660 



is difficult to ascertain the loss of a very small 

 quantity of azot, and it may be admitted, that in 

 general the functions of respiration are confined 

 to the removal of carbon and hydrogen from the 

 body. 



A moistened mixture of phosphat and carbonat 

 of lime, cannot be nourishing like substances 

 equally destitute of azot, (such as sugar, gum, 

 starch,) but drawn from the organic kingdom. 

 Our digestive apparatus is like a galvanic pile, 

 which decomposes only certain substances. The 

 assimilation ceases, not solely because the matter, 

 which the stomach receives, does not contain 

 aliments similar to those, which compose the 

 human body; but also because the digestive 

 power, that of chemical decomposition, does not 

 extend indifferently to all combinations. We 

 can scarcely dwell on these speculations of ge- 

 neral physiology, without inquiring what would 

 have been the state of society, or rather of the 

 human race, if man had no need of the produc- 

 tions of organization and vitality as aliment. 

 No habit can essentially change the mode of 

 nutrition. We shall never learn to digest and 

 assimilate earth : but since the grand experi- 

 ments of Gay-Lussac and Thenard have made 

 known to us, that only slightalifferences in the 

 proportions of oxygen, hydrogen, and carbon, 

 distinguish the hardest wood from the substance 



