2o6 



NATURE 



[November 6, 19 19 



loidal catalysts, upon which depends in great part 

 the sweep of our health and of our diseases. In 

 these enzymes which accelerate metabolism we 

 may admire again, as in the simpler catalysts, the 

 exquisite economy of energy in vital processes ; 

 how small the energy transactions may be, and 

 these often reversible, which may compass great 

 ends. A striking example of such economy is 

 now being demonstrated to us in the calculated 

 balances of voluntary muscular activity. The 

 minute quantities of vitamine suggest that they, 

 too, are catalysts, and function without much 

 waste. 



Diet and Nutrition. 



During the last half-century the subject of 

 dietetics has been strictly analysed on quantitative 

 lines, and its energies calculated in caloric and 

 other units. Yet even herein our attainment is 

 far from complete. About this well-worn, almost 

 hackneyed subject a breeze of new and far-reach- 

 ing ideas is gathering. Our balances, as in the 

 children's milk, and in the analysis of the diseases 

 of deficiency, are eluded by imponderables, by the 

 infinitely little ; our quantities are set at naught. 

 For health and disease the new vitamines 

 to which I have alluded, like some other 

 hormonic and enzymic imponderables, are as 

 potent as they are intangible. Hormones 

 work in infinitesimal ranks; and I believe no 

 antibody has as yet been isolated. Once more we 

 find that Nature laughs at our formal categories, 

 at our several compartments of protein as such, 

 of carbohydrates as such ; a straitlaced reckoning. 

 No one class of foods, it appears, will build or 

 burn without another; carbohydrate metabolism 

 leans on that of protein, the protein on carbo- 

 hydrates, and all these on the fats, in mutual 

 function ; each of these is engaged in the totality 

 of the chemical changes. For instance, deficient 

 carbohydrate means deficient oxygenation of fats, 

 and imperfect protein distribution. 



Nor is this all; some of our great ancestors, 

 likewise having penetrating ideas of the infinitely 

 little, supposed that the sources of nutrition must 

 contain a supply to each and every living tissue of 

 its own form of minute identical elements ; be they 

 of bone, of muscle, of blood, of "nerve," and so 

 forth, each being proper to its particular tissue, to 

 which it attaches itself (Homceomerism). This 

 crude notion, it is true, made no great way ; still 

 until lately we have all of us supposed some, if a 

 more general, congruity of form between the nutri- 

 tive elements and the qualities of their various 

 destinations. But the study of the reduction of 

 foods to amino-acids, and issues of like researches, 

 are telling us to-day that there is no necessity even 

 for the food proteins to be of similar constitution 

 to the tissues which they subserve. To the almost 

 magical part played by certain elements, such as 

 calcium, as stabilisers, or of the alkali-metals as 

 labilisers of equilibrium I need but allude. The 

 bearings of these dietetic researches upon practice, 

 for example in the treatment of diabetes, are too 

 obvious for reiteration. 



NO. 2610, VOL. 104] 



If we turn now to the cell, as described to us by 

 Virchow, we realise that our knowledge of this 

 tiny microcosm is as yet only beginning. The 

 infinity of extension is not strange to us, for some 

 of it we can see ; but the infinity of the universe of 

 the little, which far escapes even our microscopes, 

 does not so strike the imagination. Still, even 

 of this inward universe and its intense activities, 

 as by present research they emerge into the field 

 of the mathematical physicist, of the spectro- 

 scopist, of the radiologist, of the physical chemist, 

 we are beginning to conceive something. The 

 microcosm is no longer Man, but the cell of which 

 he is built. To our wonder we see that, even 

 within such tiny spheres, some of them filtrable, 

 are multiple systems moving in relative independ- 

 ence of each other. The cell membrane is formed 

 chiefly perhaps by the physical processes we have 

 considered. Yet puzzling and intricate as these 

 reactions are, they are all-important to the 

 physician ; as, for instance, in the relations of the 

 glomerular epithelium to sugars; its unerring dis- 

 crimination between substances, even isomeric, in 

 the blood, as between glucose and lactose ; or 

 again in the constant and subtle opposition of tie 

 normal intestinal epithelium to the entrance of 

 poisonous elements, or foreign proteins, into the 

 vessels and tissues. 



For the Future ? 



This rapid glance over a small part of the field 

 of the medical sciences may serve to reinforce the 

 lesson of their profound and instant bearing upon 

 practice, and the need for linking up the laboratojy 

 with the wards. Only by disinterested research 

 on the large patient and prophetic lines of the pure 

 sciences can progress be made. The isolated 

 academic worker, as well as the practitioner, loses 

 by this isolation ; he loses the spontaneous out- 

 crops of problems and crucial instances which so 

 often spring up in practice, but fail to show them- 

 selves in the laboratory. So complete and mis- 

 chievous, however, has been the barrier between 

 research and the industry of medicine that a re- 

 action from " laboratorism " to symptomatology 

 has set in, because there are no intermediary 

 workers — no engineers — between the knowledge 

 getters and the knowledge dealers. Thus we 

 have laboratory investigators completely out of 

 touch with practice, and practitioners faithless of 

 theoretical principles — just "Philistines." 



As the engineer is something of a mathematician, 

 something of a physicist, so the professor of medi- 

 cine must be something of a physicist, something- 

 of a biochemist. Through these middlemen the 

 man of science and the practitioner should mutu- 

 ally feed each other. In every adequate clinical 

 school, then, there must be a professoriate ; whole 

 time — or nearly whole time — professors, each with 

 his technical laboratory, biochemical and patho- 

 logical, who with their assistant staffs shall be 

 engaged continually in irrigating our profession 

 from the springs of the pure sciences. 



