712 INTRATRACHEAL INJECTION 



pleasant-tasted drugs are used, by mixing them with 

 palatable food, or disguising them in gruel, milk, or even in 

 water. Dogs and cats will often bolt concentrated drugs 

 rolled up in a piece of meat. Although absorption is not 

 so active from the posterior portions of the digestive tract, 

 nutrients and soluble medicines introduced into the rectum 

 enter the circulation. 



The pulmonary mucous membrane has a superficies of 

 fifty times the extent of the skin surface, and actively 

 absorbs substances in the gaseous form. By this channel 

 are administered anaesthetics, when their general effects are 

 required ; balsams and anodynes to relieve morbid con- 

 ditions of the respiratory passages ; diluted sulphurous 

 and chlorine gases to destroy bronchial filariae. But other 

 volatile drugs may thus be introduced into the body, while 

 others, in a finely divided state, can be inhaled with such 

 a readily diffusible volatile body as a chloroform, or ether. 



INTRATRACHEAL INJECTION has lately been adopted both 

 in this country and abroad. Tolerably bland fluids in 

 considerable quantity can, with impunity, be introduced 

 into the trachea, and agents too bulky to be used hypo- 

 dermically can thus be absorbed into the blood more quickly 

 and directly, and with less risk of having their activity 

 impaired than when administered through the digestive 

 tract. Various experiments on dogs, made at St. Peters- 

 burg, indicate that the effects of curare, strychnine, and 

 cocaine are frequently produced in ten seconds, and more 

 rapidly than when these drugs are injected subcutaneously. 

 Turpentine by this channel exerts its lethal action very 

 effectually on the bronchial parasites which attack cattle 

 and sheep. The injection is effected with a syringe having 

 a stronger needle than that used for hypodermic purposes. 

 Intratracheal injections intended to produce general effects 

 should be non-irritant and well diluted in water, alcohol, or 

 oil. Beyond a slight gain in time, intratracheal injections, 

 other than those intended to act locally, have no advantage 

 over hypodermic injections. Drugs have occasionally been 

 injected directly into the lungs. 



Intravenous injection of medicines is resorted to when 

 immediate effects are desired. In this way sterilised salt- 



