412 



NA TURE 



\_August 29, 1889 



factors in producing diseased conditions, and, on the other, 

 by determination of those factors through examination 

 of diseased organs ; that is to say, by the methods of 

 experimental pathology and pathological anatomy re- 

 spectively. The first of these is almost unrepresented in 

 the volume, save by the record of work done away from 

 Edinburgh. We venture to express a hope that, the 

 laboratory offering as it does every facility, this neglect 

 of constructive pathology is apparent and not real, and 

 that it is due not to the absence of experimental inquiry, 

 but to the fact that investigations along these lines have 

 not become completed in the course of a short twelve 

 months. 



The facts and suggestions contained in the article upon 

 tuberculosis, by Dr. Woodhead, above referred to, are 

 deserving of a far wider circulation throughout the 

 country than is rendered possible by the conditions under 

 which they now appear. On the Continent, and, especially 

 at this moment, in France, the infectiousness of tuber- 

 culosis, and the appalling extent of its distribution, is at 

 length exciting that serious and general attention which 

 precedes active measures. No disease contributes so 

 largely to the lists of mortality. As Dr. Woodhead points 

 out, the maximum affection by mesenteric tubercle — by 

 tuberculosis of the lymphatic glands of the intestines — is 

 attained between the ages of one and five years, and a 

 large mass of evidence would seem certainly to indicate 

 that the cause is to be sought for in the milk derived from 

 tubercular cows. 



" Many Commissions on the subject have sat, and 

 have delivered themselves of what must, to all who 

 know anything about the matter, seem most sound 

 judgments, but nothing is done. Where is our inspection 

 of milk — not a mere chemical analysis — but a thorough 

 chemical and biological examination 1 Where are our 

 c'auses for the compulsory notification of disease, either in 

 the farm or the farm-house ? Where are our regulations 

 for the examination at regular intervals, and by competent 

 veterinary authorities, of the cattle from which the milk 

 is derived ? . . . We must strike at the root of the whole 

 matter as regards the connection between bovine and 

 human tuberculosis. We then not only remove one set 

 of centres of infection, but in so doing we, in turn, 

 diminish the number of human centres from which the 

 disease may spread." 



Finally, a word is deserving to be said concerning the 

 appearance of the volume. No expense has been spared 

 in making the reports worthy of their origin. The type 

 is large and clear, the individual contributions are well 

 and profusely illustrated ; the appearance of the volume, 

 as a whole, is excellently calculated to make critics fulfil 

 the motto of the College displayed ingenuously upon the 

 back — '''■ Non sinit esse feros." J. G. A. 



TREA TISE ON HYDROD YNAMICS. 



Treatise on Hydrodynamics. Vol. II. By A. B. Basset, 



M.A. (London : George Bell and Sons, 1888.) 

 nPHIS second volume of Mr. Basset's "Treatise on 

 J- Hydrodynamics," the publication of which followed 

 at no long interval that of his first volume, is in all re- 

 spects a fitting complement to that work, and fulfils the 



expectations of value and completeness aroused by its 

 appearance. 



The prevailing impression on studying this volume and 

 contrasting it with the first is, that many more avenues 

 for research and discovery lie open in the subjects here 

 treated, than can possibly be found in the more fully 

 explored parts of hydrodynamics that constitute the 

 subject-matter of the first volume. 



This impression is borne out by the fact that many 

 results here collected together are the results of recent 

 years, placed in this volume in a more accessible form 

 than when engulfed in the original papers. When we 

 find that this book enters fully into such diverse branches 

 of the subject as vortex motion, tides, and viscous fluids 

 — not that these exhaust its contents — we can realize the 

 width and variety of reading necessary to make the 

 matter of the book as valuable and accurate as it un- 

 questionably is, and also the probability that the author 

 must expect to see these chapters rendered incomplete 

 by the advance of knowledge in these directions. 



The chapters on vortex motion owe their results and 

 form largely to the writings of Prof J. J. Thomson ; in 

 the discussion of the stability of the vortex it seems im- 

 possible to evade long and arduous algebraical processes, 

 even though the kinematical surface condition used may 

 be of the simplest. The author himself has given in 

 addition an investigation of the fluted vibrations of 

 a circular vortex ring, making use of toroidal functions, 

 and obtaining the same equation for the periods as in 

 the case of similar vibrations of a columnar vortex. 



We have read with considerable interest a method 

 given in the first chapter on vortex motion, in which the 

 principle of inversion is applied for the first time to a 

 hydrodynamical problem. It is true that its success is 

 restricted to cases of motion in two dimensions ; but a 

 new field might be opened up if, by use of co-ordinates 

 in an inverse system, the ordinary equations of motion 

 would admit of yielding at once two solutions to each 

 problem, in a way similar to the electrical method of 

 inversion. Apparently, the co-ordinates cannot so be 

 changed, nor is any simplification obtainable in the case 

 of viscous fluids, where certain product terms are always 

 disregarded. 



Another most interesting chapter is that on the motion 

 of a liquid ellipsoid under its own attraction ; here the 

 various shapes possible to rotating fluid are passed in 

 review, and, placed as they are in order, beginning with 

 the familiar instance of Maclaurin's spheroid, the neces- 

 sary criteria that separate one possible surface from 

 another are easily distinguished. 



The question of the stability of some of these shapes is 

 considered, and reference made to the papers of Poincar^ 

 in the Acta Mathematica, though certain ex cathedrd 

 statements in Thomson and Tait's " Natural Philosophy] 

 have to go unexplained. 



To enter on the discussion of waves and tides seemj 

 by contrast with vortices, to begin a fresh subject, si 

 totally distinct are the equations and methods ; yet thesJ 

 two chapters are not the least valuable in the book. Th( 

 chapter on waves contains all the known solutions 

 waves in canals or on the sea, and also includes Sir 

 Stokes' masterly investigation of the form of the wave 

 front in the deep sea. In the chapter on tides, after 



