of the metals of the succeeding groups are soluble and therefore do not precipitate." This is a very antiquated way of stating the case. Speaking in terms of the "solubility product" and "common ion effect" concepts would be more in keeping 'with modem expression. I n the test for antimony given on page 34 the author refers to the use of platinum as a "catalytic agent." It is rather "electrolytic" in its function, since it assists in the release of positive zinc ions from the -'Helmholtz double layer" at the surface of the zinc. The technic is bad in places. For instance, on page 22 the use of a beaker is prescribed where a test-tube would he more serviceable in the interest of economy. In the above criticism the reviewer has not mentioned all the weak points contained in this work, but referred t o only scattered "samples." To sum i t all up, the reviewer can see no place for this book in the hands of a novice pursuing a modern course in qualitative analysis. EDWARD X.ANDERSON
Rubber, The Five O'clock Tea, The Vanishing Vegetable Dyes, Camphor, The Potato, Bread Fruit, The Poppy, Tobacco, Cotton, and The Tree of the Leper. Quaint maps, decorated in the old style, add t o the pleasing appearance of the book. The references a t the end of the chapters are also of some value. Ifstimulating the imagination of a highschool student is desirable, and none denies that, then this book has a place in the high-school library. There is not a great deal of chemistry in it, although chemists must be interested in the story of logwood black. This dye, we are told, was first brought from tropical America and because of its merit a t once aroused opposition from the old-fashined dye workers of England. Actually during the reign of Queen Elizabeth a British law was -passed ordering that "whereas the clothes dyed with logwood are solde and uttered t o the great deceit of the Queenes loved subjects he it enacted by the Queene, our Soveraygn Ladie, that shall be openly all such Logwood. burned by the authorities." Indigo, too, had t o force out the inferior blue dye obtained from woad. Woad growers perCargoes and Harvests. DONALDCUL- suaded Henry IV of France to prevent noss PEATTIE. D. Appleton & Co., the use of indigo and t o get Emporer 1926. 311 pp. 13.25 X 20.5 cm. Rudolph to banish i t from Germany as 52.50. "a prejudicial, cheating, corrosive, deAs the publishers announce, this is a vouring and diabolical substance." The story of romantic exploration and the ad- penalty for possessing indigo was death, venturous discovery of those plants which dishonor, and confiscation of property. Had the author been a chemist he above all others figure in the existence of mankind. "The discovery and explora- would not have made the misleading tion of every day commodities has a statement on page 133 that "from camhistory as colorful as any romantic tale. phor is derived celluloid, which, combined with nitric acid, produces the Tea, cocoa, camphor, tobacco, and cotton have histories of difficulties, strife, in- modern high explosives." I n the Rubvention, famine, and exploration that make ber Chapter there was little or nothing said of vulcanization. But this is, after fascinating reading." These are large claims and yet they are all, a hook on plants and possibly we not without foundation. The author has should not ask for much, or for very indeed a lively imagination and uses it accurate chemistry. I n its awn field well as he writes chapters on Plant Power, the book has merit. The Spices of Ind, Quinine, The Age of HARRYN. HOLMES
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