CHLOEOFOEM. 617 



Chloroform 



is the best agent for producing general insensibility in horses 

 during surgical operations. To prevent it from becoming de- 

 composed, it should be kept in glass-stoppered bottles in a cool 

 place and covered with blue paper. 



USES. — The usee of chloroform are : (1) To produce insensibility 

 to pain ; and (2) to obtain muscular relaxation, as in breaking 

 down adhesions (p. 273), in cases of difficult foaling, and in the 

 reduction of inguinal hernia (p. 285). 



ACTION. — There axe three stages in the continued effect of 

 chloroform on the horse : (1) Nervous excitement, which will be 

 shown by struggling and frequently by neighing. During this 

 time the increased action of the heart is manifested by violent 

 throbbing of the carotid artery, the rapid pulsations of which can 

 be seen in the jugular groove (p. 118). (2) Insensibility. (3) 

 Paralysis of the organs of breathing, and finally paralysis of the 

 heart. In giving chloroform for ordinary surgical purposes, its 

 action should not be allowed to go beyond the second stage. The 

 more quickly insensibility is obtained, within of course safe limits, 

 the less dangerous will be the effect; for if its production is in- 

 duced by the prolonged inhaling of even a comparatively small 

 proportion of chloroform in the respired air, the horse's system 

 wiU get saturated with the drug, and consequent danger of death 

 will ensue from failure in the action of the heart. As the horse 

 bears the effect of chloroform extremely well, do not be afraid to 

 give it to him in a fairly concentrated form. At the same time, 

 remember that he requires air for breathing. Profiting by the 

 knowledge of the weakening effect which the prolonged administra- 

 tion of chloroform, even when well mixed with ,air, has on the 

 heart ; as soon as the horse is rendered insensible, give him only 

 sufficient of the vapour to keep him under its influence to the 

 extent we reqmre. In judging of the state of safety in which the 

 patient is when under the influence of chloroform, be guided almost 

 entirely by the condition of his breathing; for the action of the 

 lungs in chloroform poisoning, ceases before that of the heart. 

 Stoppage of breathing and irregular breathing are two symptoms 

 of chloroform poisoning, the observation of which shoidd at once 

 warn the operator to discontinue the administration of the drug. 

 Holding in the breath at first, will be a sign that the chloroform 



