Chemistry and Physics. 329 



supplied which gives reference to the substances detected by the 

 tests. The number of tests given is in some cases remarkable ; 

 for instance, no less than 49 methods are given for detecting 

 dextrose. Another section of the book is devoted to the tests of 

 purity of the more important reagents. Another chapter gives 

 descriptions and methods of preparation of a large number of 

 test-papers, and several tables, mostly of specific gravities of 

 liquids, are. given. 



4. Treatise on Applied Analytical Chemistry; by Yittorio 

 Villavecchia (with collaborators), translated by Thomas H. 

 Pope. Vol. I. Large 8vo, pp. 475. Philadelphia, 1918 (P. 

 Blakiston's Son & Co.). — This is the first installment of a pro- 

 posed two-volume work dealing with methods and standards for 

 the chemical analysis of the principal industrial and food prod- 

 ucts. The present volume takes up the analysis of potable and 

 industrial waters, commercial chemicals, fertilizers, cement 

 materials, metals and alloys, fuels, tar and its derivatives, mineral 

 oils and fatty substances and the industrial products derived 

 therefrom. The second volume will deal with flesh-foods, milk 

 products, flour and starches, sugars and saccharine products, 

 beer, wine, spirits and liqueurs, essential oils, turpentine, var- 

 nishes, rubber, tanning materials, leather, coloring matters, and 

 textile fibers and fabrics. 



The author is the director of the chemical laboratories of the 

 Italian Customs. He states that most of the methods described 

 have been tested in the laboratories under his direction, and 

 many of them carried out and studied almost daily by specialists 

 who have cooperated in preparing the book. 



In examining the portions of the book covering the fields with 

 which he is most familiar the reviewer has been most favorably 

 impressed with the general excellence of the methods recom- 

 mended as well as with the clear and concise manner in which 

 they are described. It is believed that the work will be par- 

 ticularly useful to all who are interested in industrial analysis. 



H. L. w. 



5. Motion of a Spinning Projectile. — In a long (48 pages) 

 mathematical paper by J. Presoott some very interesting prop- 

 erties of the motion of solid projectiles of standard form in air at 

 small angles of elevation are brought to light. To simplify the 

 analytical processes Bashforth assumed that the resistance of 

 the air varies as the cube of the velocity of the projectile. It is 

 shown in the present paper that this relation is unsatisfactory 

 because, in general, it holds true only for very small ranges of 

 velocity. Let B and V denote resistance and velocity respec- 

 tively. By plotting BV~ 2 as ordinate against V as abscissa the 

 curve is approximately a horizontal straight line for values of V 

 lying between and about 800 feet per sec. Between 800 and 

 1300 ft. per sec. the curve rises abruptly and almost vertically to 



