ANTIDOTAL MEASURES. 37 



upwards into the air several times. This is certainly a very 

 effective method of filling the thorax, but there is always danger 

 of rupturing some large abdominal vessel in fat animals, and 

 in the large and weightier breeds it cannot always be managed. 



A fourth method which sometimes brings success is to force 

 air or stimulant vapour (such as that of amyl nitrite) by means 

 of a special form of bellows (Higginson's enema syringe can 

 be improvised for the purpose) up the nostrils and so into the 

 lungs. This is done in a jerky manner and the air is then 

 forced out again with a succession of short, sharp compressions 

 on the ribs. 



In practising any of these ways care must be exercised, as 

 rupture of the liver or mesenteric artery is an occasional sequel 

 to performing artificial respiration too energetically, especially 

 in fat and aged animals. 



Recovery will sometimes follow simple inversion or swinging 

 the animal round by the hind legs, these acts being performed 

 with the idea of causing a flow of blood to the head and thus 

 relieving the over-congested heart. These methods are, how- 

 ever, open to the objection that they tend to diminish the 

 capacity of the chest by throwing the weight of the abdominal 

 organs against the diaphragm. 



Cold affusions to the head and chest, and striking the body 

 with a wet cloth are also recommended, but certainly must not 

 be trusted to alone. 



Tracheotomy is sometimes advisable, but in cases of this kind, 

 where whatever is done must be done immediately, this opera- 

 tion is often a matter of difficulty, especially in the smaller and 

 long-haired breeds. 



Venesection has been practised, but cannot be relied on. 

 The medicinal antidotes found to be of the most value are : 

 strong ammonia vapour, amyl nitrite, hydrocyanic acid 

 (Scheele's), and subcutaneous injections of ether, saline solu- 

 tion, or strychnine. 



Whatever antidote is chosen it is obvious that the chances 

 of success are enormously increased if the agent can be admin- 



