THE `HE condition of Europe outside the reach of history and the changes by which it has come to be what it is, the appearance of man and his progress in culture, combine to form a subject which cannot, in our opinion, be treated satisfactorily in the present state of knowledge. New facts are being daily brought to light, the speculations of yesterday are being tested by the discoveries of to-day, and the accumulation of materials necessary to form a sound judgment even in any one department, such, for instance, as archæology, is so great, that it may well daunt the courage of the boldest writer who knows the nature of the task before him. In the two books before us the subject is treated from totally different points of view. Dr. James Geikie takes his stand upon the glaciated mountains of Scotland, and attempts to throw the glacial net woven in his previous work, "The Ice Age," over the whole of Europe, and the Marquis de Nadaillac records the facts which he has collected from various quarters, America included, in what may be called a prehistoric gazetteer. The one avowedly takes up the position of an advocate, and pushes glacialism and interglacialism to an extreme, while the other takes the safer, though humbler, ground of a man who has no original views to put forward. The works of both will be useful exactly in proportion to the knowledge and judgment of the reader. There is wheat in both works, but it needs a careful winnowing, as we shall proceed to show. In his previous work Dr. James Geikie proposed a classification of the Pleistocene deposits of Europe based mainly on observations which he has made in certain parts of Scotland, and attempted a more minute subdivision of the glacial strata than the threefold arrangement generally recognised by European geologists. He advocated a complicated series of arctic glacial and of warm interglacial periods, layers of clay with boulders representing the one, and strata of sand, gravel, loam, or peat the other. His views are by no means accepted, even for Scotland, and the small progress made in general classification during the last twenty years may be estimated from the fact, that scarcely any two geologists agree in correlating the clays and sands on the east and west side of the Pennine Chain with one another and with the glacial strata of Wales, Cumbria, or Scotland. There also is a considerable difference of opinion as to the clays themselves having been derived from glaciers or from icebergs. In his present work he treats these difficulties as solved, and devotes one large section to show "English geologists" (why English?) that all the fluviatile and caveaccumulations with Palæolithic man and the Pleistocene mammalia usually termed Post-glacial, are "of Interglacial, and not of Post-glacial date." The latter term is here used in the sense of being "later than the last great VOL. XXIII.-No. 588 extension of glacier ice in Europe," while the former represents the interval of time between the retreat of one set of glaciers and the advance of another, or that between the deposits of one set of icebergs and those of another. Lyell, Prestwich, Evans, Hughes, and the great majority of those who have worked at the subject hold that the Pleistocene mammalia invaded Europe before the glacial cold had set in, and swung to and fro according to the fluctuations of temperature while the glaciers were advancing and retreating, and that there is proof that Palæolithic man and the extinct animals were in Britain "after the last great extension of the glaciers" (if they were glaciers and not icebergs). We will then appeal to the facts which have been repeatedly urged in the Proceedings of the Geological Society and of the Anthropological Institute, as well as in most of the separate works published in Britain since the year 1860. The area over which Paleolithic implements and Pleistocene mammalia occur in direct relation to the glacial deposits is principally the valley of the Thames and of the Severn, and the Midland and Eastern counties. In the first of these they occur in fluviatile strata, such, for example, as the gravels on which London stands, which are composed of materials derived from the destruction of "the chalky boulder clay." In the valley of the Severn the Pleistocene mammalia are imbedded also in the detritus of the boulder clay of that region (Lucy). In the neighbourhood of Cambridge (Hughes, Fisher) the same is the case. In the neighbourhood of Bedford, Wyatt, Prestwich, and Lyell pointed out long ago, not only that the gravels containing the flint implements and fossil mammals were composed of materials that resulted from the wreck of the boulder clay, but that the deposit rested in a hollow which had been cut through "the great chalky boulder clay" of the district. At Hoxne the mammaliferous gravels with Palæolithic implements rest on that boulder clay. The clays in question are the only signs of the extension of glaciers (? icebergs) over those districts, and the fluviatile deposits are obviously of later date. This conclusion Dr. James Geikie does not venture to dispute, but he asks us to believe that formerly another sheet of boulder clay has covered up all these deposits, and that it has been removed so completely that no trace of it is now to be seen. fixes his attention on the purple clay and the Hessle clay, which occupy an exceedingly limited area, in Yorkshire and Lincolnshire, and imagines that they represent glacial periods, one of which, not specified, extended over the fluviatile strata in question, and caused these strata to be inter- instead of post-glacial. These boulder clays are local and unimportant, and have not been met with over any deposit containing Palæolithic implements. In advancing this speculation he is drawing a cheque on our credulity which is not likely to be honoured. The strata in question are proved by their position to be later than the glacial deposits of the districts in which they occur; it is for him to prove that they are earlier than glacial deposits elsewhere. This he has not done. Still less can his conclusion be accepted that Palæolithic man and the Pleistocene beasts associated with him are solely "interglacial" in Britain and on the Continent in non-glaciated areas. The cases quoted above, and they might be greatly increased, prove that man and the Pleistocene beasts were Р He in Europe "after the last great extension of glaciers"- Croizet and Jobert obtained a rich fauna, universally conor in the Post-glacial times. There is also reason to believe that man was living in Europe before and during the Glacial period, or, in other words, in Pre-glacial, Glacial, and Inter-glacial times, although the alleged discovery of man in the Victoria Cave, relied upon by Dr. J. Geikie, has been shown to have been founded on a mistake, and the interglacial age of the implements at Brandon and Thetford, which he quotes as being of great importance, is not accepted by very good judges such as Dr. Evans and Prof. Hughes. These however may be dismissed as throwing no light on the question as to the existence of man in Britain after the great extension of the glaciers. Dr. J. Geikie's method of arriving at the climate of his "Inter-glacial periods" is equally faulty. He considers that they were warm and genial, because of the presence of certain land shells, such as Cyrena fluminalis, the climatic value of which is at present unknown, of certain marine shells, the distribution of which is dependent on the warm and cold currents, and of land-mammalia now found only in southern latitudes, such as the hippopotamus, the limit of whose endurance of cold is yet to be proved, since those in the Zoological Gardens in London will take their tubs in frosty weather. But, unfortunately for his argument, the last animal is associated with arctic species, such as the reindeer, in all the caves (Kirkdale, Durdham Down, &c.) except two, and in all the river deposits (Bedford, Acton, &c.) except some three or four, in which it has been found in this country. With equal reason we might argue that the climate was arctic from the presence of reindeer. The consideration which he urges, that the two groups of animals could not live side by side because they do not live now, is met by the direct testimony of their associated remains, not merely in this country but on the continent. The hyænas, for example, of Kirkdale and of the Vale of Clwyd ate reindeer and hippopotamuses, and dragged them into their dens, where their gnawed fragments occurred in one and the same stratum. We may remark that in dealing with the fauna of the Victoria Cave Dr. J. Geikie omits all notice of the reindeer, the presence of which destroys his argument as to climate. This selection may be taken as a fair sample of the mode in which he has dealt with the whole evidence offered by the Pleistocene mammalia. He deals with it, not with the impartiality of a judge, but as an advocate; and has only called those witnesses which count on his side. The vast numbers of reindeer associated with the remains of Palæolithic man from the caves of Cresswell as far as the Alps, and from the Pyrenees into the valley of the Danube, prove that the climate in those regions was in those times not "a warm inter-glacial" climate, but one in harmony with hat indicated by the blocks of stone in the gravels pointed out by Prof. Prestwich. The interglacial net is spread far and wide over the Continent. It includes not merely the forest with fig-trees and Judas-trees and laurestinas of Moret, which, as Saporta points out, would have been killed off by a spell of hard frosts, to say nothing of such a climate as is implied by the supposed preceding Glacial period, of which there is no evidence in that locality. It covers the deposits of Mont Perrier, near Issoire, from which MM. sidered typical upper Pleiocene. It covers also the mammaliferous deposit of Liffe, near Gandino in the Italian Alps, in which the mammalia identified by Forsyth Major are unmistakably Pleiocene. It is even stretched so as to take in the so-called Pleiocene man of Olmo, near Arezzo, the age of which, as Dr. Evans has pointed out, is proved to be Neolithic by the associated implements. Thus we have things of widely different and of well-ascertained age 'grouped together under the head of "interglacial," and we have in this fact proof that the classification is so far worthless, as indeed every system must be which is based on ice, and ice only. In further illustration of this we may quote the view of our author, that in the period usually termed Prehistoric, or recent, but by him "Post-glacial," Europe was connected by land with the Faröes, Iceland, and Greenland, and that the climate was genial. It is assumed that the "last glacial period" killed off all the Pleistocene forests in those latitudes, and that the present traces of forests are the result of subsequent growths, extending from one point to all the rest along a continuous tract of land. If we allow this, surely in the far north, to say the least, they are "interglacial," seeing that they are wedged in between "the last Glacial period" and the present glacial conditions. But we can allow neither his assumption nor can we accept his geography. The Post-glacial glaciers of Scotland spoken of on p. 526 seem to us proof that the ice-classification breaks down, and the admission that the Great Ice age is merely a stage or phase of the Pleistocene period" is a frank confession tending in that direction. “ It is only necessary to say a few words about the two large volumes of the Marquis de Nadaillac. His attitude of reserve with regard to Meiocene and Pleiocene man is judicial and impartial. But we would point out that here and there in the work serious errors are to be remarked. He considers, for example, the Archæopteryx a tertiary bird; he associates the Liassic fish of Lyme Regis with the "Tertiary fishes of Lebanon and Monte Bolca," and he writes of the Ichthyosaurus and Plesiosaurus as if they belonged to the Eocene age. In neither of these works can we find any addition to what has been already known about Prehistoric Europe, and in both there are omissions of well-known facts which it is impossible to notice within the limits of these columns. W. BOYD DAWKINS tures up to 60° C., is described and figured at p. 348, and consists essentially of a closed vessel with triple walls, the space between the inner and middle plate filled with water, the outer containing air. For higher temperatures a simple tin plate thermostat was employed, the space being filled with water for temperatures up to 100° Cent. and with glycerine or oil for higher temperatures. The source of heat was always a gas-flame with the usual thermo-regulator. Numerous tabulated results are given of experiments upon moist and dry seeds at various temperatures, and it was found, as might be anticipated, that perfectly dry seeds can withstand a high temperature, even between 120° and 125° Cent., without injury. extract of beef. 2. Many forms of bacteria can produce reproductive germs in air, while others, as B. Termo, seein only capable of producing germs in putrescent matter. 3. Air from the soil contained occasionally germs of bacteria. 4. Air from the Fever Hospital contained no germs, owing to the completeness of the ventilation and disinfection. 5. Air from a sewer contained abundance of germs of bacteria capable of reproducing. Neelsen, in his paper on Blue Milk, finds that the special organism in it may assume three or four different forms, sometimes like Bacterium, then like Bacillus, then like a Chroococcus, and lastly like a Leptothrix. He discusses the Theory of Cohn and others that the Bacteria form many separate genera and species, and the Theory of Lankester and Warming, that they are forms of a protean species, and seems to conclude that the germs of a given form may under different conditions develop in one or other direction, as observed by him in blue milk. Dr. Koch describes how bacteria can be observed, prepared, and photographed, this paper forming the sixth of the extremely important series of researches on bacteria which have from time to time appeared in the Beiträge. A thin layer of bacteria with the fluid containing them is to be dried on a thin cover of glass. By placing the glass Dr. Schroeter continues his observations on the Devecover with the dried material in absolute alcohol, or better, lopment of Rust, and Dr. Oscar Kirchner describes the in a 0'5 per cent. solution of chromic acid, the bacteria Development of Volvox minor, Stein. Dr. Hielsher are fixed to the cover, although the coagulated ground describes the Anatomy and Biology of the Genus Strepsubstance in which the bacteria are imbedded can be tocarpus, and details many interesting facts regarding made to swell up and the bacteria themselves to resume that curious and beautiful genus. When the seed of their natural forms when the cover is placed in a solution Streptocarpus polyanthus germinates, numerous advenof acetate of potash (1 part to 2 of distilled water). The titious roots form on the primary axis, one of the two bacteria can be coloured by means of aniline, the best of cotyledons soon disappears, while the other develops all being aniline brown; but methyl violet and fuchsin greatly, and forms a perennial foliage leaf. On the will also answer. The stained object can be preserved petiole of this leaf numerous adventitious roots develop permanently on slides by mounting in Canada balsam, and the primary axis disappears. The leaf produces concentrated solution of acetate of potash, or in glycerine. | adventitious buds from which the flowers develop, while Twenty-four photographs of bacteria, mostly from specimens stained with aniline brown, illustrate the paper; and in some, as 5 and 6 on Plate XIV., the cilia of bacillus are very beautifully shown, magnified 500 and 700 diameters. it also develops a series of adventitious leaf-buds. Dr.. Beinling contributes a paper on the formation of adventitious roots and buds on the leaf-cuttings of Peperomia. Prof. Klein describes in detail the anatomy of Pinguicula Koch finds that it is easier to photo-alpina as an insectivorous plant, and points out that the graph the cilia than to observe them directly with the microscope. The other papers in this part are on certain Ustilaginæ, by Dr. Schroeter; and on two new species of Entomophthora (E. conglomerata and E. rimosa) discovered upon dead gnats, by Prof. N. Sorokin. The first and second parts of vol. iii. contain eleven papers. Four of these are devoted to Bacteria, and form the seventh to the tenth of the series of Researches on Bacteria already alluded to. The titles of the papers are VII. Experiments on Infection with Micrococcus prodigiosus, by Dr. A. Wernich; VIII. Researches on the Bacteria in Air, by Dr. Miflet; IX. On the Action of the Electrical Current on the Multiplication of Bacteria, by Dr. F. Cohn and Dr. Mendelssohn; and X. Studies of Blue Milk, by Dr. F. Neelsen. Two of these papers may be briefly mentioned. By means of a specially contrived apparatus fitted with a new continuous aspirator, the invention of Paul Boehme in Brunn, atmospheric air from different localities was examined. These were (1) air in Botanical Laboratory; (2) in Fever Hospital; (3) in the Pathological Theatre; (4) in the Surgical Theatre; (5) air in Botanic Garden; (6) air for soil; and (7) air for drains. The results were briefly as follows:-1. Germs of bacteria capable of developing are abundant in the air, and could readily be collected and cultivated in a special mineral solution, malt extract, or [solution of Liebig's plant occurs in two forms, one with green leaves, the other with the leaves more or less red-brown in colour, and that the tissues assume an intense yellow colour when acted on with caustic potash solution. The remaining papers are by Dr. Schwartz, Chemico-botanical Studies on the Acids in Lichens, and Dr. Eidam on the Gymnoasci. The various papers ably sustain the reputation of this work, and all of them will well repay careful study. LETTERS TO THE EDITOR [The Editor does not hold himself responsible for opinions expressed Dust and Fogs I MUCH regret the Hon. R. Russell, in his letter to NATURE, vol. xxiii. p. 267, takes such an extremely desponding view of the influence which my experiments on cloudy condensation are likely to exercise upon the present attempts to rid the atmosphere of our large towns of their ever-recurring fogs. The object of these experiments was to find out what caused fogs, in the hope that with the knowledge thus acquired we might be better able to find a remedy. The preferable course seemed to be to find the cause first, and then if possible devise some remedy, rather than try remedies at haphazard. It is certainly very far from my desire to discourage the present attempts which are being made to clear the atmosphere of our large towns of smoke, and I have recognised the advantages which would result from the adoption of more perfect forms of combustion. In my paper I have simply distinguished between fogs and smoke, and separated them for distinct consideration and treatment, and have at the same time directed attention to some points which ought to be considered before deciding on their prevention. With regard to Mr. Russell's difficulty in reconciling the result of the experiments with what is observed with regard to fogs in London, Paris, and other large towns, it appears to me to have arisen entirely from not putting sufficient weight on the allimportant influence of the amount of vapour in the air of the different places. It is condensed vapour which forms the fog, and dust simply determines whether it will condense in fine- or coarse-grained particles. The atmosphere of Paris, compared with that of London, is an extremely dry one, and the air is seldom in a condition to produce fogs. The atmospheres of the other towns mentioned are also drier, some of them very much drier, than that of London. London however will probably be always more subject to fogs than other cities on account of its great size, some part of it being always in its own smoke. Considered from a different point of view, might not the fog of January 31, 1880, referred to by your correspondent, be cited in evidence of a conclusion the opposite of that drawn by the writer, and in favour of the correctness of the experimental results? From this point of view the low white fog cleared away because it was formed in the comparatively pure air of the streets, while the higher fog did not clear away because it was formed in the products of combustion The true explanation however would rather appear to be, that where the fog was white it was also of less depth than in those places where it "extended high" and mixed with the smoke; and the sun, which was only sufficient to dispel the lesser depth more or less," would evidently be insufficient to clear away the greater depth. It is however impossible to form any definite idea as to how this par ticular fog conducted itself, without much fuller information as to air-current, &c. I have communicated to the secretary of the Royal Society of Edinburgh a second experimental paper on fogs, with special reference to dry fogs. In this paper the full answer to the latter part of Mr. Russell's letter will be found. JOHN AITKEN Darroch, Falkirk, January 24 Professors Exner and Young My statement in respect to Prof. Exner's having announced the thermo-electric neutrality of a bismuth-antimony pair immersed in pure nitrogen, rested upon a note in NATURE (vol. xxii. p. 156), and this it seems was based upon a statement in L'Electricité. I have seen those of Prof. Exner's papers which have appeared in the Annalen der Physik, and there is certainly nothing of the sort in them; but I supposed that it must be contained in some other paper in some one of the numerous other publications to which I have not access here. It never occurred to me, until within a very short time, that there could be any mistake as to his having made such an assertion. or where the error originated I cannot quite understand; but I trust Prof. Exner will accept my apologies for my share in its propagation, and that he and all concerned will be satisfied that no misrepresentation was intended on my part. The incident is a good illustration of the extreme care necessary in commenting upon the views of another person. C. A. YOUNG Princeton, U.S.A., January 12 The Flying-fish How IT is remarkable that there should still be any doubt as to the facts in connection with the flight of the flying-fish. Dr. Günther ("Study of Fishes," p. 622), summarising the observation of Möbius, says that "they frequently overtop each wave, being carried over it by the pressure of the disturbed air" (in the open sea !). Again, flying-fishes "never" fall on board vessels "during a calm or from the lee side." At night "when they are unable to see they frequently fly against the weatherboard, when they are caught by the current of air and carried upwards to a height of twenty feet above the surface of the water." Surely the fish going at the rate of at least ten miles an hour would on striking the "weather-board" be dashed, bruised and helpless, back into the water instead of coming over the side fresh and vigorous, flapping about on the deck. Except when "by a stroke of its tail" it turns towards the right or left, Möbius concludes that "any deflection from a straight course is due to external circumstances, and not to voluntary action on the part of the fish." I have watched flying-fish repeatedly, and have invariably seen them fly, or rather glide, over the surface of the sea, and from one to two feet above it, rising gently to the swell when there was no wind, and occasionally turning to the right or left without touching the water. I do not say that when there is a breeze the tail of the fish may not touch it, but I think that, with the foam and spray of the broken water, it would be very difficult to be sure of it, and, moreover, if the tail was used the motion would be a jerking one. Mr. Wallace speaks of their 'rising and falling in the most graceful manner," which, although he is referring to another species, applies also to the North Atlantic form (Exocatus evolans). Mr. Bennett ("Gatherings," &c., p. 14) says that they "spring from the sea to a great elevation." This is probably in reference to their coming on board ship at night, attracted, it is supposed, by the lights. I believe the pectoral fins are kept extended without any motion, except perhaps as Mr. Whitman, a recent observer, says, just when they rise from the sea. He gives 800 to 1200 feet as the greatest distance he has seen them fly, and about forty seconds as the longest time out of the water. By what mechanical means they move when out of the water is still to me a mystery. I have never known the flying-fish to be pursued by other fish, nor ever seen any bird near them; indeed few birds are ever seen far from the land north of the southern tropic, where flyingfish are most abundant. The dolphin (Coryphæna) is supposed to be their greatest enemy. I had once an opportunity of seeing one opened in the West Indies-its stomach was quite full of Orthagoriscus mola, very young, being not quite an inch long. FRANCIS P. PASCOE 1, Burlington Road, W., January 21 Mr. S. Butler's "Unconscious Memory" I MUST reply to the review of my book, "Unconscious Memory," in your issue of the 27th inst., and to Dr. Krause's letter on the same subject in the same issue. Mr. Romanes accuses me of having made "a vile and abusive attack upon the personal character of a man in the position of Mr. Darwin," which I suppose is Mr. Romanes' way of saying that I have made a vile and abusive personal attack on Mr. Darwin himself. It is true I have attacked Mr. Darwin, but Mr. Romanes has done nothing to show that I was not warranted iu doing so. I said that Mr. Darwin's most important predecessors as writers upon evolution were Buffon, Dr. Erasmus Darwin, Lamarck, and the author of the "Vestiges of Creation." In the first edition of the "Origin of Species" Mr. Darwin did not allude to Buffon nor to Dr. Erasmus Darwin, he hardly mentioned Lamarck, and he ignored the author of the "Vestiges" except in one sentence. This 'sentence was so gross a misrepresentation that it was expunged-silently in later editions. Mr. Romanes does not and cannot deny any part of this. I said Mr. Darwin tacitly claimed to be the originator of the theory of evolution, which he so mixed up with the theory of "Natural Selection" as to mislead his readers. Mr. Romanes will not gainsay this. Here is the opening sentence of the "Origin of Species": · "When on board H.M.S. Beagle as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts, as will be seen in the latter chapters of this volume, seemed to throw some light on the origin of species; that mystery of mysteries, as it has been termed by one of our greatest philosophers. On my return home it occurred to me in 1837 that something might perhaps be made out on this question by patiently accumulating and reflecting upon all sorts of facts which could possibly have any bearing on it. After five years' work I allowed myself to speculate upon the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions which then seemed to me probable; from that period to the present day I have steadily pursued the same object. I hope that I may be 1 See Zoologist for November, 1880. What could more completely throw us off the scent of the earlier evolutionists, or more distinctly imply that the whole theory of evolution that follows was an original growth in Mr. Darwin's own mind? Mr. Romanes implies that I imagine Mr. Darwin to have "entered into a foul conspiracy with Dr. Krause, the editor of Kosmos," as against my book "Evolution, Old and New," and later on he supposes me to believe that I have discovered what he calls, in a style of English peculiar to our leading scientists, an erroneous conspiracy." The idea of any conspiracy at all never entered my mind, and there is not a word in "Unconscious Memory" which will warrant Mr. Romanes' imputation. man may make a cat's paw of another without entering into a conspiracy with him. 66 A Later on Mr. Romanes says that I published "Evolution, Old and New," "in the hope of gaining some notoriety by deserving, and perhaps receiving, a contemptuous refutation from Mr. Darwin. I will not characterise this accusation in the terms which it merits. I turn now to Dr. Krause's letter, and take its paragraphs in order. 1. Dr. Krause implies that the knowledge of what I was doing could have had nothing to do with Mr. Darwin's desire to bring out a translation of his (Dr. Krause's) essay, inasmuch as Mr. Darwin informed him of his desire to have the essay translated "more than two months prior to the publication of " my book, "Evolution, Old and New." This, I have no doubt, is true, but it does not make against the assumption which I made in "Unconscious Memory," for "Evolution, Old and New," was announced fully ten weeks before it was published. It was first announced on February 22, 1879, as about to contain copious extracts" from the works of Dr. Erasmus Darwin and a comparison of his theory with that of his grandson, Mr. Charles Darwin. This announcement would show Mr. Darwin very plainly what my book was likely to contain; but Dr. Krause does not say that Mr. Darwin wrote to him before February 22, 1879 -presumably because he cannot do so. I assumed that Mr. Darwin wrote some where about March 1, which would still be more than two months before" the publication of "Evolution, Old and New." 66 2. Dr. Krause says I assume that "Mr. Darwin had urged him to insert an underhand attack upon him (Mr. Butler)." I did not assume this; I did not believe it; I have not said anything that can be construed to this effect. I said that Dr. Krause's concluding sentence was an attack upon me; Dr. Krause admits this. I said that under the circumstances of Mr. Darwin's preface (which distinctly precluded the reader from believing that it could be meant for me) the attack was not an open, but a covert one; that it was spurious-not what through Mr. Darwin's preface it professed to be; that it was antedated; that it was therefore a spurious and covert attack upon an opponent interpolated into a revised edition, the revision of which had been concealed. This was what I said, but it is what neither Mr. Romanes nor Dr. Krause venture to deny. I neither thought nor implied that Mr. Darwin asked Dr. Krause to write the attack. This would not be at all in Mr. Darwin's manner. 3. Dr. Krause does not deny that he had my book before him when he was amending his article. He admits having taken a passage from it without acknowledgment. He calls a page and a half" a remark," I call it "a passage.' He says he did not take a second passage. I did not say he had; I only said the second passage was "presumably taken from my book, whereas the first "certainly' was so. The presumption was strong, for the passage in question was not in Dr. Krause's original article; it was in my book, which Dr. Krause admits to have had before him when amending his article, and it came out in the amended article; but if Dr Krause says it is merely a coincidence, of course there is an end of the matter. 4. Dr. Krause, taking up the cudgels for Mr. Darwin, does not indeed deny the allegations I have made as to the covertness, and spuriousness, and antedating of the attack upon myself, but contends that "this is not due to design, but is simply the result of an oversight"; he is good enough to add that this oversight "could only be most agreeable" to myself. When I am not in the wrong I prefer my friends to keep as closely as they can to the facts, and to leave it to me to judge whether a modification of them would be "most agreeable to me or no. What, I wonder, does Dr. Krause mean by oversight? Does he mean that Mr. Darwin did not know the conclusion of Dr. Krause's essay to be an attack upon myself? Dr. Krause says, "To every reader posted up in the subject this could not be doubtful," meaning, I suppose, that no one could doubt that I was the person aimed at. Does he mean to say Mr. Darwin did not know he was giving a revised article as an unrevised one? Does he mean that Mr. Darwin did not know he was saying what was not true when he said that my book appeared subsequently to what he was then giving to the public? Does he pretend that Mr. Darwin's case was not made apparently better and mine worse by the supposed oversight? If the contention of oversight is possible, surely Mr. Darwin would make it himself, and surely also he would have made it earlier? Granting for a moment that an author of Mr. Darwin's experience could be guilty of such an oversight, why did he not when it was first pointed out, more than twelve months since, take one of the many and easy means at his disposal of repairing in public the injury he had publicly inflicted? If he had done this he would have heard no more about the matter from me. As it was, he evaded my gravamen, and the only step he even proposed to take was made contingent upon a reprint of his book being called for. As a matter of fact a reprint has not been called for. Mr. Darwin's only excuse for what he had done, in his letter to myself, was that it was "so common a practice" for an author to take an opportunity of revising his work that "it never occurred" to him to state that Dr. Krause's article had been modified. It is doubtless a common practice for authors to revise their work, but it is not common when an attack upon an opponent is known to have been interpolated into a revised edition the revision of which is concealed, to state with every circumstance of distinctness that the attack was published prior to the work which it attacked. To conclude: I suppose Mr. Romanes will maintain me to be so unimportant a person that Mr. Darwin has no call to bear in mind the first principles of fair play where I am concerned, just as we need keep no faith with the lower animals. If Mr. Darwin chooses to take this ground, and does not mind going on selling a book which contains a grave inaccuracy, advantageous to him. self and prejudicial to another writer, without taking any steps to correct it, he is welcome to do so as far as I am concernedhe hurts himself more than he hurts me. But there is another aspect of the matter to which I am less indifferent: I refer to its bearing upon the standard of good faith and gentlemanly conduct which should prevail among Englishmen-and perhaps among Germans too. I maintain that Mr. Darwin's recent action and that of those who, like Mr. Romanes, defend it, has a lowering effect upon this standard. S. BUTLER Geological Climates WHEN a reader of the intelligence of Mr. Wallace misunderstands my words it becomes plain to me they have failed to convey my meaning. I do not accept the interpretation he has put upon them, nor do I admit that even that interpretation would tell so much in favour of his theory as he supposes. As however I agree with him that the question is far too large to be fully discussed in your columns, I shall allow the controversy, so far as I am concerned, to terminate, and shall publish my detailed views on geological climate in another SAMUEL HAUGHTON way. Trinity College, Dublin, January 27 On the Spectrum of Carbon IN the discussions on the spectrum of carbon which have recently appeared in your journal much stress is laid on the impossibility of volatilising that substance by any heat which man can produce. I think this assumption is not warranted by experience. Two or three facts in Despretz' account of a remarkable set of experiments which he made about thirty years ago, seem to me to show it to be unfounded. This is given in the Comptes rendus, vol. xxviii. He exposed rods of anthracite to the action of 125 Bunsens (zincs 5 in. high) and also to the solar focus of an annular lens 36 in. diameter. The rods bent under the combined action, and even appeared to fuse! In vol. xxix. he describes experiments with rods of sugar-charcoal under a battery of 500 similar cells. The electric egg was covered suddenly with a hard block crystalline powder. He thinks attempts to fuse carbon should be made in condensed nitrogen and in metallic vessels. In the same volume he says that with 600 cells rods of sugar charcoal bend-swell at the |