W. M. Hut chin gs — Willemite in Slag. 31 



The only exception, perhaps, to this is the lignitic deposit at Soulac, 

 with Elephas meridionalis, which seerus to be a remnant of the 

 Upper Pliocene (Arnusien). 



The " Sable des Landes " predominates everywhere between the 

 Gironde and Garonne, and the sea. Its exact age, as we have seen, 

 is not very clear, but it is older than the coast alluvium and dunes 

 of the department. 



The best centre, perhaps, to study the Bordelais Miocenes is the 

 village of Saucats. Although it is only twelve miles from Bordeaux, 

 this place is not very accessible, and to go to it and return to 

 Bordeaux every day wastes much time. The village inn might 

 afford worse accommodation. There is absolutely nothing to see in 

 regard to sections in the immediate neighbourhood of Bordeaux 

 itself, nearly all the classical Miocene sections being within a few 

 miles of Saucats. Another good centre is Bazas. 



In conclusion, I must express my hearty thanks to Professor Fallot 

 for his kindness and assistance rendered during my visit to the 

 Bordelais, and for giving me permission to study the fossils of the 

 Tertiary basin of the south-west of France contained in the splendid 

 private collection of the Faculte des Sciences under his charge. 



VII. — Note on an Occurrence of Willemite in a Slag. 

 By "W. Maynard Hutchings, Esq. 



CRYSTALLIZED silicate of zinc, Willemite, has frequently been 

 observed, artificially formed, in metallurgical operations, but 

 so far as I am aware no case has been recorded of its crystallizing 

 out from a magma of slag of a different composition, of which the 

 zinc silicate formed only a comparatively small proportion. 



Willemite has been observed in crusts of silicate formed in zinc- 

 muffles during the working of zinc-ores. Stelzner and Schulze 

 describe 1 crystals formed in this manner in cavities in the retorts in 

 which they studied the formation of zinc-spinels. I have myself 

 obsei'ved the mineral in very perfect rhombohedral crystals, 

 occurring in cavities of firebrick supports of retorts, in such a 

 manner that their formation was evidently due to zinc vapour 

 passing through the material of the retorts and oxidizing in contact 

 with the siliceous material of the firebrick. Ebelmen formed a 

 crystallized zinc silicate by fusion of silica and zinc oxide in boric 

 acid, but this product does not appear to have been proved to be 

 crystal! ographically Willemite. 



The occurrence I wish to record is in a slag produced in large 

 quantity during the smelting of certain lead-dross containing zinc 

 oxide in a small blast-furnace. The resulting slag contains 12 — 15 

 per cent, of zinc oxide, the remainder consisting almost wholly of 

 a basic ferrous silicate. 



In cavities in the large slag-balls, after solidification, large 

 numbers of slender acicular hexagonal crystals were noticed. They 



1 Jahrbuch fur Min. Geologie und Talaontologie, 1881, I. 





