302 Dr. Edwards, De V Influence 



however, as already noticed, that the parent exceeds the 

 temperature of its oftspring aftet birth, it is naturally con- 

 cluded that its consumption of air is also greatest. This was 

 experimentally confirmed, and is in unison with other facts. 

 In the first part of this work the vertebratae of cold blood 

 were also found to consume least air in proportion to their 

 diminution of temperature. Temperature seems to act 

 uniformly with all the vertebratae, and their consumption of 

 air is in proportion. The mammifera have a lower tempe- 

 rature than birds, and they consume less air than the latter. 

 Fish and reptiles consume less air than the warm-blooded, 

 and possess a lower temperature. 



The influence of the seasons upon respiration is considered 

 in the sixth chapter. Many changes occur in the atmospherd 

 during the revolutions of the seasons, varieties in the tem- 

 perature, and the pressure and density of the air. Dr. 

 Edwards shows that the faculty of producing heat with 

 warm-blooded animals is greater in winter than in summer, 

 the constitution of animals being adapted to their individual 

 climates ; and in reference to the relation of this faculty to 

 the consumption of air, it is presumable, all other cir- 

 cumstances being alike, that the consumption ought to be 

 increased with the faculty of developing heat, and the expe- 

 riments justify the presumption. 



Upon the subject of transpiration, it is shown that the aii^ 

 not only exercises a vivifying effect upon the constitution, 

 but one little less important in removing a vaporous sub- 

 stance from the surface of the body, and which is separated 

 from the fluids before its conversion into vapour, and known 

 by the name of perspiration or sweat, which transpires from 

 the skin. The variations in the temperature of the air pos- 

 sess great influence over this function. Experiments on this 

 subject were detailed most fully in our last Number, relative 

 to cold-blooded animals ; and therefore these need not now 

 be repeated in respect to the warm-blooded, for the results 

 are exactly similar, as to transpiration in equal and succes- 

 sive periods, the comparative influence of dry and moist 

 states of the air, and the effects of air in motion and in repose. 

 Inspection of the table annexed to the work displays the 

 similarity of the effects produced by the same physical agents 

 npon cold and warm blooded animals, and this accordance 

 serves to afford mutual support to the different investi- 

 gations. 



We are now arrived at the fourth and last part of this 



