des Agens Physiques sur la Vie. 3qA 



Work. Much, however, of this part appertains to what has 

 been already detailed upon other animals. But the modifi- 

 cations of* heat in the human being, from the period of birth 

 to maturity, Will be fouiid highly intferesting. They accord 

 precisely with th^ results obtained among the lower animals 

 and mamrniferffii and pr^sfent analogical proofs of the general 

 application of principles laid down in the preceding portions 

 of our notices. 



While, hdwet^r, We trace analogy throughotii the animal 

 kingdoni, it must be remembered that there are infinite 

 sources of variation arising from the extensive variety of 

 species modifying those principles, which are governea by 

 a general harmony of effect. Of all animals, man exhibits 

 this variety the most, possessing, as he does, attributes above 

 all the groups of his class, from his intellectual properties, 

 speech, ore, rendering his race unique and superior to all 

 others. Our curiosity cannot, therefore, be allowed to rest 

 satisfied with the general application of principles, until we 

 have observed their modifications in the human being as well 

 as in brutes. It is highly interesting to inquire into the con- 

 ditions of human phenomena, and examine the forces which 

 man opposes in his intelligent character to the physical 

 agents around him. He is equally liable to their influence, 

 exists by their contact, and yields, like other members of the 

 animal kingdom, to their destructive tendency. The essen- 

 tial distinctions appertaining to his economy are thus the 

 more necessary to be understood. His organization affords 

 him no shelter from the operations of physical laws beyond 

 that of brutes ; but the superiority of his nature may be 

 supposed to modify their Influence from causes referrible to 

 his sensibility. These have formed the subject of Dr. 

 Edwards's inquiry. 



Mart's state and condition, at his birth, place him in very 

 different circumstances from those at which he subsequently 

 arrives. Here, therefore, we see an extensive field of 

 inquiry ; and it is suggested whetherj in the infantile state, 

 man generates less heat than in naore matured existence. 

 Dr. Edwards has shown that the young of mammiferae gene- 

 rally, being born at the period when their eyes are open, 

 produce less heat than adults. It is, therefore, presumable 

 that the generating powers of heat differ in the two states of 

 existence which man goes through, the infantile and mature. 



But the power of producing heat differs among adult 

 animals, and it is desirable to know the limits of this faculty, 



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