5/2 



NA TURE 



[October 3, 1907 



(i) Besides albumen, fat, and carbohydrates, man re- 

 uLiires for his nourishment Certain substances which are 

 contained in animal and vegetable food in varying quanti- 

 ties. These substances are both in quantity and quality 

 related to the nitrogenous ingredients of food. 



(2) Digestive and other ferments, the internal secre- 

 tions, protective matters, &c., are nitrogenous substances 

 or descendants of such ; their production must therefore 

 be dependent to a certain extent on the intake of albumen 

 and the conversion of the same in the body. 



(3) Until the relations both of quantity and of quality 

 are better understood, it will be advisable for general 

 biological and hygienic reasons to favour an ample pro- 

 portion of protein in practical nutrition, and not to limit 

 the amount of protein to the minimum with which nitro- 

 genous equilibrium can apparently be maintained. 



The alcohol question also was to the fore, but a 

 somewhat guarded opinion seemed to be expressed 

 res-'irding its supposed evil effects when used in 

 moderation. Dr. Triboulet, of Paris, considered that 

 alcoholic drinks had an unfavourable action in cases 

 of tuberculosis, and that alcohol ditninishes resistance 

 .ind predisposes to tuberculosis. Dr. Moeli, of Berlin, 

 considered that alcohol is not a food, is not necessary, 

 and in manv cases is detrimental, and that its use 

 should be discouraged in every way, not only by teach- 

 ing- the masses the evil efTects of its use, but by in- 

 stituting other interests so that the lack of it should 

 not be felt. 



Industrial diseases, particularly lead and mercurial 

 poisoning, and those arising from dust, strain, &c., 

 were the subject of several papers, and many sug- 

 gestions were made to mitigate these evils. Light- 

 ing, ventilation and water supplies were also dealt 

 with, and likewise statistics. According to Prof. 

 Bailed, the recent Prussian mortality tables show that 

 as regards mortality the country has a decided 

 superiority over the "towns, but that this superiority 

 is only distinctlv noticeable among the male sex, and 

 at ages 40-50 years the towns appear to be slightly 

 more favourable than the country. 



At the general meeting telegrams of congratulation 

 were received from the German Emperor and Empress, 

 Lord Lister, and others, and three special lectures by 

 English, French, and German men of science respec- 

 tively were delivered. Dr. Haldane discussed his re- 

 searcheson the effects of high pressures andtemperatures 

 in underground workings on man. No ill effects result 

 with pressures below about three atmospheres, but 

 above these, unless the pressure is increased or de- 

 creased step bv step, as the case may be, grave effects 

 mav be produced. As regards temperature, it is the 

 wet-bulb temperature which determines the suitability 

 of atmospheric conditions in mines. The optimum 

 wet-bulb temperature is below 27° C, the maximum 

 that can be sustained without danger being 31° C. 

 Prof. Chantemesse (Paris) discussed the serum treat- 

 ment of typhoid fever. By growing the typhoid 

 bacillus in a spleen broth medium for a week, heating 

 to 55° C, and injecting into horses, the serum of the 

 latter acquires properties which usually act favourably 

 on the course of the disease when injected into the 

 patient. Thus, in the Paris hospitals from 1901-7, 

 among 5621 cases the mortality was 17 per cent., but 

 during the same period in 1000 cases treated by Prof. 

 Chantemesse with his serum the mortality was only 

 43 per cent. Prof. Schattenfroh, of Vienna, lectured 

 on the hygienic care of water supplies, and the 

 chemical and bacteriological examinations of drinking 

 water. He urged that an international commission 

 .should be formed to devise standard methods for carry- 

 ing out the latter. 



The museum arranged in connection with the con- 

 gress was of the greatest interest. The exhibits of the 

 Imperial Board of Health and of the Institute for 



NO. 1979, VOL. 76] 



Infectious Diseases were especially noteworthy. They 

 consisted of cultivations of pathogenic micro-organisms 

 and drawings and photographs of the same, patlio- 

 logical specimens of tuberculosis and other diseases, 

 series of specimens demonstrating agglutination and 

 precipitin tests for blood, travelling laboratories, &c. 

 .Ml the principal Continental firms showed chemical 

 and bacteriological ajjparatus, microscopes, and other 

 instruments, and many of the casts showing patho- 

 logical conditions were marvels of modelling. The 

 exhibit of the B.icleriological Institute of Rio de 

 Janeiro also was a large and comprehensive one, show- 

 ing what good work is being done abroad, and it is to 

 be regretted that exhibits from the British Empire 

 seemed to be almost entirely wanting. 



Demonstrations on the use of apparatus were given, 

 and one interesting exhibit under the microscope was 

 that of living active spirochetes, minute micro- 

 organisms which occur in relapsing fever, syphilis, 

 and certain animal diseases. 



THE HARD .4A7) .SOFT STATES IN DUCTILE 



METALS. 

 \X7HEN the early craftsmen first observed that 

 * * the metals they worked in were inade harder 

 by hammering, and that the original softness could be 

 again restored to the hardened metal by heat, it 

 probably did not occur to them that any explanation 

 of these useful properties was called for. At a later 

 period, when an interest in the reasons for things 

 became more general, it is probable that hardening 

 was attributed to the compacting of the substance by 

 the driving of its particles closer together so that 

 the mass as a whole became less open or porous. In 

 the same way heat annealing was probably assumed 

 to act by permanently expanding the metal and open- 

 ing up its texture. .So many analogies to these oper- 

 ations were ready to hand from the most common and 

 everyday experiences that it is not surprising that 

 even on closer inquiry this explanation should con- 

 tinue for a time to be accepted as suflicient, the more 

 so as it was obviously true that in some cases un- 

 worl-ced metal had an openness or porosity which could 

 be removed by hammering or working. While the 

 researches of chemists on the density of the metals 

 showed plainly that increase of density does not 

 alwavs result from compacting by pressure, these re- 

 searches were probablv too far removed from the ken 

 of those who were most intimately concerned with 

 the working of metals to arouse them to the insuffi- 

 ciency of the existing explanation of hardening. 



In the latter part of the past century the views of 

 physicists and chemists on the influence of molecular 

 structure on the properties of matter began to find 

 application in the field of scientific metallurgy. In 

 particular, much attention was directed to the study 

 of the crystalline constituents of alloys and to the 

 influence of heat treatment on their equilibrium. The 

 studv of the iron alloys also led to the development of 

 the view that iron itself can exist in several allotropic 

 forms; thus the idea of allotropy was introduced into 

 practical metallurgy. 



Mr. G. T. Beilby's researches,' which form the sub- 

 ject of the present article, indicate that all crystalline 

 substances can also exist in a non-crystalline or amor- 

 phous form, and that the properties of these two forms 

 are so distinct that they must be regarded as definite 

 allotropic modifications. Observations on the stability 

 of these forms, and on the conditions under which the 

 one form can pass into the other, confirm this view. 

 As these general principles have been found to apply 



1 "The Hard and Soft .S'ates in Ductile Metals." By G. T. Beilhy 

 F.R.S. Paper read before the Royal Society on June 27. 



