December i, 1923] 



NA TURE 



785 



in the science to which his life has been so zealously 

 devoted. As a consequence, the book is never dull, 

 even when treating of somewhat more recondite themes, 

 and in many parts the presentment attains a degree of 

 interest positively absorbing. Moreover, the treatment 

 of the subject matter is sober and objective, as indeed 

 one has a right to expect from an authority of so much 

 knowledge and experience. We are struck not only by 

 the author's enthusiasm for the problems themselves 

 and for their extensive scope, but also by his practical 

 recognition of their limitations ; we feel safe in his 

 guidance, because we feel he has the faculty of estimat- 

 ing values, of discriminating between the essential and 

 the unessential. The author never attempts to conceal 

 the limitations of our present knowledge ; but he 

 believes in the great future of oceanography, in the 

 wealth of stimulating discovery which the science, still 

 in its youth, has yet in store for mankind ; and he 

 contrives to inspire his readers with the same faith. 

 But, like the practical man he is, he sees also that 

 oceanography has other and more direct tasks before it 

 in the service of humanity. He realises that it is this 

 and this alone which can help us to exploit — or husband 

 — the treasures of the sea better than we are able to do 

 at present ; that oceanography, as he aptly puts it, 

 will help man in the future to become " less of a hunter, 

 and more of a farmer of the sea." 



The author has had the good fortune to come into 

 personal contact with some of the greatest oceano- 

 graphers ; and he tells of them, giving his impression of 

 their personalities in a most attractive maimer. We 

 are led to realise how much the influence of these men, 

 especially Sir Wyville Thomson and Sir John Murray, 

 meant to the author himself, and we should be grateful 

 that he has not consigned his impressions to oblivion, 

 but enabled younger generations of oceanographers 

 to partake, as it were, in some degree in the life 

 '^nd happenings of the days when modem marine 



search was first created. 



It is out of the question here to enter upon any 

 <letailed appreciation of the individual sections of Sir 

 William Herdman's book ; but if any parts should be 

 noted as particularly valuable, they are chapters like 

 the two on Wyville Thomson and John Murray, and 

 the three on plankton and food-matters in the sea ; 

 the hydrographical sections, on the other hand, scarcely 

 come up to the same level. For the rest, adverse 

 < riticism must be directed not so much towards what 

 the book contains as to what it docs not. 



There arc not a few writers who regard oceanography 

 ^ being merely the study of physical and chemical 



nditions in the sea. Sir William Herdman is not one 

 ! these. To him, the biology of the sea is as much 



eanography as are its physics, chemistry, and geology. 



NO. 2822, VOL. I 12] 



I am entirely of the same opinion. On the other hand, 

 I cannot but feel that hydrography has here been 

 rather left out in the cold. Two chapters (viii. and 

 ix.) out of seventeen, and 37 pages out of 329. This 

 seems rather scant measure, even for those more inter- 

 ested in the biological side, and even granting that hydro- 

 graphical observations occur here and there in the other 

 chapters.^ Also, the extensive work which has been 

 carried out during the last thirty years by national and 

 international investigations of the sea, in procuring 

 information as to the food fishes, their development and 

 life-histories, might, I think, have been found deserving 

 of fuller and more particular treatment. The same 

 applies to several institutions the principal task of 

 which consists in working at the practical application 

 of oceanography ; in a book strongly emphasising the 

 importance of this side of the work, they might have 

 deserved special mention, whether for their particular 

 organisation, or as having been of fundamental value 

 to the methods of applied oceanography. 



Nevertheless, though we might thus have wished for 

 more, the author gives us, even without it, very much 

 indeed, and there is ever\' reason to congratulate him 

 on the publication of this book. It is generally known 

 that Sir William Herdman has furthered the advance of 

 oceanography in his own country. In this book, he has 

 not only set up a handsome monument to himself, but 

 also — and this will doubtless please him more — has 

 proved himself an excellent advocate for his young 

 science of oceanography, both within and beyond the 

 boundaries of Great Britain. Johs. Schmidt. 



Preventive Medicine. 



An Introduction to the Practice of Preventive Medicinci 

 By Prof. J. G. FitzGerald, assisted by Prof. Peter 

 Gillespie and H. M. Lancaster. Pp. xx + 826. 

 (London : Henry Kimpton, 1923.) 375. 6d. net. 



THIS is the first " full-dress " Canadian text-book 

 of preventive medicine, so far as we know, which 

 has seen the light ; and it is a happy augury of the 

 future of public health in our sister country that so 

 complete a book founded largely on Ontario experience 

 should be practicable. 



Dr. FitzGerald, the professor of hygiene and pre- 

 ventive medicine in the University of Toronto, has, 

 with the assistance of several collaborators, focussed a 

 vast mass of important information bearing on pre- 

 ventive medicine and public health, from which British 



' Apropos of hyilrography— one pious wish from a non-British reader: 



that one could but havp thoso Fahrenheit defcreo^ 

 ill all oceano«raphical works, Ilritish inrlude<i. 

 nbic to reckon equally well with either in ll' 

 the temperatures are noted in Fahrenheit in 

 another; but to the rest oj us, Fahrenheit is r 

 I hope thi« heartfelt cry may find its way to Urit 



rt>-l inti. Centiitrade 



• iin to be 



'xample, 



iiKrade in 



:. ili^.ulvantage. 



<ii<l heart*. 



V I 



