606 MEDICINES. 



chloroform produces insensibility by causing the brain to become 

 deprived of blood; we should, to facilitate the action of this drug, 

 keep the animal's head on a higher level than his body. On the 

 other hand, when we wish to restore consciousness, we should 

 lower the head. The advisability of the precaution of withholding 

 food and water from the animal for some hours before giving 

 chloroform is self-evident. As difficulty of breathing, in chloro- 

 form poisoning, is frequently due to spasm of the muscles which 

 cause the epiglottis to close the opening (the glottis) into the 

 larynx ; it is well to antagonise their ac\ ion, in such cases, by 

 drawing the tongue forward. 



AMOUNT AND TIME REQUIRED.— The amount of chloro- 

 form required to put a horse under the influence of this drug, 

 varies greatly according to the mode in which it is given. Accord- 

 ing to the present somewhat inexact methods, the amount varies 

 from about 2 oz. to 10 oz. As a rule, I use about 6 oz. Twenty 

 minutes is an average time for bringing a horse fully under the 

 influence of chloroform. 



ADMINISTRATION. — In an operation requiring the use of 

 chloroform, one man, if possible, should be solely concerned with 

 the production of insensibility, so that the operator's attention may 

 not be distracted from his legitimate work. After the horse has 

 been cast, the chloroform may be given by a specially made 

 muzzle (I generally use RusselFs muzzle, which I find very con- 

 venient) ; by a leather or wire muzzle, inside which a sponge 

 saturated with chloroform is placed; or a towel may be folded 

 in the form of a funnel, and a small sponge or some cotton-wool 

 may be put in its centre to receive the chloroform, which 

 should be poured out a little at a time. In utilising this last- 

 mentioned contrivance, the horse, being kept with his head resting 

 on a bundle of straw, should be made to inhale the fumes through 

 his upper nostril, while the lower one is kept more or less 

 closed by the hand, so as to regulate the amount of air. In any 

 of these cases, we may commence with IJ oz. of chloroform, and 

 add a like quantity of it from time to time, as may be required. 

 With Russell's inhaler, I generally add IJ oz. at intervals of about 

 seven minutes. Mr. Harold Leeney, M.R.C.V.S., tells me that 

 instead of an inhaler, he prefers to use, for the administration of 

 the chloroform, a sponge, which he places inside one of the nostrils, 

 after having greased the inside of that nostril, so as to prevent it 

 being irritated by the chloroform. He regulates the inspiration 

 of the chloroform, by means of the pressure of his hand on 

 the other nostril. More or less successful attempts have been made 



