PREFACE 



IN the following Essay, which formed the Presidential Address to the 

 British Association at its meeting this year in Dundee, I have tried to 

 indicate in clear language the general trend of modern bio-chemical 

 inquiries regarding the nature and origin of living material and the 

 manner in which the life of multicellular organisms, especially that of 

 the higher animals and man, is maintained. I have also stated the 

 conclusions which it appears to me may legitimately be drawn from the 

 result of those inquiries, without ignoring or minimising such difficulties 

 as these conclusions present. 



There is, it may be admitted, nothing new in the idea that living 

 matter must at some time or another have been formed from lifeless 

 material, for in spite of the dictum omne vivum e vivo, there was certainly 

 a period in the history of the earth when our planet could have supported 

 no kind of life, as we understand the word ; there can, therefore, exist 

 no difference of opinion upon this point among scientific thinkers. Nor 

 is it the first time that the possibility of the synthetic production of 

 living substance in the laboratory has been suggested. But only those 

 who are ignorant of the progress which bio-chemistry has made in recent 

 years would be bold enough to affirm that the subject is not more 

 advanced than in the days of Tyndall and of Huxley, who showed the 

 true scientific instinct in affirming a belief in the original formation of 

 life from lifeless material and in hinting at the possibility of its eventual 

 synthesis, although there was then far less foundation upon which to base 

 such an opinion than we of the present day possess. The investigations 

 of Fischer, of Abderhalden, of Hopkins, and of others too numerous to 

 mention, have thrown a flood of light upon the constitution of the mate- 

 rials of which living substance is composed ; and, in particular, the epoch- 

 making researches of Kossel into the chemical composition of nuclear 

 substance which in certain forms may be regarded as the simplest type 

 of living matter, while it is certainly the fons et origo of all active 

 chemical processes within most cells have shown how much less com- 

 plex in chemical nature this substance may be than physiologists were 

 a few years ago accustomed to regard it. On this and other grounds it 

 has lately been independently suggested by Professor Minchin that the 

 first living material originally took the form, not of what is commonly 



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