CANINE AND FELINE SURGERY 



Hydrocyanic acid^ first suggested itself as an antidote to 

 chloroform whilst watching the powerful respiratory efforts 

 which it so rapidly causes when given to produce toxic 

 effects, and when used as an antidote the object must be to 

 give just sufficient to attain a temporary stimulating effect i 

 on the respiratory centre without causing over- 

 stimulation and consequent arrest. Its rapidity 

 of action is unquestionable, and it can be given 

 either subcutaneously or by the mouth. With 

 the former there are no local irritant effects as 

 a sequel ; and with the latter there is no danger 

 of any entering the trachea and producing 

 choking, because the dose is so small. The 

 method of administration which is advised 

 consists in placing a small quantitj' by the 

 aid of a drop-tube on the back of the tongue, 

 from whence it is absorbed readily by the 

 moist mucous membrane. A full medicinal 

 dose should be given, Scheele's acid acting 

 quicker than that of the British Pharmacopceia 

 strength, although, of course, it must be used 

 with greater caution, one reason being that 

 the evanescent vapour is drawn into the lungs 

 by the performance of artificial respiration, and 

 is thus more rapidly absorbed into the system. 

 Hydrocj'anic acid is of especial value because it not only 

 stimulates the respiratory centre to recommence if once it 

 has ceased, but if gi^ en in full medicinal doses it maintains 

 the breathing until it is able to look after itself, and at 

 the same time, by the deep inspirations produced, it causes 

 the entrance of a large amount of fresh air into the system. 

 Its effects, too, on the heart-beats is beneficial. The dose 

 recommended, of Scheele's strength, to be placed on the 



^ Joitrnal of Comparative Patholos:y <^"^ Therapeutics^ vol. xi., p. loi ; 

 Lancet, January i, 1898. 



Fig. 26. — Anti- 

 dote Drop- 

 tube and Bot- 

 tle for Hydro- 

 cyanic Acid. 



