348 



ON THE PLACE OF FISH IN 



The source 

 of animal 

 heat is 

 oxidation. 



clear intellect of Liebig, grasping the meaning of 

 various isolated experiments of workers in all countries 

 and devising methods for observation not known 

 before, elaborated the ' Thier Chemie,' which he gave 

 to the world in 1840. England received it simulta- 

 neously with Germany in the translation 'Animal 

 Chemistry,' the preparation of which was entrusted 

 to Dr. Gregory, one of his pupils. 



Though others had been previously feeling their 

 way here and there, and had made slight inroads on 

 the borders of a then unknown realm of research, he 

 was the first to push boldly on, exploring with instru- 

 ments of his own invention, and to point to further 

 conquests waiting to be made in the domain of the 

 Chemistry of Organised Beings. 



That with all his energy he was but a partial 

 explorer he knew full well, but that he had mapped 

 out the right lines in laying down " oxidation " as the 

 source of animal heat he felt confident. Oxidation, it 

 seems, always gives rise to heat (p. 336 and Appendix.) 



It is strange or, remembering humanum est err are, 

 perhaps it was not strange that he should fall into 

 the very error he so strongly deprecates in others 

 that of drawing conclusions from an insufficient number 

 of observations. While, as repeated subsequent expe- 

 riments have shown, he was right in pointing to the 

 oxidation of carbon as a source of animal heat, he 

 missed the track in the explanation of the source of 

 muscular power. His theory, that muscular work was 

 accompanied by the destruction of muscular substance 

 itself, could not be verified. On the contrary, whether 

 little or much muscular work is done seems to have 

 hardly any effect. As the destruction of muscular 



