November 4. i^97j 



NATURE 



Juan Teotihuacan. It is needless to point out that this 

 publication could not have been compiled had the places 

 never been surveyed and described by other explorers- 

 Mr. Holmes frankly admits that his work is no more than 

 a sketch of the sites he visited " seen at a passing glance " ; 

 but even regarded merely as an introduction to the study 

 of Mexican archaeology, its value to the student would 

 have been much increased by the inclusion of references 

 to the extensive literature on the subject, and by a 

 discussion of the work accomplished by previous ex- 

 plorers and archaeologists. 



OUR BOOK SHELF. 



Jfanuale del Chimico e dell' Industriale. By Prof. Dr. 



Luigi Gabba. Pp. xvi + 442. (Milan : Ulrico Hoepli, 



1898.) 

 La Fabbricazione dell' Acido Solforico, dell' Acido Nitrico, 



del Solfato Sodtco, dell' Acido Muriatico. By Dr. V. 



Vender. Pp. v + 312. (Milan : Ulrico Hoepli, 1898.) 

 Leghe Metalliche ed Atnalgame. By I. Ghersi. Pp. 



xii + 431. (Milan : Ulrico Hoepli, 1898.) 



The three volumes, the titles of which are given above, 

 belong to an extensive series of manuals published by 

 the firm of Hoepli, Milan. More than five hundred of 

 these Manuali Hoepli have now been published, covering 

 a variety of subjects in science, letters, arts, and 

 industries. 



Prof. Gabba's volume is a collection of tables of 

 physical and chemical data, and of analytical processes, 

 for the use of analytical and technical chemists, directors 

 of chemical works, students of chemistry, and others. 

 The tables and the descriptions of methods of detecting 

 various substances, and of carrying out a complete 

 analysis or assay, will be found very serviceable to all 

 technical chemists. The volume contains a mass of 

 physical and chemical data, and it will prove as useful to 

 analysts as engineering pocket-books are to engineers. 



Dr. V. Vender's work on the manufacture of sulphuric 

 acid, nitric acid, and hydrochloric acid, presents in a 

 concise form the essential facts of these great chemical 

 industries. In the case of each product, the substances 

 employed in its manufacture, the general principle of the 

 manufacture, the theory of the various processes, the 

 details of construction of the plants in use, and methods 

 of analysing the products, are described. The book is 

 instructively illustrated; and though the text is in Italian, 

 English chemists will find that they can read it by 

 occasional reference to a dictionary. 



In the third of Hoepli's Manuals referred to at the 

 head of this notice, Signore Ghersi provides metallurgists 

 with a handy book on metallic alloys and amalgams. 

 The volume opens with a description of alloys in general, 

 and then deals in succession with binary alloys, alloys of 

 aluminium with common metals, nickel alloys, amalgams, 

 alloys of gold, silver, and platinum, alloys for coinage 

 and medals, bronzes, brass, ternary and quaternary 

 alloys, Delta metal, fusible alloys, alloys which simulate 

 various metals, and solders. There is an appendix con- 

 taining useful tables of physical and chemical data re- 

 ferring to alloys, a long list of works cited, and a good 

 index. The author frequently refers to recent investiga- 

 tions of metallurgists in various parts of the world, and 

 his book does credit to him and to the scientific spirit 

 in Italy. 



Lectures on Quaternions. Part i. Introductory. By S. 

 Kimura, Sendai, Japan. 



We are unable to read this treatise, because it is printed 

 in Japanese. The mathematical formulce and woodcuts 



NO. 1462, VOL. 57] 



show that the author is introducing his students to those 

 elementary geometrical (curve and surface) illustrations 

 of the vector calculus (mainly vector addition and differ- 

 entials) which may be taken up without any knowledge 

 of a quaternion. The characters are printed in hori- 

 zontal rows instead of the usual vertical columns, and 

 this might be taken as the text for a sermon on the 

 modern changes in Japan. The concession is necessary 

 if a student is to read mathematical formulae with ease, 

 yet it is one which need not alarm the scholars, and 

 by making it the author takes away an objection to the 

 use of Japanese characters, and so keeps his reader m 

 touch with Japanese literature. Every Japanese reader 

 of such a treatise is well acquainted with English, and 

 if the teaching of mathematical science were to be con- 

 sidered by itself, all such books might just as well be 

 printed in English. But it is well known to all who 

 have studied the Japanese that they are not merely 

 studying our commercial and military and scientific 

 ideas, but how they may assimilate these ideas without 

 undue hurt to their own old civilisation and developed 

 instincts and fine moral character, which seem to them, 

 and indeed to some of us, of a very much higher order 

 than what we find in Europe. Well, the vector calculus 

 can do little harm to anybody ; but when Part ii. is pub- 

 lished, and the author introduces his quarternions, he 

 may lie glad that the old scholars who protect the 

 morals of his country are unable to understand what 

 he is writing about. J. P. 



Lehrbuch der Erdkunde fiir hohere Schulen. By Dr. 

 Willi Ule. I. Theil (Fiir die unteren Classen). Pp. 

 viii -f- 176. (Leipzig: G. Freitag, 1897.) 



This is an 'excellent reading-book for children, but as it 

 is printed in the German language, it will not be found 

 very useful this side of the Channel. Written in a 

 very simple manner, and dealing only with fundamental 

 ideas, the author describes clearly and concisely the 

 main physical features of the earth— such as mountains, 

 plains, continents, races, &c. Each of the different 

 countries is generally described, and typical illustrations 

 are inserted here and there. Several paragraphs are 

 also devoted to brief general descriptions of the weather, 

 climates, elementary astronomical phenomena, map- 

 drawing, &c. The author has succeeded in bringing 

 together in a methodical and natural sequence a great 

 amount of information which the children will read with 

 delight. Names and numbers have been suppressed as 

 far as possible in the text, these being added in tabular 

 form at the end of each section, more for the use of the 

 teachers than for the readers. 



The Great Meteoric Shower of November. By W. F. 

 Denning, F.R.A.S. Pp. 52. (London : Taylor and 

 Francis, 1897.) 



Upon the subject of meteor-observation, Mr. Dennmg 

 teaches " as one having authority, and not as the scribes." 

 This pamphlet, reprinted from the Observatory^ furnishes 

 meteoric observers with a number of interesting facts as 

 to past November showers of Leonids, and prospects 

 of observations between now and 1905. Mr. Denning 

 deals in succession with the position of the Leonid 

 radiant, the character of the radiant, the visible aspect of 

 the individual Leonids, the real paths of the meteors in 

 our atmosphere, minor meteor showers visible at the 

 Leonid epoch, expected phenomena at the ensuing 

 return, the observations required, and the November 

 shower from Biela's comet. Every astronomical observer 

 should possess a copy of tfte pamphlet, for the perusal 

 of it will show him exactly what points require 

 attention, and will thus increase the value of his ob- 

 servations. 



