Theories and Experiments 275 



An adult man, of good constitution, weighing 75 kilograms, has 

 ascended, on foot, to an altitude of 2000 meters on the side of a 

 mountain. He has thus accomplished a useful work of 150,000 kilo- 

 grams, representing 353 units of heat, the thermic effect of which is 

 zero, since they are transformed entirely into mechanical force, and 

 which are furnished by the respiratory combustions. Since eight 

 tenths of this transformed heat comes from the combustion of carbon, 

 the creation of the mechanical force corresponding to the useful work 

 accomplished during the ascent requires the production of 65 liters 

 of carbonic acid, above 22 liters of this gas which the man forms per 

 hour in his general capillaries to maintain his own temperature. The 

 consequences of the production of so great a quantity of carbonic 

 acid in the body are apparent. The consumption of the organic 

 materials of the blood is excessive, and the powers are rapidly ex- 

 hausted. The respiratory and circulatory movements are considerably 

 accelerated, on one hand to render possible the absorption of all the 

 oxygen necessary for such active combustions, and on the other hand 

 to rid the blood of such a proportion of dissolved carbonic acid. When 

 the pace is slow, the force expended in a given time is slight, and 

 the functional disturbances are not great. 



But if the ascent is rapid, the exhalation of gas, though very much 

 activated, is not enough to maintain the normal composition of the 

 blood, which remains saturated with carbonic acid; then respiration 

 becomes uneasy; the dyspnea is extreme, and is accompanied by head- 

 ache, vertigo, and drowsiness .... We easily understand why a halt 

 of a few instants is enough to dissipate all these symptoms. 



As soon as the man is resting, the expenditure of energy ceases, 

 the activity of the respiratory combustions drops rapidly to the degree 

 strictly necessary for the maintenance of his temperature, the utili- 

 zation of oxygen is only 22 liters per hour, the blood is very quickly 

 freed of the excess of carbonic acid which it contains, and all the 

 disturbances of the respiratory and circulatory functions disappear 

 at the same time .... 



As a result of these considerations, we think that we are author- 

 ized to say that the larger part of the functional disturbances 

 characteristic of mountain sickness should be attributed to a true 

 intoxication by carbonic acid dissolved in too great proportions in the 

 blood. To express our ideas completely, we shall add that an intoxi- 

 cation of the same sort, the inevitable result of too great an expendi- 

 ture of energy, is one of the principal causes of the serious symptoms 

 observed in overdriven animals. 



This interesting and original theory, supported by indisputable 

 calculations and the great authority of the learned professor of 

 medical physics, should gain great success and be epoch-making in 

 science. Henceforth, all will vie with each other in repeating it; 

 already Dr. Aug. Dumas 112 has been the first to do so in his inaugu- 

 ral thesis. 



But the theory of M. Gavarret does not satisfy him; he ac- 

 cepts and supports with well-made calculations the theories of the 



