152 SANGUIFICATION. LECT. VII. 



and Gavarret in their study of the exhalation of carbonic 

 acid during the act of respiration in man. 



From the very extensive and apparently accurate experi- 

 ments of these distinguished physiologists, it appears that 

 carbonic acid which is exhaled during respiration varies 

 much according to the sex, the age, and some particular 

 physiological conditions. The difference between the 

 numbers 5 and 14-4, expressing with the latter the quan- 

 tities, taken in grammes, of carbon, which contribute to 

 form the carbonic acid expired during an hour. The first 

 of these numbers was obtained in a child of eight years old, 

 and the other in a young man of twenty-six years of age. 

 Observe, however, that in children the temperature being 

 considerably higher than in adults, and the mass which is 

 heated in these latter being larger, the loss of heat which 

 they suffer ought to be proportionately greater. 



Andral and Gavarret have also found, that in females the 

 establishment of puberty does not augment the quantity of 

 carbonic acid exhaled, but that this exhalation becomes 

 more active when age or other causes put a stop to the 

 phenomenon of menstruation. 



Notwithstanding this, we remark no perceptible difference 

 of temperature in the body of a female before, after, or during 

 the period of menstruation, or in the state of pregnancy. 

 And without having recourse to these experimental data, it 

 will be sufficient to consider that in certain maladies there 

 is a rapid diminution of temperature, and in others, on the 

 contrary, a very great increase throughout the body, without 

 our being able to admit of a corresponding variation in the 

 respiratory function. 



Conclusions. Lei us conclude, then, that in the exist- 

 ing state of physico-chemical knowledge, it must be assumed 

 that the chemical actions which take place in animals during 

 the transformation of their tissues, under the influence of 



