Theories and Experiments 265 



accurate "in a book", these are the very words of Coindet, "so 

 opposed, I am proud to say, to all I have written". Without dis- 

 cussing what relates to pathology, we shall go straight to the 

 convincing reply which M. Jourdanet 101 made in opposition, not 

 to the data reported by Coindet, but to the conclusions which this 

 doctor drew from them: 



M. Coindet states that the respiration is not merely accelerated, 

 but that it is ample, deep, profound. Now what do this amplitude, 

 this depth, and this profundity amount to? We find the definite 

 measure of them in the passage of his correspondence in which we 

 see that 25 subjects gave an average of 6 liters of air breathed per 

 minute, in 20 respirations. That is therefore an average of 30 centi- 

 liters of air for each respiratory movement. It is evident that this 

 volume of air represents only a very moderate thoracic amplitude . . . 



Our colleague is no more fortunate when he states that, on the 

 great elevations of Anahuac, more air passes into the lungs in a given 

 time than at sea level; for the 6 liters which he collected in the sub- 

 jects of his observations are not above the very ordinary average 

 furnished by men from 20 to 30 years old at the pressure of 76 centi- 

 meters. And we should also note that, considering the rarefaction of 

 the air of Mexico, these 6 liters weigh only 6 grams, instead of 7.8 

 grams, the weight of the same volume of air at sea level .... 



So, according to M. Coindet himself, at an altitude of 2277 meters, 

 respiration is not ampler, or deeper, or more active than at sea level. 

 (P. 150.) 



The reply appears incontrovertible on this phase of the ques- 

 tion. The chemical considerations remain. 



Here M. Jourdanet criticizes an obscurity in Coindet's wording, 

 which no doubt has already impressed our readers, but which 

 makes the reading of the different observations contained in the 

 memoir itself quite incomprehensible. In the table reproduced 

 above, we have copied verbatim these words: Average percentage 

 of carbonic acid per minute: 4.24. What does this information 

 mean? Does it refer to a percentage calculated in volume or in 

 weight? This question is asked in regard to each of the observa- 

 tions. 



We are quite surprised (M. Jourdanet says naturally) at the 

 obscurity which reigns in the report of M. Coindet. Let us take, for 

 example, the first experiment: 



"H. Staines .... Number of inspirations per minute 22; number 

 of liters of air in one minute 6.4; carbonic acid 4.64%." 



Considering these 6.4 liters of air breathed by the subject of the 

 experiments, we cannot help thinking that the 4.64% of carbonic acid 

 indicates the proportional quantity of this gas in volume also. But 

 further on (Gaz., 1864, p. 36, first column), these figures are repeated 

 under the heading: Weight per 100 of carbonic acid expired in one 

 minute. Evidently the wording is not clear. 



