THE ORIGIN OF LIFE 143 



and, while it is conceivable that the chemist might syn- 

 thesize all the compounds found in dead protoplasm, to 

 reproduce a single detail of the ultramicroscopic structure 

 of a living cell lies wholly beyond his power and province. 

 "Long ago," says Wilson (in the already quoted address on 

 the "Physical Basis of Life"), "it became perfectly plain that 

 what we call protoplasm is not chemically a single substance. 

 It is a mixture of many substances, a mixture in high degree 

 complex, the seat of varied and incessant transformations, 

 yet one which somehow holds fast for countless generations 

 to its own specific type. The evidence from every source 

 demonstrates that the cell is a complex organism, a micro- 

 cosm, a living system." {Science, March 9, 1923, p. 278.) 

 With the chemist, analysis must precede synthesis, and 

 it is only after a structural formula has been determined 

 by means of quantitative analysis supplemented by analogy 

 and comparison, that a given compound can be successfully 

 synthesized. But living protoplasm and its structures elude 

 such analysis. Intravitous staining is inadequate even as a 

 means of qualitative analysis, and tests of a more drastic 

 nature destroy the life and organization, which they seek 

 to analyze. "With one span," says Ame Pictet, Professor 

 of Chemistry at the University of Geneva, "we will now 

 bridge the entire distance separating the first products of 

 plant assimilation from its final product, namely, living 

 matter. And it should be understood at the outset that I 

 employ this term 'living matter' only as an abbreviation, 

 and to avoid long circumlocution. You should not, in reality, 

 attribute life to matter itself; it has not, it cannot have both 

 living molecules and dead molecules. Life requires an or- 

 ganization, which is that of cellular structure, but it remains, 

 in contradistinction to it, outside the domain of strict chem- 

 istry. It is none the less true that the content of a living 

 cell must differ in its chemical nature from the content of 

 a dead cell. It is entirely from this point of view that the 

 phenomenon of life pertains to my subject. ... A living 



