352 



NATURE 



[November 25, 1915 



additional knowledge that has been rendered available 

 during the past twenty years or so. 



The spontaneous racemisation of optically active 

 compounds is discussed by S. Komatsu in the third of 

 his " Studies in the Stereochemistry of Quinquevalent 

 Nitrogen" (Mem, Coll. Sci., Kyoto, vol. i., No. 5, 

 July, 1915). In the case of a typical optically-active 

 iodide it was shown that fusion brought about the 

 decomposition shown in the equation, 



N(CH,)(C,H3)(CeH0( CH„.C„H,)I 



-> N(CH3)(C3H,)(C,H3) + C„H,.CH,.I. 

 On allowing the fused mass to stand for a few days 

 the iodide was reproduced, but when purified by re- 

 crystallisation from alcohol it was completely inactive. 

 In this way direct proof w^as obtained of the theory 

 first put forward by Pope in 1899 to account for the 

 autoracemisation of these compounds. 



The fifth part of the Memoirs of the College of 

 Science, Kyoto (July, 1915), contains a complete investi- 

 gation of the system : sodium sulphate-sodium 

 chromate^water. It is shown that at 15° C. the deca- 

 hydrates of sodium chromate and sodium sulphate are 

 mutually misclble in all proportions. At 25°, however, 

 the formation of these mixed crystals is limited to 

 34 mols. per cent, of the chromate. When more 

 chromate is added, the mixed crystals are decomposed, 

 and the anhj'drous sulphate separates. On further addi- 

 tion of sodium chromate, a new salt appears, which is 

 probably a hexahydrated chromate not possessing the 

 power of forming mixed crystals with the sulphate at 

 25° C. Indications have been obtained of the possible 

 formation of a double salt of the composition 



2Na,SO„Na,CrO„3oH,0. 

 Attention may also be directed to a series of papers in 

 part 3 of these memoirs on the alloys of (i) Sb and Te, 

 (2) Te and Se, (3) Te and Sb, (4) Tl and Se. These 

 include a complete investigation of each system from 

 the point of view of the phase rule, and are illustrated 

 by microphotographs of various alloys. The com- 

 pounds detected include Sb.Tej, PbTe, TUSe, TlSe, 

 TLSe,,, whilst Te and Se are shown to form two series 

 of mixed crystals descending to a eutectic point at 

 95 per cent. Se and 130° C. 



In No. 3 of vol. i. of the Bacteriological Series of 

 the Memoirs of the Department of Agriculture in 

 India, Mr. N. V. Joshi claims to have isolated a new 

 nitrite-forming organism from soil, differing morpho- 

 logically from others hitherto known. Its thermal 

 death point lies between 70° and 80° C, and its 

 optimum temperature of action at between 25° and 

 35° C. An increased proportion of carbon dioxide 

 in the atmosphere acts as a stimulus to, the activity 

 of this organism. 0-2 gm. of glucose in 50 c.c. of 

 Omelianski's solution totally inhibits nitrite formation 

 by this organism, and 02 gm. of asparagin greatly 

 retards it. In solutions containing phosphates, ammo- 

 nium chloride, ammonium sulphate, ammonium car- 

 bonate, asparagin and urea serve as sources of 

 nitrogen ; in the absence of phosphates, ammonium 

 carbonate is the only substance which can be easily 

 changed to nitrite. 



In a recent review of a small book called "An 

 Introduction to Mining Science" (October 21, p. 198) 

 NO. 2404, VOL. 96] 



it was pointed out that in this as in all works which 

 propose to teach just such portions of science as find 

 direct application to any branch of technology the 

 educational benefit to be gained from a study of the 

 science is deliberately sacrificed to expediency. One 

 of the authors of this book has taken exception to 

 this statement. We have no objection to putting his 

 protest on record, but we are unable to open our 

 columns to a discussion of the points raised by the 

 review. Our reviewer holds — and most people will 

 agree with him — that in teaching an art the 

 proper understanding of which requires the know- 

 ledge of certain portions of pure science, one of 

 two methods may be adopted : either the student may 

 be taught the science as a systematic entity, and then 

 taught the incidence of such portions of the science 

 as bear upon the industry in question, or else the 

 teaching may be restricted to such portions of the 

 science as are required for the special purpose in view. 

 The former method has a higher educative value than 

 the latter, because the reasoning faculties of a student 

 are educated by the systematic study of the science 

 in its logical development, whilst the latter method, 

 even though it might teach all the scientific facts that 

 bear upon an industr}', sacrifices the educative advan- 

 tages of the former. 



Messrs. Longmans and Co. announce for publica- 

 tion in their series of Text-hooks of Physical Chemistry 

 part ii. of "Electro-Chemistry," by Dr. E. B. R. Pri- 

 deaux; "A System of Physical Chemistry," by Prof. 

 W. C. McC. Lewis; "Practical Spectrographic Ana- 

 lysis," by Dr. J. H. Pollok ; and "Crystallography," 

 by T. V. Barker. In their Monographs on Physics 

 will be issued, "The Emission of Electricity from Hot 

 Bodies," by Prof. O. W. Richardson; "Electric 

 Waves," by Prof. G. W. Pierce; and "Atmospheric 

 Ionization," by Prof J. C. McLennan. 



Messrs. West, Newman and Co. have nearly ready 

 for publication, " Vigour and Heredity," by J. Lewis 

 Bonhote. It will be illustrated by coloured and un- 

 coloured plates and diagrams. 



OUR ASTRONOMICAL COLUMN. 

 The December Meteoric Shower. — This not- 

 able stream is an annually recurring one like 

 the August Perseids, and it will be visible this 

 year at a period when there will be little interference 

 from moonlight. The radiant point apparently moves 

 from near theta to alpha Geminorum, and the activity 

 of the display seems prolonged over nearly three 

 weeks. More observations are required as to the place 

 of the radiant on successive nights. As observed by Mr. 

 W. F. Denning at Bristol, the smoothed positions are 

 approximately as under : — 



