Chemistry and Physics. 233 



sediment, filtering through ignited asbestos into a perfectly dean 

 bottle. This solution when kept in the dark is stable for a long 

 time, and it should be standardized with a 1/50 normal solution 

 of oxalic acid which has been acidified with 10 cc. of 10 per cent 

 sulphuric acid, which in turn lias been treated with just enough 

 permanganate solution to give it a faint pink color. The stand- 

 ardization is made after heating the oxalic acid solution to 65° 

 in a water bath. — Jour. Indust. Engr. Chem., 10, 119. 



h. l. w. 



4. An Elementary Study of Chemistry; by McPherson and 

 Henderson. Serond Revised Edition. 12mo, pp. 576. Bos- 

 ton, 1917 (Ginn and Company). — This is the smaller and more 

 elementary of two text-books on general chemistry by these 

 authors, both of which books appear to have met with much favor 

 among teachers. The fact is evidently appreciated that the 

 book under consideration gives more attention to fundamental 

 principles, and is more comprehensive in other respects than is 

 frequently the case with books intended for the same grade of 

 instruction. The present edition has been revised to meet the 

 advances in chemistry during the past decade, some changes 

 have been made in the arrangement of the matter, and a little 

 more space has been given.to the compounds of carbon. The last 

 change seems well justified, for, as the authors argue, many stu- 

 dents take no more than one year of chemical study, and it 

 seems unreasonable that these should have no knowledge of the 

 organic compounds that are met with in everyday life far oftener 

 than the majority of inorganic compounds. It seems to the 

 reviewer that this improvement might well have been carried 

 still farther by including a few structural formulas explaining 

 the very important matter of isomerism in organic substances. 

 However, it is difficult to decide upon the things to be 

 included and omitted in a text-book of limited scope, like this 

 one, and it may be said that the book has many very excellent 

 features, and that it appears to be, on the whole, an unusually 

 satisfactory one. h. l. w. 



5. A Class-Book of Organic Chemistry; by J. B. Cohen. 

 12mo, pp. 344. London, 1917 (Macmillan and Co., Limited. — ■ 

 This text-book is intended for the use of first year medical stu- 

 dents and for senior science students in schools. The theoretical 

 and practical sides of the subject are treated concurrently, so 

 that the book serves the double purpose of text-book and labora- 

 tory manual. It appears that this combination has been 

 effected in a very satisfactory manner, so that the bearings of the 

 two sides of the subject, as it is studied, are kept very clearly in 

 view. The topics are very well selected for the purpose of giving 

 a good general knowledge of this vast subject. The course is 

 divided into three parts. In the first part the general princi- 

 ples underlying determinations of purity, empirical and molec- 



Am. Jour. Sci.— Fourth Series, Vol. XLV, No. 267.— March, 1918. 

 16 



