450 RESPIRATION. 



occasionally found in the blood may be eliminated by the 

 lungs. Alcohol is partly removed from the system in this 

 way; and its presence, with certain odorous principles, in 

 the breath is pretty constant in those who take liquors ha- 

 bitually in considerable quantity. The odor of garlics, onions, 

 turpentine, and many other principles which are taken into 

 the stomach, may be recognized in the expired air. The 

 lungs are among the important organs for the elimination of 

 foreign matters from the system. 



The action of the lungs in the elimination of certain gases, 

 which are poisonous in very small quantities when they are 

 absorbed in the lungs and carried to the general system in 

 the arterial blood, is very well shown by the experiments of 

 Bernard. Sulphuretted hydrogen, which produces death in 

 a bird when it exists in the atmosphere in the proportion of 

 1 to 800, may be taken into the stomach in solution with 

 impunity, and even be injected into the venous system ; in 

 both instances being eliminated by the lungs with great 

 promptness and rapidity. 1 Nysten showed that the carbonic 

 oxide, one of the most violent and rapid in its effects of any 

 of the poisonous gases when inhaled, could be injected into 

 the veins with impunity, by simply taking care to introduce 

 it only as rapidly as it is absorbed by the blood. 2 



The lungs, then, while they present an immense and rap- 

 idly absorbing surface for volatile poisonous substances, are 

 capable of relieving the system of some of these substances 

 by exhalation, when they find their way into the veins. 



1 BERNARD, Lemons sur les Effets des Substances Toxiques et Medicamenteuses, 

 Paris, 1857, p. 58. In an experiment on a dog of medium size, injecting a little 

 more than a fluid drachm of water saturated with sulphuretted hydrogen into the 

 jugular vein, the gas was detected almost instantly in the expired air, and the 

 animal suffered no inconvenience from the operation. The gas appeared in the 

 breath in sixty-five seconds, when about an ounce of the solution was injected 

 into the rectum. We have repeatedly verified the experiment of Bernard showing 

 the almost instantaneous elimination of this gas by the lungs, when injected into 

 the veins. 



2 NYSTEN, Recherchesde Physiologic, etc., Paris, 1811, p. 81 et seq. 



