Notices respecting New Books. 663 
continuous-current machines, alternators, and direct-coupled gen- 
erating sets, and a useful chapter on the methods approved by the 
American Institute of Electrical Engineers, the Verband Deutscher 
Elektrotechniker, and l’Association Francaise des Propriétaires 
d’Appareils 4 Vapeur. The Appendix contains various specimen 
test-sheets and tables. 
In some respects the book is not quite up-to-date, and the 
sentence at the foot of p. 44 regarding the calorimetric method of 
determining efficiencies, regarding which the author says that ‘“ en 
pratique cette méthode est inapplicable,” is a strange commentary 
on Mr. Threlfall’s recent paper on “‘ The Testing of Electric Gen- 
erators by Air Calorimetry,” read before the Institution of Elec- 
trical Engineers. The names of English engineers are frequently 
misspelt ; thus, we read of ‘ M. Swenburn,” “ Sylvanus Thomson,” 
&e. These, however, are only minor blemishes in a reaily useful 
book. 
Traité @ Analyse des Substances Minérales. Par ADOLPHE CaRNot, 
Membre de (Institut. Tome Secoud: Meétalloides. Paris: Ch. 
Dunod. 1904. Pp. 822. 
Tuts is the second volume of a comprehensive treatise on the 
analysis of mineral substances, and deals with metalloids; this 
term has, however, to be given a somewhat elastic interpretation, 
the author including within the present volume titanium, tungsten, 
molybdenum, vanadium, &e. The method of treatment, which is 
uniform throughout, consists in giving the occurrence in nature 
and properties of the element under consideration, and of its more 
important compounds; then follows a detailed and careful study 
of the most useful and reliable methods for detecting and quanti- 
tatively estimating the element, and for separating it from 
elements previously considered. 
A very important and highly commendable feature of the book is 
the amount of attention given to matters of technical importance 
to engineers, agriculturists, and others engaged in various branches 
of industry in which some knowledge of chemistry and chemical 
analysis is essential. As an example of the thoroughness which 
the author brings to bear on his task, we may mention that in the 
section devoted to carbon the various methods of determining 
the calorific values of solid, liquid, and gaseous fuels are fully 
considered, and an illustrated description is given of Mahler’s 
calorimetric bomb. Similar thoroughness characterizes the other 
sections of the book, and renders it an important work of reference 
not only for the professional chemist, but for many others who, 
in the course of their professional work, have occasion to seek 
more detailed information on various subjects which may more 
properly be said to belong to the province of the technological 
chemist. 
In addition to its thoroughness, the book possesses all those 
admirable qualities for which French writers of high-class text- 
books have long been renowned, and which should secure for it a 
welcome place in every chemical library. 
