THEORY OF SECRETION. 6*67 



by which these vital affinities are produced, and 

 the activity of the various tissues maintained. 

 Nor is this any more remarkable, than that the 

 chemical union of water with the aromatic con- 

 stituents of tea, coffee, medicinal infusions, and 

 many other bodies, including the various salts, 

 should be owing to the transition of caloric from 

 one to the other. Nor is it more strange, that the 

 caloric disengaged in the lungs during respiration, 

 should there convert chyle into blood, than that 

 the same active principle should cause oxygen 

 and hydrogen to unite in the formation of water, 

 or that solar caloric should determine all the che- 

 mical and vital transformations of the vegetable 

 world. 



Moreover, that animal heat is the cause, and 

 not the effect of secretion, as maintained by 

 Philip and many others, would appear from the 

 following undeniable facts : 1. That the secre- 

 tion of perspiration is much more copious during 

 summer than winter, and in tropical than in the 

 higher latitudes ; while it is known to be greatly 

 augmented by the high artificial temperature of 

 glass works, foundries &c.* and that sweating is 



* Dr. Southwood Smith found, that workmen who are exposed 

 to the intense heat of the London gas works, lose from two to 

 five pounds of perspiration in the space of one hour, twice a day, 

 making the aggregate from four to ten pounds, during which 

 they consume enormous quantities of malt liquors. (Philosophy 

 of Health, vol. ii. p. 396.) 



