On the Belgian Whetstones. By Rev. A. Rénard. 281 
well as petrographic, I am inclined to admit that the bands or 
zones of the whetstone are real layers imbedded in the Cambrian 
formation of the province of Liege, and that they were deposited in 
the same way as the adjoining slates, in the Cambrian sea, with the 
proper characteristics that make them differ, from the very moment 
of their deposition, from the sediments that furnish phyllades. 
Without denying that a metamorphic action has affected this mass, 
in a general way, I am inclined to think that this phenomenon 
alone has not been able to effect the concentration of the mineralo- 
gical elements that constitute the whetstone. 
In conclusion, I add that this rare rock of Salm and the neigh- 
bourhood presents a mineralogical composition such as I have never 
found in any of the rocks ordinarily designated as razor-stones. I 
may be permitted here to thank MM. Richter and Dana for the 
information and specimens of whetstones they have forwarded to me. 
