August 20, 1915] 



SCIENCE 



249 



end of each year, but at the end of a stated 

 period he receives his original capital back 

 again in full. There are, however, some forms 

 of investment where the original capital is not 

 returned to the investor. In such cases provi- 

 sion must be made for the redemption of the 

 capital by setting aside some portion of the 

 annual income as a redemption fund. A mine 

 is a typical form of investment," etc. Now 

 there is very serious objection to all this great 

 detail and clearness on a subject which is not 

 at all clear. You can not value a mine prop- 

 erly unless you know the price at which the 

 product will be sold, and even then unless you 

 know the amount of ore the mine contains, and 

 the difficulty or ease of mining it. The im- 

 pression is given that the mine will run out; 

 what justification have we for such an im- 

 pression? In the case of porphyry deposit of 

 copper, where the total tonnage can be prop- 

 erly estimated, we can perhaps undertake to 

 find some value of a mine. In the case of vein 

 mines, however, there is no such possibility. 

 Some mines have been worked for hundreds 

 of years and are apparently richer to-day than 

 ever before (Tintos, for example). 



Moreover may it not be the rule rather than 

 the exception that capital is not returned? 



The average price level has risen so rapidly 

 in the last fifteen years that a person who put 

 his money out on loan fifteen years ago and 

 received it back now, would have, in purchasing 

 power, not more than one half to two thirds of 

 that which he loaned. For the author, he would 

 have his original capital back in full. From 

 an economic point of view, he would have a 

 very highly depreciated capital returned to 

 him. He would be no better oS than if he had 

 invested in a mine, that was a mine, fifteen 

 years ago — probably much worse off. 



We realize fully that it is not in the prov- 

 ince of the elementary book which Skinner has 

 written to go into every sort of detail in re- 

 gard to investments, but it does seem to us 

 as though a short account of the bearing of 

 the major economic phenomena upon invest- 

 ment should be included. 



Edwin Bidwell Wilson 

 Massachusetts Institute of Technologt 



Prehistoric Man and His Story. By Pro- 

 fessor G. F. Scott Elliot. London, Seeley, 

 Service & Co., 1915. Pp. 16, 398; illustra- 

 tions and diagrams 64. 



This is the second book by British authors 

 on the general subject of prehistoric man to 

 appear in 1916. The present volume however 

 differs so widely from the one by Sollas that 

 there is room for both. Besides the work by 

 Elliot includes chapters on the neolithic period 

 and the age of metals. Both agree in devoting 

 much space to a comparison between prehis- 

 toric archeology and the ethnology of living 

 primitive races. 



In the initial chapter, on the preparation of 

 the earth, it is pointed out that remains of 

 lemurs have been found in the Eocene of North 

 America and Europe, and the question is 

 raised whether a " generalized lemur-monkey- 

 man " could have lived at the time. If so he 

 could have wandered all over the northern 

 hemisphere from San Francisco to New Jersey, 

 also from England to Japan. The climate was 

 warm but not oppressively hot. As to food the 

 land would have been considered a paradise 

 by any living primitive race. The Miocene 

 descendants of the common Eocene ancestor 

 would have had to contend with carnivorous 

 animals. 



A discussion of " Homosimius precursor" 

 naturally leads to the question of eoliths. 

 These are flints of various ages which " have 

 certainly been struck or chipped in an un- 

 usual way." While it is still not possible to 

 say whether (or not) they were utilized by 

 man, the author believes the evidence in favor 

 of the artifact nature of some of the eoliths is 

 more weighty than that to the contrary. 



The next three chapters are devoted to miss- 

 ing links, the human body, and the limit of 

 humanity. As one might expect, comparison 

 of the brains of apes and of men shows con- 

 siderable differences; on the whole, however, 

 the general likeness is more striking than the 

 contrasts. The differences between man and 

 his Pliocene ancestor is " clearly in brain 

 rather than in eyesight or manual dexterity." 

 The author is a monogenist and also ad- 

 heres to the orthodox belief that the Old 



