376 RESPIRATION 



suppressed, this circumstance would prove as little the unimportance 

 of cutaneous gaseous transpiration, as the interesting experiments of 

 Regnault and Reiset, on frogs whose lungs had been extirpated, 

 could prove that the lungs of frogs are superfluous organs. In 

 these experiments the frogs not only continued to exist for a very 

 long time, but they also consumed a considerable quantity of 

 oxygen (although scarcely as much as half the amount consumed 

 by the uninjured animals) : thus, for instance, 1000 grammes' weight 

 of these animals consumed in one hour 0*047 of a gramme. The 

 ratio of the oxygen to the transpired carbonic acid and to the 

 nitrogen was nearly the same as in the uninjured animals. 



This leads us to the consideration of the abnormal phenomena 

 which the interchange of gases in the lungs occasionally presents, 

 and which are consequent on anomalies, functional or other derange- 

 ments of individual organs, or diseases. This subject is, however, 

 beset with so many difficulties that we have hitherto been obliged 

 to content ourselves with the determination of the absolute or 

 relative quantity of excreted carbonic acid, and even these limited 

 experiments have not yet led us to any important results. 



In entering upon these pathological relations we cannot pass 

 over an accurate observation made by Bidder and Schmidt,* 

 although we shall recur to it more fully in the following paragraph ; 

 we allude to an experiment on the respiration of dogs, in which all 

 the bile was carried off externally by means of a biliary fistula. 

 For every kilogramme of this dog, which was kept almost entirely 

 without food, there were absorbed in one hour 1*146 grammes of 

 oxygen, and 1*146 grammes of carbonic acid were exhaled; hence, 

 of every 100 parts of absorbed oxygen 77*0? were returned with 

 the carbonic acid : for every kilogramme of a dog operated upon in 

 this manner, but receiving an abundant supply of flesh, there were 

 absorbed in one hour 1*153 grammes of oxygen, while T327 

 grammes of carbonic acid were excreted; hence, of every 100 

 parts of absorbed oxygen 83*7 parts were contained in the carbonic 

 acid. We simply give these numbers in the present place as facts, 

 since we purpose analysing this experiment more fully in a future 

 page. 



Three different methods have hitherto been proposed for the 

 investigation of the interchange of gases in the lungs during morbid 

 conditions ; but these are unfortunately nearly all equally open to 

 objection. In the first place, animals were experimented upon, in 

 which certain abnormal processes had been induced by the opera- 

 * Op. cit. pp. 368-386. 



