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cesjes receive each a passing notice of one page as is t h e case with t h e Freiberg method of leaching roasted silver-bearing copper matte, while the author’s interesting modification of t h e last process is treated with considerable detail in rg pages. Cyanidation, covering 41 pages, is represented mainly by a full abstract of t h e excellent paper of T. H. Oxnani ’ on t h e treatmeut of auriferous silver ores at Palmarejo, Mexico. Electrodeposi:ion of precious metal from cyanide solutions, especially important in silver-metallurgy, is not touched upon. T o take up a few special features. T h e first 1 5 2 pages deal w i t h chlorodizing roasting. After a brief general statement of pri’nciples a n d of behavior of t h e leading minerals, there is given a n important chapter on t h e fine crushiiig of ore a n d how i t has to be governed by t h e cliaracter of the component minerals with regard to subsequent chloridation and success in leaching. T h e discussion of t h e anlount of s a l t required and the time of addition brings out many points as to chloridatiou and volatilization which are not generally known, in fact, will be new to most readers. I n the chapter on furnaces, t h e leading ones t h a t have been proposed and used a r e assigned their proper places; t h e mode of operating i s treated in its different aspects with t h e results to be expected and t h e results t h a t have been obtained. T h e author’s designs for dust-chambers with a special discussion of the correct manner of handling argentiferous zinc-lead ores and calcareous ores .closes this chapter which stands forth preeminently as the most important one of t h e book. Tank-lixiviation with precipitation and working up of precipitate is taken u p with working drawings of apparatus which give a clear conception of modern practice. I n studying t h e chapter on trough-lixiviation, t h e reader obtains t h e iinprcssion t h a t this niethod, invented by the author, is a n accepted improvement on tank-lixiviation, which i t is not. T h e description o u g h t to be read in connection with Stetefeldt’s review of t h e method. T h e critical remarks upon t h e Russell and Kiss processes, while brief, are a relief in view of t h e many laudatory papers that have been written about them. While t h e Patera process has seen its best days on account of t h e encroachnient of smelting upon leaching a n d of t h e growing importance of cyanidation, it will retain some of its former importance for a considerable time. T h e metallurgical profession is therefore under much obligation to t h e author for having brought together in book form some of t h e H. 0 . HOFMAN. leading features of his wide experience. BOTANY A N D PHARMACOGNOSY. BY HENRY KRAEMER,Ph. B., Ph. D. Second revised and enlarged edition. J. B. Lippincott Company, Philadelphia.
T h e new edition is twice t h e size of t h e old one, t h e number of illusTran. Am. Inst. of Min. Eng., 1906,36, 234-87.
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trations has been more than doubled, and in many other respects generally improved. T h i s has been done without changing t h e a r r a n g e ment of t h e subject matter. T h e work is divided into three parts. T h e first treats of botany, t h e second of pharniacogiiosy an2 t h e third of reagents and microscopic technique. Under botany the first go pages are devoted to t h e ,structure and general characteristics of the different groups of [Jlants, beginning with t h e lower forms of plant life, t h e algae, and ascending t o tlie higher forms, t h e sperniophites, or seed plants. T h e n e s t 6 j pages treat of t h e “Outer Morphology of Angiosperms” in t h e order of root, stem, leaf, flower, fruit and seed. T h e following 67 pages treat of the “Inner Morphology of the Higher Plants,” taking up t h e plant cell, its contents a n d forms ; then follows t h e structure of different parts of plants. T h e n e x t 180 pages are devoted to t h e “Classification of Angiosperms Yielding Vegetable Drugs.’’ T h e habitat with a short description of each plant is given, and also t h e active constituents. T h e last 11pnges of part one are given to t h e “Cultivation of Medicinal Pla 11t s . ’ ’ T h e part devoted to Pharniacognosy is divided into two chapters. T h e first 278 pages a r e given to t h e study of “Crude Drugs,” giving source, description and constituents. T h e following 9.1 are given to a systematic, microscopical study of “Powdered Drugs and Foods. ’ ’ Only t h e last eight pages are devoted to “Reagents and Microscopical Tech u i que. ’ ’ T h e entire work i s beautifully illustrated with 3 2 1 plates and about 1500 figures. These a r e distributed throughout the t e x t , which is a decided improvemelit over t h e former edition, where t h e illustrations were given in a separate part of the work. T h e present arrangement permits of t h e ready comparison of t h e illustrations with t h e subject matter. Most of the illustrations a r e from fine pen drawings, while others are half-tone reproductions, some of which are t-ery good, while others a r e inferior, lacking in detail, due doubtless to improper exposure. I n general t h e technique of the work is fine, and tlie author and publishers a r e to be congratulated upon t h e results of their efforts. T h e book is one that should be in tlie hands of every one interested in the A . B. STEVENS. s t u d y of botany a n d pharmacognosy. A H A S D Y R O O K F O R BREWERS. BY HERBSRT EDLV.4RDS W R I G H T . 562 pnges, X e w York : D. \’an Sostrand Cornpany.
Third edition,
T h e principal aim of t h e author h a s been to give t h e conclusions of moderu research in so far as they bear upon t h e practice of brewing, in such a form t h a t a novice of fair intelligence niay understand them. The trained chemist o r physiologist however, will also be benefited by t h e s t u d y of this book, In fact between these branches of pure science and t h e brewing industry a very fertile reciprocal action has always been
