132 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 3 4 



aspects must contribute to any adequate description of life is not to 

 imply that a living organism is no more than a physio-chemical 

 system. It implies that at a definite and recognizable level of its 

 dynamic organization an organism can be logically described in 

 physico-chemical terms alone. At such a level indeed we may hope 

 ultimately to arrive at a description which is complete in itself, just 

 as descriptions at the morphological level of organization may be 

 complete in themselves. There may be yet higher levels calling for 

 discussion in quite different terms. 



I wish, however, to remind you of a mode of thought concerning 

 the material basis of life, which though it prevailed when physico- 

 chemical interpretations were fashionable, was yet almost as inhibi- 

 tory to productive chemical thought and study as any of the claims 

 of vitalism. This was the conception of that material basis as a single 

 entity, as a definite though highly complex chemical compound. Up 

 to the end of the last century and even later the term " protoplasm " 

 suggested such an entity to many minds. In his brilliant presidential 

 address at the association's meeting at Dundee 22 years ago. Sir 

 Edward Sharpey-Schafer, after remarking that the elements compos- 

 ing living substances are few in number, went on to say : " The com- 

 bination of these elements into a colloid compound represents the 

 physical basis of life, and when the chemist succeeds in building up 

 this compound it will, without doubt, be found to exhibit the phe- 

 nomena which we are in the habit of associating with the term 'life'." 

 Such a compound would seem to corres]3ond with the " protoplasm " 

 of many biologists, though treated perhaps with too little respect. 

 The presidential claim might have seemed to encourage the biochem- 

 ist, but the goal suggested would have proved elusive, and the path 

 of endeavor has followed other lines. 



So long as the term " protoplasm " retains a morphological signifi- 

 cance as in classical cytology, it may be even now convenient enough, 

 though always denoting an abstraction. Insofar, however, as the 

 progress of metabolism with all the vital activities which it supports 

 was ascribed in concrete thought to hypothetical qualities emergent 

 from a protoplasmic complex in its integrity or when substances 

 were held to suffer change only because in each living cell they are 

 first built up, with loss of their own molecular structure and identity, 

 into this complex, which is itself the inscrutable seat of cyclic change, 

 then serious obscurantism was involved. 



Had such assumptions been justified the old taunt that when the 

 chemist touches living matter it immediately becomes dead matter 

 would also have been justified. A very distinguished organic chem- 

 ist, long since dead, said to me in the late eighties : " The chemistry 

 of the living ? That is the chemistry of protoplasm ; that is super- 

 chemistry ; seek, my young friend, for other ambitions." 



