262 



NATURE 



[June 5, 1919 



with it the entire long train of physical terms that 

 are united with it." As there are already ninety- 

 one formulae when the end of chap. i. is reached, 

 and they are, to say the least, of controversial 

 application, those who are not looking for trouble 

 may be disposed to pass by on the other side. 

 One recalls the "great text in Galatians, Once 

 you trip on it entails. Twenty-nine distinct damna- 

 tions, One sure if another fails." But such a 

 pusillanimous attitude is not permitted to a re- 

 viewer. He has to make up his mind whether 

 the compressed mass of 117 tables and 380 

 formulae which the book contains do in fact add 

 light or darkness to the problems of the sun. 



The book is a discussion, a contribution to 

 theory; the observations upon which it is based 

 are chiefly those of Mr. Abbot, with the pyrhelio- 

 meter, but Prof. Bigelow contends that Mr. 

 Abbot's results are erroneously reduced, so that 

 whereas Mr. Abbot concludes a rise of intensity 

 of solar radiation from I'so calories per square 

 centimetre at sea-level to i'94 at the confines of 

 the earth's atmosphere, Prof. Bigelow, using the 

 same observations, says that the latter figure 

 should be raised to s'gS calories. On p. 376 he 

 remarks: "There is probably no apparatus more 

 difficult to interpret correctly than is the pyrhelio- 

 meter, because it demands a full knowledge of 

 radiation in gases, in glass, in mercury, in 

 metals, during variable transformations, in which 

 the kinetic, potential, expansion, and free-heat 

 energies are all undergoing mutual readjust- 

 ments." One may well say so, if doctors disagree 

 to that extent. On p. 210 is a r&sume of the 

 results of twelve different lines of computation, 

 every one of which gives values between 3*92 and 

 4-08. This would naturally be very impressive, 

 and one would wish to confirm it by recalculating 

 a few of the numbers. But they are not of the 

 kind that admits of this. One must accept them 

 from the author, and without questioning at all 

 their correct derivation from his formulae, it must 

 be said these formulae are of a kind to give one 

 most serious pause. They are, indeed, put forward 

 as revolutionary. On p. i we read : " In the Boyle. 

 Gay Lussac Law, P = /9RT, all the terms, includ- 

 ing the gas efficiency R, are variable." But if R 

 is not constant, all accepted gas theory, and a 

 great deal of the structure of general physics, 

 tumble down in ruins. On p. 17 is given a list 

 of quantities which must also be variable ; they 

 include among them the number of molecules per 

 unit mass of any gas. On p. 129 we read : "The 

 entire thermodynamics of radiation must be based 

 upon a series of non-adiabatic variable coefficients, 

 instead of a set of adiabatic constants, as has 

 been assumed in previous discussions." It cannot 

 be expected that we should make such a change 

 without the most imperative reasons and the most 

 direct and exhaustive proofs of its necessity. But 

 these are wanting. The reasons given in two' or 

 three sentences, on p. 16, are certainly not con- 

 vincing or inevitable. The accepted gas theory 

 is not inadequate to explain, for example, iso- 



NO. 2588, VOL. 103] 



thermal strata in the earth's atmosphere. But 

 Prof. Bigelow 's new doctrine occupies his field of 

 view so exclusively that the whole of his book^ 

 upon which immense labour must have been spent, 

 stands or falls with it. R. A. S. 



OILS, FATS, AND WAXES. 

 Technical Handbook of Oils, Fats, and Waxes. 

 By P. J. Fryer and Frank E. Weston. Vol. ii. 

 "Practical and Analytical." (The Cambridge 

 Technical Series.) Pp. xvi + 314. (Cambridge: 

 At the University Press, 1918.) Price 155. net. 



THE events of the last four years have directed 

 attention to the economic importance of the 

 edible oils and fats, and also to that of fats in 

 general, as being the source from which glycerin is 

 obtained. The national value of the industry 

 which deals with these products is now pretty 

 widely recognised. Fundamentally it is a chemical 

 industry, and a knowledge of the chemistry of the 

 oils, fats, and waxes will tend to become more 

 and more desirable for those who control it on 

 the technical side. 



Messrs. Fryer and Weston may fairly claim to 

 have assisted in the spread of such knowledge. 

 In an earlier volume they have described the 

 general chemistry of the oils, fats, and waxes, 

 and the general principles of the methods of 

 analysis used in the examination of these pro- 

 ducts. The present work is concerned with the 

 practical application of those principles. It 

 appears to be largely intended for technical 

 chemists, but students are also within its purview. 

 Of this we are reminded every now and then by 

 the italicised note : " Students should cleanse all 

 apparatus in hot soft soap solution. . . ." One 

 seems to remember those students ! 



Both classes of users will find the volume very 

 helpful. All the usual methods of analysis are 

 described, with recent improvements and develop- 

 ments, and there are plenty of practical hints 

 and notes. 



The earlier parts of the book "begin at the 

 beginning " with descriptions of apparatus and 

 methods of manipulation, whilst the important 

 matter of proper sampling receives due attention. 

 In explaining the "standard" analytical deter- 

 minations, the general plan adopted is to start 

 with a definition, give a short outline of the 

 method, offer remarks upon it, and describe the 

 apparatus and materials required, before going on 

 to the actual experiments. The directions are 

 categorical, and are couched in a mood which 

 may be characterised as the abbreviated impera- 

 tive : " Dissolve dry fatty acids . . . decant off 

 alcohol . . . distil off ether." A number of 

 photographs of apparatus are included in the text. 



Among the best and most important of the 

 sections is the one which deals wuth the inter- 

 pretation of the results obtained in the analyses. 

 It is one thing to be able to carry out experi- 

 ments on oils, fats, and waxes ; It is quite another 

 to know what the results really indicate. The 

 authors discuss this question in some detail. They 



