February 26, 1920] 



NATURE 



689 



the convenience of students, divided into two 

 volumes, of which the " General Chemistry " is 

 the first, leaving- " Analytical Chemistry " to the 

 second. The volume before us deals with the 

 principles of chemistry, and gives a series of 

 more than 300 experiments in illustration of 

 them. The text is sufficient to show the bearing 

 of the experiments, in addition to the instructions 

 for the performance of them, but it is presumed 

 that a course of lectures dealing more fully with 

 the subject will be given concurrently with the 

 practical work. 



(2) The "Treatise on Qualitative Analysis " has, in 

 the present edition, been " rewritten, recast, and 

 enlarged in order to adapt it to modern methods 

 of teaching." It is essentially a book of facts, 

 for it treats of the detection of the rarer as well 

 as the more common metals and acids, a con- 

 siderable number of organic acids both aliphatic 

 and aromatic, a few hydrocarbons, halogen, nitro- 

 and other derivatives, alcohols, ethers, aldehydes, 

 ketones, carbohydrates, glucosides, organic bases, 

 eighteen alkaloids, and finally nineteen different 

 gases. In addition to all this there are instruc- 

 tions for making stirring rods, boring corks, etc., 

 for performing various operations, such as pre- 

 cipitation, filtration, washing, and drying, and as 

 to the use of the spectroscope, a description of 

 laboratory fittings, recovery of residues, lists of re- 

 agents, and various tables. There is also a small 

 section which gives lists of simple salts, mixtures, 

 and minerals suitable for practice, though these 

 do not include organic substances, the rarer 

 elements, or gases. Thus teachers, as well as 

 students in all stages of their work, will find 

 assistance in this volume. 



It is curious how long a time it takes for some 

 facts of first importance to work their way into 

 text-books that are written for students. It has 

 been known for more than fifty years that man- 

 ganous chloride, when introduced into a flame 

 in the ordinary manner, colours it brightly green, 

 but scarcely any text-books note the fact. We have 

 known students to be led astray by this omission. 

 The authors here state definitely that the com- 

 pounds of the metals Zn, Mn, Ni, and Co show 

 no characteristic flame colorations, and in the 

 tables a green flame is followed by the inference 

 — Ba, Cu, B0O3, exactly as in almost every text- 

 book on the subject. There is a tendency to be 

 more " theoretical " than practical in the statement 

 that ammonium carbonate and nitrate are decom- 

 posed by heat into gases, and "they are therefore 

 volatilised without producing white fumes or a 

 sublimate." 



The full instructions in the tables, and the very 

 large number of notes appended to them, are 

 NO. 2626, VOL. 104] 



evidence of the care taken by the authors, and 

 the many editions that have been issued show 

 that this care is appreciated, and it is deservedly 

 so, by those for whose use the book is intended. 



C. J. 



A MATHEMATICIAN'S MISCELLANY. 

 Pensees sur la Science, la Guerre et sur des Sujets 

 tres Variis. By Dr. Maurice Lecat. Pp. vii-t- 

 478. (Bruxelles : Maurice Lamertin, 1919.) 



M LECAT is a great reader with catholic 

 tastes. For twenty years he has been in 

 the habit of copying out all the passages that 

 have struck him in the reading which occupies his 

 leisure. He has now, at the instance of a friend, 

 collected and arranged them in a volume of 

 480 pages of double columns. There are about 

 11,000 extracts from some 1500 authors grouped 

 under subject headings. The first 1200 refer to 

 various branches of science and its most distin- 

 guished exponents. The remainder, dealing with 

 every possible subject, grave and gay, of topical 

 or perennial interest, come under titles arranged 

 alphabetically ; we proceed in due order from 

 Abstraction, Abus, . . . Allemagne (the longest 

 section), to Voltaire, Voyage, Yeux, Zola. The 

 quotations, whatever the language of their origin, 

 are usually, but not always, translated into French. 

 The whole is furnished with two elaborate indexes 

 and the dignity of an appendix. 



The industry that has produced the book is 

 amazing — so amazing that it is surprising that 

 obvious slips should have been allowed to pass in the 

 information concerning authors. A reviewer who 

 should take the opportunity it affords for ridicule 

 would lack even that small portion of humanity 

 usually allotted to his kind. But we fear that 

 M. Lecat is too optimistic in his hope that his' 

 collection will serve as an instrument of intel- 

 lectual research by providing a compendium of 

 the best thought of mankind. In both selection 

 and arrangement such a work inevitably bears 

 the impress of the editor. No one man, even 

 with the voracity of M. Lecat, can consume all 

 literature; the portion that he can digest is in- 

 finitesimal. Though writers of at least eight 

 languages are included, ranging from David (the 

 son of Jesse) to Max Harden, and from Homer to 

 the Morning Post, it is only natural that those 

 who have used the French language should have 

 the preponderance. Nor do our author's wide 

 interests and his passionate plea for impartiality 

 enable him to conceal from his readers that he is 

 a Belgian, a good son of the Church, and a 

 mathematician. Even if he had been able to 

 avoid the exclamatory "sic!", his best efforts 



