138 Notices respecting New Books. 



known that satisfactory results can be secured by this simple 

 device. In the appendix on the absolute system of measurements 

 the dimensions of dielectric capacity and magnetic permeability 

 are each given as zero, with the result that the same quantities 

 appear to be of different dimensions according as they are measured 

 in electrostatic or electromagnetic units. 



The translators have given a fair rendering of the German text, 

 but unfortunately they have retained nearly all the misprints of 

 the original. This is the more remarkable seeing that a printed 

 list of corrigenda exists, and has been issued with (at any rate, 

 some) copies of the German edition. Out of this list of fifteen mis- 

 prints only three are corrected in the present translation. Several 

 additional ones have been introduced, the most unfortunate of 

 which is the use of the word "density" for "specific gravity" on 

 p. 44, just in the place where a distinction is being drawn between 

 the two terms. In the tables at the end ol" the work a few minor 

 omissions and misprints occur ; for example, in Tables 30, 32, and 

 33 the units of measurement are not stated, while in Tables 22 

 and 22(a) C.M.G. is printed for C.G.8. The symbols used by 

 Prof. Kohlrausch have generally been retained, especially in the 

 sections dealing with electricity, where the use of i for current- 

 strength and iv for resistance will scarcely commend itself to 

 English readers. On the other hand, Kohlrausch's n for refractive 

 index has been replaced by fj, in accordance with English usage. 

 The volume forms an important addition to the literature of the 

 physical laboratory, and can easily be cleared of such superficial 

 blemishes as have been indicated. James L. Howard. 



Watts 1 Dictionary of Chemistry. 



Watts' Dictionary of Chemistry ; revised and, entirely rewritten. 

 Dy M. M. Pattison Muir. M.A., and H. Eorster Moeley, M.A. 

 Assisted by eminent Contributors. In four volumes. Vol. IV. 

 London : Longmans, Green, & Co., 1894. 



This fourth and concluding volume of the well-known chemical 

 dictionary brings to a close a standard work of reference of 

 which the first volume appeared in 1888. Altogether we shall 

 not be far wrong in stating that the editors have taken about a 

 decade in revising, rewriting, compiling, and editing the vast 

 amount of material which constitutes the modern science of 

 Chemistry. That they have done their task well has already been 

 acknowledged in noticing the former volumes in the pages of this 

 Magazine. It is with great satisfaction that we are enabled to 

 renew this acknowledgment in the case of the present volume, 

 which extends to 922 pages and contains an Appendix of 34 

 pages comprising the more noteworthy of the recent discoveries in 

 inorganic chemistry. 



A dictionary of science is not an easy work to treat of from a 



