NA TURE 



jSg 



THURSDAY, JIT.Y 



1908. 



A TREATISE ON CHEMISTRY. 

 A Treatise on Chemistry. By Sir H. E. Roscoe, 

 F.R.S., and C. Schorlemmer, F.R.S. Vol. ii., The 

 Metals. New edition, completely revised bv Sir 

 H. E Roscoe and Dr A. Harden. Pp. xvi+1436. 

 (London: Macmillan and Co., Ltd., 1907.) Price 

 3oj> net. 



SIR HENRY ROSCOE is to be congratulated on 

 having completed a new edition of that portion 

 of Roscoe and Schorlemmer 's well-known " Treatise 

 on Chemistry " which deals with the metals. In the 

 first edition the metals were described in several 

 separate parts, which are now included in the present 

 stout volume of more than 1400 pages, forming the 

 second volume of the new edition of the "Treatise." 

 The characteristics of this treatise are well known to 

 English chemists. It constitutes a half-way house be- 

 tween a complete catalogue raisonne of chemical facts 

 and principles of which Gmelin's handbook is the 

 last great example and the modern dictionary and 

 treatise in which only important facts are recorded, 

 and then in the briefest possible manner, historical 

 allusions being either altogether omitted or reduced 

 to their simplest terms. 



The present volume presents an orderly and 

 readable account of the metals and their compounds, 

 due regard being paid to the history of their dis- 

 covery. The volume opens with a general discussion 

 of the metals, which might with advantage be ex- 

 panded. Then follow clear accounts of the methods 

 used in the determination of atomic and molecular 

 weights, of valency, including a brief description of 

 ^Verner's view of valency, of the classification of the 

 elements, in connection with which it may be noticed 

 that the system of classification adopted in the volume 

 is that of groups of natural families, which is un- 

 doubtedly still the most convenient for the purposes of 

 ■description — and description is the key-note of the 

 present treatise. Atomic weights are given both in 

 relation to hydrogen and to oxygen as unity. The 

 physical properties of metals and the constitution of 

 •salts follow next, and here it is interesting to notice 

 that electrolytic dissociation is accepted without com- 

 ment, although little use is made of the hypothesis 

 throughout the book, and the older type of chemical 

 equation is preserved. No fewer than thirty-four 

 pages are devoted to spectrum analysis, a section 

 which might well be considerably condensed. More 

 than forty pages are given to crystallography, another 

 special subject of great importance. In view of the 

 unwieldy size of the present volume, it is a question 

 whether both these special subjects should not receive 

 {ess detailed treatment in a treatise on the metals. 

 The remainder of the volume relates to the descrip- 

 tion of the metals and their compounds, to which 

 1 177 pages are devoted. 



It must be confessed that, without changing the 

 readable type in which the book is printed, and 

 without omitting the historical notices and descrip- 

 tions of metallurgical and manufacturing processes 



NO. 2022. \"or.. 



which form the most valuable feature of the 

 "Treatise," there is room for very considerable con- 

 densation both in form and substance. Critical 

 revision, both from a literary and a chemical stand- 

 point, would lead to many changes for the better, and 

 a reduction of the volume to nearly half its present 

 dimensions without at all impairing its value. Nearly 

 five pages are devoted to gunpowder of the old type, 

 with voluminous tables relating to explosive processes 

 and products, taken from the work of Noble and Abel 

 of thirty-five years ago. Several pages are given to 

 a description of processes of preparing alum which 

 have long since been abandoned, yet in this account 

 there is no allusion to the industry which once 

 flourished on the Yorkshire coast, although alum 

 manufacture in Italy and .Asia Minor is mentioned. 

 It would be easy to multiply instances of this kind 

 and to point out many cases in which the exercise of 

 a more critical judgment would have been beneficial, 

 not only in eliminating unessential or unimportant 

 material, but also in restricting a too luxurious 

 licence in the use of words. 



The historical information included in the volume is 

 generally of great interest to the chemist as well 

 as to the less technical reader, but here again much 

 is recorded which is of doubtful value. The derivation 

 of magnetite from Magnesia, a town in Lydia now 

 known as Manisa, is at least plausible, but to urge 

 in its support that Plato and Theophrastus called the 

 mineral the " Heraclean stone," Heraclea being 

 another name for Magnesia, is not likely to commend 

 itself to anyone with knowledge of the subject. 

 Magnetite is common throughout this country. 

 Heraclea was probably a different town from Magnesia, 

 and magnetite was probably found near both. One 

 turns with interest to magnesium and manganese tor 

 information as to the origin of these words and their 

 connection with magnetite, but the subject is left in 

 confusion. It is a curious coincidence, if nothing 

 more, and one of interest to the philologist, that tin.' 

 soil in the neighbourhood of Magnesia is particularly 

 rich in the earth of that name. 



The statement that " an alcoholic solution of fen ic 

 chloride was formerly employed as a quack medicine 

 of repute, known by the name of Lamotte's golden 

 drops," might well have been supplemented by the 

 information that this solution is included in tin; 

 British Pharmacopoeia, and is still well known as 

 " tincture of steel." 



By far the most valuable sections of the bonk- 

 for the chemist will be the descriptions ol 

 modern metallurgical and manufacturing pro- 

 cesses, which have been brought well up to date. 

 More attention might have been given to the revision 

 of the paragraphs relating to the occurrence of metals. 

 The new source of tin in the highlands of West 

 Africa, from which an appreciable output of the metal 

 is already being obtained and which promises to have 

 a great future, is not alluded to ; whilst the occur- 

 rence of tungsten as wolframite with the tin ore 

 of the Malay States is not mentioned under tung- 

 sten, although the separation of tungsten from tin is 

 alluded to in connection with the metallurgy of tin. 



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