380 RESPIRATION 



tery, chronic diarrhoea, and pulmonary phthisis. The temperature 

 of the expired air rises and falls with the number of the respira- 

 tions." This confused assemblage of names of diseases and symp- 

 toms, and of obsolete and recent titles of disease, sufficiently attests 

 the nature of these investigations. 



Hannover has attempted to determine the quantity of carbonic 

 acid exhaled in chlorosis ; he employed four girls in these experi- 

 ments, which so far admitted of comparison with Scharling's observa- 

 tions, that three of these girls were of nearly the same age as the girl 

 experimented upon by the latter observer ; the fourth girl, when in 

 a state of perfect health, and at the age of 1? years, expired 0'4546 

 of a gramme of carbonic acid in one hour for every 1000 grammes 

 of her weight. Hannover's three chlorotic patients, whose respec- 

 tive ages were 15, 16, and 18 years, exhaled, according to similar 

 calculation, 0*6666, 0*6105, and 0'5874 of a gramme, and, conse- 

 quently, an amount of carbonic acid far exceeding the quantity 

 eliminated by the healthy girl. This fact is the more worthy of 

 notice as there is reason to believe that the blood-corpuscles parti- 

 cipate in the absorption of oxygen, and in the formation of car- 

 bonic acid, although in those cases in which it has been proved 

 with tolerable certainty that the blood-corpuscles are considerably 

 diminished, it has been found that the excretion of carbonic acid is 

 increased rather than diminished. Although we are not quite 

 justified in concluding from this fact, that the blood-cells are 

 devoid of all influence on the formation and excretion of carbonic 

 acid, it is quite certain that they do not contribute very essentially 

 to the interchange of gases, and that the source of the carbonic 

 acid, as we learn from other experiments, has to be mainly sought 

 in the metamorphoses of the tissues, and only to a very slight degree 

 in the processes occurring in the blood-cells. Moreover, in these 

 chlorotic patients, the absolute quantity of the excreted carbonic 

 acid stood in an inverse ratio to the number of the respirations, 

 which, as we have already seen, is the reverse of what we observe in 

 the normal state. Hannover was unable to discover any increase 

 of animal heat, notwithstanding the great development of carbonic 

 acid ; indeed, chlorotic patients generally complain much more of 

 cold than of heat. 



All these experiments of Hannover were conducted with the 

 greatest care in every respect ; for besides making a very accurate 

 examination of the special form of disease, he very carefully noted 

 in each respiratory experiment the numbers of the pulsations and 

 respirations, the temperature, the height of the barometer, the 



