226 



SCIENCE. 



[N. S. Vol. XXIII. No. 580. 



condensed statement of present beliefs and 

 theories as to the occurrence and formation of 

 ore deposits. It is marked by good common 

 sense. Iron, copper, gold and silver, silver- 

 lead (a genetic group) follow roughly in the 

 order of their importance. Then follow very 

 brief statements regarding a host of minor 

 metals, the sources, distribution, uses and 

 production of which are briefly given, with 

 valuable lists of references. 



Throughout the book one can often see 

 wheTe one might wish more added, but there 

 is little to correct or omit. Each teacher will 

 naturally supplement as circumstances de- 

 mand. A few comments on matters in the re- 

 viewer's province may be pardoned. 



The occurrence of the copper ' beneath 

 higher ground ' is the weakest of the argu- 

 ments for the role of descending waters and 

 lateral secretion in the formation of the Lake 

 Superior copper deposits. Indeed, the fact it- 

 self is rather questionable. The reviewer 

 probably misled Dr. Ries by mentioning it 

 first in the paper cited by him, but that was 

 done to attract local interest to the matter. 

 The progress of developments seems to show 

 that the prevalence of mines on higher ground 

 is mainly due to ease of discovery. 



So, too, the reference (p. 290) to electrolytic 

 refining of Lake Superior copper needs to be 

 qualified. That has not been the normal 

 method of treating these deposits of native cop- 

 per, though very unfortunately, as it seems to 

 me, western copper has been brought into the 

 district and treated electrolytically. There 

 are certain grades of concentrates from the 

 Quincy and Calumet and Hecla which it pays 

 to treat electrolytically to save the associated 

 silver, and there has been a little copper, like 

 the Mohawkite from the Mohawk Mine, where 

 the amount of arsenic and nickel was enough 

 to warrant electrolytic treatment, together with 

 the product of the impure slags and various 

 drippings and skimmings and oxidation prod- 

 ucts that go to the cupola. But the vast bulk 

 of genuine lake copper has not been handled 

 electrolytically. It reduces the toughness a 

 little. 



Recent and up to date as the book in general 

 is, it is not recent enfgigb' to recognize the 



report of the joint committee on the Lake 

 Superior stratigraphy' and the triple division 

 of the Huronian. Nor is the statement that 

 the ' archean iron-bearing formations are un- 

 productive' true so long as the Vermillion 

 Range is left in that variously delimited 

 group. 



A word of especial commendation should be 

 given to the illustrations. Numerous cuts 

 and small but clear maps of distribution are 

 inserted in the text, which is printed on un- 

 glazed paper of good quality, while the half- 

 tones are well brought out by being generally 

 inserted on glazed paper. This is easier on 

 the reviewer's eyes, and probably easier on the 

 binding than the use of glazed paper through- 

 out as in Chamberlin and Salisbury's new 

 ' Geology.' Comparatively few are expressly 

 drawn for the work, but that is no criticism, 

 for they are recent (almost all of the last ten 

 years), clear and pertinent. In fact it is a 

 positive favor thus to skim the cream of the 

 various state and special reports. One could 

 hardly ask for more, except perhaps a few 

 diagrams of production such as are so valu- 

 able a feature of Branner's syllabus. 



The proof-reading seems exceptionally clean, 

 but a few errors of sense have been obtained, 

 mainly from the author, and are appended." 



^Journal of Geology, 1905, p. 104. 



^ Errata : Page 15, fifth line from bottom, read 

 (1, 3) instead of (13) . Page 22, eighth line from 

 top read 10,000,000,000 instead of 10,000,000, 

 Page 28, twelftli line from below, read 250 in 

 stead of 150. Page 36, reference 21, read ' Coosa. 

 Page 38, last line, read 1863 instead of 1883 

 Page 72, sixth line from top, omit ' per cent, 

 after 20. Page 115, analysis of chalk should have 

 4.42 SiO.. Page 142, ninth line from top, plate 

 reference should be placed after Alabaster on line 

 above. Page 163, line 10 from below, insert 

 natural before abrasive. Page 202, SiO., of first 

 analysis, should be 63.07 instead of .07. Page 

 286, line 19 from top, read ' 2,000 or 2,500.' Page 

 306, Fig. 62, pattern for Potosi limestone, is wrong 

 in legend; the Potosi limestone is represented by 

 upper one fourth inch of left and right end of 

 section. Page 329, fiftli line from bottom, read 

 ' the metals.' Page 429, under Michigan, insert 

 iron ores, 256, 261, 265. Page-434, under Texas, 

 take out '^'iller's'jearth,' 175. 



