194 Scientific Intelligence. 



any pure organic halide by means of this reaction. For instance, 

 chloracetic acid could not be changed to propionic acid, nor 

 benzyl chloride into phenylethane. It does not appear, however, 

 that electrolytic dissociation is a requirement for the reaction, for 

 mercuric cyanide reacts like the chloride. — Herichte, xlvi, 3738. 



H. L. \V. 



2. Solubilities at the Critical Temperatures of Solve?its. — 

 Fritz Friedrichs has made experiments with a large number of 

 substances, mostly inorganic salts, by placing them in sealed 

 glass tubes w T ith liquid anhydrous ammonia and also with liquid 

 sulphur dioxide, and then heating the tubes to the critical tem- 

 peratures of the liquids. Although the continuity of the liquid 

 and gaseous condition of solutions has been observed previously, 

 Friedrichs has made an interesting contribution to our knowledge 

 of the solubility of salts in the two liquids used for his experi- 

 ments. For example, the fact that potassium iodide dissolves 

 readily in liquid ammonia and passes into the gaseous state with 

 the ammonia at the critical temperature of the latter is striking, 

 as is also the similar behavior of dilute solutions of silver iodide 

 in the same solvent. It would be interesting to find to what 

 extent such gaseous solutions of solids could be expanded, and 

 still hold non-volatile solids in solution. h. l. w. 



3. Organic Chemistry for Advanced Students / by Julius B. 

 Cohen. Vol. II, 8vo, pp. 427. New York, 1913 (Longmans, 

 Green & Co. Price, $4.50 net). — The first volume of this very 

 useful text-book was published in 1907. The present volume fills 

 up gaps left in the first one according to the author's present plan 

 of presenting the subject in his lectures. The course as modified 

 gives more attention to the physical side of organic chemistry 

 than was the case with the first volume. The chapters of the 

 book deal with the valency of carbon, the nature of organic reac- 

 tions, dynamics of organic reactions, physical properties and 

 structure, and color and structure. The book makes an excellent 

 addition to the first volume. h. l. w. 



4. Industrial Chemistry for Engineering Students ; by Henry 

 K. Benson. 12mo, pp. 43 J. New York, 1913 (The Macmillan 

 Company. Price, $1.90). — The purpose of this text-book is to 

 describe from the standjDoint of chemistry the more common 

 materials used in the various branches of engineering. The 

 topics of greatest interest in engineering, such as fuels and com- 

 bustion, clay products and cement, are treated more fully than 

 others. There are short chapters on the manufacture of pig iron, 

 the commercial forms of iron and steel and industrial alloys, 

 but no other metallurgical subjects are treated. The references 

 to the literature of the subjects that are included are very exten- 

 sive and valuable, and the book appears to give a very good pre- 

 sentation of the subjects for the purpose in view. As the book 

 does not touch upon many important chemical industries it is 

 hardly suitable for students of chemistry and chemical engineer- 

 ing. The book appears to be lacking in the critical discussion of 



