158 



BACTERIOLOGY. 



to operation, have been carefully sterilized in the steam 

 sterilizer. The animal must be kept under close observa- 

 tion for about an hour after injection. 



The form of syringe best suited for this operation is 

 of the ordinary design, but one that permits of thorough 

 sterilization by steam. It should be made of glass and 

 metal, with asbestos packings. The syringes commonly 

 employed are those shown in Fig. 25 — A, Koch's ; -B, 

 Strohschein's ; 0, Overlack's. 



Fig. 25. 





The operation is one that cannot be learned from 

 verbal description. It can only be successfully per- 

 formed after actual practice. 



If the precautions which have been mentioned are 

 observed, but little difficulty in performing the opera- 

 tion will be experienced. 



Its convenience and simplicity over other methods for 

 the introduction of substances into the circulation com- 

 mend it as an operation with which to make oneself 

 familiar. The animals sustain practically no wound, 

 they experience no pain — at least they give no evidence 

 of pain — and no anaesthesia is required. 



