i86 



NA TURE 



[August 12, 1909 



their treatment form a section quite distinct from 

 tfie remainder of the volume. 



At the same time, it must be remembered that the 

 whole work is one written for the student, and from 

 this point of view it may be maintained that the 

 logical arrangement is to be preferred. The useful- 

 ness of such an extended general treatise on physics 

 is, however, far from being limited to the purposes of 

 a university course, and the convenience of the older 

 student who needs his theory for its application to 

 practice might well have received more consideration. 



It is to be remarked also that Prof. Bouasse's 

 " Cours de Physique " is essentially a treatise on 

 mathematical physics. The author takes a keen in- 

 terest in the most recent developments in phvsical 

 science from the theoretical point of view, but it is 

 not to him that we should turn for information as 

 to experimental work. 



This premised, it may be said that the work is 

 one which should command attention. Prof. Bouasse 

 has the faculty of presenting his mathematics in a 

 clear and attractive fornij and his theoretical discussion 

 of practical points often presents novelties of value to 

 the practical experimenter. 



The first chapter is devoted to the discussion of 

 Maxwell's equations of the electromagnetic field. It 

 is unfortunate that so much reference to vol. iii. of 

 the work should be necessary, but, nevertheless, the 

 matter is presented with admirable clearness, and the 

 student has no cause to complain of the author's 

 dictum : — 



" The reader cannot spend too much time 

 on this first chapter; if he understands it well, all 

 the rest of the volume will appear clear to him. If 

 he fails to understand it — nous ne saurions trap hii 

 conseilhr d'abaiidoniicr la ihcorie elcctronmgiictiquc 

 de la lumiere." 



Then follows the section of some seventy pages on 

 Hertzian waves and their application in wireless tele- 

 graphy. The treatment is of interest; it includes 

 an account of the general theory and a mathematical 

 discussion of various practical questions, especially the 

 propagation of a disturbance along a wire; but it is 

 necessarily incomplete, and would be of more value in 

 a volume not so specially devoted to optical theory. 



The main part of the work is that devoted to the 

 discussion of double refraction and of polarised light. 

 The theory is directly based on that of the propagation 

 of electromagnetic waves in an anisotropic medium ; 

 from this is deduced the equation of the wave surface 

 and the construction of Fresnel. This leads up to a 

 sufficiently full treatment of the phenomena connected 

 with double refraction as dealt with in any modern 

 treatise on physical optics; as elsewhere, the mathe- 

 matical presentment has many original and attractive 

 features. 



In the succeeding chapters reflection and refraction, 

 dispersion and absorption are fully discussed from the 

 standpoint of the electromagnetic theorv. A some- 

 what brief treatment of the electron theory leads to 

 the consideration of the Zeemann effect, and the pheno- 

 mena of emission, phosphorescence and fluorescence, 

 &c., while the concluding cliapter deals with the 

 KO. 2076, VOL. Si] 



thermodynamics of space, including such topics as 

 Poynting's experiments on radiation pressure and the 

 discussion of Stefan's law. 



As has been sufficiently indicated, the whole of the 

 section of physical optics here dealt with is treated as 

 a deduction from the equations of the electromagnetic 

 field. This may be a simplification from the point of 

 view of theory, but we are inclined to think that to 

 the student it may give an air of unreality to a subject 

 which, above all others, is based on the most complete 

 and e.xact experimental data. 



OUR BOOK SHELF. 



On the Poison 0/ V enotnous Snakes and the Methods 

 of preventing Death from their Bite. Reprinted 

 papers by the late Sir Joseph Fayrer, Sir Lauder 

 Brunton, and Major Leonard Rogers. Pp. iii+174. 

 (London : Macmillan and Co., Ltd., 1909.) Price 

 2S. 6d. net. 

 This publication consists of a re-issue in book form of 

 si.x papers reprinted from the Proceedings of the Roval 

 Society. Tlie first four papers deal with the physio- 

 logical action of snake venoms. They were first pub- 

 lished more than thirty years ago, and then represented 

 important advances in knowledge. They cannot, how- 

 ever, be expected to reflect the present-day knowledge 

 of the action of snake venoms. The fifth paper, be- 

 longing to the same period, deals with chemical 

 methods of destroying the activity of cobra poison, 

 such as by chloride of gold or of mercurj'. The last 

 paper, which was published in 1904, and is the 

 only one of the series in which the last-named author 

 cooperated, deals with the experimental results of the 

 treatment of snake-bite by free e.xposure of the wound 

 and local application of potassium permanganate. 



To be of practical service in the treatment of snake- 

 bite, any remedial measure must be rapidly available 

 and easilv applicable. To meet these conditions, one 

 of the authors devised a special instrument consisting 

 of a small lancet-shaped blade to expose the wound 

 made by the serpent's bite, this blade being set in a 

 short wooden handle, which is hollowed so as to form 

 a receptacle for sufficient permanganate of potash. 

 Experiments were made on rabbits and cats to test the 

 value of the method and instrument. The results, 

 especially in the latter animals, were encouraging, 

 in so much as it was found that death could be pre- 

 vented from a dose of venom considerably larger than 

 that which was sufficient to kill a control animal. 

 At the same time, it may be pointed out that the con- 

 ditions of these experiments do not represent ade- 

 quately the conditions obtaining in an ordinary case 

 of snake-bite. The efficacy of the antidotal action of 

 potassium permanganate depends solely upon how- 

 far the venom can before absorption be destroyed by 

 intimate contact with the permanganate. In the 

 authors' experiments the venom was injected into the 

 subcutaneous tissues, in which case it was relatively 

 easy to ensure contact of the venom with the antidote, 

 whereas in a case of snake-bite the venom is injected 

 usually into deeper tissues, when it is much more 

 difficult to bring the permanganate into contact with 

 the venom. It is thus probable that these e.xperimental 

 results ascribe to this method of treatment a value 

 higher than would be found to attend it in practice. 



While from its simplicitv and cheapness this method 

 of treating snake-bite ought not to be lost sight of, it 

 probably does not represent the ideal attrunment, which 

 is by local application and general administration of 

 an anti venomous serum, and further efl'orts ought to 

 be made in the direction of obtaining such serums of 



