236 



THE GEOLOGIST. 



successfully lias the cutting-edges of tlie crystal placed at right angles to 

 each other, and passing through a point of intersection made by crossing 

 the edges. A polished diamond, however perfect may be its edges, when 

 pressed upon the surface of the glass, splinters it with the slightest of pres- 

 sure ; but with the natural diamond the most accurate lines are produced 

 on glass, and their surfaces are so finely burnished that if, ruled close to- 

 gether, they decompose light and afford the most beautiful prismatic effect, 

 — all the colours of the rainbow flash from them as from the silvery inte- 

 rior of a pearl-oyster shell. Diamonds are also employed as drill-points to 

 perforate rubies, and bore holes in draw-plates for fine wire, and also for 

 drilling in hard steel. Some inquiries have been made recently in regard 

 . to using them as a substitute for steel picks in dressing millstones. We 

 apprehend that they are altogether too expensive for this purpose at pre- 

 sent ; but if some of our inventors would make the discovery of manufac- 

 turing diamonds as cheaply as we make charcoal, which is of the same 

 composition, we might be able to recommend them to our millers. The 

 coke obtained from the interior of gas retorts, in many cases, is found so 

 hard that it will cut glass ; but as its point endures but for a short period, 

 it cannot be made available as a substitute for the natural diamond for 

 such purposes in the arts. A circle of rough diamonds has lately been 

 used on a hollow cylindrical auger for boring into hard rocks. 



Mammalian Remains. — Bones of the following Mammalia were re- 

 corded by M. Torchi in a letter read before the French Geological Societv, 

 6th April, 1846 (Bull. Geol. Soc. Fr. vol. iii. p. 440-442), found in different 

 strata of the sub-Apennine deposit at Imola, in Romania. Elephant found 

 at Ruisseau de Bergullo in "sable quarzeuso-calcaire conchy lifere " (ma- 

 rine shells) ; Elephas primigenius, Ruisseau Pratella, in " terrain quar- 

 zeuso-calcaire ; Elephant, Vallee delle Grazie, Ruisseau Pratella, Ruisseau 

 Bergullo, in the same sand ; Rhinoceros, Ruisseau Pratella, in the same 

 sand : Hippopotamus, Ruisseau Pratella, Ruisseau delle Grazie, in the 

 " derniere assise de laMarne fleuve," sub-Apennine ; Equits, Ruisseau Pra- 

 tella ; Cervus, Mont Castellano, Ruisseau Pratella, Fleuve Santerno, in the 

 sand ; Ruminant ; Volatile, Ruisseau de Goccianello, Ruisseau Pratella, 

 in the sand— S. J. M. 



Nebeaska Salt Basins. — About 50 miles west of the Missouri river 

 there is a remarkable salt region covering about 1500 acres. It consists 

 of four basins depressed several feet below the common level. The bottoms 

 of the basins are composed of black mud covered over in warm dry 

 weather with a thin stratum of salt, causing them to look like fields of 

 snow. The salt is collected in scrapers, and occasionally a man will scrape 

 ii]) a waggon-load a day. In and about all those basins there are numerous 

 strong brine springs, and farmers come from miles around to boil and 

 scrape salt for their use. It is of excellent qualit} 7 , and the cr} r stals are 

 large and clear, like those of the solar salt of S3a-acuse, New York. 



Nuts of Cortlax^eje, Isle of Wight. — In the ' Euumeratio Rerum 

 Naturalium quae in Musseo Zannichelliano asservantur,' Yenetiis, 1736, is 

 the following entry : — 



" Tabula quinta. 14. Nuces Corylacese effossa? in insula Vecti, Anglia?." 

 The same entry occurs also in the earlier catalogue of Zannichelli's col- 

 lection, entitled * Ex Natures Gazopliylaeio penes Joannem Hieronynium 

 Zanniclielli.' Yenetiis, 1726. — S. J. Mackie. 



