October 24, 191 2] 



NATURE 



2iy 



of some astronomers watching Mars split into 

 two, then into four, and finally into about 500 

 bits. This cluster then proceeds to swallow 

 Jupiter and Saturn; the sun blows up, and the 

 earth starts off somewhere on a wild career, 

 with a piece of sun just big enough to keep it 

 fairly warm. Then two of our astronomers suffer 

 a magical shrinkage in size, entering the infra- 

 tonic (less than electronic) world. And here we 

 mav as well leave them, for N.\ture is a scientific 

 journal, and this book, though a romance of 

 science, is more of the former than the latter. 



J. .\. H. 



NEW BOOKS OX CHEMISTRY. 

 (i) Per-acids and their Salts. By Dr. T. Slater 

 Price. Pp. vi+123. (London: Longmans, 

 Green and Co., 1912.) Price 3s. net. 



(2) Researches on Cellulose. III. (1905-1910). By 

 Cross and Bevan (C. F. Cross and E. J. Bevan). 

 Pp. X+173. (London: Longmans, Green and 

 Co., 1912.) Price 75. 6d. net. 



(3) Modern Research in Organic Chemistry. By 

 F. G. Pope. Pp. xii + 324. (London: Methuen 

 and Co., Ltd., n.d.) Price -ps.'Gd. 



(4) A Second Year Course of Organic Chemistry 

 for Technical Institutes. The Carbocyclic Com- 

 pounds. By F. B. Thole. Pp. vii-|-i86. 

 (London: Methuen and Co., Ltd., n.d.) Price 



(5 1 Experimental Science. II., Chemistry. By 

 S. E. Brown. Pp. vii+140. (Cambridge 

 University Press, 1912.) Price 2S. 

 (6) Eirst Year's Course of Chemistry. By James 

 Sinclair and George W. M'Allister. Pp. vii + 

 165. (London: G. Bell and Sons, Ltd., 1912.) 

 Price IS. 6d. 

 (71 Elementary Quantitative .inalysis. By Dr. 

 William Briggs and H. ^^^ Bausor. Pp. viii + 

 122. (London: W. B. Clive, University 

 Tutorial Press, Ltd., 1912.} Price 2.'r. 

 (8) Chemical Theory and Calculations. An Ele- 

 mentary Text-book. By Dr. F. J. Wilson and 

 Dr. I. M. Heilbron. Pp. iv-fi^S (London: 

 Constal)le and Co., Ltd., igi2.) Price 2.?. 6d. 

 net. 

 (i) T~^'^- PRICE'S monograph on the per- 

 J_>/ acids and their salts is the second 

 volume of a series of monographs on inorganic 

 and physical chemistry, the previous volume (Mr. 

 Soddy's book on the chemistry of the radio- 

 elements) having been reviewed recently in these 

 columns. One half of the book is occupied with 

 an account of the persulphuric acids and per- 

 sulphates, the remainder of the volume dealing 

 with perborates, percarbonates, pernitric and 



xo. 2243, VOL. go] 



perphosphoric acids ; pertitanates, perzirconates 

 and perstannates ; pervanadates, percolumbates, 

 and pertantalates ; perchromates ; permolybdates, 

 pertungstates and peruranates. The new volume 

 will go far to establish the reputation of the series 

 for thoroughness and utility. More than three 

 hundred references are given to the literature of 

 a subject which would scarcely have been credited 

 by the ordinary readers with having provided 

 material for one-half this number of papers. 



A word of comment may be added in reference 

 to the author's criticism of the view that in 

 presence of concentrated sulphuric acid, the per- 

 oxidised material consists mainly of pertetra- 

 sulphuric acid, H2S4OJ4. Such solutions on dilution 

 undoubtedly yield an oxidised acid of the formula 

 HoSOj. But the appearance of this acid is quite 

 compatible with its formation by hydrolysis on the 

 dilution of a solution containing the higher acid, as 

 shown by the equation 



H,,S40,4+ 3H,0 = 3 FLS04+ HjSOj ; 

 such a hydrolysis would not disturb the ratios of 

 "persulphuric oxygen" to "peroxide oxygen," on 

 which the formula H.2S40j4 was based. The 

 hydrolysis of Marshall's acid to Caro's acid, as 

 shown by the equation 



H2S20g-fH,0 = HjS05 + H2S04, 

 by dissolving it in concentrated sulphuric acid and 

 then diluting, presents some analogy to the con- 

 \ersion of ethylene into alcohol by a similar pro- 

 cess ; in each case the initial process may very well 

 be a condensation of the hydrolyte with the acid 

 to form a more complex substance, which is then 

 easily hydrolysed on dilution. 



(2) The third volume of Messrs. Cross and Sevan's 

 " Researches on Cellulose " covers the five years 

 from 1905 to 1910, but has been delayed to include 

 research vs,'ork published in 191 1. Special interest 

 attaches to the final chapter on technical develop- 

 ments, in which a brief account is given of some 

 important modern cellulose industries. It is noted 

 that in the artificial silk industry the last five 

 years have been marked by rapid developments, 

 j accompanied by a rapid gravitation to the level of 

 competitive prices. This has arrested the develop- 

 ment of the collodion processes, and has ac- 

 centuated the struggle between the cuprammonium 

 and viscose processes, in reference both to relative 

 costs and to the textile qualities of the products. 

 A remarkable development consists in the produc- 

 tion of transparent films of viscose in lengths of 

 1000 to 10,000 metres at an average width of a 

 metre, and at a thickness of o"25 down to 001 mm. 

 In view of the fact that the process involves (i) 

 coagulation, (2) purification from sulphur, (3) 

 bleaching and purification by special washings. 



