CHEMICAL ASPECTS OF LIFE — HOPKINS 143 



fail to be associated with a steady increase in knowledge of the whole 

 field of chemical organization in living organisms, and to this increase 

 we look forward with confidence. The promise is there. Present 

 methods can still go far, but I am convinced that progress of the kind 

 is about to gain great impetus from the application of those new 

 methods of research which chemistry is inheriting from physics: 

 X-ray analysis; the current studies of unimolecular surface films 

 and of chemical reactions at surfaces; modern spectroscopy; the 

 quantitative developments of photochemistry; no branch of inquiry 

 stands to gain more from such advances in technique than does 

 biochemistry at its present stage. Especially is this true in the case 

 of the colloidal structure of living systems, of which in this address 

 I have said so little. 



IV 



As an experimental science, biochemistry, like classical physiology 

 and much of experimental biology, has obtained, and must continue 

 to obtain, many of its data from studying parts of the organism in 

 isolation, but parts in which dynamic events continue. Though 

 fortunately it has also methods of studying reactions as they occur 

 in intact living cells, intact tissues, and, of course, in the intact ani- 

 mal, it is still entitled to claim that its studies of parts are consistently 

 developing its grasp of the wholes it desires to describe, however 

 remote that grasp may be from finality. Justification for any such 

 claim has been challenged in advance from a certain philosophic 

 standpoint. Not from that of General Smuts, though in his powerful 

 address which signalized our centenary meeting, he, like many philos- 

 ophers today, emphasized the importance of properties which emerge 

 from systems in their integrity, bidding us remember that a part 

 while in the whole is not the same as the part in isolation. He has- 

 tened to admit in a subsequent speech, however, that for experimental 

 biology, as for any other branch of science, it was logical and neces- 

 sary to approach the whole through its parts. Nor again is the claim 

 challenged from the standpoint of such a teacher as A. N. White- 

 head, though in his philosophy of organic mechanism there is no real 

 entity of any kind without internal and multiple relations, and each 

 whole is more than the sum of its parts. I nevertheless find ad hoc 

 statements in his writings which directly encourage the methods of 

 biochemistry. In the teachings of J. S. Haldane, however, the value 

 of such methods have long been directly challenged. Some here will 

 perhaps remember that in his address to section I 25 years ago he 

 described a philosophic standpoint which he has courageously main- 

 tained in many writings since. Dr. Haldane holds that to the en- 

 lightened biologist a living organism does not present a problem for 

 analysis ; it is, qua organism, axiomatic. Its essential attributes are 



