L. ('. COOLEY. 61 



ISOMERISM. 



But there is another source to which the non-vitalist is 

 inclined to look for hope. I refer to the chemical theory 

 of the constitution of matter. Kekule's hypothesis has 

 enabled the chemist to point out the relations of the 

 atoms in the molecule, and this enables him to lay hold 

 not simply of the properties of substances, but of the 

 very source from which these properties spring. The 

 fact that common alcohol and methylic ether, very un- 

 like in character, contain exactly the same elements and 

 in identical proportions, illustrates the principle, now 

 well established, that the properties of a substance are 

 due to the relations of the atoms in its molecule as well 

 as to the nature and quantity of its constituents. 



Now to bring the same constituents together in differ- 

 ent ways and secure the combination of their atoms in 

 different relations is a legitimate object in chemical 

 synthesis. It is to be expected, therefore, that two or 

 more substances, with different sets of properties, may 

 result from the combination of the same atoms. This, 

 I say, the chemist may expect. 



Now let us see the bearing of this upon the question 

 of living matter. We are told that there is a colorless, 

 structureless fluid, which is the basis of all vegetable and 

 animal life. That there is nothing living but proto- 

 plasm, and that the presence of this living matter gives 

 to every part of an organized structure the power to 

 exhibit its peculiar function. In this germinal fluid 

 therefore, if anywhere, say they, the vital force resides. 



Well, now. tlie chemical constituents of this living 

 matter are carbon, hydrogen, oxygen and nitrogen, the 

 same elements from which the chemist may make so 

 many liquids which are colorless, structureless and 

 which in other respects resemble protoplasm. But all 

 these manufactured articles differ from protoplasm in 

 the total absence of any display of vitality, which is its 

 most supreme characteristic. 



But this difference in properties, it is said, may be due 

 to a difference in the relations of the atoms in the mole- 

 cules as in the case of alcohol and methylic ether already 

 mentioned, and hence, as the argument runs, ir only 

 remains for the chemist to put the atoms of carbon, hy- 



