Manuel d'analyse chimique appliquée a l'examen des produits Industriels et commerciaux

Abstract

THE author states in his preface that he has written with a threefold aim, namely: (1) to give general methods of qualitative and quantitative mineral analysis and organic analysis of an elementary character, free from all details not absolutely useful; (2) to avoid methods of work that are too long for those who are pressed for time or who have not sufficient general knowledge, giving in each case only one method (or occasionally two) that leads quickly and surely to the desired result; and (3) to bring together in one volume the methods of examination of the more important, though the most diverse of the products which one meets with in the laboratory of the industrial chemist. Accordingly we find in some 556 pages of clearly printed and well-spaced matter some preliminary observations with reference to apparatus, a section on qualitative analysis, and methods for the quantitative examination of the commoner metals and minerals containing them, besides, among other things, water, inorganic pigments, cements, &c, compounds of the alkalis, manures of various kinds, soils, animal and vegetable products, such as cellulose, tannin, milk, fruits, fermented liquors, wines, and textile fabrics, the estimation of acetone in methylated spirit, and the determination of the flashing point of petroleum, &c. It is obvious that where so much ground is covered in so comparatively small a space, that in some cases at least there cannot be room for more than a mere summary of the details of the method given. It is generally a matter of opinion as to which is the best of several alternative methods, and often, too, a slight variation in the sample from what is most usual, renders a variation in the process desirable. It must have been a very difficult task to select the one or two methods in each case; but, taken as a whole, they are fairly representative. If the space devoted to the figures of beakers and other apparatus, and to the exceedingly meagre description of the qualitative reactions of the common acids and bases had been devoted to an expansion of the other part of the book, the usefulness of the volume would have been much increased. We doubt, for example, the need for telling any one who concerns himself with such work as is here described, that mercuric salts give a precipitate with sulphuretted hydrogen which changes from white to black, and is insoluble in alkaline sulphides; that hydrochloric acid and chlorides give no precipitate, and that iodide of potassium gives a beautiful red precipitate very soluble in excess of the reagent. These are all the qualitative reactions given for mercuric salts, and it may well be said of them that, though true, they are not the whole truth even concerning the precipitates mentioned. As a reminder for students who have to learn what they can about many things in a very little time, the volume will no doubt prove very valuable, and the practical analyst will sometimes find suggestions that will prove useful to him.

Manuel d'analyse chimique appliquée a l'examen des produits Industriels et commerciaux.

By Émile Fleurent. Pp. iii + 582. (Paris: G. Carré et C. Naud, 1898.)