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SCIENCE 



[N. S. Vol. LII. No. 1336 



the reduction of foods into the more complex 

 amino-acids before 'being rewoven into the 

 tissues of life. From medicine began our rec- 

 ognition of the plowman as the first parent of 

 animals and man, and our fuller knowledge of 

 "the green plant as the fundamental capital- 

 ist." 



Herbs gladly cure our flesh, because that they 

 Fiaide their acquaintance there. 



In the dark soil the nitrifying bacteria live on 

 inorganic matter; so in the light some inor- 

 ganic colloidal systems can build up formalde- 

 hyde (B. Moore). Medicine has introduced 

 the chemist to the domain of the hormones 

 and chalones, themselves also bodies of the 

 simpler chemical constitution — some crystalliz- 

 able, all able to resist prolonged 'boiling — 

 blended into a wonderful physico-chemical co- 

 ordinating system, secretly at work all the 

 time under the diagrams of the innocent neu- 

 rologist. We may suppose indeed that every 

 active tissue of the body, or every cell, even of 

 bone and skin, or of the substrate of mind 

 itself, like every individual of a social organ- 

 ism, contributes some element to the organic 

 whole, some inward production necessary for 

 grovrths, or for signals." There may be a 

 world of pathological (alien or perverted) hor- 

 mones as yet unexplored. May the dive in- 

 wards of epithelial cells in cancer be due to 

 some inversion of chemotaxis, possibly under 

 the influence of an alien (parasitic?) enzyme? 

 Within the body then all parts are the " en- 

 vironment " ■of each — so that we have both an 

 inner and an outer " climate," an aspect of 

 the microcosm not to be forgotten in the field 

 of mental disease. Thus it is that '' Each part 

 may call the farthest, brother." And these 

 agents have a field of action far beyond the 

 body, as we see for example in the sexual hor- 

 mones. If there be a " migration hormone " 

 its sphere is the world. 



Again, is it not largely by medicine that the 

 study of enzymes has thrown light upon the 

 operations of catalysis which, like the rollers 

 under a log or, as we now think, more by en- 



- Mathews, ' ' Physiological Chemistry, ' ' second 

 edition, p. 835. 



gagement and disengagement like rack and 

 pinion, is incessantly forwarding, by various 

 intermediate series, and by reversible actions 

 at points of concentrative equilibrium, the 

 processes of nature? The vitamines may be 

 of this kind, agents which have upset our 

 cruder calculations of nutritive values ; for in- 

 stance, in the feeding of children, we no longer 

 take cane sugar to be the vital equivalent of 

 lactose, nor margarine of butter ; not all the ni- 

 trogen of nutrition is included in protein, nor 

 are phospho- and amino-lipins, nucleic acid, 

 amino-acids, and so on, mutually convertible 

 in the body. We must admit that the funda- 

 mental principles of nutrition have yet to be 

 redetermined. Moreover the war has forced 

 us to remember the mutual dependence of food 

 kinds; that of course fats and carbohydrates 

 are not wholly independent or equivalent; the 

 carbohydrates can not make up any great lack 

 of fats, nor can oxidation of fats proceed in 

 the absence of carbohydrates. 



Another system of balances in the body, as 

 of the reciprocal functions of lung and kidney, 

 is more obviously chemical. Medicine has 

 taught us how the lung deals with the CO: ions, 

 the kidneys with sundry other acids, so that 

 the blood reaction is maintained with extreme 

 nicety; and that other systems — for example, 

 the vasomotor — are probably little less sensi- 

 tive, and that there are other subtle causes of 

 anoxaemia besides the cardio-pulmonary (Hal- 

 dane) ; so that in medicine it is of the first im- 

 portance that in all abnormal conditions the 

 oxygen tension of bloods should be syste- 

 matically ascertained and compared. The, 

 hydrogen ion concentration is consistently 

 higher upon flesh diet, lower upon vegetable 

 diet; but I think we have not yet learned to 

 discriminate so subtly as Charles Kean who is 

 said to have chosen his viands according to the 

 parts he had to play — pork for tyrants, beef 

 for murderers, mutton for lovers. 



Next after the origin of life itself, from 

 ancient times to this day no enigma has at- 

 tracted and baffled the curious mind of man 

 more than that of living " form." Many of 

 our keenest minds — Haldane, D'Arcy Thomp- 

 son, Os'born, Dendy, McBride, I mention a few 



