418 Chronicles of Science. [July, 



Mineralogy," read before the American Academy of Sciences.* The 

 author advocates the extension of mineralogical science, so as to 

 embrace the entire range of inorganic substances whether occurring 

 native, or produced by the chemist's skill; and then, passing to the 

 great problem of classification, discusses the objects of a " natural 

 system " and the basis upon which it must be founded. " Such a 

 classification," says Dr. Hunt, " will be based upon a consideration 

 of all the physical and chemical relations of bodies, and will enable 

 us to see that the various properties of a species are not so many 

 arbitrary signs, but the necessary result of its constitution." Not 

 until this shall be accomplished, at least in a measure, can 

 mineralogy expect to take equal rank with the kindred sciences of 

 systematic botany and zoology. 



Mr. T. Davies, of the British Museum, calls attention to the 

 occurrence in Cornwall of the rare oxide of antimony called Senar- 

 montite. The mineral occurs in opaque octoheclral crystals lining a 

 cavity in a specimen of Jamesonite from Endelhon.| 



Every mineralogist is familiar with the calcite-shaped crystals 

 from the Fontainebleau sandstone. Somewhat similar groups of 

 crystals have recently been found in a valley near Heidelberg, and 

 have been described by Professor Blum.J They occur in the centre 

 of certain irregularly-shaped sandstone nodules, which have been 

 weathered out from the Bunter Sandstone of the surrounding rocks. 

 The crystals present the scalenohedral form of calcite, but consist 

 entirely of sandstone. Professor Blum supposes that the calc-spar 

 originally crystallized in the midst of loose sand, which afterwards 

 concreted around the crystals, forming a solid mass ; the enclosed 

 calcite being subsequently removed by the percolation through the 

 external sandstone of water holding carbonic acid in solution, and 

 its place supplied by the deposition of silica, which had served as a 

 cementing medium to the sandstone. Occasionally a cavity exists 

 between the investing and the enclosed sandstone; but originally 

 the sandstone must have closely covered the calcite, since it bears 

 the sharp impression of its crystals ; the space, therefore, between 

 the kernel and its shell shows that the quantity of silica introduced 

 was insufficient to entirely replace the carbonate of lime which had 

 been removed. 



Dr. How's " Contributions to the Mineralogy of Nova Scotia " 

 are continued in the ' Philosophical Magazine ' for May.§ Several 

 analyses are given of certain dark-coloured pebbles found at Corn- 

 wallis, King's Co.; and although the results show that the com- 



* ' Silliman's American Journal of Science and Arts,' March, 1867, p. 203. 

 t ' Geological Magazine,' April, 1867, p. 192. 



X Bunter Sandstein in Formen von Kalkspath. Leonhard's Jahrbuch, 1867. 

 Heft III., p. 320. 



§ 'Phil. Mag,' May, 1867, p. 336. 



