LOCAL ANAESTHESIA BY INFILTRATION. 63 



the needle of the syringe is passed from the cut surface towards the 

 skin, so that the path which the suture^ needle will afterwards take 

 is rendered oedematous. The bleeding from tissues thus rendered 

 oedematous is remarkably slight ; on incision the injection fluid is 

 first of all discharged without admixture of blood, then little points 

 of bright arterial blood appear in the fluid from the wound. 



According to Schleich the injection of distilled water also induces 

 local anaesthesia. A solution of 2 per cent, chloride of sodium sets 

 up local anaesthesia without previous hyperaesthesia ; 3 per cent, 

 solutions of sugar produce more or less pronounced anaesthesia. Pietro 

 Ghisicui has experimentally studied at the Turin Veterinary School 

 the results obtained by the above-mentioned formulae, and by distilled 

 and sterilised water. 



The quantity of cocaine solution or of distilled and sterilised 

 water employed varied ; generally he used from 2 J to 16 drachms of 

 the strong solution, 3 fluid ounces of the moderately strong solution, 

 4 \ fluid ounces of the weak solution, instead of \\ to 4 \ fluid ounces 

 of water. He noted a fleeting hyperaesthesia during the operation, 

 the tissues became turgescent, infiltrated, oedematous, and anaemic. 

 The oedema produced by the water and by the solution of Schleich 

 disappears after eight or nine hours. The vitality of the tissues is 

 unaltered, and cicatrisation takes place regularly. Complications, 

 such as stupefaction, nervous or functional troubles, etc., have not 

 been observed. 



From twenty-two experiments made with water, and the same 

 number with Schleich's solution, the author draws the following 

 conclusions : 



Anaesthesia by infiltration should be more common in veterinary 

 practice. Schleich's method is very useful, practical and cheap. 

 Solutions of cocaine may be replaced by distilled and sterilised water, 

 with which complete local anaesthesia is obtained, lasting as long as 

 that produced by Schleich's solution. In laparotomy water and 

 cocaine solutions have an unsatisfactory effect, apparently due to 

 the ready distension of the tissues, which prevents the requisite 

 action of the fluids. 



Bayer tried Schleich's method in animals, and with such good 

 results that he recommended it strongly, especially where casting 

 the horse might be inadvisable. As an experiment, he made an 

 incision about four inches long through the mucous membrane of 

 the tongue and then sutured the wound. He also trephined the 

 superior maxillary sinus without causing any apparent pain. The 

 horse was operated on in the standing position, and was not restrained 



