November 30, 1899] 



NA TURE 



99 



This is unintelligible in view of the fact that the 

 difference between the initial and final pressures does 

 not increase, while in case of supply from a cylinder of 

 compressed gas, it actually decreases. On p. 232 we 

 find the sentence : " Below the temperature of zero 

 degrees ice slowly sublimes." Some misprints have 

 escaped correction. On p. 208 the minus sign is omitted 

 between k and i in equation (7). On p. 243 the second 

 " i " in the name Lavoisier has been omitted. 



If in a new edition such mistakes be corrected, and 

 the latter part of Chapter iv., Section 3, be rewritten, 

 the book will be useful as weU as interesting to the class 

 of readers for whom it is chiefly intended. 



Prof. Lef^vre's book is very well written and clearly 

 illustrated. Within the narrow limits of 175 pages it con- 

 tains a considerable amount of correct theory, a very in- 

 teresting history of the experimental development of gas- 

 liquefaction, some discussion of industrial applications, 

 and a very full list of references to original authorities ; and 

 all this with a surprismg freedom from the evils of over- 

 compression. The arrangement is not altogether perfect. 

 Prof. Dewar's apparatus figured on pp. 55 and 61 apply 

 the combination of free expansion with counter-current 

 interchange, a method of which there was earlier authen- 

 ticated invention both in England and Germany. These 

 applications should have been described in .Section 35 

 under the head " Machines a ddtente sans travail 

 exterieur," and after the invention on which they depend ; 

 or, if it was thought advisable to discuss them out of 

 chronological order, their dependence on the combin- 

 ation in that invention should have been clearly brought 

 out. The illustration of Mr. Triplets apparatus on p. 84 

 might well have been omitted. The employment of 

 three-stage compressors, with cooling coils between the 

 stages, with purifiers, water-separators, and pressure- 

 gauge, was familiar to pneumatic engineers for years 

 before they were employed by Mr. Tripler in liquefying 

 air ; and the vitally important interchanger and expansion 

 valve remain such a mystery that the illustration gives no 

 idea what they are like or whether they differ essentially 

 from the invention of Dr. Linde and Dr. Hampson. On 

 p. 70 the statement that helium was liquefied at the tempe- 

 rature of boiling hydrogen needs correcting in accordance 

 with later results. Chapter ix., on modern commercial 

 refrigerating machines, is very much out of proportion 

 with the rest of the book ; a discussion of this subject, 

 which entirely passes Sy the great American and British 

 developments in this field, might as well be omitted 

 altogether. 



A CONTRIBUTION TO ZOO-GEOGRAPHY. 



Studien zur Geographic. Von Dr. W. Kobelt. Zweiter 



Band. Pp. x -H 369. (Wiesbaden : Kreidel, 1898.) 



IN this, the second part of his " studies," Dr. Kobelt 

 deals at full length with the characteristics of the 

 fauna and to some extent also, of the flora of the 

 " Meridional Sub-region." This region very nearly cor- 

 responds to the Mediterranean sub-region of Dr. Wallace ; 

 its northern limits are a trifle more extensive, embracing 

 as they do the Crimea and Bessarabia. 



As might be expected from the nature of his own 

 zoological studies, the author lays most stress upon the 

 NO. 1570, VOL. 61] 



distribution of Mollusca, and gives a series of elaborate 

 and apparently very full tables of species found in the 

 different departments into which he divides the region 

 described in this volume. It must not, however, be in- 

 ferred from this that other groups of animals are 

 neglected or even treated with indifference. 



A great deal is said about the range of the vertebrata 

 of this part of the world in the past as well as in the 

 present, all the orders of that assemblage of animals 

 being taken into consideration. There is one group of 

 terrestrial, aquatic and semi-aquatic invertebrates which 

 are not at all discussed by Dr. Kobelt. This group — 

 that of the earthworms and their allies — might profitably 

 have been dealt with, inasmuch as their range, so far as 

 is known, marks out very well not only the limits of the 

 Palasarctic region (excluding only Japan), but also enables 

 a line to be drawn between the more northern and the 

 Mediterranean portions of the region dealt with by Dr. 

 Kobelt. Inasmuch as a large portion of the meridional 

 region is occupied by the Mediterranean sea, the author 

 is, we think, wise in paying some attention to the fauna 

 of that sea, as well as of other stretches of water in- 

 cluded within his area. A special chapter is devoted to 

 the Mediterranean, and the author commences by ad- 

 dressing himself to the problem as to whether that inland 

 sea is really an independent tract or a section of the 

 Atlantic. 



The colossal faunistic and structural monographs 

 issued by the Naples Zoological Station, as well as the 

 results of elaborate studies carried on at similar institu- 

 tions along the coasts of the Mediterranean, have made 

 us well acquainted with the shallow water fauna of that 

 sea. We are less informed as to the pelagic creatures, 

 especially mammals, and about the deep-sea fauna. As 

 to the former, observes the author, " the mammalogist 

 will, with a regretful shrug of the shoulders, confess him- 

 self incompetent " to speak with accuracy. So far as we 

 know, the whales are not special to that sea ; nor does 

 palaeontological evidence hint at the Mediterranean as a 

 centre of origin. Oliver Goldsmith, in his "Animated 

 Nature," pomted out that the Mediterranean dolphin 

 occurred in the Red Sea. He was doubtless right, 

 though the reasoning employed may have been defective, 

 and there is no prevision of the Suez Canal ! The sperm 

 whale is found therein, and (if we may regard the sea 

 beast from which Perseus delivered Andromeda as a 

 " monstrous physetere " !) was even known to the ancients. 

 Pliny's Orca was, it appears, rather that " sea should'ring 

 whale" than a gladiator. The dolphin of the Mediter- 

 ranean has received many names, but there seems to be 

 little doubt that that whale of Greek coins is exactly the 

 same as the dolphin of the coasts of the Atlantic. " As 

 concerns mammals," concludes Dr. Kobelt, "the Medi- 

 terranean is an impoverished gulf of the Atlantic Ocean.' 



In the characteristics of the Mollusca found, and 

 some other animals, the Mediterranean presents tropical 

 characters which are, partly at least, in reality due to the 

 Suez Canal. Mr. E. A. Smith, of the Natural History 

 Museum, contributed some years since a number of 

 interesting facts to the Zoological Society bearing upon 

 such immigrations. The Mediterranean, as is well 

 known, sinks in places to profoundly abyssal depths ; the 

 actually greatest depth appears to be 4400 metres ; but 



