388 Scientific Intelligence. — Mineralogy. 



and new soil is turned up from the pit, and mixed with the su- 

 perior soil ; this, as well as the deep stirring of the ground, ren- 

 ders the vegetation more luxuriant — Communicated by P. Mat- 

 thew, Esq. author of Treatise on Naval Timber. 



MINERALOGY. 



3. Chiastolite. — According to Dr G. Landgrebe of Marburg, 

 as stated in Schweigger-Seiders Journal, H. 5. 1830, this mi- 

 neral contains silica 68.497; alumina 30.109; magnesia 1.125 ; 

 water and carbon 0.269; = 100.00. The remarkable structure of 

 this mineral is well known ; we may add from Weiss that many 

 salts, as muriate of soda for example, when dissolved in°'fatty 

 substances, as butter for example, and again crystallized from 

 them, exhibit in their crystals the same structure as observed in 

 chiastolite. 



4. Magnetic Reaction of Platina. — In a piece of Russian 

 platlna the size of a walnut, Gtibel detected the two magnetic 

 poles. Its magnetism was so powerful that a middle-sized 

 needle was attracted by it, and a magnetic needle was, at a cer- 

 tain distance, set in motion by it. Many similar pieces of pla- 

 tina, from the size of a hazel nut to that of a hen's egg, in the 

 collection of the Imperial Mining Academy of St Petersburg, 

 exhibit similar properties. 



5. Olizoner Zircon of Breithaupt. — Colour pitch or brown- 

 ish black, seldom dark grey. Occurs in rolled pieces and in 

 hyacinth crystals. Lustre vitreous. Opaque. Fracture con- 

 choidal. Cleavage scarcely discernible. Hardness equal that 

 of orthoclase felspar. Specific gravity from 3.987 to 4.032. 

 From Island of Ceylon. The low degree of hardness, and the 

 specific gravity, render it probable that it forms a distinct 

 species. 



6. Specific gravity of Datolite. — Some late writers have 

 stated the specific gravity of datolite as high as 3.3. Brei- 

 thaupt, however, finds the generally given specific gravity to be 

 the correct one. In two varieties of datolite he found the spe- 

 cific gravity to be 2 9298, and 2.9911. 



7. Professor Jamesbii's Manual of Mineralogy and Geolo- 

 gy. — This work, which will form one or two compendious vo- 

 lumes, is now in the press. 



