November 4, 1909] 



NA TURE 



assumes nothing' without direct proof; we have no 

 right to a-isume beforehand that some other law might 

 not be found operating in the organic world. The 

 crude calorimetric researches of Lavoisier and the 

 early pioneers of this subject certainly showed great 

 discrepancies between the results obtained and those 

 calculated from the energy value of the diets 

 employed ; but as technique has improved so has it 

 been shown that all such discrepancies were the result 

 of imperfection in the methods used. For the 

 improvements in method, and the patient working out 

 of the problem as well as the final demonstration of 

 the truth of the great law of energy conservation in 

 the world of life, there is no one to whom we owe 

 more than to Prof. Rubner himself. 



W. D. H. 



COLOUR MANUFACTURE. 

 A Treatise on Colour Manufacture. A Guide to the 

 Preparation, Examination, and Application of all 

 the Pigment Colours in Practical Use. By George 

 Zerr and Dr. R. Rubencamp ; authorised English 

 edition by Dr. Charles Mayer. Pp. xiv + 605. 

 (London : C. Griflin and Co., Ltd., 1908.) Price 

 30S. net. 



THIS volume is the most complete publication on 

 colour manufacture which has vet been pro- 

 duced in English. After dealing with the general 

 preparation of materials, and describing the various 

 types of grinding and sifting machines, in part ii. 

 the manufacture of artificial mineral colours in dealt 

 with in a very thorough manner, although in certain 

 details inaccuracies are, as is to be expected, to be 

 found. 



Part iii. deals with the raw materials used in colour 

 making, their properties, adulterations, and tests for 

 purity. This section should prove very valuable in 

 many colour works where the raw materials are 

 bought in large quantities, and reliable information 

 of this kind will enable them to be readily examined 

 to test their purity. 



The natural mineral colours and black pigments 

 are then dealt with, and following upon this is a 

 description of organic colouring materials and their 

 utilisation in making lake pigments. The first 

 section deals with natural organic substances, while 

 the second section deals with the application of the 

 coal tar colours to the manufacture of lakes. This 

 section should prove of considerable value to colour 

 makers, as it contains a scientific classification of the 

 coal tar derivatives, and so reveals the principles upon 

 which such lakes must be prepared. It is, of course, 

 impossible that such a treatment of the subject should 

 be up to date, as fresh coal tar products and fresh 

 methods of obtaining trustworthy lakes from them are 

 constantly being produced, but a study of these 

 chapters will give the student a thorough grip of the 

 principles underlying the manufacture of these lakes, 

 and some interesting information will be found at 

 the end of this section of the book on the reactions 

 of the more important lakes from artificial colouring 

 materials, which should be of use to those who wish 

 to match samples that have been submitted. There is 

 NO. 20S8, VOL. 82] 



also a brief account of the use of pigments in different 

 ways which, while very general in character, contains 

 some very interesting information. 



In the appendix w-ill be found a table of solubilities 

 of many of the salts used by the colour maker, in cold 

 and in hot water, which should prove of practical 

 value, while there are in addition specific gravity 

 tables for a certain number of these salts which should 

 also be of use. 



As has been stated, there are certain errors in detail 

 to be noted, more especially in connection with the 

 finer colours which are used for artists' purposes, and 

 two of these which happened to have caught the eye 

 of the reviewer may be pointed out. On page 154, 

 Indian yellow is incorrectly described as being the 

 same thing as cobalt yellow, Indian yellow being a 

 preparation of euxanthic acid obtained from India, 

 and cobalt yellow is described as being not very fast 

 to air and light, while, as a matter of fact, it is one 

 of the most permanent pigments to be found in the 

 artist's palette. Again, under blue colours on p. 203, 

 cobalt blue is spoken of as being now of no technical 

 value. Considering the very large use of cobalt blue 

 by artists and for superior decorative purposes, this 

 statement is scarcely justifiable. The description of 

 the manufacture of cadmium yellows is also very far 

 troni complete, and no doubt other similar small errors 

 could be found throughout the book, and are inevit- 

 able in a work of this kind. 



A more serious defect is one which is to be found 

 in a great many works on colour manufacture. While 

 elementary information on qualitative and quantitative 

 analysis is published — see, for instance, the discussion 

 of the methods of volumetric analysis on p. 343 — • 

 information which it is only right to suppose is per- 

 fectly familiar to the modern colour maker and colour 

 chemist, and simple qualitative tests are given which 

 are to be found in all elementary books on qualitative 

 analvsis, little information is supplied as to the com- 

 plete analysis of modern pigments. Such informa- 

 tion would be of value even to the skilled analyst, 

 who, when he comes across some pigment, wishes to 

 know the probable defects to look for, the kinds of 

 adulteration likely to be present, and the most rapid 

 manner of handling with a view to making a suffi- 

 ciently complete analysis for practical purposes. Some 

 attempt to deal with this problem was made by Hurst 

 in his book on pigments, but a more complete scien- 

 tific handling of the subject is very much required. 



In conclusion, this book may be safely recommended 

 to all those interested in colour manufacture, as con- 

 taining a great deal of useful and valuable informa- 

 tion brought together in a clear and practical form. 



UNIVERSITY ADMINISTR.ATION. 

 Univcisity Admi)nstratioii. By Charles W. Eliot. 

 Pp. 266. (London : Constable ; Boston and New 

 York: Houghton, Mifflin and Co., 1909.) Price 65. 

 net. 



UXI\'EKS1TY politics has long been a current 

 phrase, and questions of university government 

 and policy have been increasingly discussed of recent 

 years ; yet, in spite of the rapid increase in the number 



