THE INDUCTION OF NARCOSIS IN HORSES. 
341 
There are other necessary precautions to be taken, after 
the horse is upon the ground. The girth is loosened or en¬ 
tirely dispensed with and the assistants must be instructed not 
. to sit upon the chest, although they may take a position upon 
the region of the gluteal muscles when occasion requires ; in 
other words, the respiration must remain absolutely free. 
During the administration, the pulse must be noted, together 
with the respirations ; these at first are increased, but soon re¬ 
turn to normal, the inhalation, however, is to be suspended 
upon irregularity of breathing, and when the character of the 
pulse betokens a weak heart. In a single case 1 observed 
general muscular twitchings (clonic spasms) which also caused 
me to cease the chloroform. A stage of excitement is exhib 
ited by some horses, but with the generality it is seldom or 
never seen; it is manifested by neighing and struggling in 
the hobbles ; it lasts generally only a minute, and is followed 
by the stage of depression. 
Many horses close the eyes shortly after the inhalation is 
commenced, and a rolling of the same is also sometimes no¬ 
ticed, a short period of nystagmus. With the diminution of 
consciousness and irritability, the animal usually reopens the 
eyes, or more properly, the lids involuntarily part. From the 
fact that even before lull unconsciousness, many patients fail 
to show irritability of the eye when the cornea is touched, I 
find it of little advantage to use the corneal reflex to deter¬ 
mine when the administration of the anaesthetic should cease. 
The rattling in the throat, which when occurring in man, 
demands immediate attention, is not, in our patients so immi¬ 
nently serious. It is produced by the vibrations of the velum 
pendulum palati consequent upon the efforts of the animal to 
respire through the mouth ; to avoid this the tongue is held 
outside the mouth at the commissure ; should consciousness 
return or manifest evidences of returning, the chloroform is 
re applied; when full narcosis is once induced, it remains 
about twenty minutes after the removal of the inhalation ap 
paratus. 
I have held subjects under complete narcosis for from one 
to two hours by simply reapplying the flannel, etc,, as soon as 
