Present and Prospective 209 



the important part which chemical activities play 

 i.i vital processes. Considering closely how many 

 different chemical actions enter into each of the 

 various bodily functions of the body — assimilation, 

 respiration, secretion, excretion, generation, sen- 

 sation — all going on harmoniously to maintain a 

 unity of being, yet each liable to incalculable dis- 

 orders," the eternal wonder is that it holds to- 

 gether so long and so well as it does. In the 

 performance of these functions not the whole 

 organism only but every cell of it generates 

 poisons which would be fatal if they were not 

 got rid of. The breath of man is fatal to man ; 

 his excretory products would poison him if he 

 did not get away from them or them away from 

 him ; the fatigue of an organ or tissue is not clue 

 to the using up of its energy and matter only, 

 but also to the toxic products of waste which pass 

 into the blood-stream and are hurtful when they 

 are not perchance of economic use to other 

 organs or tissues. The proteid molecule of food 

 suffers decomposition into a dozen intermediate 

 products before its elements are built into living 

 tissue, and at every stage of the series there is 

 the possibility of a pernicious vitiation. The 

 numerous and various enzymes or ferments which 

 work in the processes of metabolism, each pro- 

 ducing its particular chemical change, are liable 

 tj their several toxic mischances. In its nor- 

 mal state the intestinal canal contains numerous 

 poisons and possibilities of poison — mucus, albu- 



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