November 4, 1898.] 



SCIENCE. 



637 



show the degree of purity and extent of over- 

 lapping of contiguous parts of adjoining belts. 



In conclusion, I beg to express the hope that 

 mj' protracted absence in remote parts of the 

 West, while engaged in tracing the boundaries 

 of the life zones, may ameliorate my offense in 

 not having seen all of Mr. Cockerell's writings. 

 C. Hart Merriam. 



San FKANcrsco, Cal., October 11, 1898. 



SCIENTIFIC LITERATURE. 

 Angeivandle Elehtroehemie. Z welter Band: Anor- 



ganische Elektrochemie. Dritter Band : Or- 



ganische Elektrochemie. Von Dr. Franz 



Peters. Hartleben's Verlag, Wien ; Pest, 



Leipzig. 



The first volume of this book was reviewed 

 in Science by Professor Smith (April 9, 1897). 

 In the light of this notice of the general pur- 

 port of the book by so able an authority, at- 

 tention need only be called to the appearance 

 of the subsequent volumes and to their con- 

 tents. The second volume, on the electro- 

 chemistry of inorganic substances., is divided- 

 into two parts. The first deals with the elec- 

 tro-chemistry of the metalloids and alkali 

 metals, including methods of obtaining hydro- 

 gen, of purifying water, of obtaining chlorine, 

 bromine and iodine, oxygen and ozone, arsenic 

 and antimony. It is interesting to note under 

 carbon that it volatilizes at about 3,600° in the 

 arc of the electric lamp, and that Moissan has 

 succeeded in converting it into vapor in the 

 electric furnace. It did not, however, assume 

 the liquid state, but passed at once into vapor. 

 The beautiful work of Moissan on highly heated 

 carbon is taken up at some length. The elec- 

 trolytic separation of lithium and sodium is 

 .then taken up, the methods of Grabau, Borsch- 

 ers and Castner in the production of sodium 

 receiving special treatment. 



The second part of the second volume is 

 devoted to the alkaline earths, the earths and 

 heavy metals. 



The third volume deals entirely with the 

 electro-chemistry of 'organic compounds. The 

 extent to which organic compounds can be pre- 

 pared by the action of the current is shown by 

 the number of classes of substances included in 

 this volume. In the paraffin series there are 



thirteen classes, including hydrocarbons, alco- 

 hols, ether, ethereal salts, acids. In the aro- 

 matic series there are seventeen classes, includ- 

 ing hydrocarbons, nitro, sulphur and amine 

 derivatives of the hydrocarbons, phenols, alco- 

 hols, aldehydes, ketones and acids. This vol- 

 ume closes with an account of some of the 

 practical uses of organic electro-chemistry, as 

 electrodyeing, electroprinting, electrotanning, 

 etc. 



Insofar as it deals with the electrolytic depo- 

 sition of the metals, this book covers some of 

 the same ground as the well known work of 

 Borschers, which deals with electro-metallurgy 

 in such a masterly manner. But the work of 

 Peters covers a much wider field, and will 

 doubtless prove to be a valuable contribution to 

 practical electro-chemistry. 



H. C. J. 



Up-to-date Air-brake Catechism. By Robert 

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