464 



NATURE 



[December 8, 192 1 



some twenty-four pages of part i ; it is necessarily- 

 treated very summarily, and much of the informa- 

 tion is given by diagrams. This makes it essential 

 that these should be accurate and self-explanatory. 

 Fig. 2 is open to the criticism that it fails to 

 show the great differences between the inter- 

 planetary spaces ; the orbits are represented as 

 equidistant, and Saturn's period is given as twelve 

 years. Fig. ii quite fails to show the sun's pre- 

 eminence compared with the planets. The letter- 

 press under the portrait of Prof. J. C. Adams is 

 disfigured by the substitution of Neptune for 

 Uranus as the perturbed planet. Fig. 6 (the total 

 solar eclipse of 1919) is described as being taken 

 at Greenwich, instead of Sobral, Brazil. On p. 23 

 it is stated that "mutual friction raises at least a 

 large part of them (the meteors forming a comet) 

 to white heat." This is quite improbable, since 

 the meteors are travelling on parallel paths with 

 practically equal velocities. In the large diagram 

 illustrating the spectroscope the luminous body 

 appears to be a star, since the sky is dark and 

 other stars are shown. However, no object except 

 the sun could throw a large, bright spectrum on a 

 screen, and in this case a slit (absent from dia- 

 gram) would be essential for show-ing the Fraun- 

 hofer lines. 



There are several excellent reproductions of 

 solar, lunar, planetary, and nebular photographs, 

 and a bold coloured drawing of a gigantic solar 

 prominence. The descriptive matter is attrac- 

 tively written, and includes a short exposition of 

 the theorv of giant and dwarf stars, and of the 

 Moulton-Chamberlin planetesimal theory, which, 

 however, postulated the approach of but one star 

 to our system, not one for each planet, which 

 latter would be utterly improbable. 



A. C. D. Crommelin. 



Die Ursachen der diluvialen Aufschotterung und 

 Erosion. Bv W. Soergel. Pp. v-f-'74. 

 {Berlin : Gebruder Borntraeger, 1921.) 18 marks. 

 In translating the title of this suggestive work 

 we are troubled by the term "diluvial," which 

 has, we fear, become fixed in German termino- 

 logy ; also by the fact that we have no equiva- 

 lent for the expressive w-ord "Aufschotterung." 

 The author refers the formation of the true 

 Schotter, the boulder-beds, to oochs of cold 

 semi-arid climate, when frost acted on a surface 

 free from vegetation. Weathering was then me- 

 chanical. Valley-erosion, on the other hand, indi- 

 cates a humid climate, when vegetation protected 

 the rocks from block-denudation, when weathering 

 was chemical, and when the free flow of water 

 worked havoc with the preceding products of 

 "Aufschotterung." Herr Soergel shows how even 

 so large a cause as upheaval or subsidence of the 

 land is unlikely to promote regional erosion or 

 aggradation in a network of valleys running in 

 different directions. The tilting or buckling of 

 the land-surface in such a case leads to changes 

 that vary from one district to another. Hence 

 the author sees in the regional features of "dilu- 

 vial " times in Europe evidence of repeated 

 NO. 2719, VOL. 108] 



climatic change, and he finds support in the 

 animal remains that are associated with deposits 

 formed respectively in epochs of erosion and 

 glacial aggradation. The " monoglacial " view is 

 thus rejected ; boulder-beds connected with epochs 

 of erosion are merely local and do not indicate a 

 continuity of the cold conditions that produced 

 the great "Aufschotterungen." 



G. A. J. C. 



Flora of the Presidency of Madras. By J. S. 

 Gamble. Part 4, Ruhiaceae to Ebenaceae. 

 Pp. 579-768. (London : Adlard and Son and 

 West Newman, Ltd., 1921.) 105. net. 



The present instalment of this handy little flora 

 is mainly occupied with the two large families 

 Rubiaceae and Compositae, the former including 

 representatives of forty-five genera, and the latter 

 of sixty-two. The Rubiaceae include plants of 

 widely varying habit ; small-flowered, creeping, 

 erect, or climbing herbs recall the development of 

 the family in temperate climates, and shrubs or 

 trees represent the tropical development. The 

 latter include handsome flowered species, as in 

 the Ixoras and Gardenias. Hydrophylax maritima, 

 a succulent creeping herb, is a useful sand-bind- 

 ing plant on the dunes of the east and west coasts. 

 Many genera familiar in temperate regions occur 

 among the Compositae in the hill districts ; the m 

 Dandelion is an introduced weed both in the Nil- " 

 giris and the Pulney Hills. The nineteen species 

 of the genus Senecio include, besides herbs of our 

 ragwort type, several shrubby climbers; and Ver- 

 nonia, with twenty-nine species, includes herbs, 

 shrubs, and small trees. 



In contrast with the rich development of the 

 Ericaceae and Primulaceae in Northern India the 

 Madras Presidency is very poorly represented. 

 Ericaceae comprise only one Gaultheria and one 

 Rhododendron, and Primulaceae six species in all, 

 one of which, Anagallis arvensis, the pimpernel, 

 occurs only in the blue-flowered form. The genus 

 Primula is absent ; but there are six genera of the 

 allied family, Myrsinaceae, one of which, ^giceras, 

 is a constituent of the mangrove forests of the sea- 

 coasts and tidal creeks. 



A Handbook of Laboratory Glass-blowing. By 

 B. D. Bolas. Pp. vii+io6. (London: George 

 Routledge and Sons, Ltd. ; New York : E. P. 

 Button and Co., 192 1.) 35. 6d. net. 

 Although it is without doubt desirable to have a 

 professional glass-blower attached to a physical 

 or chemical laboratory, a knowledge of simple 

 glass-blowing is essential to students generally.! 

 While Mr. Bolas carries the subject rather furtherj 

 than the simple repair of apparatus, for hel 

 describes also the construction of glass laboratory! 

 ware, he gives clear and concise instructions fori 

 the manipulation of glass which should prove! 

 of considerable serv^ice to laboratory workers.! 

 Most of the operations are illustrated by clear linel 

 drawings of the various stages through which thej 

 material passes before it assumes its final form. 



