652 REPORT— 1895. 



pared artificially is produced in the organism ty .1 direct process of building up ? 

 Is not the opposite view quite as probable ? May they not, from the simplest to 

 the most complex, be products of the degradation of still more complex molecules ? 

 I venture to suggest — not without some temerity lest our colleagues of Sections I 

 and K should treat me as an intruder — that this view should be given a fair trial. 

 1 am aware that the opposite view, especially as regards plant assimilation, has 

 long been held, and especially since 1870, when v. Baeyer advanced his celebrated 

 theory of the formic aldehyde origin of carbohydrates. It is but natural to con- 

 sider that the formation of a complex molecule is the result of a building-up 

 procefis. It must be remembered, however, that in the living organism there is 

 always present a compound or mixture, or whatever we like to call it, of a highly 

 complex proteid nature, which, although at present indefinite from the purely 

 ■chemical point of view, is the essence of the vitality. Of course I refer to what 

 biologists have called protoplasm. Moreover, it is perhaps necessary to state what 

 as really nothing more than a truism, viz., that protoplasm is present in and forms a 

 part of the organism from the very beginning of its existence — from the germ to 

 the adult, and onwards to the end of life. Any special chemical properties per- 

 taining to protoplasm are inseparable from the animal or plant until that period 

 arrives which Keliule has hinted at when we shall be able to ' build up the forma- 

 tive elements of living organisms' in the laboratory.' But here I am afraid I am 

 allowing the imagination to take a flight which I told you a few minutes ago that 

 rtime would not admit of. 



The view that requires pu.shing forward into a more prominent po.sition than it 

 'has hitherto occupied is that all the chemical transformations in the organism — at 

 any rate all the primary changes — are made possible only by the antecedent com- 

 'bination of the substances concerned with living protoplasmic materials. The 

 •carbon dioxide, water, &c., which the plant absorbs must have formed a compound 

 or compounds with the protoplasmic material of the chloroplasts before starch, or 

 sugar, or cellulose can be prepared. There is, on this view, no such process as the 

 direct combmation of dead molecules to build up a complex sub.^tance. Everything 

 must pass through the vital mill. The protoplasmic molecule is vastly more 

 complex than anj' of the compounds which we have hitherto succeeded in 

 synthesising. It might take up and form new and unstable compounds with 

 •carbon dioxide or formic aldehyde, or sugar, or anything else, and our present 

 methods of investigation would fail to reveal the process. If this previous com- 

 bination and, so to speak, vitalisation of dead matter actually occurs, the appear- 

 ance of starch as the tir.st visible product of assimilation, as taught by Sachs, or 

 -the formation of a 12-carbon-atom sugar as the first carbohydrate, as shown by 

 the recent researches of Horace Brown and G. II. Morris, is no longer matter for 

 wonderment. The chemical equations given in physiological works are too purely 

 •chemical ; the physiologists have, I am afraid, credited the chemists with too much 

 knowledge— it would appear as though their intimate familiarity with vital pro- 

 cesses had led them to undervalue the importance of their prime agent. In giving 

 ■expression to these thoughts I cannot but feel that I am treating you to the strange 

 spectacle of a chemist pleading from the pliysiologists for a little more vitality in 

 the chemical functions of living organisms. The future development of vital 

 ■chemistry rests, however, with the chemist and physiologist conjointly ; the isola- 

 tion, identification, and analysis of the products of vital activity, which has 

 hitherto been the task of the chemist, is only the preliminary work of physiological 

 •chemistry leading up to chemical physiology. 



Peotoplasmic Theoet of Vital Synthesis. 



The supposition that chemical synthesis in the organism is the result of the 

 combination of highly complex molecules with simpler molecules, and that the 

 unstable compounds thus formed then undergo decomposition with the formation 

 of new products, may be provisionally called the protoplasmic theory of vital 

 synthesis. From this standpoint many of the prevailing doctrines will have to 



' liature, vol. xviii. p. 212. 



