having a lot of corn is told what proportion of alfalfa, or roots, ought to be fed along with corn to attain the best economic results. This part of Mr. Coburn's book is valuable.

In the earlier chapters Mr. Coburn deals with the various races and breeds of swine in the States, and also with the principles of breeding; but, as may be inferred from the following quotation, although he writes at some length, he does not get much beyond the current nebulous ideas held by stock-breeders on these subjects :

"There exists in some sections of Old Mexico a type of 'hog' which is the product of crossing a ram and a sow, and the term 'Cuino' has been applied to this rather violent combination. The ram used as a sire to produce the Cuino is kept with the hogs from the time he is weaned. . . . The Cuino reproduces itself and is often crossed a second and third time with a

ram."

IN the preface the authors state that this volume is based on the teaching of the Edinburgh school of pathology, where the first chair of pathology in the United Kingdom was founded, and as such we welcome its appearance. At the same time, we do not note any features particularly novel, either in the subject-matter or in its arrangement, and in some respects the book seems to be lacking as a text-book of general pathology. Thus the important factor of heredity in disease, and shock and collapse, are not even mentioned, and we do not understand why a discussion of the nature of gout and the chemistry of uric-acid metabolism "do not come within the scope of the present volume."

The opening chapter deals all too briefly with the cell in health and disease. An excellent summary of modern views on cell-structure and cell-division is presented to the reader, but the section on the chemistry of the cell is mainly occupied with the recommendations of the Chemical and Physiological Societies on protein nomenclature.

The chapters which follow deal respectively with general retrogressive processes, disturbances of the circulation, inflammation and repair, progressive tissue changes, animal parasites, and immunity.

An excellent account is given of fatty change, and modern views respecting it are succinctly stated. Lardaceous disease is similarly well treated, but we do not understand why authors will persist in employing the terms " waxy and "amyloid" to designate it, for "lardaceous" has the claim of priority; it is official in the "Nomenclature of Diseases" of the Royal College of Physicians, and the material present is universally known as lardacein.

The chapter on inflammation and repair gives all essential details on this important subject. The classification of tumours, admittedly a difficult subject, adopted by the authors is that advocated by Adami. This seems to us unnecessarily complex for the medical student and practitioner. The structure of tumours is given at some length, and the chief views on the

causation of tumours are summarised. As regards the latter, one or two points brought out by recent research have been omitted. For example, the occurrence of heterotype mitosis in malignant growths is referred to, but Bashford and Murray's criticism of Farmer, Moore, and Walker's work in this connection does not appear, and in discussing the supposed sarcomatous metamorphosis of carcinoma no mention is made of the fact, which now seems certain, that it is the connective tissue stroma of the carcinoma which is thus transformed, and ultimately overgrows the carcinomatous elements. The vegetable parasites are omitted, as these are dealt with in text-books of bacteriology, but an excellent and fairly full account is given of the animal parasites, protozoan and metazoan. Immunity is discussed in twenty-five pages, and the essentials of the subject are conveyed to the reader.

On the whole, the book may be regarded as a very useful text-book of general pathology. It is excellently got up, and a word of praise must be bestowed on the illustrations, 162 in number (also four coloured plates), the majority of which are the work of Mr. Richard Muir, and as a rule depict very clearly the subjects they represent, though it may be questioned whether so many are really necessary, as they tend to distract the student from an examination of the actual specimens themselves.

(1) Der Bau des Weltalls. By Prof. Dr. J. Scheiner. Dritte, verbesserte Auflage. Pp. 132. (Leipzig: B. G. Teubner, 1909.)

(2) Die Planeten. By Dr. Bruno Peter. Pp. 131. (Same publishers, 1909.) Price 1.25 marks each. (1) THE series "Aus Natur und Geisteswelt" is well known. It consists of a number of little treatises, in which men of science occupying prominent positions have attempted to explain in an accurate and comprehensive manner the results of past inquiries, and the position to which our knowledge has extended in various directions. In the former of the two specimens before us, Dr. Scheiner gives the substance of six popular lectures delivered in Berlin to a number of high-school teachers in the course of which he attempted to describe so much of the universe as comes within the range of our telescopes. He endeavoured to bring home to his audience the magnificent scheme of distances on which the planetary and stellar systems are planned; he traced the detection of proper motion of the fixed stars, and showed how the sun's movement in direction and amount can be determined. The phenomena of the sun are explained in some detail, preparatory to the examination of the spectra of stars, a subject which is discussed somewhat fully, as might be expected from a member of the staff of the Potsdam Observatory. Herein, as the author points out, he is on the sure ground of observation. But in his last chapter he approaches the more speculative subject of the origin and constitution of the universe. The subject is handled with skill, and, notwithstanding the limited space to which the author is restricted, he has succeeded in making his subject both clear and interesting. We do not wonder that the little work has passed through three editions, for, apart from that longing to satisfy an intelligent curiosity which appeals to so many, the material is put in a very attractive form, which should appeal to many readers.

(2) Dr. Peter has a simpler subject, in which the facts have been many times detailed, and he has little scope for either originality of treatment or lucidity of arrangement. As the planets extend in order from the sun, so he must follow them from Mercury to Neptune. A Vulcan is hinted at within Mercury's orbit, but the

hypothetical planet outside Neptune does not attract comment. Since the satellites of Jupiter and Saturn come under notice, more attention might have been given to the moon and to the phenomena of eclipses. The plan of the book, however, aims rather at the description of the surface than of the motion of the planets, though naturally the tale of the discovery of Neptune is told once again. It might seem that there is scarcely room for such a book, considering the number of popular works that are extant, but there is some difficulty in keeping even these works abreast of the time. As an example we may quote the sentence, "Bestimmt sieben, wahrscheinlich sogar acht Monde umkreisen umkreisen Jupiter." Notwithstanding the recent issue, there is here opportunity for correction in the next edition.

Untersuchung und Nachweis organischer Farbstoffe auf spektroskopischem Wege. By J. Formánek, with the collaboration of E. Grandmougin. Pp. 252. Second edition. Part i. (Berlin: Julius Springer, 1908.) Price 12 marks.

THE first edition of this work appeared in 1901 in a single volume. In part i. of the new edition which is now before us, subject-matter to which only forty-two pages were devoted in the first edition has been elaborated and added to so largely that it occupies the whole of part i. The introduction deals with spectroscopic methods in general, but more particularly with absorption spectra of coloured solutions and the influence of solvents, concentration, reagents, temperature, &c., on the latter. Then follow chapters on the spectroscope, general observations on the relationship between colour, absorption, fluorescence, and constitution of coloured compounds and dyestuffs, and on the relationship between chemical constitution and absorption spectra of dyestuffs belonging to individual classes. The latter include di- and tri-phenylmethane dyestuffs, quinonimide dyestuffs, fluorindene and triphendioxazine, acridine dyestuffs, and anthraquinone dyestuffs. No mention is made in this part of the azodyes, or the dyes of the indigo group, while of natural dyestuffs only alizarin is mentioned. It is to be presumed, however, that these important classes will receive due consideration in part ii., which represents the practical part of the work.

Although a vast amount of work has been done by different observers on the absorption spectra of the organic dyestuffs, the information is so scattered as to be difficult of access to the ordinary individual, and this is probably the main reason why this important subject has hitherto not received the attention which it merits. There is, however, ample testimony that this particular application of the spectroscope is being more and more appreciated by the manufacturers of dyestuffs on the one hand, and the users on the other. This is borne out by the fact that such an eminently practical body as the Société industrielle de Mulhouse has made a pecuniary grant to the author to enable him to publish the new edition. Prof. Formánek has made a life-long study of his subject, and a comprehensive and up-to-date book on this particular application of spectrum analysis, such as the present edition promises to be, would be much appreciated. It is to be hoped that the completion of the work will not be

long delayed.

well known that these properties, while still remaining additive, involve factors depending on the constitution of the molecule, e.g. method of linking, ringformation, &c., all of which should be taken into account in the calculation of the value of the particular property in the case of any given substance. It is the thorough-going application of this principle in the calculation of thermochemical constants, extended so as to include, not only the specific thermochemical values of double and triple bonds, but also the thermal value of the "strain" in ring-compounds and of the single bond in chain-compounds, that the book under review expounds. The author's method of calculation has already appeared in several articles published in the Chemical News, on which the present monograph is based.

The author's method will best be understood from the following-Let H be the value of a hydrogen atom plus the link joining it to a carbon atom. Let C be the value of a carbon atom, not including the value of its valencies; let L1, L2, L、, be the values of the single, double, and triple bonds respectively. Knowing the constants for four "hydrocarbons, it is possible to calculate the value of the following:C+4H=a, 2H-L1 =B, 4H-L2=y, 6H-L,-8. These are the "fundamental constants for carbon and hydrogen. Moreover, the formula of any compound can be written in terms of these fundamental constants, and the theoretical value so obtained can then be compared with the experimental number.

This method the author has illustrated by the calculation of a large number of heats of combustion of substances belonging to different groups of compounds, and, with comparatively few exceptions, excellent concordance with the experimental numbers has been obtained. In this fact the method has its justification.

In an interesting section the author discusses also the relation between heats of combustion of ring-compounds and von Baeyer's strain theory, and he shows that in general there is perfect agreement. No simple relationship, however, has been obtained between the angle of deviation and the thermal equivalent.

The book is one which deserves and will no doubt

obtain the attention of all who are interested in the relations between the thermochemistry of compounds and their chemical constitution; and the method of calculation is, moreover, one which will not improbably find application in the case of other physical properties of an additive character. It is an important addition to the literature of thermochemistry. A. F.

An Angler's Season. By W. Earl Hodgson. Pp. xii+299. (London: A. and C. Black, 1909.) Price 3s. 6d. net.

angler's attention, and An Angler's Season" is no A BOOK from Mr. Hodgson is always worthy of the exception to the rule. Dealing as he does solely with salmon and trout, and almost entirely with Scotch waters, the author's season begins in January allotted; throughout there is much good reading, a and ends in October, and to each month a chapter is deal of sage advice, and some controversy. Early in February Mr. Hodgson is already at issue with the dry-fly fisherman, and his attack on the "Hampshire method" waxes furious, but he says nothing of those who fish with the dry fly in Aberdeenshire waters and find the method successful. Fault is also found with some anglers for their "habitual indifference to the weight of a basket " and their love of nature; surely an angler is no worse for also being a naturalist, or at least taking an interest in the natural history of fishes. A study of what naturalists have written would have shown the danger of Mr. Hodgson's theory that taking large fish only, and restoring all of

smaller size to the water, would have the effect of increasing the average weight of the stock of fish in three years' time, and would, we think, have prevented the red flesh of some trout being attributed to richer feeding rather than to a differently constituted menu. We think, too, that the theory set forth to

account for the absence of a run of salmon in some rivers of the east of Scotland in May, June, and July is somewhat strange, and cannot be maintained in the light of our present knowledge of the salmon's lifehistory.

There are throughout the book numerous practical hints of value upon such subjects as flies and baits, and as to the time and place for fishing under various conditions of water and weather; in the last chapter there is also a most thrilling tale of a riverside adventure. The illustrations, reproduced from photographs, are excellent, but are almost invariably separated by many pages from the corresponding text, and there is a good index. L. W. B.

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 with the writers of, rejected manuscripts intended for this or any other part of NATURE. No notice is taken of anonymous communications.]

A New Departure in Seismology.

ON the photographic records obtained from British Association types of seismograph it has been noticed that when the films have been moving slowly (60 mm. per hour) there have been slight thickenings in the trace, while if the recording surface has been moving quickly (240 mm. per hour) the line which ought to be straight is slightly wavy. These irregularities, which have hitherto received but slight attention, are so small that they may be easily overlooked. When the thickenings were first observed it was supposed that their existence was due to a flickering at the source of light or to some irregularity in the movement of the record-receiving surface. When, however, it was observed that these markings frequently occurred at the same time at different stations, as, for example, at Shide and Bidston, the conclusion was that they were due to movements of the ground, and might be the surviving phases of large movements with origins at a distance.

A very good illustration of this is given by comparison of the times of occurrence of the after-shocks which followed the earthquake of January 14, 1907, in Jamaica, with the times at which suspicious irregularities were found on the seismographic traces at Shide and Bidston. Between January 14 and July 5, 148 shocks were noted in Jamaica. Forty-three minutes after the occurrence of fifty-one of these shocks irregularities were found on the films at the stations mentioned. As forty-three minutes is the time we should expect a "surface " wave to travel sixty-seven degrees, or from Jamaica to England, the inference is that the slight irregularities represent movements which had their origin in Jamaica. Corresponding markings, with the exception of one at Göttingen on July 5, do not appear in the registers from European stations, which are more than six or seven degrees farther from Jamaica than Britain.

not

Another instance of the recording of after-shocks are the markings seen on seismograms after the disaster which, on December 28, 1908, ruined Messina and Reggio. Between December 29 and January 30 at Mileto, forty miles from Messina, 225 shocks were noted. Eight of these reached the Isle of Wight, while on January 1 and 13 at Göttingen, Hamburg, and Laibach, only two were noted. The reason that so small a number travelled a considerable distance indicates that the originating impulses were weak. That a larger number should be recorded in Britain than at comparatively near stations is not so clear.

With smoked paper recording surfaces, whether the multiplication of recording levers be 10 or 200, a certain slackness in joints and elasticity of pointers prevents any record of motion being obtained until a certain amplitude of ground motion has been reached. With photographic

recording apparatus where a light source is far from a recording surface, a thick line may obscure any minute movement. These instruments are therefore unsuitable as recorders of very small movements. This, at any rate, has been my experience.

The British Association type of instrument, when properly adjusted and installed, does, however, pick up

these neglected movements-a result which is shown very clearly in the registers for this year.

It seems to me that beneath observatories all over the world earth-messages may be passing every few minutes, but these are not recognised because instruments generally in use are not capable of recording the same. To investigate this possible new departure in seismology, old types of instruments will have to be improved or adopted.

Shide, Isle of Wight, July 2.

new

ones

JOHN MILNE.

Tables of Bessel Functions.

A COMMITTEE of Section A of the British Association for the Advancement of Science, appointed to undertake the further tabulation of Bessel functions, is at present considering the advisability of unifying and completing the existing tables with the view of the publication of a complete table of Bessel functions.

The committee would be glad of information as to existing tables of Bessel and Neumann functions with a real or complex argument, in addition to the following, of which the members are already aware :—

(1) Meissel's Tables (reprinted in Gray and Mathews' treatise on Bessel functions) giving J(x) and J,(x) from x=0_to_x=15·5 at intervals of 0-01 [12 places]; also a table of the first 50 roots of the equation J(x)=o to 16 places.

(2) British Association Tables (1889, 1893, 1896 Reports) giving (x) and 1,(x) from x=0 to x=51 at intervals of 0.001 [9 places]; also I,(x) to I,,(x) from x=0 to x=6.0 at intervals of 02 [11 and 12 significant figures]; also a table of J(x√√i) from x=0 to x=6 at intervals of 0.2 [9 places]. (Part of these tables are reprinted in Gray and Mathews.)

(3) Tables of Jn(x) in Gray and Mathews from no to n=60 and from x=0 to x=24 at intervals of unity [18 places].

(4) B. A. Smith's Tables giving Y。(x), —Y,(x), and from (log 2 −7)J.(x) — Y ̧(x), (log 2-7),(x) —Y,(x), x=0 to x=1.00 at intervals of 0.01 and from x=1.1 to x=10-2 at intervals of 0.1 [4 places: error not exceeding 2 in the last place]. (Messenger of Maths., vol. xxvi., 1897, and Phil. Mag., vol. xlv., 1898.)

(5) Aldis' Tables of I,(x), I,(x), K。(x), K,(x) from x=0 to x=11 at intervals of 0.1 [16 places]. (Roy. Soc. Proc., 1896 and 1899.)

(6) J. G. Isherwood's Tables of K.(x) to K,,(x) from x=0 to x=5 at intervals of 02 [5 significant figures]. (Manchester Lit. and Phil. Soc., vol. xlviii., 1904.)

The committee will be grateful to be allowed, through the medium of NATURE, to invite any readers who are aware of the existence of tables of Bessel functions other than the above to make known this fact.

Communications should be addressed to the secretary of the committee, Dr. L. N. G. Filon, University College, Gower Street, W.C. M. J. M. HILL.

University College, Gower Street, W.C.

Baskets used in Repelling Demons. IN the issue of NATURE published on May 27 Mr. Kumagusu Minakata inquires regarding the use of baskets in repelling demons in countries other than Japan. In Calcutta, and I believe in other parts of India, it is customary when a new building is being erected to set up on the highest part of the scaffolding a pole, to the top of which a round basket and a scavenger's broom are attached. The basket and broom are apparently recognised as emblems of the low-caste sweeper, and therefore as being disgusting objects. They are supposed to ward off ill-luck from the building. Their use in this instance may thus be compared to the use in many countries of obscene objects or gestures as a protection against malicious spirits or the evil eye. N. ANNANDALE.

Indian Museum, Calcutta, June 13.