Mr. Levy on a New Mineral Species. 



221 



second satellite L 12 18 30 M. T. at Greenwich, 



Feb. 9th. Immersion of Jupiter's I 2 5i 00 M. T. at Bushey. 



second satellite I 2 52 21 M. T. at Greenwich. 



These observations were made with one of Mr. Dollond's 5 feet 

 achromatic telescopes, — the magnifying power 86. 



Summary of a Meteorological Table, kept at Bushey Heath in 1826. 



The Barometer, Thermometer, and Winds were observed between 

 9 and 10 o'clock in the morning, at which hour the temperature of 

 the external air is nearly the same as the mean temperature. See 

 column 3 and 8. 



The greatest altitude of the mercury in the barometer was on 

 December 28th, 30-068 inches; the least, on the 14th November, 

 28-590 inches. Thermometer highest 28th of June, 88° ; lowest 

 16th January, 19°. 



XLVI. On a New Mineral Species. By A. Levy, Esq. 

 M.A. F.G.S.* 

 ly/TR. HEULAND has lately added to his collection a small 

 -'-*-'• group of quartz slightly chlorited, upon -which are seen 

 some crystals belonging, I believe, to a new species, which 

 at his suggestion I propose to call Mohsite, in honour of Pro- 

 fessor Mohs. 



An acute rhomboid of 73° 43' represented fig. 1. may be 

 considered as the primitive form of this substance. It does 

 not yield to mechanical division in any direction, as far as I 

 could judge upon the small quantity I had to examine. The 

 fracture is conchoidal and shining. It is brittle, but scratches 

 glass very easily. It is opaque, iron black, and possesses a high 

 metallic lustre. It has not the least action on the magnet. 



All the crystals upon the specimen I have seen are twin 



* Communicated by the Aiitlior. 



crystals, 



