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The Year-Book

of Science.



An Illustrated, Priced, and Descriptive Catalogue of the ments of Science which are used in teaching and demon every branch of Physical Science, as well as of the Im which are used in Original Research and in the appos Science to Technical Industries and Pursuits. PRICE TO NON-CUSTOMERS, 2s. 6d. POST



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For Geologists, Mineralogists, Prospectors. For Quantitative and Qualitative Analysis; compris sible Glass Case Assay Balance, 74 pieces of App Chemicals. The Tools in Polished Mahogany cases.. cloth, locks and keys. The complete set contares black leather travelling case. Very compact, £25 12* WILLIAM HUME, 1 Lothian Street, Edito

Instrument Company, Cambridge Address all communications "Instrument C Cambridge."

Price List of Scientific Instruments, sent post Illustrated Descriptive List sent on receipt of is The Cambridge Scientific Instrument Comp St. Tibb's Row, Cambridge.




COMPTES RENDUS HEBDOMADAIRES SÉANCES DE L'ACADÉMIE DES SCIENCES. T 26 to 33, 42, 43, 45 to 87, 90, 91. 28 Vols. Half Calf, the (4 Tables, 2 Titles, and 7 Numbers wanting.) In al

1880. 10 105.

A long Series of this important Work, containing Articles by Bailly, Berthelot, Bertrand, Biot, Cauchy, Chasles, Dupi Gauss, Hermite, Jacobi, Jamin, Jordan, Lacroix, Levere Monge, Poinsot, Poisson, Poncelet, Saint Venant, Secchi, Ser Verdet, and many others.

COSMOS. Revue encyclopédique hebdomadaire des Sciences et de leurs applications aux Arts et l'Indus B. R. de Monfort, redigée par l'Abbé Moigno. (Fa to 1863, 10 Vols. (Second Series), Les Mondes, 186; Third Series. Vols. 1 to 3. In all 69 Vols. 8vo, Haf 1882. £10 108.


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cation, Science, and Literature. Vols. 4 to 431800. 41 Vols. in 20, Cloth, and 2 in Numbers. £40 Sets of this important Journal are very scarce. It ca mathematical questions and solutions, the republication a form, did not commence until 1864. Pages 25 to 48 of Ve and Contents of Vol. 40 are wanting; otherwise it is perfect

This Day is Published, 8vo, Cloth, 492 pp., with 174 Illustrations and a Map, £1 IS.

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C.M.Z.S., of Jerez.

(A Limited Number of Copies on Large Paper, ROYAL 8vo, at Two Guineas.)

GURNEY & JACKSON, 1 Paternoster Row (Successors to Mr. Van Voorst).


QUALITATIVE CHEMICAL ANALYSIS. alitative Analysis Tables and the Reactions of certain Organic Substances. By E. A. Letts, D.Sc., Ph.D., F.R.S.E., F.C.S., &c. (Belfast: Mayne and Boyd, 1892.)

HE author in his preface says, "Every teacher has his own methods-acquired not only from his exrience, but also largely through the researches of others and this book embodies mine." Therefore the volume innot fail to be welcome to those who take an interest the teaching of analytical chemistry. But it is surrising to find that Prof. Letts has until quite recently llowed the old method of dictating reactions and ethods to his students, and allowing them to work from eir own notes. For the last fifteen years there has een no lack of text-books of qualitative analysis, and 'rof. Letts has found, what probably all teachers of the ubject are aware of, that students rarely take accurate otes. But, however exact they may be, every one knows hat manuscript is not so easily deciphered nor so readily eferred to as a printed page.

The methods of work given are, of course, more or ess on the ordinary lines. The final test for bismuth depends upon the production of its black suboxide, and this reaction has much to recommend it, though probably many would prefer the oxychloride reaction. The use of ammonium molybdate as a separative reagent in qualitative analysis we do not consider advisable for many reasons, but no complaint can be lodged against it on the score of ts accuracy.


There can be no doubt whatever that both Prof. Letts and his students will find considerable advantage in the use of boldly-printed statements of methods. But the author begins his preface by stating that although the book has been written chiefly for his own students, he will be glad if it prove of service to others also. This ays the volume open to general criticism, and prompts us to complain that it is neither so clear nor so systematic as it might have been. As to the want of clearness, there are a few expressions that can easily be altered in a second edition, and these we lay no particular stress upon. example, at page 27, in the description of Bunsen's dry tests, we read:-"The charred end of the match is next moistened with fused carbonate of soda." At page 40 it states that the solution "is mixed with its own volume of chloride of ammonium." One assumes this to be a solution, but if so the strength of it is not given, and we fear that the bulk of the solution to which it is to be added will be likely to vary enormously according to the peculiarities of the student and the character of the substance he is at work upon.

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The more important want of clearness may be exemplified by taking the case of a student who has Epsom salts given to him as a simple salt. This can hardly be called an out-of-the-way substance, but so far discover, the student in following these tables would examine it by the following series of operations: Heating on platinum wire to see the colour of the flame.

Heating on a borax bead in the outer and inner flames. Heating on a carbonate of soda bead. Heating on charcoal (if a white mass resulted, which with cobalt nitrate gave a "faint pink," the metal might be recognised here, but as magnesium sulphate does not readily yield this reaction in most cases the student would pass on). Heating on charcoal with sodium carbonate. Heating in a glass tube closed at one end. Repeating with bisulphate of potash. Repeating with black flux. Repeating with magnesium wire. He would then dissolve the substance in water, and test a part of the solution for ammonia by heating it with caustic alkali. Then heat a part on a platinum wire for the flame colouration, a test that has already been done on the solid, and then pass on to the examination of the solution in the ordinary way for the base, and finally search for the acid if it is not already found. It may be taken for granted that this fiddling about with the substance is not intended, but the volume does not appear to contain directions as to how to go more directly to work.

The want of system that we complain of is acknowledged by the author himself in picking out certain parts and labelling them as "systematic." If the whole were systematic this distinction would obviously be meaningless. As this fault exists in many of the text-books and in much of the teaching that we have had experience of, we are tempted to make a few general remarks upon the matter without special reference to the volume under notice.

That qualitative analysis is often regarded as a very unimportant branch of chemistry, may account for its comparative neglect. One constantly meets with students who are able to perform quantitative operations of not too complex a character with commendable accuracy, and that can with a little guidance do many sorts of "research work," but are wholly unable to perform with certainty a qualitative analysis of a comparatively simple substance. They may happen to find most or all of its constituents, but they have no confidence in their result; they do not feel sure that they have missed nothing, or indeed that everything they have found is unmistakably present, and generally they have little if any idea of the degree of accuracy of their work. They cannot distinguish between a principal constituent and one that is present in a comparatively small proportion. This incompetency must be ascribed very largely to the fact that students are too often urged on to work that a casual observer might regard as more important. The foundation is neglected for the sake of the superstructure. But having regard only to that amount of practice in qualitative work that still remains possible for the average student, there is too often a lack of method that is surprising if not disastrous. As a rule, it is considered desirable to get first an idea of the general character of the substance given for examination by a few dry tests, but these, as often done, are not only of no use, but serve in a conspicuous manner to train the student in the making of careless and imperfect observations, and in the dodging about from one operation to another with no idea of the proper sequence or inter-dependence of the various parts of the work. In the analytical examination of even the simplest of substances, from the

time when the student receives it until he has made his last note, every operation ought to be in an order for which very definite reasons can be given, and the completed work ought to be of such a character that anything added to it would be superfluous; anything taken from it would leave it imperfect; and any change in the order of its various parts would be to its detriment. This character of work is generally sought after in the separation of metals from a solution; but the rest of a qualitative analysis, namely the preliminary examination and the testing for acids, is too often a collection of odd operations, which, if the student is lucky, will lead him sooner or later to the desired result, but if he is unlucky may fail to do so through no fault of his own.




Gemeinverständliche Vorträge aus dem Gebeite der Physic. Von Prof. Dr. Leonhard Sohncke. (Jena : Gustav Fischer.)

IT is a matter of common remark that the books on

scientific subjects which reach us from Germany are, as a rule, so special and detailed in character as to be totally devoid of interest, except to those immediately concerned with the subjects of which they treat. This being the case, it is all the more refreshing to meet with such a collection of popular addresses as Prof. Sohncke has gathered together in the volume before us. He has not restricted himself in his choice of subjects to any one branch of physics; on the contrary, the nine lectures of which the book is made up represent as many different divisions of natural philosophy, and were delivered quite independently before various audiences in Germany.

The first lecture of the series bears the somewhat obscure title, "What then?" and was suggested by a great strike among the coal-miners of Westphalia, which led to a temporary cessation of the German coal supply. The author depicts what would be the consequences if the world's coal supply were exhausted, in terms almost as pathetic as those of Prof. Jevons which moved an English Parliament to appoint a commission on the subject. But recognizing that, after all, coal is only stored up solar energy, Prof. Sohncke endeavours to look at the brighter side of the question by discussing the possibility of utilising the sun's energy in other forms, and so enabling man to remain "lord of creation" even in those days when the entire available coal supply of the world reposes on the

shelves of some scientific museum.

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tains a short history of the arguments and exper which led to the substitution of the ether theore trical action in the place of the older action-at-s-¿ theories. While admitting the existence of a me which transmits both optical and electrical distur the author thinks it more probable that gravita true action-at-a-distance, and in so doing he tacit that a medium is a necessity. The notion of an emp is so foreign to English men of science of this gen that we certainly consider Prof. Sohncke's sin of the question to be worthy of attention. He s "Even if we could finally succeed in proving that at-a-distance is really the result of a transmission some medium, we must not suppose that all ¿F are then removed. For the process of such a sion is by no means simple, and cannot be er without further assumptions; on the contrary, tem midable difficulties arise even here. Directly m give a concise explanation of the compression of . and its subsequent expansion when performing vibrations, we find that a choice must be made b two assumptions equally hard to accept. Either is itself capable of compression and expansion of consists of separate vibrating atoms to which assign the property of exerting mutual forces: other at a distance."

From a purely scientific standpoint, the le "Newer theories of atmospheric electricity and storms" is undoubtedly the most valuable of the the subject being one on which Prof. Sohncke with some authority. After describing the older of the origin of electrical charges in the atr discusses those newer ones which were suggest, discovery of Hertz that ultra-violet light faci discharge of electricity from a charged body the best known is that of Arrhenius, who suppose ordinarily a dielectric, to be rendered feeblyby the action of light. According to this theory is negatively charged, and when its atmosphere nated some of the charge is conducted away to The conduction must be electrolytic, otherwis would become charged. Prof. Sohncke obj theory mainly on the ground that the discharg of light cannot be considered as due to the way, since it is manifested only when the light fall on, and are absorbed by, the negative Further, it is not easy to see how elementar as oxygen and nitrogen can be electrolytes cluding he defends his own theory, accordig atmospheric electricity is produced when a la with particles of ice meets another charge: * drops, the electrification being due to the fr against water. In support of his view the act the fact that hailstones are found to be es reaching the ground.

The appearance of a volume like the prese variably gives rise to some regrets that the is no longer of one language and one speech. 2that some friend of popular science may be the contents of the book to furnish a English readers.



BRITISH JURASSIC GASTEROPODA. Catalogue of British Jurassic Gasteropoda, comprising the Genera and Specics hitherto described, with refernces to their Geological Distribution and to the Localties in which they have been found. By W. H. Hudleston, M.A., F.R.S., P.G.S., and Edward Wilson, F.G.S. 8vo, pp. xxxiv+147. (London: Dulau and Co., 1892.)

TEXT in importance to a monograph on any group of fossils is a catalogue of the species giving their stribution, their synonymy, and references to the figures d descriptions. The value of such a catalogue is ormously increased when, as in the present case, the thors have made a prolonged and careful study of the bject. The late Prof. John Morris was able, with arcely any help from other workers, to publish a critical talogue of all British fossils; the first edition appeared 1843, the second in 1854. But since that date so much ogress has been made in paleontology that the accomishment of such a task by any one man would now be 1 impossibility. Prof. Morris always hoped to bring it a third edition of his work, and after his death committee was formed to carry out this project. But e labour appears to have been too great and the comittee soon ceased to exist. This is greatly to be reretted, for although the work must of necessity have een distributed among various authors, a certain amount f uniformity in treatment would at any rate have been ecured and publication hastened.

In the preface we are told that Mr. Hudleston is mainly esponsible for the Oolites and Mr. Wilson for the Lias. Inder the term Jurassic the authors include everything rom the Lias to the Portland-stone: the Rhætic beds, Ithough not regarded as strictly Jurassic, are treated in he supplement. The total number of gasteropods reorded by Samuel Woodward from these formations in 830 was only 89, whereas in the present work the Jumber given is 1015. Of these 15 come from the Rhætic, 314 from the Lias, 681 from the Oolites, and 5 from the Lias and Oolites. In the Lias the gasteropods are characterized by the species belonging to comparatively few genera. Although, as far as genera are concerned, the Lias shows considerable affinity to the Oolites, there is nevertheless a great break in the continuity of the species, only five being common to the Lias and Oolites. Gasteropods are most abundant in the calcareous beds, so that the Lower Oolites have yielded by far the larger number of forms, the Inferior Oolite being richer than the Great Oolite. In the Middle and Upper Oolites there is a decided decline in the gasteropods, especially of the argillaceous beds.

After the introductory remarks the authors give a valuable bibliography of the British Jurassic Gasterpoda, and then a list of the genera, in which each is placed in its proper family and reference given to the original description. By the use of different type the genera are divided into four classes, (1) those fully accepted by the authors, (2) those accepted with doubt, (3) those given as Jurassic by other authors but not accepted, (4) synonyms. In the catalogue proper the authors have adopted Morris's plan, each page being divided into two columns; in the larger are given the name of the species, the

references, the synonyms, and the cross-references; in the smaller the geological horizon and the more important localities, the locality first named being that from which the type was obtained or the first place from which the species was recorded in Britain. The dates of publications are often omitted, but since they can be found in the bibliography this is not very inconvenient except in the case of serials. The present locale of types is not given, although this would have been a comparatively easy matter, especially since so many catalogues of types have been recently published.

With regard to the orthography the authors have kept to the older and more usual method. For instance, the capital initial is used for species when derived from proper names, and the single i for the genitive is not always adopted. Thus we find a considerable variation in the terminations, such as, Cricki (p. 124) Crickii (p. 77), Waltoni (p. 42) Waltonii (p. 139), Suessea (p. 29) Suessii (p. 138), Wrightii (p. 46) Wrightianus (p. 70). These are, however, purely matters of opinion and do not in any way detract from the great value of the work, which exhibits so much painstaking accuracy and sound criticism.



The Year-Book of the Imperial Institute of the United Kingdom, the Colonies, and India, and Statistical Record of the Resources and Trade of the Colonial and Indian Possessions of the British Empire. Compiled chiefly from official sources. First issue 1892. Issued under the authority of the Executive Council, and published by John Murray, &c. Large octavo pp. xvi. and 824.

THE Imperial Institute has lost no time in issuing a handsome and comprehensive year-book, compiled by the Librarian, Mr. J. R. FitzGerald, who has diligently and successfully gathered together a stack of varied information bearing on the purposes of the Institute. It is a question which time alone can answer whether amongst the many admirable year-books of statistics, commerce, and the colonies which have established themselves as annuals of proved utility, there is room for a new and bigger book overlapping their information, and containing few, if any, novel features. It would be out of place to discuss this question in a notice which ought to be confined to the scientific aspects of the work. The object of the year book, as expressed in the preface, is to deal "statistically with the physical geography, the natural resources, and the industries and commerce of the Colonies and India," and with certain other related facts. It would not be fair to criticise severely the first issue of so large and comprehensive a compilation; but it would help towards the attainment of the compiler's aim if the description of the physical geography of the regions touched upon could be made as full as the historical introductions, and as statistical as the commercial and the character of the soil in the colonies where tables. More notice ought to be taken of the geology geological surveys are in progress; and climate certainly deserves better treatment. We do not think space would be wasted in giving the mean monthly temperatures and rainfall for the average year, and for two extreme years, at a few representative stations in the larger colonies. This information cannot indeed be found in any existing which exist abundantly, and are rarely made available to books, but must be worked out from original records practical workers.

The treatment of natural resources might also be

improved by a firmer grasp of scientific principles. The commercial statistics are, as might be expected, much fuller, better arranged, and more serviceable than those relating to physical geography; but we imagine that few members of the Imperial Institute, likely to make use of the book, are without the original records relating to their own department. The difficulty of proportion and perspective is rather seriously apparent in the treatment of India, which has to be passed over more lightly than the colonies, because equal detail would involve the sacrifice of much space. Thus the great internal trade of India is scarcely touched upon, and the wants and tastes of consumers in the ultimate Indian market, by whom imports are finally absorbed, are not laid before the British merchant.

Beneath Helvellyn's Shade. By Samuel Barber. (London: Elliot Stock, 1892.)

THIS book consists of notes and sketches in the Valley of Wythburn, and is brightly and attractively written. Perhaps the best chapters are those on clouds, the various forms of which have been carefully studied by the author. He has also many interesting remarks on various aspects of Cumberland scenery, on the customs of the people, and on antiquities. Occasionally, perhaps, Mr. Barber adopts too much the tone of a preacher, but his impressions and ideas are for the most part fresh and vivid. The book will especially please those who have themselves felt the charm of Wordsworth's country.


[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.]

Dr. Joule's Thermometers.

RESPECTING the question asked by Mr. Young (NATURE, vol. xlvii. p. 317), I am glad to have an opportunity of stating that shortly after Joule's death I obtained the sanction of his son to examine the scientific apparatus that were left in his


I found a number of thermometers, and amongst them the two chiefly used by Joule in his researches. These thermometers have been placed in my charge for the present. I have made careful comparisons of them with a standard of the "Bureau international des Poids et Mesures," and therefore indirectly with the air or hydrogen thermometer. A standard issued by the Technische Reichsanstalt has also been used as a check. I spent a good part of last winter on the work and am now only waiting for an opportunity to repeat some of the measurements. The results will be published in due course, and I think will prove of interest. As Joule compared his thermometers with one used by Rowland, we shall in this way have an indirect comparison of Rowland's air thermometer with those by which the Berlin and Paris standards have been independently fixed.

One question arises on which I should be glad to have some information, and I should be grateful to any of your readers who could help me. The glass of which Joule's thermometer is made does not behave like the English glass now in use; and it would be important to know the probable composition of glass used in England about the year 1840 for thermometric purposes. As my experiments are not concluded I do not wish to speak with too great a certainty; but I believe it will be found that if we could return to the glass of Joule's thermometer, we should have a substance as well and possibly even better adapted to the manufacture of thermometers than the modern Jena or French thermometer glass.

I am sorry I cannot give a very definite answer to Mr. Young's question. Joule does not, as far as I know, anywhere give the actual readings of the freezing point, but only its changes. Rowland, in quoting the comparison between Joule's thermo

meter and his own, gives 22.62 as the actual reading ef zero. I have not at the present moment access to Ro paper, and have no note of the date at which this com was made (either 1879 or 1880).

Such a formula as that given by Mr. Young can be depends on the temperature at which the thermometer b only have a limited application. The zero of a therm kept previous to its immersion into ice, and with ̈*. annealed thermometers the secular changes are much s than the temporary ones. Last winter Joule's thermometers changes in zero from 23°51 to 23:00 on the arbitrary se original temperatures varying from 7° to 30°.

All observations lead to the conclusion that the changes of a thermometer gradually vanish, so the corresponding to any temperature approaches a Young's formula would make the zero rise indefinitely ARTHUR SCEEST.

Dust Photographs and Breath Figures. YOUR two correspondents on February 9 add inters 1, stances of these phenomena. I am sorry that one of my s was not clear. In saying "Two cases have been repute where blinds with embossed letters have left a later the window near which they lay," I meant to describe “not in contact.

is a

I have questioned my neighbour Dr. Earle case. The plate-glass window of an hotel in Londo inside a screen of ground glass lying near but not t upon the latter are the words "Coffee Room" in frosted letters. One day as he was at breakfast the s taken away, but the words were left plainly vis window, and no washing would remove them. The ober curiously similar, but each narrator was ignorant of the tale. A friend, Mr. Potter, asked me if I knew whether in which he was lodging had been an hotel, for on ar they saw "Coffee Room " on one of the windows. Iren the house had been an hotel two or three years previ there had been brown gauze blinds with gilt letters.

Mr. Thiselton-Dyer's observation appears not so man these two as to the dust picture of a water-colour d which I spoke in my former paper.

I look forward to seeing the effects at Canterbury. Winchester College, February 13. W.B.C

Fossil Plants as Tests of Climate. MR. DE RANCE's note relating to the above st NATURE, p. 294, mentions that "Heer has determine.. nificent flora of more than 350 species from these! tertiaries, and that he at once pointed out the absence and subtropical forms." My contention, founded on study of his determinations and of the original spec London and Dublin, and to some extent in Copenhags not fifty, or perhaps not the half of fifty, of these deter are entitled to the smallest weight; and again that thoug he saw nothing subtropical in the flora, he subsequen the presence of palms, &c., upon utterly insufficient da however, wishing to rid the "magnificent" flora of p useless and misleading encumbrances, I am far from depreciate the extraordinary significance and value of the remains, and which clearly shows that in early Eocen coast of Greenland supported in certain places fors included the redwood, the plane, and even the mag ciated with many more northern forms. This is cons the tropical vegetation existing during a part of the p temporary lower tertiary period in the south of Engin facts are sufficiently inexplicable, but there is no tea magnify the difficulties they present. As to the Green they have not been proved to contain any forest trees 20 not, and which in fact do not, flourish in their moder sentatives, when planted in certain favourable spots coast of Ireland, and even of Scotland. We are not e to assume that Greenland as a country was characters. vegetation, for this might be as erroneous as to regant Scotland as countries generally characterised by arbutus. The flora of a country is in fact most like y served in its most sheltered spots, in lake bottoms b Killarney, or where small rivers quietly steal into the of deeply recessed bays like those of Bantry and forest pools like some in the Mount Stewarts' woods

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