436 VEGETABLE DRUGS 



arily produce ansestliesia 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. Wlieu 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 (equivalent 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 ansesthetio 

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

 solution may be used in any amount and can be made con- 

 veniently from the tablets prepared by chemists. The 

 ordinary solution contains : 



1 part of cocaine hydroohloride. 



2 parts of common salt. 



0.1 part of morphine hydrochloride. 

 In 1,000 parts of sterile water. 



Note.— Since writing the above, it has been fonnd that the morphine in 

 Schleich's solution is an irritant rather than a local anaesthetic, and when large 

 quantities of cocaine or eucalne are to be used under the sliin— or danger is, for 

 any reason, to be anticipated— the writer would strongly advise the employment of 

 a normal salt solution (4 grains sodium chloride to 1 drachm of water), containing 

 from 1-10 to 1 p. c. of cocaine (or euoaine, 1 p. c). These weaker solutions wlU 

 usually cause complete and safe local anaesthesia. The solutions should always be 

 warm— at body temperature— and not over twenty-four hours old, as acid develops 

 which interferes with the anaesthetic action. They are most conveniently made 

 by solution of cocaine tablets In salt solution at the tune of operation. 



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