crystalline schists. Throughout the drifts of the coastal plain he has found a greater or less proportion of granite erratics, as well as, in many cases, minute rolled-shell fragments. He maintains that these drifts are the result of two opposing forces, one radiating from Snowdonia, and the other acting from the sea to the southwards, and their characteristics change as the one or the other force preponderated. The other divisions of the paper are taken up with a description of the Merionethshire drift and that of Mid-Wales, numerous sections being given. Attention is called to a remarkable glaciation of the rocks at Barmouth. In a concluding part, giving inferences and suggestions, the author discusses the land-ice and submergence hypotheses, and concludes that his observations distinctly strengthen the grounds for believing in a submergence of the land to an extent of not less than 1400 feet. An appendix contains details of nineteen mechanical analyses of tills, sands, and gravels, and a bibliography of papers, observations, and theories of the high-level drifts of Moel Tryfaen. The reading of this paper was followed by a discussion, in which Mr. Lamplugh, Mr. J. W. Gregory, Mr. H. W. Burrows, the President, and others took part. Zoological Society, March 15.-Prof. W. H. Flower, F. R.S., President, in the chair.-Mr. Sclater exhibited and made remarks on the skin of a Wild Ass obtained by Mr. J. D. Inverarity in Somali-land.-A report was read, drawn up by Mr. A. Thomson, the Society's Head Keeper, on the insects bred in the Insect-house during the past season. -Mr. Seebohm exhibited and made remarks on two pairs of Picus richardsi from the island of Tsusima in the Japanese Sea.-Mr. Oldfield Thomas exhibited and described a head (placed at his disposal by Messrs. Rowland Ward and Co.) of the East African Oryx. This Antelope, commonly supposed to be O. beisa, was shown to differ from that species in possessing long black tufts on the tips of its ears. It was proposed to be called O. callotis.-Dr. H. Gadow read a paper on the classification of Birds, in which the results arrived at, after a long study of the structure of Birds for the purpose of completing the part "Aves" of Bronn's "Thierreich," were set forth.-A communication was read from Mr. C. Brunner v. Wattenwyl and Prof. J. Redtenbacher, containing a report on the Orthoptera of the island of St. Vincent, West Indies, collected by Mr. H. H. Smith, the naturalist sent to that island by Mr. Godman, in connection with the operations of the Committee appointed by the British Association and Royal Society for the investigation of the fauna and flora of the Lesser Antilles.-Mr. Oldfield Thomas read a paper on a collection of Mammals from Mount Dulit, in North Borneo, obtained by Mr. Charles Hose. Fourteen species were represented in the collection, of which four were stated to be new to science. Amongst these was a new Carnivore of the genus Hemigale, proposed to be called Hemigale hosei.-Dr. R. Bowdler Sharpe gave the description of some new species of Timeliine Birds from West Africa. Entomological Society, March 9.-Mr. Frederick DuCane Godman, F.R.S., President, in the chair.-Prof. C. Stewart exhibited and made remarks on specimens of Cystocalia immaculata, an Orthopterous insect from Namaqualand, in which the female is far more conspicuously coloured than the male, and the stridulating apparatus of the male differs in certain important details from that of other species. A long discussion ensued, in which Dr. Sharp, F. R.S., Mr. Poulton, F. R.S. Mr. Distant, Mr. H. J. Elwes, Colonel Swinhoe, and Mr. Hampson took part.-Mr. Elwes exhibited specimens of Ribes aureum which were covered with galls, as to the nature of which the Scientific Committee of the Horticultural Society desired to have the opinion of the Entomological Society. Mr. Fenn, Mr. Tutt, and Mr. Barrett made some remarks on these galls.Mr. Elwes also exhibited a large number of species of Heterocera recently collected by Mr. Doherty in South-East Borneo and Sambawa. Colonel Swinhoe, Mr. Hampson, and Mr. Distant took part in the discussion which ensued.-Mr. Barrett exhibited a series of specimens of Noctua festiva, bred by Mr. G. B. Hart, of Dublin, which represented most of the known forms of the species, including the Shetland type and the form formerly described as a distinct species under the name of Noctua conflua. Mr. Fenn and Mr. Tutt made some remarks on the specimens. Mr. W. C. Boyd exhibited a specimen of Dianthecia Barrettii, taken at Ilfracombe last summer. It was remarked that Mr. W. F. H. Blandford had recorded the capture of D. Barrettii-which had until recently been supposed to be : confined to Ireland-from Pembrokeshire, and that its capture had also since been recorded from Cornwall.-Mr. Tutt exhibited specimens of Polia xanthomista from Mr. Gregson's collection, which had recently been sent to him by Mr. Sydney Webb.-Mr. G. A. James Rothney exhibited and read notes on a large collection of Indian ants which he had made in Bengal between 1872 and 1886, comprising some ninety species. He stated that eighteen of these species had been described by Dr. Mayr in his paper entitled "Ameisen Fauna Asiens, 1878 he also said that Dr. Forel had recently identified several other new species in the collection, and that there were about ten species and one new genus which Dr. Forel had not yet determined. -Mr. H. Goss exhibited, for Mr. T. D. A. Cockerell, of Kingston, Jamaica, several specimens of palm leaves, from the garden of the Museum in Kingston, covered with Aspidiotus articulatus, Morgan. The leaves appeared to have been severely attacked, the scales entirely covering the upper surface in places.-Mr. F. D. Godman contributed a paper by the late Mr. Henry Walter Bates, with an introduction by himself, entitled "Additions to the Longicornia of Mexico and Central America, with remarks on some previously-recorded Species."-The Rev. A. E. Eaton communicated a paper entitled "On new Species of Ephemeride from the Tenasserim Valley." Linnean Society, March 17.-Prof. Stewart, President, in the chair.—Mr. E. M. Holmes exhibited specimens of Phacelocarpus disciger, a new species of seaweed from Cape Colony, collected by Dr. Becker near the mouth of the Kowie River. One of the specimens exhibited bore antheridia which have not previously been described in this genus. The species differs from those already known in bearing the organs of reproduction on the surface of the frond instead of on the margin.--Mr. Buxton Shillitoe exhibited and made some remarks upon the flowers of Leucojum vernum and Helleborus viridis.—On behalf of Mr. Allan Swan, the Secretary read a paper on the vitality of the spores of Bacillus megatherium, upon which criticism was offered by Mr. G. Murray.-Mr. S. B. Carlill submitted a paper entitled "Notes on Zebras," in which he discussed the position assigned to the zebra in the genus Equus; the use and nature of striped coats; the contention that the sallenders on the legs of the Equida represent the hoof of the first digit of their polydactyl ancestors; and the evidence bearing upon Prof. Owen's view that the cave horse was in some respects zebrine. He concluded by advocating a systematic attempt to domesticate one or more species of zebra for transport work. Domestication, he considered, would not only render these animals eminently useful, but would be the only means of preserving them from extinction. CAMBRIDGE. A Philosophical Society, March 7.-Prof. G. H. Darwin, President, in the chair.-The following communications were made:Some experiments on electric discharge, by Prof. Thomson. series of experiments were shown in which the electric discharge took place in bulbs without electrodes. It was shown that the colour of the discharge through the same gas varied very greatly with the density of the gas and the intensity of the discharge. This was illustrated by two bulbs, each containing air; the discharge through one was a bright blue, and through the other an apple-green. Another experiment showed the gas at a very low pressure could not act as an electro-magnetic screen, though it did so at a higher pressure. The laws governing the absorption of energy by conductors placed near very rapidly alternating currents were illustrated by experiments which showed that there was much greater absorption of energy by small pieces of tin-foil than large masses of brass or copper. -The capture of Lexell's comet by Jupiter, by the President (Prof. Darwin). The paper contains a more exact estimation of the radius of the sphere of Jupiter's influence than that given by Laplace. If a comet come within this sphere, its orbit will be seriously transformed by the planet. The radius is estimated by the principle that at its boundary the effect of the perturbing force of Jupiter on an orbit round the sun is the same as the effect of the perturbing force of the sun on an orbit round Jupiter. The radius comes out to be '058 times the distance of Jupiter from the sun, Laplace's approximation being 054 times the same distance.-The change of zero of thermometers, by Mr. C. T. Heycock. The author described the result of experiments he had made in conjunction with Mr. Neville to overcome the change in zero which thermometers undergo when heated for a long time. The method consisted in boiling the thermometers for eighteen days in baths of either mercury or sulphur; at the end of this time the zeros were found to be practically fixed unless they were exposed to higher temperatures than those of the substance in which they were boiled. The paper was illustrated by a curve showing that the change in zero was very rapid for the first few hours, amounting in a special case to 11° C. for twenty hours' heating, but that afterwards the change became almost nil as the heating was continued.-The elasticity of cubic crystals, by Mr. A. E. H. Love.-Changes in the dimensions of elastic solids due to given systems of forces, by M. C. Chree. Expressions are found for the mean values of the strains and stresses in any homogeneous elastic solid, whether æolotropic or isotropic, under the influence of any given system of bodily and surface forces. The expressions for the mean values of the strains, more especially of the dilatation, are employed in determining the changes in the dimensions of elastic solids in a variety of special cases. The effects of gravitational and centrifugal forces are more particularly considered.-On the law of distribution of velocities in a system of moving molecules, by Mr. A. H. Leahy. A short proof is given of the Maxwell law of distribution based upon the principle that a system of molecules, whose velocities are instantaneously reversed, will return to its former configuration. The limit which must be put to the least number of molecules in a gas if the ordinary assumptions of the kinetic theory of gases may be relied upon is also examined, and a note made on the evidence that a system of molecules will ultimately attain to a steady state of distribution. EDINBURGH. In Royal Society, March 7.-Prof. Sir W. Turner, VicePresident, in the chair.-Prof. Cossar Ewart read a paper on the cranial nerves of man and Selachians. He compared the cranial nerves of the skate and shark genus with those of man, and discussed their probable identity. The facial nerve of the fish is much more developed than that of any other vertebrate, but is entirely sensory, while in man it is a motor nerve. some mammals, though not in man, there are vestiges of the lateral sense-organs. These organs occur in the tadpole, but are practically absent in the fully-developed frog. It would seem, therefore, that the mammals originally possessed rudiments of these organs, but that these rudiments disappeared as development proceeded. March 14.-The Rev. Prof. Flint, Vice-President, in the chair.-Mr. Robert Irvine read a communication, by Dr. John Murray and himself, on the changes in the chemical composition of sea-water associated with marine blue muds. The observations recorded were made on mud dredged from Granton Harbour and from the old quarry near Granton.-Dr. John Murray read a paper, by Mr. Irvine and himself, on marganese nodules in the marine deposits of the Clyde sea-area. Manganese occurs in great quantities in that area, and this forms a striking exception to the usual distribution of manganese as regards depth of water. Dr. Murray, therefore, in a previous paper on this subject, suggested that the large occurrence of manganese in the Clyde area had its origin in the waste products discharged into the river from the manufactories at Glasgow. During the past year a great many dredgings have been taken on the west coast of Scotland and in basins to the north of the Mull of Cantyre, with the result that very little manganese was found, while, as before, large quantities were obtained in the Clyde sea-area-so much so that it would almost pay to dredge it on the Skelmorlie Bank. Dr. Murray's explanation is therefore strongly confirmed.-Dr. Murray exhibited a specimen of extremely pure chalk from Christmas Island (about two hundred miles from the coast of Java)--Dr. Noel Paton read a paper on a case of the occurrence of crystalline globulin in urine.-Prof. Tait read an additional note on the isothermals of carbonic acid at volumes less than the critical volume. The March 21.-The Hon. Lord M'Laren in the chair. Keith Prize for the period 1889 91 was presented to Mr. R. T. Omond, Superintendent of the Ben Nevis Observatory, for his contributions to meteorological science; and the MakdougallBrisbane Prize for 1888-90 was presented to Dr. Ludwig Becker for his paper on the solar spectrum at medium and low altitudes. -The Astronomer-Royal for Scotland made a further communication on Nova Auriga. The atmospheric conditions were remarkably favourable for observation until the 11th day of February, when the star was of the fifth magnitude, but since that time, until the 18th of this month, only occasional observa tions were possible. Between the 8th and the 18th no observations were obtained, and the star had meanwhile fallen from the sixth to the ninth magnitude. In the beginning of March it was fully 130 times as bright as it is at present. The spectrum is now nearly continuous throughout with traces of bright lines. Thus Nova Aurige presents closer analogies to Nova Coronæ than to Nova Cygni, in which an originally continuous spectrum with bright lines changed to a discontinuous spectrum presenting only one bright line close to one of the great nebular lines. One of the lines in Nova Auriga is very close to this nebular line, but there is reason to believe that it is due to a substance other than that which gives the nebular line.-Dr. R. H. Traquair read a paper on the fossil Selachii of Fife and the Lothians. Five new species are included. sea. GLASGOW. Geological Society, March 10.-Mr. Dugald Bell read a paper on the alleged submergence in Scotland during the Glacial epoch, with special reference to the so-called "highlevel shell-bed at Chapelhall, near Airdrie, 512 feet above the This "bed" had first been brought into notice by Mr. Smith, of Jordanhill, in a paper to the Geological Society in 1850, and had since been generally accepted as proving a submergence of the land to at least that extent. Its existence, however, rested on very imperfect evidence. It was said to have been found in digging a well near the summit of one of the high ridges of boulder-clay in the district; and was described as a bed of fine reddish clay, about 2 feet thick, and thinning away rapidly on all sides, lying in a hollow of the boulder-clay, which was 14 feet or more in thickness both above and below it. The well seems to have been built up before Mr. Smith had an opportunity of examining the section, though he got some shells said to have been found in the clay, and which were all of one species, Tellina calcarea. From that day to this no geologist had seen the clay, though it had been sought for all around, and though another well had been sunk within a few yards of the old one, in the hope of finding it. At the very utmost, it seems to have been a limited strip or patch of shelly clay, intercalated in the boulder-ciay, such as had been found in many other localities, and could not fairly be taken as a sufficient proof of submergence. The more they were considered the greater seemed the improbabilities which the theory of a submergence and re-emergence of the country to this extent, and at that time, involved. There was not a particle of corroborative evidence. No shells had been found at a similar level in other parts of the midland valley, nor in the numerous side-valleys, where they would be more likely to be preserved than on this exposed knoll in the centre. None had been found in the upper boulder-clay, which, if all this valley had been a sea-bottom before the "second glaciation," should contain abundance of at least shelly fragments. Further, a "mild interglacial period" would probably accompany such a submergence, and this shelly clay was supposed to have been laid down during such a period; but the only species of shells found in it indicated, not mild, but extremely cold conditions. face of all these difficulties, it was suggested that the layer containing these shells may have been transported (probably in a frozen condition) by the ice-sheet, as in many other instances that were well known. This seemed to be by far the more probable account of it, and got rid of the complications connected with a first glaciation, a deep submergence, a reemergence, and a second glaciation closely resembling the first. The position of this patch of shelly clay, admittedly in the track of the old ice-sheet, and in front of an obstruction presented by the highest rising ground in the district; the highly Arctic character of the organisms; the very colour of the clay (as reported) being different from the clays of the immediate neighbourhood, -all favoured this conclusion. This Chapelhall clay, therefore, he submitted, ought no longer to be cited as a proof of submergence. An animated discussion followed. PARIS. In Academy of Sciences, March 21.-M. d'Abbadie in the chair. A study of the properties of amorphous boron, by M. H. Moissan. A full account is given of the physical and chemical properties of pure amorphous boron. The following conclusions are arrived at by the author:-Boron combines more readily with the metalloids than with the metals; it has a great affinity for fluorine, chlorine, oxygen, and sulphur. At a red heat it displaces silicon and carbon from their oxides. It combines with nitrogen directly only at a very high temperature; it readily reacts with a large number of salts. Its action on metallic oxides, easily reduced by carbon, is very violent. (See P. 522.) On the preparation of boron iodide, by M. H. Moissan. On the origin of colouring matters in the vine; the ampelochroic acids and the autumnal coloration of vegetation, by M. Arm. Gautier.-Experiments on vascular reflex action, by M. L. Ranvier.-Contribu'ion to the history of morbid associations: coexistence of stercorary retention with general diseases and injuries of the great visceræ, the kidneys in particular, by M. Verneuil.-Surface and population: European States, by M. Émile Levasseur. The following values have been taken from the tables given : - The methods of arriving at these numbers and other information relating to them are fully explained.-Report on a memoir, presented by M. Blondlot, on the propagation of Hertz vibrations.-Observations of comet a 1892 (Swift), made at the Paris Observatory with the West Tower equatorial, by M. G. Bigourdan.-Observations of comet e 1892, made at the Paris Observatory with the same instrument, by the same author.Observations of Swift's comet (1892 March 6), made with the great equatorial of Bordeaux Observatory, by M. G. Rayet.On the common periodicity of sun-spots and aurore, by M. Terby. (For the last four communications see Our Astronomical Column.) On the tensions of saturated vapours of different liquids at the same pressure, by M. Edmond Colot. The experiments made by the author bear out the law that between the temperatures and 0 of the saturated vapours of any two liquids which correspond to the same pressure, there exists the linear relation = A0 + B, where A and B are two constants, the values of which depend on the nature of the liquids under consideration. On a standard condenser, by M. H. Abraham. With a view of making a new determination of v, M. Abraham has constructed an air condenser having a capacity of about 500 in electro-static C.G.S. units. The arrangement is described, and estimations are given of the probable accuracy which can be attained. The ratio of the electro-static to the electro magnetic unit (2) has not yet been found. -On electro-capillary phenomena, by M. Gouy.-On the manifestation of negative electricity during fine weather, by M. Ch. André During fine weather a negative electrification of the air is extremely rare. Several theories have been put forward to account for this, but an examination of some of the records of atmospheric electricity, made at the Lyons Observatory, leads M. André to conclude that the appearance of negative electrification during fine weather is an exaggeration of a diurnal variation of which it is a particular case.-Crystalline absorp tion and the choice between the different theories of light, by M. E. Carvallo. If a ray of monochromatic light traverse a double-refracting crystal, the absorption only depends on the position of the Fresnel vibration. The intensity of the emergent ray is given by M. Becquerel's formula It Ni = √iolex cos2 a + ex cos2 B + ex cos2 y), where is the intensity of the incident ray; i, the intensity of the emergent ray; a, B, y, angles between Fresnel's vibration and the axes of optical elasticity; x, the thickness of the crystal traversed by the ray; and e, the base of Naperian logarithms. The author finds that this law is verified in the important case where only one of the three components exists also applies to heat rays. Finally, when an extraordinary ray traverses tourmaline in a direction oblique to the axis, its state of polarization varies progressively until the thickness traversed is that which would destroy the ordinary ray. This state then remains invariable up to emergence, when the ray sharply regains the state of original polarization.On the determination of chemical equilibrium in solution systems, by M. Georges Charpy.-Combinations of cuprous iodide with ammonium thiosulphate, by M. E. Brun. The following com. pounds have been obtained: Cul. 2NIII. 8(NH4)2S2O3 ; 4Cual. CuSO ̧ . 7(NH ̧)„S„Ø ̧. 4H,O; and Cu2I ̧. (NH4)2S,O ̧. HO. The author proposes to study similar compounds yielded by sodium and potassium thiosulphates, and also compounds given by other iodides, such as those of silver and lead.-Study of the velocity of decomposition of diazo compounds, by MM. J. Hausser and P. Th. Muller.-Some bases homologous with quinine, by MM. E. Grimaux and A. Arnaud.-The essence of Licari kanali, by M. Ph. Barbier.-Combinations of the fatty acids with the ethylene series of hydrocarbons, by MM. Béhal and Desgrez.-On the natural synthesis of the vegetable hydrocarbons, by M. Maquenne.—On the presence, in straw, of an aerobic ferment reducing nitrates, by M. E. Bréal.-On the hereditary transmission of acquired characters by Bacillus anthracis under the influence of a dysgenesic temperature, by M. C. Phisalix.-On the nitrogen in the blood, by MM. F. Jolyet and C. Sigalas.-Anatomy of the hypogastric nervous system of mammals, by M. Lannegrace.-On the Pliocene bird fauna of Roussillon, by M. Ch. Depéret.-The sickle at the end of the Stone Age, by M. Emile Cartailhac.-On the régime of artesian wells in the El Golea region, by M. Georges Rolland. -On a particular cause of contamination of water having its source in limestones, by M. E. A. Martel. BOOKS, PAMPHLETS, and SERIALS RECEIVED. BOOKS.-Travels amongst the Great Andes of the Equator, and Supplementary Appendix to ditto: E. Whymper (Murray).-Diagram Illustrating the Leblanc Soda Process, and Key to ditto: J. J. Miller (J. Heywood).— Dictionary of Political Economy: Edited by R. H. I. Palgrave, Part 2 (Macmillan).-Bibliothek des Professors der Zoologie und Vergl. Anatomie, 1891 Dr. L. von Graff (Leipzig, Engelmann).-The Universal Atlas, Part 13 (Cassell).-Le Climat de Rio de Janeiro: L. Cruls (Rio de Janeiro). The World and the Flood: A. J. Stuart (Shanklin). PAMPHLET. The French Peasantry since the Revolution of 1783: L. Nottelle (Simpkin). SERIALS.-Quarterly Journal of Microscopical Science, No. 131 (Churchill). -Bulletin de la Société Astronomique de France, cinq. année, 1891 (Paris). THURSDAY, APRIL 7, 1892. MENDELEEFF'S PRINCIPLES OF CHEMISTRY. Mendeléeff. The Principles of Chemistry. By D. ALL English-speaking chemists will cordially welcome the appearance of this book, if for no other reason than because its author in its preparation was led to the recognition of that fundamental principle of chemistry with which his name will always be associated-the principle which is embodied in what is now known as the periodic law. This fact alone would serve to stamp the book as one of the classics of chemical science. But, even apart from this circumstance, the work has very remarkable, and, indeed, exceptional, merits. Probably no scientific treatise ever more strikingly reflected the personality of its author. We have absolutely nothing like it in our language. In grasp of principles, in philosophic breadth, in copiousness of detail, in richness of speculation and suggestion, it is altogether unique among chemical manuals. Every true and earnest student of chemistry is certain to be profoundly influenced by it, even if he cannot always bring himself to subscribe to its doctrine. Of course, the facts are, for the most part, those which are common to all the larger treatises on systematic chemistry, but these are set out and marshalled in a manner wholly original. The intent and purpose of the book is to demonstrate the broad general principles on which chemistry as a science rests. This, it may be urged, is the intent and purpose of every chemical treatise. It may be so, but in many cases the philosophy is lost sight of―obscured, indeed, by the facts, just as the houses may obscure the view of the village. In Mendeléeff's work experimental and practical data have their place, but only as means to an end, and that end is as evident on every page as it was in Dalton's immortal work. Fascinating as the book is, it must be admitted that it is by no means easy reading; and he who wishes to master its contents and to assimilate its teaching will need to gird up his mental loins. Part of the difficulty is doubtless due to the different genius of the languages, but much more depends upon the impossibility of entering into the spirit of an author, or of quickly realizing his drift and meaning, when his whole mode of thought is so very dissimilar to that which obtains among Western people. It may be that herein lies part of the peculiar charm of freshness of the work. The book of the Siberian chemist is to the ordinary run of text-books what the novels of Tolstoi or Turgenieff are to the common run of works of fiction. But there are difficulties of another kind. Probably no other book in our language-certainly no other chemical treatise-contains such an extraordinary number of footnotes. There is scarcely a page without a footnote, and some of the pages are practically little else than footnotes. The continuity of description or of argument is constantly being broken, often by a footnote extending over several pages, and frequently so diffuse and involved that, by the time the reader has disposed of it, the statement in the main text to which it had reference has been lost sight of, and must needs be picked up again. Moreover, the repeated interruption is aggravated by the circumstance that these notes are printed in "nonpareil small," which adds enormously to the physical fatigue of reading and studying the work. The author, indeed, recommends that they should be read only by the advanced student, or on a second perusal of the work; but we are afraid that no intelligent reader will follow this advice when once he has begun to dip into them. They are, in fact, like the postscripts of ladies' letters-often more important, more instructive, more suggestive, and more characteristic, than the main body of the text. But, in truth, the book is not fitted for a beginner its proper readers are those for whom the footnotes are specially intended. It requires, too, to be read with discrimination. It was said by Davy that analogy is the fruitful parent of error, and it must be confessed that Mendeléeff's love of analogy frequently leads him to generalizations which are more ingenious and suggestive than intrinsically sound or well grounded. The translator and the editor have, doubtless, had difficulties to contend with. They tell us that they have not considered themselves at liberty to make any alterations in the matter of the work, and they have striven to give a literal rendering of it. They have felt that, on the whole, it would be better to have some inelegance of language rather than risk the loss of the exact shade of the author's meaning. Unfortunately, in too many instances the translator and his editor have not gained in precision of meaning what they have lost in elegance of statement. Thus, for example, on p. 12 we read: "The means of collecting and investigating gases were already known before Lavoisier's time, but he first showed the real part they [the means or the gases?] played in the processes," &c. What, too, is the meaning of the statement on p. 83? "Under ordinary circumstances the quantity of aqueous vapour [in the air] is much greater [than what?], but it varies with the moisture of the atmosphere." Presumably, for "moisture" we are to read "temperature." On p. 164, in the description of the experiment of burning phosphorus in oxygen, it is recommended that "the cork closing the vessel should not fit tightly, otherwise it may fly off with the spoon." That the cork should fly off with the spoon is contrary to well-established precedent: if anything is to fly away with the spoon, it should, of course, be the dish on which the bell-jar is represented as resting. To say (p. 417) that common salt containing magnesium chloride "partially effloresces in a damp atmosphere" is opposed to fact, and was surely never so stated by Mendeléeff. Van der Waals's equation is written: We have taken the pains to compare the English version with the German translation of Jawein and Thillot in a number of instances where the meaning is obscure, or where statements are made which appear to be erroneous, and in no single instance is the fault to be traced to the author. We think, too, that the limitation imposed on the translator and editor by themselves has operated injuriously in another way in cases where subsequent research should modify or supplement particular statements in the original, it was surely open to them, in the interests of knowledge, to substitute truth for error. Thus we know from the work of Winkler and Hempel the conditions under which exact determinations of oxygen by means of alkaline pyrogallol can be made; we know, too, that atmospheric ammonia and nitric acid are not by any means the main sources of the supply of nitrogen to plants; ammonium chloride is not now usually prepared by sublimation. The statement of the principle of Kjeldahl's method, given on p. 246, is inaccurate the radicle ammonium has not been obtained, nor is the old view of the nature of the so-called "ammonium amalgam" any longer tenable, nor is there any direct proof of the existence of ammonium hydrate. Flagstone, at least in this country, is not a form of carbonate of lime: it is usually a fine-grained micaceous sandstone. The apparatus employed by Cavendish in his memorable synthesis of water in no wise resembled that described and figured on p. 167; thanks to the symbol adopted by the publishing Society which bore his name, it seems now well-nigh impossible to get rid of the belief that the pear-shaped stoppered eudiometer was devised and used by him in the course of his investigation: as a matter of fact, the explosions were made in a simple Volta tube. With respect to the illustrations in general, we think that the majority of them could well have been spared; all of them have done duty in other works, and many of them are calculated to give an erroneous impression of the thing sought to be represented. Thus the coke-tower figured on p. 443 resembles nothing actually used; Fig. 60, which is stated to be a Davy lamp, is either a Mueseler or a Clanny lamp; Fig. 47 does not illustrate the method of preparing nitric acid employed in this country, nor does Fig. 93 represent a modern blast-furnace. The only figure of a zinc-furnace given is that of the practically obsolete per descensum method. We have been constrained to point out these blemishes, not in any hypercritical spirit, but solely because of our wish that Mendeléeff's great work should have been given to English and American readers in as perfect a form as possible. The blemishes, after all, are only as the spots on the sun. It is a great boon to get the book even as it is, for no thoughtful reader can fail to be quickened and animated by its fruitful and suggestive pages. T. E. T. THE LIGATION OF THE GREAT ARTERIES. A Treatise on the Ligation of the Great Arteries in continuity, with Observations on the Nature, Progress, and Treatment of Aneurism. By Charles A. Ballance, M.B., M.S. Lond., F.R.C.S., and Walter Edmunds, M.A., M.C. Cantab., F.R.C.S. (London: Macmillan and Co., 1891.) THIS HIS work is the result of investigations carried out by the authors during the last seven years, and contains the results of long and careful study. The authors were evidently desirous of getting to the bottom of their subject, and in their endeavours to do so, have used every method of research at their disposal. The first chapter is devoted to a short account of hæmorrhage in man, and contains valuable statistics as to the results of the ligature of the main arteries. This part will, of course, prove of the greatest interest to the pure surgeon. The second chapter contains a paragraph on the necessity of experiments on animals for the purpose of studying the mechanism of hæmorrhage; this paragraph might well have been omitted in a book written for the professional and scientific public, who are already convinced of the necessity of pathological experiments if pathology is to make any advance at all. The greater part of this chapter, however, is full of valuable facts concerning the occurrence of the disease of arteries in animals; whilst in the third chapter the structure of arteries is described, and, in this connection, the experiments made by the authors on the longitudinal tension of arteries require special mention. Physiological occlusion and pathological obliteration of |