266 



NATURE 



[July i8, 189: 



various oils from cruciferous and other seeds which now 

 pass under the name of " rape oil." 



In the eleventh chapter, which extends over 273 pages, 

 the natural oils, fats, and waxes are systematically 

 arranged and separately described, a ver>' excellent and 

 most valuable feature being a series of tables appended 

 to the description of each oil, fat, and wax, giving the 

 physical and chemical constants (1) of the oil itself, (2) of 

 the mixed fatty acids, and 13) of the wax alcohols. It is 

 a pity these tables were not arranged so as to be readable 

 without having to turn the book half round, which might 

 have been done by cutting each t.ible in half No less 

 than 106 oils, &c., are thus separately described, and 

 their physical and chemical constants are collected and 

 arranged in about 175 tables. The usefulness of these 

 tables to the analyst cannot be over-rated, though it does 

 not appear to be clear in all cases by what method the 

 melting and solidifying points of the fatty acids were 

 determined. The "saponification values" arc expressed 

 per mille, and the iodine and other values per rent., but 

 there is no reason why the simpler plan of expressing all 

 the quantitative values in percentages should not be 

 adopted. The section on butter fat, the analysis of which 

 was the first to be placed upon a scientific basis, occupies 

 twenty-three pages. 



In chapter xii. the analysis of the raw materials and 

 products of the fat and oil industries is treated, and in 

 the concluding chapter some examples of the interpre- 

 tation of results arc given ; but space does not admit of 

 further reference. 



This book is unique : the analyst will find in it prac- 

 tically all the available information upon the subject up 

 to date, with full references to the original papers ; and it 

 will increase the author's already high reputation. 



L. Arch BUTT. 



TRACES OF A DELUGE. 



On Certain Phcnomeiui bclongini; to the Close of the 

 last Geological Period, and on their bearing upon the 

 Tradition of the Flood. By Joseph I'rcstwich, D.C.L., 

 P'.R.S., &c. (London : Macmillan and Co., 1895.) 



H.\I) the story of the Deluge a foundation in fact; 

 in other words, is it a record of some inundation 

 which affected a considerable area of the earth's surface ? 

 This is the question which I'rof I'restwich sets himself 

 to answer in the small volume before us — a volume 

 which combines a paper read to the Victoria Institute 

 with some of the material communicated to the Royal 

 and the Geological Societies. 



In the south of England, especially in the neighbour- 

 hood of the coast, a drift is often found, varying in 

 thickness from a few inches to a few feet, which consists 

 of angular fragments of rock with loam derived from 

 adjacent higher ground, and lies on the slo|)es of the 

 hills and at the bottom of the valleys. Frequently it is 

 absent, but where hollows occur in the surface of the 

 underlying rocks, it has accumulated in greater quantities, 

 and occasionally even exceeds eighty feet in thickness. 

 In some localities it rests on an old raised beach, and 

 is banked up against a buried sea cliff; in others it fills 

 up fissures in ihc rocks. In the last case it frequently 

 NO. 1342, VOL. 52] 



contains the bones of mammals, many of them now 

 extinct — at any rate in Britain. These are neither 

 worn nor gnawed, but are commonly broken and split. 

 Its fossils, almost without exception, are of terrestrial 

 origin. Similar deposits occur in the Channel Isles and 

 on the French coast, and in many places around the 

 Mediterranean, not to mention others. What is the 

 origin of this " rubble drift," " head," osseous or fissure 

 breccia .' 



Prof. Prestwich refers all these deposits to one epoch 

 of verj- limited duration. He supposes that there was 

 a rather widespread subsidence, amounting, in some 

 places, to a few hundred feet, during which the sea 

 overflowed the lower land. This was sufficiently rapid 

 to make the in\ading water muddy ; then, before the 

 marine molluscs had time to establish themselves in the 

 new territory', the land was upheaved by ierks (^with 

 intervening pauses). These sudden disturbances of its 

 bed set up currents in the sea, strong enough to sweep 

 heavy debris, and even largish blocks of rock, from the 

 higher to the lower ground, and to precipitate the 

 material into any open fissures. By this tumuUuous 

 action the bones of the terrestrial mammals which had 

 been drowned by the submergence would be dispersed 

 and shattered, and it explains, in his opinion, all the 

 phenomena better than any other hypothesis. .As man 

 was living at the time, it gave rise to llic tradition of 

 the Flood. 



.\n adequate discussion of Prof Prestwich's hypothesis 

 is impossible in our limited space ; but we may be per- 

 mitted to remark that it is not free from serious difficulties. 

 Many geologists would dispute the assumption that these 

 deposits all belong to one and the same epoch. Others 

 will doubt whether the sudden upheavals, which he 

 postulates, would be adequate to produce currents, 

 capable of moving the larger debris, or whether the 

 earth movements would suffice, as he supposes, to m.ike 

 gaping fissures. Some will think that he hardly ap- 

 preciates the effect of " cloud bursts," such as may be 

 seen in many mountain and even lowland districts of 

 Europe, in transporting ddbris very similar in character 

 to the ''head." It is admitted that since this was de- 

 posited denudation has wrought some changes in the 

 contours of the country, and this may exjjlain the apparent 

 isolation of some patches of the "head," whether it fill 

 fissures or cap tabular hills. In several cases the ordinary 

 explanation of breccias (admitting as an adjunct the 

 action of snow) seem to us more simple than that pro- 

 posed by Prof Prestwich, and his mode of accounting 

 for the abundance of hippopotamus bones at San Ciro, 

 near Palmero — that as the land sank they were embayed 

 between its precipitous face and the advancing sea, and 

 at last were drowned can hardly be called probable. 

 Lions and hy;enas might have jjcrished in that way, 

 but the hippopotamus seems far from helpless in the 

 water, ;md is likely to have saved itself 



We think, then, that Prof Prestwich's hypothesis will 

 be received with some scepticism ; nevertheless, it de- 

 mands careful consideration as an attempt to solve a 

 very difficult problem, which is put forward by one who 

 may now be termed the Nestor of British geologists, and 

 who has paid especial attention to questions of this 

 nature. 



