484 



NATURE 



[June 17, 1920 



ture, should prove of value to the organic chemist, 

 but there is little attempt to compare the relative 

 advantages of the compounds so described as con- 

 stituents of technical explosives, and a compre- 

 hensive review of the whole subject is lackiog. 

 A later section contains .the compositions of a 

 large number of explosive mixtures, drawn mainly 

 from the patent literature. It may be noted that, 

 whilst many complex mixtures containing am- 

 monium nitrate as their principal constituent are 

 cited, there is no mention of the simple amatol 

 mixtures which were so extensively employed 

 during the war. The closing chapter describes 

 the usual methods of testing explosives, and of 

 performing the analysis of the raw materials and 

 finished products. The illustrations include 

 numerous photomicrographs of- crystalHne com- 

 pounds, nitrated fibres, and prepared mixtures. 



C. H. D. 



had: A Dog. By Albert Payson Terhune, 

 Pp. 309. (London and Toronto : J. M. Dent 

 and Sons, Ltd., 1920.) Price 65. net. 

 Those who like dogs will find this tribute very 

 interesting, and will, we think, be able to confirm 

 much of it from personal experience. Those who 

 begin the book with a prejudice in the other 

 direction are, we think, likely to change their 

 position. The story is told enthusiastically, but 

 there is no nonsense about it, and the anthropo- 

 morphism is restrained. Some comparative 

 psychologists of the severer sort have said that 

 the fatal thing is a personal interest in the 

 creature observed, and the danger of mingling 

 emotion with inference, and inference with 

 observation, is well known. We might admit 

 this, and yet hold that comparative psychology 

 is likely to be advanced by intimate studies such 

 as Mr. Terhune has given us of "Lad." There 

 may be glimpses of reality to be got in this way 

 which the analytic method does not reveal. In 

 any case,. the author has told, in a very delightful 

 way, the story of a charming companion endowed 

 with considerable complexity of character which 

 nurture enhanced. For " Lad " was a " real " dog, 

 and the chief happenings in nearly all the stories 

 about him are "absolutely true." He lived out 

 a full span of sixteen years, and his epitaph reads 

 "Thoroughbred in Body and Soul." 



A Theory of the Alechanism of Survival: The 

 Fourth Dimension and its Applications. By 

 W. Whately Smith. Pp. xi+196. (London: 

 Kegan Paul, Trench, Trubner, and Co., Ltd. ; 

 New York: E. P. Button and Co., 1920.) 

 Price 55, net. 

 There is nothing striking or new in this argu- 

 ment, neither is there anything extravagant in 

 its application. The author expounds in a clear 

 and easy manner the familiar notions of flatland 

 and of a possible fourth dimension, and suggests 

 that a hypothesis is necessary to explain the 

 somewhat doubtful phenomena with which 

 psychical research deals. These notions, he 

 thinks, afford the basis of a hypothesis. 

 NO. 2642, VOL. 105] 



Letters to the Editor. 



[The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond ivith 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.'] 



London University Site and Needs. 



I HAVE been surprised that no word of protest has 

 been raised against the scheme of locating the Uni- 

 versity of London on a limited plot of land in the 

 centre of the city. If the site were for administration 

 purposes alone, combined, perhaps, with lecture-rooms 

 for those subjects which require no practical instruc- 

 tion, the area offered might' be adequate, but could 

 only be rendered suitable for its purpose at such an 

 enormous cost for site, removal of existing buildings, 

 and erection of new edifices, that nothing but the 

 most urgent necessity could justify; nor would the 

 new position be one whit better or more convenient 

 than South Kensington. It is, however, understood 

 that the buildings to be erected are not only for 

 administration purposes and lectures, but also to' meet 

 all requirements of the scientific departments. 



Now it can be easily shown that provision for 

 scientific subjects will require a far greater area of 

 land than the amount suggested in the Government's 

 offer. For the population of London one thousand 

 would be a moderate estimate for the number of 

 students who might be expected to need instruction in 

 any one of the great departments of science, of w hich 

 not fewer than twenty would need to be provided- 

 Taking into consideration passages, staircases, pre- 

 paration rooms, and assistants' rooms, for everv 

 working place in any practical department a floor 

 area of at least ten square yards is wanted. Therefore, 

 for each of the twenty subjects not less than 

 ten thousand square yards of ficor-space would be 

 necessary. In addition to this, each will require 

 lecture theatres, demonstration rooms, and research 

 roorris ; and for this, on a moderate estimate, we 

 must add 50 per cent, to the above figure. This gives 

 a total requirement for the twenty practical depart- 

 ments of not less than fifty acres of floor-space, 

 in addition to the area wanted for administration 

 purposes, libraries, museums, and for the sub- 

 jects which do not need accommodation for prac- 

 tical work. Unless, therefore, the "skyscraper" 

 system is to be utilised for university buildings, the 

 Ill-acre plot proposed to be given up for the purposes 

 of the University of London is absurdly inadequate, 

 especially since not more than 8 acres of such a site 

 could possibly be covered by actual buildings. 



The problem is, however, much more complex than 

 is represented by a mere computation of floor area. 

 Anyone who has experience of a practical department 

 knows the supreme importance of placing it in an 

 entirely separate, self-contained building or institute, 

 thereby allowing abundance of light for all rooms and 

 furnishing space for any necessary future extension. 

 Such institutes cannot be erected on a limited site. 

 They require. far more land than can ever be provided 

 in the centre of a town. It is, therefore, certain that 

 a single university adequate for the needs of London 

 cannot be established in the situation proposed by the 

 Government ; and it is not too much to assert that 

 its purchase and the cost of erecting buildings upon 

 it would be a most wasteful expenditure, involving 

 at the lowest estimate a total of five millions sterling \ 



The alternative is to decentralise the teaching by 

 placing several university centres — say four to begin 



