BY-PKODUCTS OF PROTOPLASMIC ACTION. 81 



formation of soluble and gaseous matters which escape" 

 (Ibid. 108). 



It will be the business of organic chemistry to test 

 this, and thus confirm or disprove Beale's theory. At 

 present things are hardly far enough advanced for a 

 complete discussion of the question, but reasons are 

 not wanting for believing that such by-products are 

 always formed, and then reabsorbed and decomposed 

 and converted again into living matter, and from that 

 to pabulum, either on the spot or through the compli- 

 cated process of blood formation possessed by the 

 higher animals, till finally nothing but highly oxidated 

 and effete matters are excreted by the emunctories. 

 In muscular work, for example, most probably a por- 

 tion of nitrogenous protoplasm, corresponding to -the 

 force evolved, dies and splits up in every muscular act 

 for the notion that force is evolved by the direct 

 combustion of starch and fat is, no doubt, a gross 

 chemical figment yet there is no increased elimina- 

 tion of urea, for of the long list of products known and 

 unknown in addition to lactic and carbonic acids, the 

 bulk of them, and probably nearly all the nitrogenous 

 ones, are re-converted into blood, and the amount of 

 urea secreted depends upon the character of the diet 

 and not on the amount of muscular work, as will be 

 more fully shown in chap. viii. In the low organisms, 

 whose business is destruction rather than economy, 

 these by-products are more plainly seen. For example, 

 in the alcoholic fermentation of sugar, which is a vital 

 process performed by the protoplasm of the yeast cells, 

 besides alcohol and carbonic acid, into which cf emically 

 sugar might be entirely resolved, certain by-products 



