I9I3.] EXCHANGE VALUE OF METEORITES. 519 



Diablo as unity. It is thus not a money value, but an exchange 

 yalue index. 



In the next chapter is a group classification of all meteorites 

 known in 1897, giving figures under U (original weight), N, B and 

 W for each fall. In the determination of U and A'' and in their 

 discrepancies, many uncertainties arise, and on this account two 

 values are given for some falls and other values are omitted 

 altogether. In some of his value-pairs Wiilfing indicates the less 

 probable of the two within parentheses. Again where both values 

 are doubtful, they are enclosed in brackets. 



In 1899, the late Professor E. Cohen, author of many important 

 scientific studies of meteorites, published a table* collating the 

 Wiilfing exchange values with the trade prices of eight dealers. For 

 each fall, he showed in one column the lowest dealer's price in 

 pfennigs, then the highest, and in a third column the medium or 

 average of all prices. The Wiilfing exchange values (X 13) he 

 gave in a fourth column. This table afforded a basis for comparing 

 the theoretical exchange value with the actual market price of each 

 fall. 



Professor Cohen called attention to the fact that previously no 

 account had been taken of the area of a slice, maintaining that this 

 feature should receive full consideration in estimating the value. 

 Examining the tabulation, he pointed out that about one third of 

 the falls compared, showed large variations between the medium 

 trade price and the Wiilfing exchange value. Most of the relativelv 

 low figures of Wiilfing he ascribed to the fact that although the 

 masses are very large, they are securely held against partition by 

 sale or exhange. On the other hand, many of Wiilfing's relatively 

 high figures are due to the fact that they belong to the rarer groups, 

 which, according to Wiilfing's critic, come on the market only by 

 chance, and with no fixed value. Finally Cohen stated that it is 

 not the number of owners which affects the value of a particular 

 fall, but the number of owners who are able to part with some of 

 their holding, a collector of pieces under 15 to 30 grams being 



4 "tjber den Wiilfing'schen Tauschwerth der Meteoriten im Vergleich mit 

 den Handelspreisen," Mitth. aus dent naturwiss. Ver. fiir Neu-Vorpommern 

 u. Riigen, 1899, XXXI., pp. 50-62, Greifswald. 



