THE ADMINISTRATION OF AN.TSTHETICS 



35 



The third pattern of apparatus plays a medium part 

 between the other two, as its object is to force a current of 

 air over the surface of the chloroform (Fig. 23). 



The vapour sent over is stronger than that of the first 

 pattern, but less concentrated than that of Junker's. 



Two other modifications, suitable for hospitals or in- 

 firmaries where operations are constantly being performed, 

 consist in an arrangement whereby all pumping by means of 

 the bellows is done away with, in one pattern by means of a 

 cylinder of compressed air, with a regulating valve, attached 



Fig. 23. — The Author's Second Design of Inhaler. 



to the bottle in such a way that the current (when turned 

 on) passes either over or through the chloroform, and so 

 forces the mixed vapour onwards into the mask (Fig. 24) ; 

 and in a second pattern by means of a small electrical motor- 

 pump arrangement, whereby air is either sucked or forced 

 automatically, the supply of electricity being obtained either 

 from a small battery (D) or by direct attachment (E) to the 

 main current (Fig. 25). 



Whichever inhaler is used, care must be taken to produce 

 anesthesia slowly, and to administer the vapour as regularly 

 and steadily as possible. The average length of time required 



