266 Historical 



We repeat with M. Jourdanet: Evidently the wording is not 

 clear; but an important circumstance throws complete light on it. 

 It is the comparison which Coindet makes between the figure he 

 obtained and those of Vierordt, Brunner, and Valentin. These 

 physiologists very certainly meant the percentage in volume, and 

 Coindet could not have been confused about that, because the 

 passage we copied above is the word for word reproduction of a 

 new paragraph of the deservedly popular book of M. Beclard, 10 - 

 from which only the words "percent in volume" have been left 

 out. To M. Coindet, then, the matter concerns a proportion in 

 volume, and his own experiments would show, if this were the 

 case, a considerable decrease in the intra-organic combustions on 

 the Mexican plateau, since, the quantity (in volume) of carbonic 

 acid exhaled there being the same as at sea level, the quantity 

 in weight would evidently be much lower, in a proportion meas- 

 ured by the very decrease of the atmospheric pressure. 



But here is another thing. M. Jourdanet, who was then in 

 Mexico, desirous of settling this doubtful question, asked M. Murfi, 

 "true author of these analyses", and obtained from him an answer 

 showing clearly that: 



The experiments of the College of Mines gave an average of 4 

 grams and 51 centigrams of carbonic acid per 100 liters of air expired, 

 measured at a temperature of 14 degrees and at a pressure of 58 

 centimeters. 



The contradiction is glaring: Coindet specified volumes, M. 

 Murfi states that it is a matter of weights, and M. Jourdanet, 

 naturally giving more credence to the statements of the Mexican 

 chemist, draws from them a really crushing conclusion for his 

 adversary: 



It is therefore unquestionable (he says) that the subjects of the 

 experiments of the College of Mines produced 4.51 grams of carbonic 

 acid per 100 liters of expired air. On the other hand, the report of 

 M. Coindet, agreeing in this with the statement of M. Murfi, says that 

 the quantity of expired air was on the average 6 liters per minute. 

 Who can doubt then that if 4.51 grams of carbonic acid correspond to 

 100 liters of air, the 6 liters expired by the subjects of the experiments 

 contained 27 centigrams. It is therefore certain that the quite unde- 

 niable result of the respiratory proportion of the College of Mines 

 was that the subjects from twenty to thirty years old produced 27 

 centigrams of carbonic acid per minute, that is, 16 grams and 20 centi- 

 grams per hour. 



The conclusions of M. Coindet do not agree with these figures; 

 for not only did these alarming figures not authorize him to say that 

 respiration in Mexico is identical with that at sea level, but they 



