known in the inorganic domain. Of course, we have our psychical life, but can we say that this makes a thoroughgoing distinction between organisms and inanimate bodies? How can we tell? Thus there ends a masterly book-scholarly, keenly critical, and rigidly objective. We do not think that the author shows the sufficiency of chemico-physical formulæ for the description of the phenomena of life, but we have the strongest admiration for his searching criticism of the doctrine of the autonomy of the organism. His book should be read along with Johnstone's "Philosophy of Biology."

(2) "The time is now more than ripe," Dr. Haldane writes, "for bringing the great biological movement of the nineteenth century into definite relation with the main stream of human thought," and his lectures form an important contribution towards the fulfilment of this task. The first lecture contrasts the mechanistic and the vitalistic interpretations. The former is certainly good so far as it goes, for the living creature can be usefully considered as a very complex material system, conforming to the laws of dynamics, exhibiting physical and chemical processes that are in line with those of the inorganic world, and as for consciousness (if that be demonstrable) it makes no difference to the energy balance whether the organism is conscious or not. It is true that the activities of the organism are very wonderfully co-ordinated towards securing the survival of the individual and the race, but it is replied that there are effective nervous and chemical means which secure this co-ordination, and have been wrought out in the course of untold ages of variation and selection. It has to be admitted, however, that what goes on is more complicated than the working of any machine known to man; that mechanical interpretations of such functions as excretion and respiration have had to be aban'doned from time to time because they did not cover the facts; that heredity, variation, and development seem facts per se; and that the organism is strangely autonomous. For these and similar reasons there is periodic reaction from mechanism to vitalism.

"Vitalism assumes that the intimate processes are guided or controlled by an influence which is manifested only in living organisms, and which acts in a manner wholly different from anything known in the inorganic world.".

To Dr. Haldane the theory of vitalism is no more acceptable than that of mechanism. For if a vital principle controls what goes on in the organism, can it do so without a breach in the conservation of energy; and if it guides, how does it know how to do it? The hypothetical vital principle is unproved, unintelligible, and useless.

In this chapter, the answer to Driesch's argument from embryonic development seems to us very far from clear.

The second lecture contains a criticism of the mechanistic theory. It has been useful in stimulating research, but it is inadequate for the redescription of what is essentially vital. A minute increase in the hydrogen ion concentration of the blood induces an intense activity of the respiratory centre, but we do not know the chain of events between the stimulus and the response.

"In the case of stimulus and response there is in reality no experimental evidence whatsoever that the process can be understood as one of physical and chemical causation."

Or what are we to make of the "recovery of functional activity after destruction of centres or nerve paths on which this activity normally depends?" Moreover, the fact is that "physicochemical explanations of elementary physiological processes are as remote as at any time in the past." Even if we could picture the vast assemblage of delicately-adjusted cell-mechanisms, keeping themselves in working order year after year, keeping in exact co-ordination with all the other cell-mechanisms, and so on, how can we conceive of this condensed into a germ-cell, uniting with another germ-cell, and then developing afresh. And the difficulty of thinking mechanically of reproduction recurs when we picture the continual renewal of cells and plasm within the body, the ceaseless work of maintaining a structural and functional specificity. Dr. Haldane concludes that "the phenomena of life are of such a nature that no physical or chemical explanation of them is remotely conceivable." In speaking of the mechanistic view of the germ-plasm, the author says, p. 58: "On the one hand we have to postulate absolute definiteness of structure, and on the other absolute indefiniteness." But it seems to us that the word indefiniteness is here used in a sense not inconsistent with definiteness, namely, in reference to the number of divisions. that may occur. If we understood one division, we should not boggle over an indefinite number of them.

In his third lecture Dr. Haldane turns the tables on the mechanists. The physical and chemical concepts are, after all, but working hypotheses; the notion of a real and self-existent material universe does not survive Hume's criticism. In any case, when we pass to the world of organisms we need new concepts, especially that of the living organism, a specific entity, actively maintaining and reproducing its individual structure, with functions which are determined in definite relation to the whole unified

activity, an autonomous active whole. "The conception of organism is a higher and more concrete conception than that of matter and energy." In the ruins of the atomic theory, it is already being extended to the whole of nature. "We are

not seeking to reduce the organic to the inorganic, but the inorganic to the organic." To us it appears unnecessarily dogmatic to assert that "there is not the remotest possibility of deriving the organic from the inorganic." Would it not serve to say that we cannot think of the origin of organisms from the inorganic world, if the reality of the latter is supposed to be exhausted by the current concepts of chemistry and physics? And are we not bound in fairness to admit that while the physical and chemical formulæ need not be regarded as exhausting the reality of the inorganic world, they serve for certain practical purposes exceedingly well, and must bear a definite relation to reality since we successfully stake our lives and our reputations (as scientific prophets) on their validity.

The fourth lecture finds a philosophical foothold in the recognition of personality as the central fact in the world. We may consider a man as a material system weighing seventy kilogrammes, and this partial and abstract way of looking at him is sometimes of use; we may also consider him as an organism, maintaining specific structure and activity, and this is also useful; but we get nearest the real man when we know him as a person. Personality-mere organism-matter: "the relation is simply one of different degrees of nearness to reality in the manner in which phenomena are described." But personality is more than an individual concept; "the personality of any individual is the spiritual inheritance of ages; the individual participates in the life of the species; personality includes within itself our whole universe. We know extremely little about what we call matter; "the reality behind the appearance of a physical world has and can have no existence apart from personality." And thus, as the physiologist in his first two lectures sought to lead us away from the error of mechanism, so the philosopher in the last two seeks to lead us to the conclusion that the world, with all that in it is, is a spiritual world. But the realist has also something to say for himself!

rapidity with which processes relating to fuel manufacture and its preparation are changing, and of the new uses to which the fuels are put when made, there is ample room for new-comers. The author writes specially for the large class of readers to whom power production is of chief importance, and he has produced a volume which will be an extremely valuable addition to their bookshelves.

The subject divides itself naturally into three divisions-solid, liquid, and gaseous; Mr. Brame discusses each separately, and adds a section on fuel analysis, calorimetry, and the control of fuel supply. Under the title "Solid Fuels" are included wood, peat, coal, coke, coalite, and the minor fuels; liquid fuels include petroleum and tar oils with their derivatives, together with alcohol. The longest section, that on gaseous fuels, contains an account of the manufacture and properties of water gas, of Siemens and Dowson gas, and of blast-furnace and coke-oven gases.

Well-informed as the author appears generally to be, he makes a strange omission when discussing the velocity of flame propagation in an explosive mixture-the stranger in a book bearing specially in view the production of power-in that he omits reference to the striking influence on this velocity of "turbulence" in the gaseous mixture. As Clerk has shown in the reports of the Gaseous Explosions Committee, turbulence is of first importance in influencing the velocity with which the explosion spreads to all parts of the gas, and that except for this no high-speed gas or petrol engine would be able to run at the speeds necessary for their effective use.

The Bonecourt system of surface combustion is described briefly, but perhaps as fully as can be expected in a book dealing with fuel itself rather than with its manner of use. The author compares the 90 per cent. efficiency of this system when applied to the heating of steam boilers with the 55 to 65 per cent. which is usual with cokeoven or blast-furnace gases used in the older way. This improved method of steam raising is potentially of great practical importance, and we are glad the author has found space to include a number of interesting efficiency figures.

Under the title "Economic Aspects of Liquid Fuel" the author discusses the present situation in which fuel users are placed owing to the rapid change in price. He reiterates the relative insignificance of the annual oil output compared with the coal output, and affirms his belief in the possibility and the economic advisability of the production of alcohol for power uses. This is one of the best parts of the book, and the author is assuredly correct in saying of industrial alcohol:

HIS book is a most valuable addition to the

THIS series of metallurgical text-books published by Messrs. C. Griffin and Co. It gives in a concise but wonderfully complete form the upto-date practice in the extraction of the following metals from their ores: copper, lead, gold, silver, platinum, mercury, zinc, cadmium, tin, nickel, cobalt, antimony, arsenic, bismuth, and aluminium. Under the heading of each metal are considered (1) its physical and chemical properties; (2) the alloys of which it is the chief constituent; (3) the composition and applications of commercial brands; (4) the chief ores and processes by which the metal is extracted from them and rendered suitable for industrial or other purposes; (5) the principles and conditions on which the success of these processes depends; and (6) examples of actual practice in important extraction works. The author states that special attention has been given to the metallurgy of gold, silver, copper, and lead, which undoubtedly constitute the most important members of the above group. This statement is thoroughly justified, for, so far as we have been able to ascertain, every important modern successful process has received attention.

In writing this book the author has had in view not only the student engaged in a course of metallurgical training, but also the man who is actually dealing with practical problems; and he is particularly well qualified to present both these important aspects of the subject. It is perfectly true, as he points out, that much valuable information with regard to modern metallurgical practice may be found in technical periodicals and the proceedings of societies. Those who have the opportunity of consulting such publications will, we think, find his critical comparisons of similar processes of great value, while to the man whose time is limited or who has no technical library within reach the book will be one of the most valuable that has ever been published. The clear and full table of contents enables a reference to

any particular process, and, indeed, to any special feature of it, to be readily made.

The author writes with rare, indeed, almost unique, knowledge of the metallurgy of copper, and his mastery of the subject cannot be better illustrated than by mentioning that in the compass of eighty-one pages every important aspect is dealt with. The ore now being pyritically smelted at the Tennessee Copper Co.'s works at Copperhill runs rather lower in copper than the figure 2 to 2 per cent. mentioned by him (p. 100); it does not exceed 19 per cent., and is tending to become even lower in grade. We think that the Chilian Mill might have received more attention than the three lines devoted to it on p. 208. At the present time almost, if not quite, all the Cripple Creek gold ores are reduced by Chilian mills, the Stamp Mill having been practically superseded in this district. 1710° C. is given for the melting point of platiIt is now generally recognised that this figure, which was obtained on the thermo-electric The value scale by extrapolation, is too low. 1755° C. quoted recently by the Bureau of Standards is probably much nearer the true figure.

num.

Harker's value of

TH

HIS little book has a special interest at the present time. The author deals with the history of science as applied to industry, and while avoiding any violent diatribes against the supineness of the British manufacturer, he points out what may be done to recover the supremacy of our trade. The employment of more scientific men in most of our works is strongly advocated, not only of the higher class of research men, but also of the class of routine analysts. The first class is required to devise new processes along scientific lines, to disuses and outlets for bye-products, and always to be on the look-out for methods for gaining the maximum yield of finished products at the minimum of cost.

cover

"To many business men the employment of such a man may appear a luxury; almost a gamble! The few that have such men are only employing them for some specific object, and maybe will rest content when that object is attained. Such an attitude is fatal."

If the German manufacturers had been content to take this line, the magnificent industries which they have built up would certainly not have come into existence. We have now, at this moment, an opportunity of recovering the ground we have lost.

The Government Committee on the Chemical Trades is composed of men who will command the confidence of everyone, and their recommendations will have great weight. It must not be forgotten, however, that nearly all trades would be benefited by scientific help. The attitude of mind induced by scientific education is just the one required for the successful development of a business. If the manufacturers as a whole would realise this, they would see to it that their sons or those who are to carry on their business, have a thoroughly good scientific education, such as may now be got at many of the Universities and technical colleges in the country. It is not the classical or the modern side of our schools which is going to supply the successful manufacturer of to-morrow, it is the side where a man is taught to bring all his useful knowledge to bear on the achievement of success. Mr. Illingworth's book is the most successful attempt which has been made to explain the situation, and we believe that if the Government would send a copy of the book to each manufacturer in the country, the cost would be a mere nothing compared with the effect which would be attained.

OUR BOOKSHELF.

A Little Book on Map Projection. By Mary Adams. Pp. viii+108. (London: George Philip and Son, Ltd., 1914.) Price 25. net. It is very satisfactory to find that at the present time care is being taken that the principles of map projection are being studied as soon as the use of maps is seriously undertaken. At one time this part of their subject was much neglected by geographers, and left to those whose mathematical aptitude was especially developed. In this book Miss Adams aims at meeting the needs of the secondary and the higher elementary schools; and in clear and simple language sets forth the difficulties of an adequate cartographical representation of the earth's surface. Simple explanations are given of the principal types of projection, and then the distortion of the original spheroidal surface when it is represented on a plane surface is explained, and the compromises which have to be adopted are set forth. After this preliminary exposition, into which no mathematics enter, there follows a more detailed discussion of the principal zenithal, conical, and cylindrical projections, as well as certain special projections. These are illustrated. by diagrams, and the explanation which is given. of each should enable anyone to obtain a clear idea of the essential character of each kind.

A short appendix gives a more mathematical account of Mercator's, the Zenithal, and Mollweide's projection, but with this exception no demand of any but elementary mathematical knowledge is made upon the reader.

A short bibliography, which might be usefully extended by the inclusion of some well-known

German and Italian works, shows the student where he may find a more advanced treatment of the subject. The book is carefully written and well adapted to those for whom it is intended, and, while it cannot give them that complete knowledge of the subject which mathematical treatment alone can supply, it will pave the way to an intelligent appreciation which is of the utmost value to all who use maps.

Chemical Engineering: Notes on Grinding, Sifting, Separating and Transporting Solids. By J. W. Hinchley. Pp. viii+103. (London: J. and A. Churchill, 1914.) Price 2s. 6d. net. In this series of articles, reprinted with some additions from the Chemical World, Mr. Hinchley provides, for the use of students intending to take up chemical engineering, a concise and practical outline of a subject of wide scope. The articles are illustrated with seventy sketches and diagrams, and their thoroughly practical character will be much appreciated by students of this branch of technology.

where is the velocity of the medium, and c/u is the velocity when at rest. The repetition of Fizeau's experiment by Michelson and Morley gave for water the value 0-434±0.02 for the coefficient k, whereas the value of the theoretical coefficient, taking the known values of μ and A for sodium light, is 0.451, which is well within the limits of the possible error.

The experiments of Gutton (Journ. de Phys.. ii., p. 196, 1912) show clearly that in the case of a very dispersive medium like carbon disulphide the velocity of propagation of nearly homogeneous light is the group velocity, and not that of an absolutely monochromatic train of waves. If this is universally true, as Lord Rayleigh and Gouy have predicted, then in the expression for the convection-coefficient k, the symbol must stand for the ratio of the velocity of light in free space to the group velocity. If we call the ordinary coefficient of refraction, we have λ δμο Мо δλ

expression, we find that they are respectively + 0.016 and +0.022, so that the theoretical value of k becomes 6.451+0.038, that is, 0.489. This even is in worse agreement with the experimental value 0-434 than the value 0-451 usually given, but a consideration of the experimental conditions shows that the value to be deduced is in reality 0-492, which is in excellent agreement. The argument will shortly be published in full. E. CUNNINGHAM. St. John's College, Cambridge, October 14.

Flint Fracture.

Ir is to be regretted that the letter of Mr. Reid Moir in NATURE of September 24 has received no reply. If chemists, mineralogists, petrologists, and physicists could have been made to realise the fruitful fields for profitable and far-reaching research opened to them by this subject, our knowledge would be in a very different state to-day, and many of the contentions and mysteries would be replaced by demonstrable facts.

In all text-books we see descriptions, or references, to lydite, the touchstone of the goldsmith, and in museums and collections we see specimens bearing this name; all kinds of origins are claimed for it; sedimentary, volcanic, metamorphic, and one has even seen meteoric. In text-books we see descriptions of the pebbles in the Blackheath beds; we are told they are pebbles of flint still retaining their original black colour. As a matter of fact, they are not black flint; they are now of various colours. It is their surface that is black; the metamorphosed portion may not be thicker than tissue paper, but other examples can be found upon a sea-beach where it is an eighth of an inch thick, and from this onward until the whole is metamorphosed, and we have the jet-black mineral, which does duty under the name of lydite!

Just one more example. The same text-books describe the beautiful "Egyptian jasper "; some say the locality from which this has been derived is unknown; others venture to suggest one. One of the many metamorphoses of flint is jasperisation. We see this commence on the surface of flints (one of the things called patination); this proceeds in intensity and centrewards until the whole substance is altered, and we have the rich mottlings of yellows and browns,

If we take half a dozen pieces of flint of exactly the same shape and size, and apply exactly the same force, administered in exactly the same manner, and of exactly the same intensity, the results may be very different in each case. Before we can argue from the effect to the cause, we must know something about the nature of the object acted upon. We must start with the origin and nature and varieties of silica, the various metamorphoses and molecular rearranging to which each variety is subject, and how each variety, in each state, responds to dynamic agency, whether administered by nature or man.

So also when we come to dynamics we must study every mechanical possibility, single them out, and name them, so that every observer may know what the other is speaking about. There must be no "peculiarities known only to the student," and "no features known only to myself." Each phenomenon must be capable of separate study, and receive a special name, so that all understand what they are talking about.

There are few who appreciate the splendid work which Mr. Reid Moir has been doing more than myself, but I am quite sure that if he were to restart the subject, on the lines here indicated, in a very short time he would regard the points he raises with very different eyes. W. J. LEWIS ABBOTT. 8 Grand Parade, St. Leonards-on-Sea.

Filtering Power of Sand.

THE letter of Mr. C. J. Watson in NATURE for October 15, recommending that "Nachtblau" (nightblue) should be used for experiments on adsorption by sand, leads us to point out that so far back as 1909 we demonstrated before the International Congress of Applied Chemistry (Section IV.B, p. 7) the striking experiment in which a solution of this dye issues perfectly colourless after passing through a column of purified sand. Since this date the experiment has been frequently used for demonstration purposes at lectures on adsorption by ourselves and others.

We showed in 1909 the remarkable quantitative relations existing between the weight of sand and the weight of dye absorbed; each degree of fineness of the sand is characterised by a remarkably sharp co

64

Mr. Reid Moir refers to lines radiating from the point of percussion on the fractured face of a flint; here is something for the physicist; they certainly are not fissures," but rather lines of force (closely connected with facetted cones and stellate fracture). The best place to see these, and study them, is in asphalt or pitch. So long as the "fracture-" or "flaking-plane" maintains itself constant, i.e. in relation to the striking-plane, they remain fairly simple. If, however, the fracture-plane resolves, or even undulates very deeply, then a very remarkable phenomenon obtains, and the lines end in a row of cones just over the escarpment, looking like a row of pointed tents with a rope passing from the centre pole of each to the point of percussion!

The last weeks of Sir John Evans, before he took to his final bed, were spent in studying a large collection brought together to put the whole subject of lithoclasiology on a scientific footing. His last words to the collector were: "Promise me that if I do not pull through this operation, you will lose no time in publishing all this. I am certain that this is where we ought to have started sixty years ago, and no real progress will be made until we start here."

weight of sand being constant for the same sand to the sixth decimal place (in one series, for example, values 0.000147 to 0-000148 being obtained). The relation of these experiments to the general theory of dyeing was dealt with in the paper cited, and also in a later communication to the Society of Chemical Industry (1912, vol. xxxi.). IV. P. DREAPER. W. A. DAVIS.

Scientific Societies and the War.

SUGGESTIONS have recently been made that certain of our scientific societies should suspend their meetings for the present, on the ground that "it is difficult to take an interest in such things just now." To those who share this feeling, it may be worth while to point out that, as already recorded in NATURE, the Académie des Sciences held its usual meeting Paris on September 7. Under that very date, in the Times review of the war for September, we find the entry, "Germans reach the extreme point of their advance." Among our gallant Allies, at all events, "le tour d'ivoire ne se rend pas." W. T. CALMAN,

British Museum (Natural History), October 16.