2 THE LAWS OF ORGANIC 



of disengaging from the blood a portion of the 

 excrementitious matter of the system, and also 

 for the purpose of regulating the generation of 

 animal heat. Although these principles are ac- 

 knowledged to be correct in their general accep- 

 tation, it is still believed that animal heat does 

 not bear an exact ratio to the number of respira- 

 tions ; and, moreover, by some it is advanced, 

 that the nervous system is the" source to which 

 this must be either altogether or in part attri- 

 buted. That animal heat is not proportionate 

 to the number of respirations, is evident to every 

 one that has paid any attention to the subject ; 

 but this consequence does not imply that it is 

 not exclusively derived from the changes which 

 the blood undergoes in the lungs, nor does it in 

 the least favoiir the opinion that it is a secretion,* 

 or that it is to be ascribed to the nervous system, 

 agreeably to the opinion of Mr BRODIE. 



III. Respiration is composed of two acts, inspi- 

 ration and expiration : the former is accompanied 

 by an enlargement of the chest and renewal of 

 atmospheric air ; the latter, by the approach of 



* " The experiments related in the last chapter, compared 

 with those on secreting surfaces, seem to me to prove, that the 

 caloric, which supports animal temperature, is evolved by the 

 same means, namely, the action of the nervous influence on 

 the blood, by which the formation of the secreted fluids is ef- 

 fected, and, consequently, that it is to be regarded as a secre- 

 tion." An Experimental Inquiry into the Laws of the Vital 

 Functions, by A, P, WILSON PHILIP, M. D. F. R. S, E. 



