34 CANINE AND FELINE SURGERY 



admitted by means of the tap, or by leaving the end of the 

 mask uncovered. 



The second pattern, known as Junker's, which has been 

 modified to suit the smaller animals by Messrs. Krohne and 

 Sesemann, allows a stream of air to be forced through a 

 quantity of chloroform, and so sends into the mask the 

 vapour of air and chloroform mixed (Fig. 22). 



With this it has been estimated that (at a temperature of 

 62° F.), with 8 drachms of chloroform in the bottle, each full 

 compression of the bellows sends over a mixture of chloro- 



Fig. 22. — Junker's Inhaler (Krohne and Sesemann's Pattern). 



form vapour and air, which may contain as much a.s 10 per 

 cent. 



This apparatus is suitable for large dogs, but with 

 small ones and cats great care must be exercised, or an 

 overdose may easily be given. When used for these animals, 

 the bellows must not be compressed to their fullest extent, 

 and the end of the mask must be left open. 



The anaesthetist should commence by pressing the ball very 

 lightly, and not to more than about one-sixth of its extent, 

 the pressure being gradually increased until sufficient vapour 

 has been given to produce anaesthesia. 



