;5o 



NATURE 



[September 22, 1910 



TEXT-BOOKS OF CHEMISTRY. 

 (i) Practical Chemistry. By Dr. James Bruce and 

 Harry Harper. Pp. viii + 240. (London: Mac- 

 millan and Co., Ltd., 1910.) Price 2s. 6d. 



(2) Qualitative Analysis. Tables for Use at the 

 Bench. By E. J. Lewis. (Cambridge : University 

 Press, igio.) Price 25. 6d. net. 



(3) Outlines of Organic Chemistry. A Book Designed 

 especially for the General Student. By Dr. F. J. 

 Moore. Pp. x + 315. (New York: John Wiley and 

 Sons; London: Chapman and Hall, Ltd., 1910.) 

 Price 6s. bd. net. 



(4) The Calculations of General Chemistry, with 

 Definitions, Explanations, and Problems. Second 

 edition. By Prof. William J. Hale. Pp. xii4-i75. 

 (London : George Bell and Sons, 1910.) Price 

 4s. 6d. 



(5) A. B.C. Five Figure Logarithms and Tables for 

 Chemists, including Electrochemical Equivalents, 

 Analytical Factors, Gas Reduction Tables, and other 

 Tables useful in Chemical Laboratories. By C. J. 

 Woodward. Pp. iv + 70. (London : E. and F. N. 

 Spon, Ltd.; Simpkin, Marshall and Co., Ltd.; New 

 York : Spon and Chamberlain ; Birmingham : 

 Cornish Bros., 1910.) Price 2S. 6d. net. 



I ) ' I ^HE first of these books contains in the space 

 -1. of 240 pages an account of the manipulative 

 methods of chemical experiment, a selection of in- 

 organic and organic preparations, instructions for 

 physical measurements, such as the densities of 

 liquids and vapour densities, qualitative analysis of 

 simple salts, and a selection of volumetric and gravi- 

 metric methods. In spite of the large amount of 

 ground which is covered, the work is excellently done, 

 and it is a great advantage to find in a single small 

 volume nearly all that is needed in the way of text- 

 book instruction for the practical work of a course 

 passing well beyond the standard of an intermediate 

 B.Sc. course, and almost up to the standard of the 

 final examination. Such criticisms as may be made 

 refer only to matters of detail, and are not intended 

 to detract from the value of a book which is un- 

 doubtedly one of the best that has appeared. It may, 

 however, be noted that the method of making ethylene 

 by means of phosphoric acid, as described by Newth 

 in the Journal of the Chemical Society, is much 

 superior to the older method, in which sulphuric acid 

 was used, and should be generally adopted. The gas- 

 regulator shown on p. 5 is less efficient than those in 

 which toluene is used, and the pyknometer (Fig. 42) 

 shown on p. 98 has been improved by the use of two 

 bulbs instead of one, as recently described by Mr. 

 W. R. Bousfield. In the volumetric work it is to be 

 regretted that only one method of preparing a 

 standard solution (normal Na^COj from NaHCOj) Is 

 given, as the checking of these methods against one 

 another forms an excellent test of the accuracy of the 

 work, and is of far greater value than the estimation 

 of acids and alkalis in variable commercial samples ; 

 moreover, the estimation of acids is far more accurate 

 if carried out with the help of a standard acid and 

 intermediate alkali than when a standard alkali is 

 used, as in the former case all the errors which arise 

 NO. 2134, VOL, SxJ 



from uncertainty as to "end-point," &c., are 

 eliminated. 



Amongst the omitted methods are the preparation 

 of standard caustic soda by weighing out sodium, 

 dissolving in alcohol and diluting, and the preparation 

 of standard acid by measuring the density of sulphuric 

 acid of 80 to 90 per cent, strength, and diluting, as 

 described bv Marshall in the Journal of the Society of 

 Chemical Industry. In the e.\perience of the present 

 writer these methods, in the hands of students as well 

 as in work of the highest attainable accuracy, lead to 

 exact results more readily than most of those that have 

 been described. In the use of permanganate it is 

 doubtful how far it is safe to rely on the purity of the 

 crystals, and as the solutions are not altogether per- 

 manent, it would be well to treat them from the 

 beginning as only approximately correct. 



(2) The best guarantee of the quality of the material 

 printed on these cards is the name of the author, 

 whose " Inorganic Chemistry " has almost created 

 a new ideal hi elementary text-books. How far the 

 idea of using printed and varnished cards will prove 

 superior to the system of practical text-books is a 

 matter that can only be worked out by actual experi- 

 ence in the laboratory. 



(3) In comparison with the majority of text-books 

 of organic chemistry, this volume starts with one 

 great advantage — that the authors have not attempted 

 to make it into a dictionary or table of physical con- 

 stants. They have, therefore, been enabled to deal 

 in a small volume with an unusually large amount of 

 interesting and "advanced" material, usually reserved 

 for works of a more pretentious character. This is in 

 many respects a distinct advantage. On the other 

 hand, they have omitted almost entirely the details of 

 methods of preparation, and so have conferred on the 

 subject with which they deal a certain impression of 

 unreality, which might easily have been removed. If, 

 however, the student who reads the book is at the 

 same time carrying out a course of organic prepara- 

 tions, the risk that he may come to regard the sub- 

 ject as one of algebra and geometry — only loosely 

 attached to experiment by the necessities of verifica- 

 tion — will be removed, and the book may then prove 

 both useful and suggestive. 



(4) The use of numerical examples is an excellent 

 way of impressing upon a student the meaning of 

 equivalents, vapour densities, molecular and atomic 

 weights ; it is also necessary in order to secure accu- 

 racy in the calculation of analytical results, especially 

 if this is to be done correctly under the hurried and 

 somewhat unpractical conditions of a " practical 

 examination." This need the author has attempted 

 with some measure of success to supply. The chief 

 fault of the book arises from the fact that most of his 

 examples appear to have originated in the study in- 

 stead oi in tlie laboratory. No chemist would be likely 

 to use in actual work the bewildering array of 

 standard solutions referred to in chapter x., 2N, N, 

 N/2, N/4, N/5, N/6, N/8, N/io, N/20, &c. ; neither 

 would anyone who had experience of the subject 

 expect to obtain a theoretical yield of nitric oxide from 

 7N nitric acid and copper. These and other calcula- 

 tions of a similar character suggest that the author 



