OF REICHERT's H.EMOMETER. 21 



between the small number, the simple character, and the rapid 

 execution of the proceedings demanded in Hsemometer measuring 

 on the one hand, and on the other, great number of rules 

 and instructions which I have given above. Since all should be 

 alive to the importance of the cautionary rules for the correct 

 execution of these proceedings, it cannot be otherwise than that 

 every one will find in these instructions much that he already 

 knows or considers self-evident, but it may also be that each will 

 find something new or something which he himself would not 

 have arrived at. The purpose in giving at length these rules is to 

 enable each possessor of a Hsemometer to use it without fruitless 

 attempts. In the very beginning he should make useful and 

 reliable measurements. The purpose could be fully carried out 

 only by a complete enumeration of all possible rules that might be 

 considered. 



Cbemietri? anb palaeontology. 



A NOVEL appHcation of Chemical Analysis was recently ex- 

 plained by A. Carnot at the Paris Academy of Sciences. 

 He has endeavoured to fix the age of prehistoric human 

 remains by noting the progressive diminution of fluorine in the 

 fossil bones of successive geological ages. Representing the pro- 

 portion found the oldest specimens as i, that of the tertiary remains 

 would be indicated by o'64, of the quaternary by o'35, and of the 

 more recent bones by 0*05 or o'o6. An opportunity of testing 

 the value of these figures was afforded by the discovery of a human 

 tibia at Billancourt (Seine), near some animal remains of the 

 quaternary period. There was a difference of opinion as to 

 whether it was of the same period as the other fragments or not, 

 but since on analysis the proportion of fluorine in the animal 

 bones was found to vary from 0-469 to 0*578, as compared with 

 0*066 in the human tibia, the more recent origin of the latter was 



regarded as established. 



— Coinptes Reiidus. 



