June ii, 1908] 



NATURE 



\2- 



PAINTS AND PIGMENTS. 

 Analysis of Mixed Paints, Colour Pigments, and Var- 



nislics. By Dr. C. D. Holley and Prof. E. F. 



Ladd. Pp. xii + 235. (New York: J. Wiley and 



Sons; London: Chapman and Hall, Ltd., 1908.) 



Price 10.S. 6d. net. 

 Modern Pigments and their Vehicles. By Frederick 



Maire. Pp. xi + 266. (New York: J. ^Viley and 



Sons; London: Chapman and Hall, Ltd., 1908.) 



Price 8x. bd. net. 



THE book written by Dr. Holley, with the assist- 

 ance of Prof. Ladd, on the analysis of mixed 

 paints, colour pigments, and varnishes, should prove 

 of considerable practical value, especially in America, 

 and should be of assistance to analysts who have 

 \\ork of this kind to do, as it brings together 

 much information which is otherwise scattered, and 

 contains a good deal which is not to be found in the 

 well-known manual by the late Mr. Hurst. Owing 

 to the very large development of the ready-mixed 

 paint trade in the United States, and the recent 

 legislation there dealing with adulteration, the 

 analysis of ready-mixed paints is of far more frequent 

 occurrence than it is in this country, where it is verv 

 rare for a public body or an architect to have a proper 

 examination made of the pigments and varnishes that 

 they use. 



The part of the book which deals with (he deter- 

 inination of the covering power and tinting power 

 of a pigment might certainly have been more de- 

 veloped. For a great many practical purposes this is 

 a most important question. If, for instance, we take 

 an ochre which is going to be used either to cover a 

 surface by itself or to be mixed with white, the 

 analysis of the ochre gives us little information of 

 ;iny practical value compared with its careful examina- 

 tion for covering power and tinting strength, yet 

 comparativeh' little is said in the text-books about this 

 method of assaying pigments. The most useful 

 practical instrument for this purpose up to date has 

 been the Lovibond tintometer, which enables the whole 

 matter to be reduced to the plotting of comparative 

 curves of tinting power, and also enables the actual 

 covering power of a white lead to be exactly and 

 accurately measured. The Lovibond tintometer is, 

 however, an instrument which requires a great deal 

 (if practice before accurate results can be obtained, and 

 recently Mr. Ives has introduced a new tintometer 

 w hich may possibly replace the Lovibond tintometer 

 for such purposes. The experiments that were made 

 in this direction by Captain Abney resulted in the 

 development of a most ingenious application of the 

 spectrum, but in ])ractice the Lovibond tintometer 

 has so far proved the more useful instrument. 



There is another direction in which the information 

 in the book is somewhat imperfect, and that is the 

 practical testing of varnishes, although the authors 

 can hardly be blamed for this, as so little has yet been 

 done to make the testing of varnishes thoroughly com- 

 plete and efficient. The practical difficulties are great, 

 .-md weather tests in the hands of different observers 

 have proved to be very delusive. One of the most 

 important questions on which there is need for far 

 NO. 2015, VOL. 78] 



more accurate information is the durability of paints, 

 prepared from different pigments and with differem 

 vehicles, when used for the protection of iron and 

 steel structures. This is rapidly becoming a very 

 serious question, as the use of steel in construction is 

 greatly on the increase, and it is not yet possible to 

 give very accurate information upon this matter. 

 While, therefore, this book by Mr. Holley and Prif. 

 Ladd may be regarded as bringing up to date the 

 information both on the analysis of pigments and 

 vehicles, and on the practical testing of their proper- 

 ties, to which the attention of chemists might well be 

 directed, it reveals very clearly that in this depart- 

 ment of applied chemistry a great deal more informa- 

 tion is required to enable us to determine the facts 

 upon which the suitability and durability of various 

 vehicles depend. 



The little book by Mr. Maire does not pretend to 

 be a scientific treatise, but merely brings together 

 much helpful information about modern vehicles and . 

 pigments, which is stated in a simple manner, with- 

 out going into chemical details, and it should there- 

 fore prove of use to architects and house-painters and 

 decorators who wish to have some general informa- 

 tion as to the materials they use from day to day, and 

 who are yet unable to understand a thoroughlv 

 scientific treatise. A fair number of the pigments 

 which are mentioned by Mr. Maire belong rather to 

 the artist's palette than to painters and decorators, 

 but there is no reason why these should not be in- 

 cluded and some reference made to them. The main 

 difficulty of the modern decorator is, however, due to 

 the introduction of a large number of pigments which 

 ar^ prepared from coal-tar dyes, fresh ones consvantlv 

 coming into the market, which may be fugitive or 

 have the property of bleeding, and about which he 

 necessarily has no information. These pigments are 

 introduced with fancy names, each colour maker 

 choosing such names as may suit himself, and con- 

 sequently a great deal of trouble has resulted in the 

 painting and decorating trade. It is hardly possible 

 for any text-book to deal efficiently with this subject, 

 beyond giving certain general warnings that before 

 using any new pigments, outside those already recog- 

 nised, careful tests should be made by the architect 

 and decorator. 



Both these books can be regarded as thoroughlv 

 useful, the one for the analyst and the other for the 

 architect and decorator, and should do something to 

 encourage a more scientific study of these questions in 

 this country. 



A. P. Laurie. 



OUR BOOK SHELF. 



A Dictionary of Spanish and Spanish-American 



Mining, Metallurgical, and Allied Terms, to ivhicli 



some Portuguese and Portuguese - .\n\erican 



(Brazilian) Terms are Added. By E. Halse. Pp. 



xiii+380. (London: C. Griffin and Co., Ltd., 



1908.) Price 10s. 6d. net. 



In view of the magnitude of the mining industries 



of Spain, Mexico, Central America,' Peru, Chile, 



Bolivia, and other .South American countries, there 



can be no doubt that there is a large and increasing- 



