November 26, 1891] 



NA TURE 



n 



of special importance to junior students of chemistry 

 Examples are given on the metric system, thermometric 

 scales, specific gravity, the gaseous laws, the weights and 

 volumes of materials entering into chemical reactions, 

 and on the calculation of the empirical formula; and per- 

 centage composition of compounds. As distinguished 

 from others on the same subject, the book contains no 

 more than the beginner requires, and is therefore less 

 apt to confuse than one more elaborate. The intro- 

 ductory part of each section, giving the principles in- 

 volved in the exercises, is clear, and the examples, 128 

 in all, seem well chosen. A table of contents, index, and 

 answers, are included. A few points in connection with 

 specific gravity might with profit be attended to. On p. 

 6, density, in reality absolute density, is defined, and then 

 specific gravity. Relative density, as it is referred to on 

 p. 31, might here be introduced, and the account would be 

 more complete if the relation between density and specific 

 gravity were clearly stated. After the formula -c = w'v, 

 on p. 9, it might be definitely pointed out that, with the 

 imits chosen, specific gravity is the weight of unit volume. 

 It is not quite accurate to lead the student, as on p. 8, to 

 infer that specific gravities are usually given for the 

 temperature of 4° C. 



The Colliery Manas^e/s Hand-book. A Comprehensive 

 Treatise on the Laying-out and Working of Collieries, 

 designed as a Book of Reference for Colliery Managers, 

 and for the use of Coal-mining Students preparing for 

 First-class Certificates. By Caleb Pamely. Pp. 552, 

 Index, and 472 Woodcuts. (London : Crosby Lock- 

 wood and Son, 1891.) 

 Xo doubt colliery managers, and students preparing for 

 examinations, would find it convenient to have a cyclo- 

 paedia of mining, but the hand-book under consideration 

 will scarcely satisfy their wants. The work is another 

 illustration of the proverb, " Ne sutor ultra crepidam." 

 Instead of being satisfied with describing mining pro- 

 cesses and mining plant, the author deliberately plunges 

 into geology and chemistry, and then finds himself quite 

 out of his depth. 



It is evident that much labour has been expended in 

 bringing together information upon various matters con- 

 nected with coal-mining ; but there are gaps which 

 require to be filled up, and errors that should be corrected 

 in a second edition. For instance, the chapter upon 

 boring is meagre. The part relating to percussive 

 boring is in the main borrowed from Greenwell, and 

 refers solely to boring by hand. Not a word is said 

 about free-falling tools. It is not correct to say that 

 ** a great advantage of the diamond-drill boring is that 

 the hole is kept true and vertical." The surveys made 

 with the ingenious " clinograph " of Macgeorge have 

 shown beyond a doubt that this is not invariably the 

 case. 



The description of tools is insufficient ; and strange to 

 say, the book contains no figure of a pick. Probably no 

 work on mining was ever written before without a figure 

 of this characteristic miner's implement. It is not for 

 want of space, because there are figures to illustrate the 

 manner of preparing oxygen and nitrous oxide. These 

 are really unnecessary : if the student wants to learn a 

 little elementary chemistry, he had better have recourse 

 to one of the numerous text-books on that subject. 



The examples of the different methods of working coal 

 are likely to confuse students, owing to the mass of 

 details by which they are accompanied. As the original 

 articles are available in the Transactions of the Mining 

 Institute of Scotland, short abstracts would have been 

 quite sufficient. 



Serious omissions are somewhat numerous. Rittinger 

 pumps, which are doing such excellent work on the Con- 

 tinent, are not mentioned ; and the following important 

 subjects are also entirely ignored : coal-washing, coking, 



NO. I I 52. VOL. 45I 



utilization of the gases for making tar and ammonia, and 

 manufacture of patent fuel. In these days, when warn- 

 ing notes are being sounded concerning the duration of 

 our coal supply, the attention of mining engineers and 

 students should be specially directed to methods of 

 turning small coal and inferior seams to profitable account. 

 The author of a hand-book ought to be in advance of the 

 times, and point out the path of economy and progress. 



In spite of its defects, Mr. Pamely's work is by no 

 means destitute of value. It contains a great deal of 

 information which managers and students will find of use 

 to them, and the excellent index will enable them to lay 

 their hands at once on any part they desire to consult. 



C. L. N. F. 



Photography applied to the Microseopc 

 (London : Ilifife and Son, 1891.) 



By F. W. Mills. 



The subject of photo-micrography is one of such absorb- 

 ing interest that it is no wonder it has become so popular 

 among amateurs. For those commencing, and for those 

 who have already made some steps in pursuing this 

 subject, the present little book is intended, and it will be 

 found to contain just that sort of information and advice 

 that is so necessary to a beginner. The main point to 

 insure good photographic results lies in the preparation 

 of the object, which requires both patience and care ; the 

 chapter dealing on this has been written by Mr. Charters 

 White, who gives good directions for cutting hard and 

 soft tissues, and for bringing materials, that are too soft 

 in their natural condition, to a state of firmness previous 

 to cutting. With regard to the choice of the necessary 

 apparatus, the author describes various forms that are 

 cheap, and which with care can be made to yield fair 

 results. In the remaining chapters all the photographic 

 manipulations are dealt with, such as exposing, develop- 

 ing, and printing, &c., and at the end is added a useful list 

 of works which treat of the subject under consideration. 



Coperiiic et la Decouverte du Systeine du Monde. By 

 Camille Flammarion. (Paris : Marpon and Flam- 

 marion, 1891.) 



An interesting book is this, and one full of information. 

 In ten chapters and 250 pages M. Flammarion traces the 

 history of astronomy from Copernicus to Newton, with 

 special reference to the life of the former and the de- 

 velopment of his system. There is little doubt that this 

 work will be as well received as others by the same 

 writer, and it really deserves the favour. G. 



Annals of British Geology^ 1890. By J. F. Blake. 

 (London : Dulauand Co., 1891.) 



It is intended that this shall be the first issue of an 

 annual publication ; and, if future volumes are prepared 

 with as much care as the present one, the work ought to 

 be of much service to geologists. Its scope is restricted 

 to writings which have appeared in the United Kingdom. 

 The author is not content with noting merely the titles of 

 the works he records. When they are of the least im- 

 portance, he gives a general idea of their contents, and 

 presents what seems to him an adequate critical estimate 

 of their value. The classification is by subjects. He 

 begins with general geology ; then come stratigraphical 

 geology, palaeontology, palieobotany, petrology, econo- 

 mics, maps and sections, and works relating to foreign 

 geology, but published in Britain. A section headed 

 " Personal Items" brings together a number of facts to 

 which it may sometimes be convenient for the student 

 of geology to refer. The volume deserves to be all the 

 more cordially welcomed because Mr. Blake is not of 

 opinion that he has at one stroke reached perfection. 

 He hopes that future volumes may be improved by the 

 co-operation of specialists in the several departments. 



