THE ACTIVE FORCES OF LIVING ORGANISMS 23 



quantity of carbonic acid given off in metabolism 

 should be greater — in other words, oxidation in the 

 muscles, which compose so large a portion of the 

 entire organism, is more intense than in the brain 

 and spinal cord, or, to put it in another way, the 

 nervous system compared to the muscular system, 

 and in all probability compared to the viscera also, 

 is an area of restricted or limited oxidation. On the 

 other hand, if we are justified in estimating the readi' 

 ness to oxidize by the relative amounts of oxidizable 

 elements, such as carbon, hydrogen, and phosphorus, 

 and by the degree in which they are already oxidized 

 in muscle and in brain matter, then it is the latter 

 which appears to have the keener appetite. 



When it is remembered that the nature of the meta- 

 bolism in the nervous system probably governs that 

 taking place in the tissues, the necessity of ascertain- 

 iBg the degree of each, and the relations which they 

 bear to one another, will at once be evident. The 

 belief that one cannot oxidize too much is, indeed, a 

 very common one nowadays, but in view of the facts 

 already mentioned it is one which requires a consider- 

 able amount of qualification, especially in those cases 

 in which the bloodvessels to the nerve centres, either 

 through hereditary or other causes, expand and con- 

 tract too freely upon stimulation. Stoking is doubt- 

 less all very well, but it is necessary not to forget the 

 damper ; and whilst we possess a multitude of methods 

 of stimulating oxidation, we have none by mean's of 

 which it can be regulated. 



