PERMEABILITY OF HIGHLY-HEATED IRON BY GASES. 277 



I have established the fact of the presence of a flint instrument, 

 characterised by workmanship of considerable finish. 



To sum up : three principal facts are at the present day registered 

 and grouped together, as the fruits of long and persevering researches, 

 carried on by a great number of observers. The man of the earliest 

 ages reveals himself by his works ; man is associated by his relics with 

 extinct races ; lastly, man makes himself the revealer of his own exis- 

 tence by himself reproducing his own image. 



For a long time people pretended to deny the presence of human 

 skill in the rude efforts of the first stone instruments ; at a later date 

 they were forced to disparage the value of the intentional fractures and 

 incisions observed in so large a number of bones belonging to the 

 horse, the ox, or the reindeer. But now the bones are turned into 

 numerous instruments ; animal figures are found reproduced from the 

 spoil of themselves ; the living reindeer has served as a model for the 

 carving of a dagger handle stuck fast in an osseous breccia. Nay, 

 still further, the statuary of the first ages has reproduced the human 

 species in a sort of lewd idol, the material of which belongs to the 

 skeleton of the elephant. 



" I have attempted to retrace here the most conclusive facts ; to my 

 eyes the decision is manifest. I wish to propose one last question 

 which I shadowed forth before. Should we separate the epoch of the 

 reindeer, which I take here as the type of the migration of species, 

 from the fauna of extinct races, with which on the other hand the rein- 

 deer is now found associated ? In the double hypothesis of the asso- 

 ciation or the superposition of the fauna, man is revealed by his pre- 

 sence or by his work. The future is not far distant which shall teach 

 us the more or less intimate correlation of these two stages. It is to 

 my mind the only really serious difficulty which at the present day 

 surrounds this interesting question. 



T. M. 



ON THE PERMEABILITY OF HIGHLY-HEATID IRON BY GASES. 

 Translated from the ' Comptes Rendus,' Feb. I5th, 1864. 



NOTE, BT M. h. CAILLETBT. 



In a late commuuicatioia te the Academy, MM. Sainte Claire and Troost made 

 known the very curious phenomenon that iron at a high temperature is perme- 

 able by oxygen. It will also be remembered, that an iron tube, filled with 



