July 8, 1909J 



NA TURE 



structure and mining history of all the chief goldfields 

 of the world. This part of the work occupies .;j4 

 pages. The goldfields are classified by continents. 

 Those of Europe are described first, and in proportion 

 to their economic importance receive longer notice than 

 those of Australia and South Africa. The longest section 

 is that on the goldfields of North America. Each field 

 is noticed separately; the descriptions are necessarily 

 short, but they are concise, and are accompanied by 

 useful reference to recent literature. The minor fields 

 are described at relatively greater length than tlie 

 others; and thus Kalgurli, with its " Golden Nile," is 

 dismissed in four pages, including a full-page map 

 and another figure. This distribution of space is, 

 however, probably the most useful, as the less-known 

 fields are often very instructive and their literature is 

 less accessible. The author has travelled extensively, 

 and his accounts of many fields have the advantage 

 of personal knowledge and original information. The 

 descriptions of the fields are therefore inevitably of 

 unequal merit. 



Among the most interesting sections are those on 

 the mines of New Zealand — though as a New 

 Zealander, it is strange that the author places Reefton 

 in Westland, and spells the name of the founder of the 

 New Zealand school of mining geologists Uhlrich — of 

 Queensland (the author was once on the staff of its 

 Geological Survey), and of Mysore. The historical 

 Introduction to the Mysore gold mines is of especial 

 interest, and the author rejects the view that the 

 ancient mines there can have been those from which 

 Solomon and the Phoenicians obtained their supplies 

 of gold. Dr. Maclaren remarks that India was then 

 a civilised State, which needed more gold than it pro- 

 duced ; and the Israelites could only have obtained gold 

 there by barter, for which they had nothing to offer. 

 This conclusion, therefore, strengthens the view that 

 the Ophir of the Phoenicians must be in southern 

 Africa, and that the gold probably came from the 

 prehistoric mines of Rhodesia. 



Dr. Maclaren's account of the separate goldfields is 

 preceded by an introduction on the chemical and 

 physical properties of gold, on natural and artificial 

 compounds of gold, and on the theories of the forma- 

 tion of gold ores. The speculative section of this in- 

 troduction is remarkable for the author's advocacy of 

 somewhat extreme positions. Thus he denies the 

 origin of any important ore deposits by other agencies 

 than meteoric waters. He admits that there may be 

 some magmatic water ; but even when he allows that 

 the gold is due to magmatic emanations, he holds that 

 the water in which it is dissolved comes from a super- 

 ficial source. He also holds to the once popular view 

 that alluvial gold and gold nuggets are formed by 

 growth in situ in the gravels from percolating gold- 

 bearing solutions. He defends this view especially on 

 the ground of the crystalline character of much alluvial 

 gold ; he quotes competent authorities who deny this 

 fact, but affirms it from his own experience. The 

 author does not explain why, on this precipitation 

 theory, nugget formation is so local, and why the 

 nuggets are so constantly found just below the out- 

 crop of reefs containing nuggety patches of gold. He 

 NO. 2071, VOL. 81] 



admits that the nuggets of Western Australia are 

 derived from gold-quartz veins, and the evidence for 

 the similar origin of the nuggets from Victoria — 

 which contains the most famous of nugget-yielding 

 goldfields — seems to the writer overwhelming. 



Another doubtful hypothesis advanced by the author 

 is the absence of any undoubted, valuable pre- 

 Cretaceous placer deposit. He rejects, or quotes with 

 apparent approval those who reject, the alluvial origin 

 of the gold in various Mesozoic, Palseozoic, and Archsean 

 conglomerates and sedimentary deposits ; and he then 

 argties that the absence of pre-Cretaceous detrital gold 

 is due to the rocks having been lowered into a zone 

 saturated with alkaline waters which removed the gold 

 in solution and re-deposited it in veins. 



Though many geologists may be disposed to differ 

 from the author in some of his conclusions as to the 

 formation of gold ores, they will be no less grateful 

 to him for this valuable and trustworthy summary of 

 the voluminous gold literature issued during the past 

 twenty years. J. ^^ • G. 



SWINE IN AMERICA. 



S-viiic in America. A Td-xt-book for the Breeder, 

 Feeder, and Student. By F. D. Coburn. Pp. 

 XV + 614. (New York : Orange Judd Co. ; London : 

 Kegan Paul and Co., Ltd., igog.) 



JUST as it might be said of the British fat bullock 

 that he has followed the turnip, so it might be 

 said of the American fat hog that he has followed the 

 corn, i.e. Indian corn. In the United States there 

 are 56 millions of swine — there are only three and a 

 half millions in the United Kingdom — and far more 

 than half these are to be found in the great corn States 

 which are drained by the Mississippi and its tribu- 

 taries. Iowa comes first with 8J millions, and Illinois 

 and Nebraska next with 43 and 4i millions. Alto- 

 gether there are about eighty million pounds' 

 worth of swine in the United States, the duty of which 

 it is to convert corn and other crops and by- 

 products into more marketable commodities, and 

 eventuallv to feed, not only the Americans, but also 

 some part of the industrial population and the armies 

 and navies of the rest of the world. 



.\n industrv so vast can do with many a text-book, 

 and Mr. Coburn has produced one for those who 

 breed, rear, and feed the raw materials for the 

 American packing houses. Many experiments have 

 been carried out in the States on the rearing and 

 fattening of swine, and the gist of these is embodied 

 in Henry's " Feeds and Feeding," which, however, 

 is a book dealing rather with principles than with the 

 details of management, and a book, therefore, for the 

 student rather than for the farmer. Mr. Coburn 's is 

 a farmer's book. He has collected Henry's and many 

 other data, and set them forth in such a way that the 

 nutritive effect and economic value of every important 

 feeding stuff and by-product is dealt with, whether 

 these foods are fed separately or with others. The 

 effects of bulky and succulent foods and of concen- 

 trates, and of these consumed separately and jointly, 

 are fully considered. Thus, for instance, a farmer 



