• KNOWLEDGE ♦ 



[Nov. 4, 1881. 



ilmnRod into fat — a cli.-ui),"" wliosc possiMlity In- went 

 fur to iirovc, — ami thrn only in tlio sanio iiicusun- iis fnt 

 itsi'lf. .Vnd lie (|uito oorrpctly nssi|,'nccl BR tliP ultiiniit<! 

 destination of tlii> p-cat l>ulk of the non-nitrogenous toin- 

 pononts of food, the beini^ (so to speak) " Imrned " within 

 the liody, l>y couiliinatiiin with oxygen taken in through 

 tiie lungs ; their liyilrocarlions lieing exhaled t>y these 

 organs in the form of water and carlionic acid. But he 

 assiimrtl that the only purpose served liy this o.xidation 

 was the protluction of h^iit ; alKruiing that all the me- 

 rhnnicnl force, exerted I'y the Animal Uody is the product 

 of a transformation of liriit'j muscular til>re into (had, 

 the " vital force " which was possessed by the living tissue 

 heing " expended in the shape of motion." The oxidation 

 of the dead material he seems to liave regarded as only a 

 consequence of its loss of power to resist chemical agencies, 

 and as a means of its removal, — serving, at the same time, 

 as an additional source of heat. And riglitly judging that 

 this chemical metamorphosis should show itself by the 

 increased excretion of urea in the urine (the kidneys fur- 

 nishing the channel through whicli most of the nitrogenous 

 "waste" is carried out of the body), he appealed, in 

 support of his doctrine, to what he supposed to lie the 

 fact of such increase, and its proportion to the amount of 

 work done. 



Notwithstanding the general acceptance of Liebig's 

 doctrine among the Physiologists of that time, there were 

 those who saw that it was attended with considerable diffi- 

 culties, notably as regards the amount of work done by 

 man and animals upon a very small allowance of nitro- 

 genous food. It was well known, for instance, that 

 Bengalee labourers (who, for their size, are very fair 

 workers*) live all but exclusively on rice, which consists 

 almost entirely of starcli ; a pound of this, with a little 

 ghee (butter), or a small bit of fish, constituting their 

 ordinary diet. And it appeared from the carefully 

 conducted experiments of Mr. Joule, of Manchester, that 

 the quantity of work done by a grass- or hay -fed ox (taking 

 into account that done by its heart vnthin its body, as well 

 as that done outside its body) was more than could be 

 accounted-for by the metamorphosis of the nitrogenous 

 constituents of its food. 



Mr. Joule was at that time engaged upon an 

 inquiry into the Mechanical equivalent of Heat, which 

 led him to suspect that the combustive oxidation of 

 the non-nitrogenous coiistituents of food might be a 

 source of mechanical poiver, as well as of heat. But 

 this doctrine was first definitely stated, and shown to be 

 one expression of the great general fact (or law) now 

 known as the Conservation of Energy, in the " epoch- 

 making " treatise published in 1845, by Mayer; who urged 

 (1) tliat the chemical force contained in the ingested food 

 and in the inhaled oxygen, is the source of the motion and 

 heat which are the two products of animal life ; and (2) that 

 the production of these forces varies in amount with the 

 chemical changes to which it is due. The animal body, he 

 maintained, is comparable, in these respects, to a steam- 

 engine, in wliich work is being done, and heat produced, by 

 the combustion of fuel ; and he calculated that the quantity 

 of carbon burnt off by the Ijody in a day (as measured by the 

 amount of carbonic acid given off in the expired air) is far 

 more than sufficient for the whole day's work, — about four- 

 fifths of it being used in the production of heat, while the 

 remaining fifth suffices for the prodiiction of the muscular 



force ordinarily exerted within and without the l»ody. He 

 affirmc'd that " the muscle is the instrument by wliich 

 clieniical change is transformed into mechanical effect, not 

 the material wliicli is itself transformed ; ' and he regardi;d 

 the blood-stream that flows through the capillaries of the 

 muscle, as bringing both the fuel and the oxygen needed to 

 burn it. With the prevision which marks true geniii-:, 

 Mayer asserted that as soon as experimental motliods should 

 become sufficiently perfect to render it possible to deter- 

 mine with precision the amount of chemical change, either 

 in the whole animal body or in a single mu.scle, during a 

 given period, and to measure the production of heat and 

 the work done during the .same period, the result would 

 show a definite correlation between them. 



This (as will be shown hereafter) has been completely 

 verified by subsequent research ; the only point in which 

 ^Mayor's doctrine has been found to need correction, being 

 one of secondary importance. 



[To he continued.) 



• I have been informed by an engineer who superintended the 

 construction of part of the Bengal system of railways, that the 

 average quantity of earthwork done by a native labourer on the 

 above diet is about two-thirds that of a higlily-fed English " navvy." 



ARE WOMEN INFERIOR TO MEN ? 



A FRENCHMAN named Delaunay has recently pul>- 

 lished a pamphlet, the object of which is to show that 

 women are intellectually and physically inferior to men. At 

 the outset it should be noticed that this M. Delaunay must 

 not be mistaken for the great French astronomer Delaunay, 

 (who died some nine years ago). The point requires noting, 

 because the present Delaunay has ere this dealt with sta- 

 tistical evidence relating to astronomical matters, en- 

 deavouring to prove therefrom that the planets Jupiter 

 and Saturn exercise a marked influence on the phenomena 

 of earthquakes. It is hardly necessary, perhaps, to say 

 that the proof was hardly so perfect as M. Delaunay 

 imagined. In fact, his reasoning would not have at- 

 tracted attention if his name had not sounded like that of 

 a very eminent astronomer, of whose death many had not 

 heard. 



M. Delaunay now devotes himself to the task of showing 

 that those who regard the two sexes as intellectually or 

 morally equal, are absurdly sentimentaL He seeks to show 

 that women are in a lower stage of development than men, 

 on grounds wliich he describes as purely anthropological, 

 though he should rather, it would seem, have described 

 them as biological, since his inferences respecting the tests 

 of development are derived quite as much from the study 

 of other animals as of men. He admits that among certain 

 lower forms of life, as insects, some fishes, and reptiles, the 

 females show a superiority to the males ; but among the 

 higher races of vertebrates (backboned animals) it is dif- 

 ferent. Among birds and mammals (he might have added 

 marsupials, or pouched animals, as kangaroos, opossums, 

 kc), the male is nearly always superior to the female. The 

 inference is, that whereas in lower races the female is 

 superior to the male, the male is equal to the female in 

 races more advanced, and superior to the female in all the 

 superior species. "The supremacy of the female is there- 

 fore," he says, " the first form of the evolution undergone 

 by sexuality, while the supremacy of the male is the last 

 form." The conclusion is calculated to be so satisfactory to 

 men that they may be permitted, perhaps, to pass over the 

 manifest weakness of the reasoning. The law, which 

 should be universal to be of avail, is admitted to be only 

 general ; and it is noteworthy that the reasoning really 

 points to the conclusion that the higher the race, the lower 

 relatively is the female : so that it would seem tkat the first 



