or 5 drachms of a 2 per 

 cent, solution, may be employed (equivalent to 6 grs. of the 

 alkaloid), or Schleich's solution may be utilized. Not more 

 than 7 to 15 drops of a 10 per cent, solution should be 

 injected into dogs. This is equivalent to gr.| and gr.lj of 

 the alkaloid. Three-quarters of a grain of cocaine is a safe 

 limit of dosage for small dogs. If a 2 or 4 per cent, solution 

 is employed, 30 M. of the former, or 15 M. of the latter 

 solution (equivalejit to gr.f of cocaine) may be injected. 

 When larger amounts of the anaesthetic solution are in- 

 dicated for dogs, Schleich's method of infiltration is appro- 

 priate (infiltration anaesthesia). 



This method depends upon the fact that the pressure 

 of saline solutions injected into the tissues causes a benumb- 

 ing of the sensory nerves, and also upon the anaesthetic 

 action of minute doses of cocaine and morphine. Schleich's 

 Bolution may be iised in any amount and can be made con- 

 veniently from the tablets prepared by chemists. The 

 ordinaiy solution contains : 



1 part of cocaine hydrochlorate. 



2 parts of common salt. 



0.1 part of morphine hydrochlorate. 

 In 1 ,000 parts of sterile water. 



Note. — Since writing the above, it has been found that the mor- 

 phine in Schleich's solution is an irritant rather than a local anaesthetic, 

 and when large quantities of cocaine or eucaine are to be used under 

 the skin — or danger is, for any reason, to be anticipated — the writer 

 would strongly advise the employment of a normal salt solution (gr.4 

 sodium chloride, to 3 i. of water) , containing from ^ to 1 per cent, of 

 cocaine or eucaine. These weaker solutions will usually cause complete 

 and safe local anaesthesia. 



