PRINCIPLES OF VETERINARY SURGERY 247 



gical Operations. Spaying of bitches, herniotomies, ablation 

 of mammary tumors, trimming the ears, and many other 

 minor and even major procedures can be quite well exe- 

 cuted by thus blunting the sensibility. In the horse, and 

 in the ox, chloral hydrate administered internally has many 

 indications. For clipping the restive horse or for shoeing 

 the vicious, unbroken colt, a state of partial insensibility 

 can be thus produced that will greatly facilitate the work. 

 In obstetrics, to arrest the forcible straining which inter- 

 feres with the manipulation of the mal-presented foetus, 

 chloral is often helpful. 



In the horse, chloral hydrate should be given only upon 

 an empty stomach if prompt and uniform results are de- 

 sired. One ounce to one ounce and a half, dissolved in a 

 quart of hot water and administered as a drench, will bring 

 about the desired state of blunted sensibility in about 

 twenty minutes. If the stomach is full the results are less 

 certain and the full effect of the drug may not appear for 

 several hours. For clipping, trimming and shoeing, this 

 method is very satisfactory. 



LOCAL ANtESTHESIA AND LOCAL 

 ANAESTHETICS. 



HISTORY. — The scientific use of local anaesthesia dates 

 back no earlier than 1884, although ice, snow, cold water 

 and other various expedients were used ineffectively since 

 time immemorial. Halstead in 1884, Corning in 1885, and 

 Reclus and Wall in 1886, were the first to describe sub- 

 derm.al applications of chemical anaesthetics in medical lit" 

 erature. Some years later (1890) Schleich in his 

 "Schmerzlose Operationen" gave the first detailed de- 

 scription of the effects of cocaine in various dilutions and 

 from various modes of application. Schleich, however, 

 gave preference to his "infiltration method" which con- 



