207 



years after conducted some experiments to determine the absorptive power of tbe air 

 passages. He found that mucilaginous decoctions and solutions of sugar or honey 

 are speedily absorbed when injected into the trachea, inducing slight symptoms of 

 suffocation for one or two hours. He also found that solutions of narcotic agents 

 and stimulants manifest their physiological effects very soon after injection, and that 

 oils and oily medicines produce a congestion of the lungs which is but slowly dis- 

 sipated, and that even very dilute solutions of mineral and vegetable acids produce 

 inflammation, with copious secretion of mucus, giving rise to symptoms of asphyxia 

 and even leading to death. 



Dr. Levi, of the University of Pisa, has recently applied this method in the treat- 

 ment of a number of diseases {Manuel praliqiie des injectmis tracheales dans le cheval, 

 1883). His experiments also tended to show that tbe mucous membrane absorbs very 

 rapidly, and is therefore less apt to suffer from tbe injection of irritating substances 

 than if the absorption were less rapid. He also determined that the injection of small 

 quantities of oily substances is not dangerous, the oil probably being emulsitied and 

 absorbed. Finally, there is always a slight reduction in the number of respirations, 

 amounting to about three or four per minute, after the introduction of liquids, even 

 when distilled water only is injected. 



Without entering into interesting questions concerning the administration of med. 

 icines in this manner in other diseases, which are discussed at length in the work 

 mentioned, we find that the author has experimented on but one case of lung worms 

 to test the efficacy of the method. Others, however, have reported cases in which 

 their success justifies a detailed account of the method for future application. 



The instrument to be used is a simple hypodermic syringe holding from 1 to 2 fluid 

 drams. The needle of the syringe must be provided with a removable solid rod or 

 trocar, so as not to become plugged when it is pushed through the skin and walls of 

 the trachea. As the needles are apt to break, a number of them should be kept on 

 hand. After the operation the syringe should be carefullj'^ washed in pure water, the 

 piston supplied with a drop of olive oil, and the trocar replaced in the needle. 



It is best to disinfect by filling the syringe and needle with a 5 per cent, solution 

 of carbolic acid, or a 0.1 per cent, solution of mercuric chloride* before washing in 

 pure water. The disinfection, however, is not absolutely necessary in this operation 

 if the syringe and needle be kept thoroughly clean. 



To administer the medicine first fill the syringe and place at the side. Hold the 

 sheep for drenching, and extend the head of the animal so as to fix and make promi- 

 nent the trachea, which will be felt as a tense elastic tube along the middle line of 

 the neck. The most convenient point for the introduction of the needle is at about 

 the middle of the length of the neck. It must be remembered that some care is to be 

 observed, as the trachea is near some important structures on either side — the jugular 

 vein, the carotid artery, and the pneumogastric nerve. Having fixed the trachea 

 with the left hand, the needle with the trocar is inserted beneath the skin, and then 

 an interannular space is sought so as not to pierce a cartilaginous ring. Or the 

 needle may be pushed directly into the trachea without necessarily avoiding a 

 cartilaginous ring. The unimpeded movement of the free end of the needle as if 

 in an empty space is a sure sign that the needle is in its proper place. The trocar is now 

 removed, the syringe screwed upon the needle, and the contents very slowly forced 

 into the trachea. Before the needle is finally withdrawn Dr. Levi thinks best to 

 wash it out with some pure water so as to remove the injecting fluid. In withdraw- 

 ing the needle this might accidentally bo discharged in the wound made by the needle 

 and set up inflammation if the substances introduced be irritating. How this wash- 

 ing out is to be done he does not state. It seems that a small pipette or medicine- 



*The former is prepared by adding 5 parts by weight of pure carbolic acid to 100 

 parts by weight of pure water previously heated ; the latter by adding 1 part of the 

 corrosive sublimate (a violent poison) to 1,000 parts of water, 



