264 



NA1UR£ 



\Jan. 20, 1881 



The Fishes of Great Britain and Ireland. By Dr. Francis 

 Day, F.L.S., &c. (London : Williams and Noro-ate, 

 1880.) 



This work is to be issued in nine parts, of which the first, 

 containing sixty-four pages of text and twenty-seven 

 plates, is now published. Waiting until the completion of 

 the work for a more extended notice, we may for the present 

 mention that in it the author purposes to give a natural 

 history of the fishes known to inhabit the seas and fresh 

 waters of the British Isles, with remarks on their economic 

 uses and on the various modes of their capture, and that 

 an introduction to the study of fishes in general is 

 promised. 



The synonymic lists of the species are given in great 

 detail ; the descriptive diagnoses treat of internal pecu- 

 liarities as well as of external form ; a good many 

 interesting details appear under the headings of Habits, 

 Means of Capture, Baits, Uses. The plates are from 

 drawings by the author, and are veiy excellent. 



A Mamtal of the Infusoria. By W. Saville Kent, F.L.S. 



(London : David Bogue, 1880.) 

 This sometime promised work has now advanced so far 

 in its publication as the third part ; when completed it 

 will merit a somewhat lengthened notice, as the most 

 important work on the subject which has issued from the 

 British press. It is intended to include a description of 

 all known flagellate, ciliate, and tentaculiferous Protozoa, 

 British and foreign, and an account of the organisation 

 and affinities of the Sponges. Each part (roy. 8vo in 

 size) contains over 140 pages and eight plates. The 

 general get-up of the work is magnificent, rather too 

 much so for the poor student, already weighed down by 

 the burden of the parts of Stein's " Infusionsthiere," but 

 very pleasant for the book fancier, and forming an im- 

 posing shrine wherein to inclose the records of these 

 early-life forms. 



The first five chapters (pp. 1-194) are introductory, 

 treating of the general history of the group : on the sub- 

 kingdom Protozoa, on the nature and organisation of the 

 Infusoria, on spontaneous generation, on the nature and 

 affinities of the sponges. The sixth chapter treats of the 

 systems of classifications of the Infusoria, adopted by 

 various authorities, from the time of O. F. Miiller to the 

 present date. The seventh chapter commences the 

 systematic description of the Flagellata. The third part, 

 just published, carries the work as far as the 432nd page 

 and to the twenty-fourth plate. 



A Complete Course of P>-ohlents in Practical Plane 

 Geometry . . . with an Introduction to Elementary 

 Solid Geometry. A New, Revised, and Enlarged 

 Edition. By J. W. Palliser. (London : Simpkin, 

 Marshall, and Co., 18S1.) 



This is a cheap manual, the cost of which can be easily 

 met by any artisan desirous of studying the subject, while 

 at the same time its contents enable it to fully satisfy the 

 wants of all examinees in first, second, and third grade 

 and similar papers of the Science and Art Department 

 Exarninations. The figures are very clearly drawn, well 

 showing given, constructional and required lines ; the 

 form of the page enables four propositions to be fully 

 treated of with the accompanying figures in four spaces 

 on each page. In the constructions we do not look for 

 novelty, but we have conciseness and great clearness 

 generally prevailing. Here and there elegance of expres- 

 sion is sacrificed to brevity ("for all the Government 

 examinations, the requirements of which this is a text- 

 book, the same rules will apply, with exception of Nos. i 

 and 6 "). We have detected only three points wbich call 

 for our notice : in Prop. 12 it strikes us as being simpler 

 to use the same radius throughout, thus doing away with 

 the necessity of taking two cases, as Mr. PaUiser does ; in 

 Prop. 37, note, it is necessary to add how the point is 



obtained ; in Prop. 212 the letter E is made to do double 

 duty in the proof. We can confidently recommend the 

 book. 



Bcricht iibcr die Thdtigkeit der Botanischen Section der 

 Schlesischen Gcsellschaft im Jahr 1877. Erstattet von 

 Prof Dr. Ferdinand Cohn. 



Most of the papers in this part are in abstract ; a few 

 however are given at some length, and are of considerable 

 interest. The additions to the phanerogamous Flora of 

 Silesia and the record of new localities for rare plants 

 occupy a considerable part of the pamphlet. Perhaps 

 the most interesting paper is that on the Date-palm and 

 Palm-forest at Elche in Spain, by General von Schweinitz. 

 The palms there grow to a height of from seventy-five to 

 eighty feet. The plants grow for about 100 years, then 

 become stationary, and next decay. Each tree bears 

 from the fifth year two to five bunches of fruit, each with 

 from 500 to 600 dates, the weight of dates yielded by one 

 tree being sometimes three centners. Many of the papers 

 in this part are contributed by Goeppert and Cohn, and deal 

 with all departments of botany. Dr. Thalheim describes 

 a series of models of diatoms made in paraffin and 

 glycerine soap, which exhibited the structure of all the 

 chief groups of this order of plants. ' 



LETTERS TO THE EDITOR 



\_Tlie 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. No 

 notice is taken of anonymous communications. 

 The Editor urgently requests correspondents to ktep their letters as 

 short as possible. The pressureon his space is so great that it 

 IS impossible otherwise to ensure the appearance even of com- 

 munications containing interesting and newel facts,'\ 



Dr, Carnelley's Hot Ice 



The remarkable observation made by Dr. Carnelley that ice 

 in a vacuum is very permanent, even though surrounded by and 

 apparently in contact with very hot bodies, has caused him to 

 suppose and maintain that the ice itself is at a high temperature ; 

 a sapposition which has been apparently confirmed by preliminaiy 

 caloriaietric determinations. This proposition has naturally met 

 with a good deal of scepticism, and certainly requires ample and 

 cautious verification ; but I venture to think that there is nothing 

 in it contradictoiy to our present knowledge of the properties of 

 matter, though if verified (as, for the reasons to be stated, I fully 

 believe it will be) it constitutes an important addition to that 

 knowledge. 



The notions which have occurred to me have made the essential 

 part of the phenomenon so much clearer to myself that I fancy 

 they will not be uninteresting to your readers. 



By the term " vapour-tension " at a given temperature I mean, 

 as I believe is usual, the pressure at which a liquid and a vapour 

 can exist permanently together at that temperature, or the maxi- 

 mum pressure which the vapour is able to exert at that tempera- 

 ture, or the vapour pressure under which a liquid ceases to 

 evaporate, or the total pressure at which it begins to boil. By 

 the term "boiling-point " I mean the temperature of a liquid 

 under a total pre!-sure equal to its vapour-tension. 



Now in order that a solid may sublime or pass directly into 

 thf vaporous condition without melting, it must be either at a 

 temperature below the melting-point, so that no liquid attempts 

 to form, or else at such a temperature that any liquid formed 

 shall instantly evaporate ; which it would certainly do if it were 

 above the boiling-point, that is if the total pressure on it were 

 less than the vapour tension. 



A solid, under either of these circumstances, gives off vapour 

 from its free surface at a rate depending on, but not necessarily 

 proportional to, the supply of heat ; for there is no definite sub- 

 liming point for a solid, any more than there is a definite eva- 

 porating point for a liquid, so that the temperature of the solid 

 need not remain constant. When a liquid is evaporating, the 

 more you heat it the faster it evaporates, but not at a compen- 

 sating rate, and the temperature rises as well : if this be true 

 for a liquid, much more will it be true for a solid, whose 



