sums now being spent upon the roads of Wisconsin. For the years 1907-1911 the appropriation by the State for highway purposes was 2000l. per annum, in 1912 it was 80,000l., in 1913 170,000l., in 1914 it had risen to 246,000l., and these figures represent less than one-third of the total amount spent on State-aided roads in the corresponding years. It must be remembered, however, that ten years ago there were practically no stone roads beyond the town boundaries. The scheme of the report is excellent: part i. is a short introduction to the characters of the available road stones and to the methods of testing; part ii. deals with limestone, which appears to be the most convenient stone for use on the roads. The quarries in each county are described separately, and county maps show the distribution. of the stone and quarries. Tests for each quarry were made by the Office of Public Roads (U.S. Department of Agriculture), part of the cost of which was borne by the State Highway Commission. The report of necessity possesses more local than general interest, yet it might well be taken as a model by the Geological Survey of Great Britain, which mentions quarries in a casual way in its memoirs, but has not yet produced one in which all the facts relating to a single important branch of the quarry industry are readily accessible. Staffordshire. By W. B. Smith. Pp. xi+155. (Cambridge: At the University Press, 1915.) Price Is. 6d. net. IN dealing with a county which includes two great manufacturing areas, an author might have been pardoned for giving an emphasis to the industrial character of Staffordshire, and for dwelling at length on the conditions which make Staffordshire the third county in industrial importance. Mr. Smith, however, has wisely balanced the more prosaic and unlovely areas against the beauty spots, such as Dovedale and the Moorlands, and the grimy factories against the fairer farms and the charming parks. The reader is introduced to dales comparatively unknown outside the county, to isolated items of interest such as the wild goats in Bagot's Park, and the Horn Dancers of Abbots Bromley. Those who have some acquaintance with Staffordshire will find much that is new in this book, which maintains the high standard of the series. Catalogue of the Books, Manuscripts, Maps, and Drawings in the British Museum (Natural History). Vol. v., SO-Z. Pp. 446. (London: Printed by Order of the Trustees of the British Museum, 1915.) Price 20s. THIS Volume of the catalogue of the collection of books, maps, and drawings in the Natural History branch of the British Museum brings the series of entries under the authors' names down to the end of the alphabet. The plan of the catalogue is that of the previous volumes, and was described when these were noticed in these columns. 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.] Palæolithic Man in South Africa. IN November of 1913 Mr. J. L. Groenewald, a farmer, of Adelaide, C.P., showed me some pieces of fossil bones, explaining that he had obtained them from a friend's farm at Boskop, in the Transvaal. He wanted my opinion as to whether they were human or not. I pronounced them to be portions of a human skull-cap of some very ancient race, and prevailed upon him to give them to me. A subsequent examination, after the parts had been fitted together and measured, made it clear that it was of a race as frontal sinus, and a somewhat greater development of the forehead. This would indicate that the Boskop man was of the Neanderthal race, but more advanced in intelligence than the type specimen. The discovery of this skull offers an explanation of the origin of the Palæolithic implements which are scattered in such vast profusion all over South Africa, and should it prove to be of the true Neanderthal race, as I have absolutely no doubt is the case, we then possess evidence that this remotely ancient type of man migrated into South Africa, and if we conclude the stone implements with which the country is strewn are his handiwork, then he must have existed here in large numbers. Mr. Piet Botha, the owner of the farm on which the skull-cap was found, readily granted permission for me to excavate. I excavated the site of the find in person, and discovered portions of a rib and collarbone, part of the mandible with a tooth in it; some more fragments of the skull, and a few roughly chipped stone implements. The remains were found at a depth of 6 ft. in alluvial gravel. On application, the South African Royal Society subsequently made a grant to this museum of 100l. to carry on further excavations. The result was disappointing, a small portion of a human thigh-bone being the only result of this more extensive excavation. The skull-cap and other remains are now in the temporary possession of Dr Peringuey, of the South African Museum, where a careful and detailed examination is being made, but which cannot be completed until various data and measurements are procured from Europe. The first report will appear in the Journal of the South African Royal Society. F. W. FITZSIMONS. Port Elizabeth Museum, Port Elizabeth, June 30. MR. FITZSIMONS'S letter is the first authentic account published in Europe of the discovery of ancient human remains at Boskop Farm in the Transvaal. There can be no mistake about the importance of the discovery; the remains of Palæolithic man have at last been found in South Africa. As regards the nature or race of the individual thus found there is room for doubt; an examination of the photographs of the the skull-cap reveal none of the characteristic features of Neanderthal man; one can exclude that race with some degree of certainty. The individual to whom the skull-cap belonged was apparently of the modern_type, with a head of remarkably large dimensions. European and American anthropologists look forward with great interest to the publication of a detailed account of the Boskop discovery. ARTHUR KEITH. Surface Tension and Ferment Action. THE Correspondence in NATURE of June 17 and July 22 by Dr. Cramer and Drs. E. F. and H. E. Armstrong on the possibility of the enzymic action of invertase being limited by surface tension, has led me to look up the laboratory records of some experiments which I made in 1892 on a cognate subject. I was at that time engaged in studying the formation of starch granules in various parts of the living plant, and the subsequent dissolution of the granules under the action of the cell enzymes. In the course of this inquiry I came across a curious fact which suggested that the action of the diastatic enzyme is to some extent dependent on physical conditions existing at the limiting surface of the starch granule and its surrounding medium. Briefly stated, this fact is as follows. If we mix with a dilute cold-water extract of max a little solid starch of a kind which is readily attacked by diastase, e.g. that from buckwheat or barley, a microscopic examination will generally indicate a ver appreciable erosion and partial disintegration of the granules within twenty-four hours, the actual time depending on the initial concentration of the enzyme If a parallel experiment is so arranged that, with al other conditions remaining the same, the starc granules are kept in suspension by the addition : about 3 per cent. of gelatine, then we invariably finc that the rate of erosion and dissolution of the starch. is very much accelerated. This difference is also found to occur even if the mobile liquid which costains no gelatine is kept in continuous movement by mechanical means. It appeared to me that very possibly the lowering of the surface tension of the liquid by the gelatine had enabled the large-moleculed diastatic enzyme to penetrate the granule with greater facility, and since the starch granules in plant-cells are suspended in highly colloidal protoplasm we might here have some sort of explanation of their rapid disappearance under the influence of very small amounts of active enzyme. Reasoning from these facts, I drew the conclusion that in a given mixture of starch and enzyme we ought to find a diminution in the rate of erosion in those parts of the liquid which are in a state of tensile stress. My first experiments in this direction were made in a flattened thermometer tube with an elliptical bore having a major axis of 0.4 mm. and a minor axis of 0.2 mm. The bore of the tube was charged with the diastatic liquid containing the starch-grains, which could be kept under microscopical observation through the walls of the tube. Under these conditions, the starch granules invariably showed a much higher resistance to erosion than did those of the same liquid contained in a small flask or beaker under similar conditions of temperature. At first sight this experi ment gave some support to the idea of surface tension playing a part, but in a variation of it in which I used a thin film of the starch mixture between two inclined glass plates, I could find no difference in the rate of erosion in layers varying in thickness from 0-3 mm. downwards. I then proceeded to investigate the action when the starch had been deposited in the interstices of porous substances, and in the first place used glasswool, which was one of the substances employed by Messrs. Beard and Cramer, as described in their recent paper in the Proceedings of the Royal Society (vol. lxxxviii., ser. B, p. 575), on surface tension and ferment action. Under these conditions the erosion even of buckwheat starch, which is the most sensitive to action of this kind, was entirely inhibited, no matter how long the reaction was allowed to continue. For a short time I was misled by this result, and it was only after I had recognised the distinct alkalinity of the solutions which had been in contact with the glasswool that I found the causa causans was of a chemical and not of a physical nature. Diastase, like invertase, is extremely sensitive to traces of alkali, and can only exercise its maximum effect in a slightly acid medium. I satisfied myself that this was the true explanation by substituting for the glass-wool in the last experiment other porous substances, such as asbestos, cottonwool, and filter paper. when the whole of the inhibitive effect disappeared. Thus failed my attempt to link enzymic action with surface tension, and even the original phenomenon with which I started, the apparent enhancing effect of a colloid like gelatine, admits of a different explanation based on the slightly acid reaction of the commercial product. It is now well known that an amylohydrolytic agent, such as a maltextract, is increased in activity by the addition of traces of acid sufficient to convert the neutral into the acid phosphates. I believe that most scientific workers have, likę myself, a scrap-heap of failures which may repay a little digging now and then. In the light of the recent discussion in your columns these few potsherds which have been recovered from the overlying débris of years may at the present moment have something more than a mere antiquarian interest. HORACE T. BROWN. 52 Nevern Square, Kensington, S.W., July 24. The Cancer Problem and Radio-activity. PROF. JOLY, in an address published in NATURE of June 10, has given some more facts in connection with the theory associating radio-activity with the cause of cancer; and his endeavour to extend the theory so as to connect some of the commodities which predispose the tissues to the disease will be read with interest by those engaged in cancer research. But there are other such commodities which Prof. Joly has not apparently taken into consideration, especially arsenic and manure; and he is not correct when the attributes "sweep's cancer" to mechanical irritation. The last point was demonstrated at the recent Home Office inquiries on pitch ulceration and cancer, in association with which extensive research has been made at the John Howard McFadden Laboratories. It appears that there are two forms of pitch, the blastfurnace variety produced at a lower temperature mostly from Scottish coal, and the ordinary gas-tar variety made from bituminous coal. Both varieties are similar in consistency, and both cause similar mechanical injury; yet blast-furnace pitch is harmless, whereas gas-tar pitch gives rise to a considerable incidence of warts and sweep's cancer. Coal-dust may cause mechanical injury amounting to laceration; yet it causes no cancer. Soot, being soft and floury, does not mechanically irritate the skin, yet it occasions in sweeps more cases of cancer than in any other trade. Tar and some of the petroleum fractions are liquids, and cannot cause mechanical injury; yet they both are sources of skin epithelioma. These commodities evidently give rise to the disease owing to the presence of some chemical agent contained in them, for the more they are concentrated the more disease do they cause. Coal causes no cancer; tar, the residue after the first stage of its distillation, causes some cases; pitch, the residue of the distillation of tar, causes such an incidence as to necessitate two official inquiries; and soot, the last residue of the carbonisation of coal, tar, and pitch, causes the most cancer among occupied males. The question is what is the substance that is being concentrated, and how does it act? The researches which have been made on this subject are based on the fact that many classes of cells can be made to divide in response to auxetics-chemical agents which contain the amidine or amino groupings. This has been shown now with many classes of cells, including human cells; and Cropper and Drew have recently found that amoebæ, when isolated from other living organisms and placed in pure water, will not divide at all without the addition of an auxetic. Auxetics are physiologically set free in a tissue as the result of cell-death caused by injury; and when they are inoculated into certain tissues can be made to give rise to benign tumour formation, both in men and animals. There is another group of substances (including most of the alkaloids, choline, cadaverine, etc., to some of which Prof. Joly refers) that increase the action of auxetics very considerably. They have been called augmentors. Since auxetics cause benign cell-proliferation-which is a very favourable condition for the onset of cancer, a large number of the coal-tar commodities and fractions were tested for auxetics by trying watery extracts of them on human cells. The commodities were sent to the laboratory by the authorities distinguished by numerals only; some were known to cause cancer, others were known not to do so; but the workers who made the tests were unaware as to which were which until the tests were complete. In this way it was ascertained that, by the simple test for auxetic or augmentor, those commodities (about 20) which give rise to cancer can be picked out from a large number (about 150) of those which do not. a Hence it is more than probable that the commodities act by virtue of the auxetics or augmentors they contain; the successive fractional distillations of coal, concentrating the auxetic in each stage, causes higher and higher incidence of cancer, until the ultimate production of soot with the highest incidence of all (chimney-sweep's cancer). Since then, all the other commodities which cause cancer, such as arsenic, manure, betel nut (a putrid mixture of areca and tobacco), tobacco and its smoke, "khangri" charcoal, some aniline dyes, and petroleum, have been tested, and all contain auxetic or augmentor. On the other hand, the harmless blastfurnace tar and pitch and the hard Scottish coal whence they are derived contain either no auxetic or augmentor or only a trace of the former. X-rays and radium rays in certain dosage will pro duce cancer; but they also cause cell-death, even amounting to ulceration, which in its turn sets free auxetics resulting in cell-proliferation, which is prone to become malignant. Atrophy following nerve disease and injury again produces auxetic in a tissue, and these atrophic areas are liable to epithelioma, as admirably described by Lenthal Cheatle.' Much work remains to be done, therefore, before the theory regarding radio-activity can be proved to harmonise with all the facts, which must include an explanation of why it causes the death of the patient and metastasis. I do not wish to question its soundness; on the contrary, an experiment which Dr. Lazarus-Barlow has kindly made in comparing the radio-activity of the auxetic fractions of gas and blastfurnace tars appears to be evidence in its favour. Even if auxetics ultimately prove to be the sole immediate cause of cell-division, some physical force must produce the division activated by the chemical agent when it has arrived within the cell, and it is possible that this force is connected with radio-activity. In conclusion it may be mentioned that the terms "industrial cancer," "smoker's cancer," "sweep's cancer," "arsenic cancer," etc., namely, the diseases caused by the commodities mentioned, refer in reality only to a predisposition to the disease. The commodities themselves do not actually cause cancer; they merely render the tissues prone to it, which seems to occur in a specific manner. This was clearly shown at the inquiries; the commodities always in the first instance produce cell-proliferation usually in the nature of warty growth; and it is not until an open ulcer has appeared, generally at the base of the wart, that malignancy supervenes. This fact, coupled with the knowledge that augmentors are produced in a proliferative site by the action of bacteria, makes one suspicious that the exciting cause of cancer is probably of bacterial, or, in any case, parasitic origin. The clinical evidence and the experiments that have been made into the causes of cell-proliferation and industrial cancer demonstrate that when we speak of the cause of cancer we are dealing with two factors- The Lister Institute of Preventive Medicine, DR. Ross's letter raises the question as to whether photosensitive molecular systems of the nature of those contained in the gelatino-bromide emulsion might not be affected by auxetics and augmentors applied under suitable conditions. If such effect was found to exist, the facts he adduces would not be out of line with the view that some molecular change within the cell finds a counterpart in actions progressing in the unstable film under the stimulus of radiation or equivalent chemical influences. The reasons set forth by Dr. Ross against the theory that soot acts mechanically appear convincing, although I cannot agree with him that this substance can be described as soft and floury. There has always been difficulty in accounting for its peculiar virulence on the mechanical theory. Some time ago I looked for the emanation of radium in soot, but found very little. If it acted like charcoal we would expect a large amount, in which case Dr. Lazarus-Barlow's views would find additional support in this direction. I may add that some of the suggestions put forward in the lecture which was in part issued in NATURE of June 10 have been under investigation here for some time. J. JOLY. Trinity College, Dublin. The Magnetic Storm of June 17 and Solar As my final note on Dr. Chree's letter in NATURE of July 22 and Mr. Buss's of July 29 may I remark that, so far as I am aware, there is no rule, "One spot, one storm"? On the contrary, a disturbed area of the sun's surface may be connected with a series of successive, or intermittent disturbances, as it is carried round by the sun's rotation. When the same region reappears at the next synodical rotation, and sometimes, if it survives as an active region, for several synodical rotations, it will continue to be associated with a series of magnetic disturbances at each rotation. For instance, in 1898, January 11 to July 31, a disturbed region of the sun, which subsisted during eight rotations, was associated with not one only, but with several magnetic storms, at each successive reappearance. Nor is the selection of such a region arbitrary, when there happen to be several other disturbances at the same time on the sun. The selection is conditioned by the activity of the region, and by its position relatively to the position of the earth, when projected on the sun. So far as I am aware, mere statistical enumerations of sun-spots, or total areas of sun-spots, and their relations to magnetic storms, take no account of these important considerations. The efficiency of a disturbed region of the sun, marked by sun-spots, is greater on the descending portion of the sun-spot curve than even at maximum. The reason of this is, because after the maximum, the mean latitude of the spots is falling towards the sun's equator, and since the heliographic latitude of the earth varies between 17°, the earth is placed in a more favourable position to be affected by a solar disturbance. In the twenty-five years, 1889-1913, there were seven years in which the mean daily projected or disc-area of sun-spots was greater than 1000 10** In the units, and eighteen years in which it was less. seven maximum years there was a mean of 100 disturbances a year, and a yearly mean daily disc-area of 15377 units. The ratio between these two numbers, or what may be termed the "efficiency ratio," is 0.065. Similarly for the eighteen years in which the mean daily disc-area was less than 1000 10- units, the mean number of disturbances was 737 per year, and the yearly mean daily disc-area was 378-9 units, which gives an "efficiency ratio" 0.195. three times as great as in the maximum years. Of these eighteen years, twelve were on the descending arm o the sun-spot curve. These numbers show that the position of a disturbed region of the sun relatively to the earth is more important than its size. In addition, the character of the spot has to be considered. To apply these principles of selection to the case of the magnetic storm of June 17. Since the beginning of 1913, all the sun-spot disturbances, with insignificant exceptions, had been confined to regions above 12° on each side of the solar equator. From June 12 to June 21 an entirely new active group of spots covering a considerable area appeared on the sun's equator. The heliographic latitude of the earth was also most favourable. The first very great magnetic storm of the present solar cycle took place on June 17, preceded by a disturbance on the 16th, and followed by a disturbance on the 18th. With regard to the 27-day period shown in the quiet magnetic days, I associated them with the whole solar hemisphere only in this sense, that, as a rule, when there is no solar spot, there is no magnetic disturbance. The proviso is added, because a region of the sun which may be free from spots may, by the presence of faculæ or flocculi, still continue to be magnetically active, after the spots have died away. In several cases the region will continue to be magnetically active, on account of the appearance of new spots near the faculæ or flocculi belonging to the former disturbance. A. L. CORTIE. Stonyhurst College Observatory, Blackburn, Lancs., July 23. Science and Food-Supply. IN connection with the proposed "Mobilisation of Science," it may be of importance for Great Britain to direct the attention of her scientific men to the possibility of increasing the food-supply produced in the country. Here she might very hopefully call upon her organic chemists for aid; by asking them to devise means for extracting nutritive material from the crops which are not now used for food. 66 Nearly all vegetable matter contains the nutritive elements needed. In a certain sense, for example, all flesh is grass"; but we cannot digest vegetable matter of that kind directly; it must be put through a chemical process before it can be assimilated. The process usually adopted is to put it into the stomachs of animals, and then we eat the animals. Through the intervention of cattle and sheep we thus eat grass in the form of beef and mutton. In a similar manner, deer and goats and many other animals which are not limited to a grass diet convert, moss, and shrubs, and bark, and small branches into nutritive material for man. The wood of trees, too, contains the necessary elements for the support of life; but we do not utilise wood for food, because we have no animals that feed upon wood. Could not chemists do something with wood-pulp in this connection? The German chemists are reported in the American newspapers to have succeeded in treating sawdust so as to extract a nutritive product that can be digested by man, the so-called "bread from sawdust." If this is true, the British chemists should certainly be able to arrive at a similar result. How secure Great Britain would be if she, too, could make bread from sawdust, and convert grass and shrubs and other vegetable matter not now utilised into food for her people. Here is a problem of the greatest consequence to Great Britain that should be brought to the attention of her scientific men. ALEXANDER GRAHAM BELL. Beinn Bhreagh, near Baddeck, Nova Scotia, July 10. THE PROMOTION OF RESEARCH BY THE STATE. THE HE Government scheme for the organisation and development of scientific and industrial research, of which we gave particulars last week, represents a welcome concession of a principle always advocated in these columns, and stated with particular force by Sir Norman Lockyer in his presidential address on "The Influence of Brain-power on History," delivered at the Southport meeting of the British Association in 1903. The duty of a State to organise its forces as carefully for peace as for war was emphasised on that occasion; and it was urged that adequate provision for scientific education and research is an essential part of a modern State's machinery, and should be efficiently organised if we were not to fall behind other nations in the applications of science to industry. The recognition of the State's responsibility in this matter would have come much sooner if our statesmen had been wise enough to understand the scientific factors of industrial success; but it has at last been given, and the unanimous approval with which the scheme has been received must be a little sur prising to the politicians who have taken so long to realise the part science is playing in the modern world, and to make provision for its national use. There is nothing, perhaps, so difficult as to alter a long-established tradition, to effect a real change in the mental attitude of a person or of a nation. It is the greatest of revolutions; it is the real revolution on which all action out of harmony with the tradition of the past depends. Such a change of attitude, so far as the official mind of the country is concerned, was announced last May by Mr. Pease, then President of the Board of Education, when he stated in the House of Commons: The war has brought home to us. . that we have been far too dependent . . . upon the foreigner, and we have realised that it is essential, if we are going to maintain our position in the world, to make better 1 For other references to what the German chemists are doing, see article on "Inorganic Fodder" in the Scientific American for July 3, p. 8; in which reference is also made to an attempt to derive from straw and hay all the nourishing matter contained therein. use of our scientifically trained workers, that we must increase the number of those workers, and that we must endeavour to secure that industry is closely associated with our scientific workers, and promote a proper system of encouragement of research workers, especially in our universities. These convictions have been translated into deeds through the issue of the Government scheme. The action which has thus been taken by the Government will be hailed by all men of science with feelings of the utmost gratification. It is difficult to overestimate the value of the consequences which may follow-which, indeed, we feel sure will follow-from the adoption of this scheme. By its inception and publication the Government acknowledges and proclaims its appreciation of the work of science, and by this acknowledgment alone it gives scientific workers that encouragement and prestige in the eyes of the country which have too long been withheld. The expenditure of any new moneys provided by Parliament for scientific and industrial research will be under the control of a committee of the Privy Council, upon the recommendation. of the Advisory Council. The appointment of Lord Haldane as a non-official member of the committee of the Privy Council connects the British Science Guild with the work contemplated by the Government scheme. Lord Haldane was the first president of the guild; and at the inaugural meeting in 1905 he said: I believe that things will not be right until we have a scientific corps under a permanent committee, just as the Defence Committee is under the Prime Minister to-day. I mean a body that will not consist mainly of officials of the ordinary kind, but of the most eminent men of science, who will be put on the footing upon which they deserve to be placed, and are recognised as a body of men who will be at the elbow of the department and can organise the scientific work of the State. I hope that if we get to this position the example of a Government adopting science will be followed by the municipalities, as I believe it is going to be followed more and more by our manufacturers. The British Science Guild may justly claim some credit for securing the State assistance for industrial and scientific research now provided for by the Government scheme. For the ten years of its existence it has persistently pointed out that our competitors have brought all the products of science into the contest they have waged against us; and it has urged the adoption of similar methods in our national affairs and manufactures. Scientific men are so closely concerned with their own particular researches that they frequently take little interest in the work of others. or in the position which science should occupy in national polity. Their inactivity in this respect is largely responsible for the neglect of science. public movement was required to direct the attention of the public in general, and the Government and political parties in particular, to the value of the great resources of science in the development of the kingdom; and this movement took shape in the British Science Guild. The purpose of the guild is not so much the acquisi |