THE ADMINISTRATION OF ANAESTHETICS 



33 



drachms of chloroform to be placed in the bottle ; by means 

 of the bellows a current of air is sucked over the surface of 

 the anaesthetic, the mixed vapour being forced onwards into 

 the mask (Fig. 21). 



When 8 drachms are in the bottle and the temperature 

 of the air about 60° F., each full compression of the bellows 

 sends over chloroform vapour well mixed with air in the 

 proportion of about I'g to 2 per cent.i In order to produce 

 anaesthesia, the bellows must be worked as hard as possible, 



Fig. 21. — The Author's Anjesthetic Inhaler (First Pattern).- 



the end of the mask being closed at the discretion of the 

 anaesthetist. 



With strong dogs of the larger breeds it is sometimes 

 necessary to assist anaesthesia by placing a little chloroform 

 on wadding in the end of the mask. For very delicate or 

 young animals the vapour can be very much more diluted, 

 either by putting less chloroform in the bottle, by only 

 partially compressing the ball, by regulating the amount 



' For the accurate demonstration of this percentage by Dr. Waller's 

 dosimetric method, I am indebted to Mr. W. L. Symes, M.R.C.S. 



^ This pattern of inhaler is the one preferred by the author for patients 

 up to the size of a large terrier, and for continuous use in larger dogs 

 when once the patient is aneesthetized. 



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