374 



NATURE 



[July 5, 1917 



are constructed even to-day, with the aid of all modern 

 equipment and inheritance, may contain fatal elements 

 of weakness, thoug-h they be promulgated 'by scientific 

 men of the highest rank and attainments." Men of 

 science are, of course, subject to the limitations of 

 prejudice, undue reverence for authority, and so on, 

 and also they and their critics often fail to distin- 

 guish clearly between legitimate theory w-ithin those 

 fields where views may be rigidly tested and audacious 

 conjecture. Prof. Hcbbs then reviews by means of 

 examples the position of science from the earliest times 

 down to the memorable defeat of Bishop Wilberforce 

 by Huxley in i860. In the fifth century we read, w^hat 

 sounds like a pessimistic prophecy, that "with the 

 invasions of the barbarian Huns and the Germanic 

 tribes there ensued the eclipse of civilisation. ..." 

 In this sketch the attempts at the control of scientific 

 theory by the Church were shown gradually to decline, 

 although in this respect the Church was quite power- 

 ful even fairly lately. Prof. Hobbs then selects some 

 examples from geology in order "to discuss what may 

 perhaps be called the psychology of theories and the • 

 ■conditions which determine their acceptance" : the 

 effect of certain features of Mallet's theory of earth- 

 quakes in removing seismology from the field of 

 geology for the period of nearly half a century, and 

 giving it over to the elasticians ; the mistaken deduc- 

 tions from the aerothermic and geothermic gradients; 

 Ferrel's mistaken deduction of whirls about the geo- 

 graphic poles, and so on. 



At a time when the supnlv of our food is controlled 

 by men who probably know little of the science of 

 nutrition, and nothing at all of physiological chem- 

 istry, the appearance (in the Revue Scientifique for 

 June 9) of an article by Prof. E. Gley, entitled " Le 

 Besoin d'Aliments Speciaux," is particularly oppor- 

 tune. Probably the vast majority of people in this 

 country think that if there is a shortage of any par- 

 ticular article of food it can, in all cases, be replaced 

 "by another without detriment to the health of the con- 

 sumer. As Prof. Gley points out, however, of the four 

 principal forms of nutritive material, mineral salts, 

 carbohydrates, fats, and proteins, mineral salts will 

 not replace, and cannot be replaced by, an> of the 

 others. Carbohydrates and fats, which supply energy, 

 are to a certain extent interchangeable, but neither of 

 them is a substitute for proteins, which in their turn 

 will not replace either carbohydrates or fats. Further, 

 vegetable proteins will not replace animal proteins. 

 It has been shown bv the researches of various workers 

 that neither animals nor man will maintain their 

 nitrogen balance or their body weight when their 

 protein food consists of the zein of maize or of the 

 globulin of lupins. Other proteins, e.g. the gliadin 

 of wheat and the hordeine of barley, whilst sufficient 

 to maintain bodily equilibrium, will not promote 

 growth. These two phenomena have been proved to 

 be due, the first to the absence of tryptophane from 

 zein and globulin, the second to the absence of lysin 

 from gliadin and hordeine. In order to maintain the 

 nitrogen balance and to promote growth the protein 

 nutriment of man must contain trvptophane and lysin. 

 It is because meat contains all the necessary amino- 

 acids, and contains them in suitable proportion, that 

 it is so valuable as a food. For the efficient working 

 of the digestive system cellulose is an indispensable 

 constituent of food. Rabbits fed on rations containing 

 no cellulose die of intestinal obstruction. The green 

 vegetables ordinarily eaten with meat are valuable 

 as supplying the necessary cellulose. Prof. Gley advo- 

 cates the consumption of dried fruits for the same 

 reason. These have the advantages over green 

 vegetables that they contain more cellulose and can 

 be obtained independently of the season. 



NO. 2488, VCL. 99] 



Dr. J. S. Haldane submitted a paper to the recent 

 meeting of the Institution of Mining Engineers upon 

 "The Spontaneous Firing of Coal," in which he 

 summarised the results of the researches carried on 

 during the last four years at the Doncaster Coal 

 Owners' Research Laboratory. Even apart from their 

 purely technical importance, some of the results ob- 

 tained form a valuable contribution to our knowledge 

 of the physico-chemistry of coal. Thus it has been 

 shown that coal, even in thin slices, is highly imper- 

 vious to the passage of gas, so that changes of atmo- 

 spheric pressure can have no appreciable influence on 

 the evolution of gas by solid coal. On the other 

 hand, it is found that coal has an extraordinarily high 

 solvent power for gases, the ordinary atniospheric 

 gases being far more soluble in coal than in water, 

 and, further, the rate of solution of these gases fol- 

 lows Henry's law, just as though they were in solution 

 in a liquid. In the case of oxygen some of the gas 

 is thus dissolved or adsorbed, while some enters into 

 chemical combination with certain of the constituents 

 of the coal. The rationale of the oxidation of coal 

 has been investigated, and the part played by pyrites 

 in such oxidation has been determined, but more 

 research is needed in order to settle the exact nature 

 of the substances most readily attacked by oxygen 

 and of the products of such oxidation. 



The growing interest in special acid-resisting alloys 

 and the many uses found for them has stimulated both 

 the search for efficient materials of this nature and 

 the study of the causes underlying their inertness. 

 The alloys developed by Prof. S. W. Parr for use 

 in calorimeter construction have shown this quality 

 of high resistance to corrosion to a marked degree. 

 The almost perfect insolubility of these alloys in nitric 

 and other acids seems to be conditioned upon a proper 

 mixture of chromium, copper, and nickel, together 

 with smaller quantities of such added metals as tung- 

 sten and molybdenum. These additions have so 

 marked an effect in improving both the acid-resisting 

 and casting qualities of the alloys that it has seemed 

 desirable to study their effects more systematically in 

 order that they may be used to the best advantage. 

 This study has been undertaken by McFarland and 

 Harder, and the results of their preliminary investiga- 

 tion have been published in Bulletin No. 93, University 

 of Illinois. The complexity of the mixtures used has 

 made the problem difficult, and has shown the neces- 

 sity for first obtaining a more complete knowledge of 

 the ternary alloys of chromium, copper, and nickel, 

 and also of the three binary systems underlying them. 

 It is quite obvious from this preliminary study that 

 much more work requires to be done to establish the 

 copper-chromium and nickel-chromium equilibria on a 

 satisfactory basis. 



Engineering for June 29 contains an illustrated 

 account of the new Cunard liner Aurania, which has 

 just been put on the North Atlantic service. This 

 vessel has extensive second- and third-class passenger 

 accommodation, and has also large cargo holds. The 

 dimensions are 538 ft. 6 in. long, 65 ft. 4 in. beam, 

 and 46 ft. 6 in. depth. The gross tonnage is 13,936, 

 and with geared turbines of approximately 7200 

 shaft-horse-power she will have a sea speed of four- 

 teen knots when displacing 21,405 tons. The calcu- 

 lated coal consumption is only about four tons per 

 hour, hence the propelling expense will be very favour- 

 able in view of the large earning power indicated by 

 the passenger and cargo capacity. The vessel has 

 been constructed under the Convention regulations by 

 Messrs. Swan, Hunter, and Wigham Richardson, and 

 the machinery' bv the Wallsend Shipway and Engineer- 

 ing Company. 



