Meteorology, — Chemistry. 373 



the inverse ratio of the square of the distance, or between the square and 

 the cube, though not in any constant ratio of an exact power. 



When copper discs of different weights are set in rotation, the force at 

 small distances seems to increase as the weights of the discs ; but at smal- 

 ler distances it varied in some higher ratio. See our last Number, p. 135. 



METEOROLOGY. 



16. Remarkable Hailstones with pyritic Nuclei. The following very 

 curious account of these hailstones is given in a letter from Professor John 

 of Berlin, to Baron Ferrussac. It forms also part of a letter from Dr Evers- 

 mann, known by his travels in Asia, dated 16 th September, from Oren- 

 burg, where he has landed property. 



" Some days before our arrival at Sterlitamak, (more than 100 versts 

 from Orenburg,) there arose a storm in which very remarkable hail fell. 

 The hailstones, which were tolerably large, contained a stony and crystalliz- 

 ed micleus. Thirty of them have been sent to our Governor, and I have 

 received two specimens." They are of a brown colour like the auriferous 

 pyrites of Beresowsky, in Siberia. Their surface is shrivelled and shin- 

 ing. The crystal forms a flattened octohedron, whose edges are salient. 

 The two diagonals of the base are five lines by four, and the distance of the 

 summits is two lines. Sometimes the four angles of the base are trun- 

 cated. It seems that the constituent parts of these crystals are sulphur and 

 metals. No analysis of them has yet been made, but I shall perhaps have 

 occasion to do this. See Bull. des. Sc. Phys. Feb. 1825, p. 117. 



II. CHEMISTRY. 



17. On a compound of Carbon of Hydrogen, with remarkable properties. 

 A paper was read at the Royal Society on the 16th June, by Mr M. Fa- 

 raday, containing an account of this curious substance which he calls a 

 Bi-carbonet of hydrogen, from its consisting of two proportions of carbon, 

 and one of hydrogen. 



This substance is a fluid deposited in vessels in which oil gas has been 

 compressed. It is colourless, has less specific gravity than water, is al- 

 most insoluble in water, but is soluble in alcohol, ether, oils, &c. It burns 

 with a dense flame, and is not acted upon to any extent by solutions of 

 the alkalies. If it is put into gas, burning with a blue flame, it makes 

 the flame bright and white. It dissolves caoutchouc readily, and will an- 

 swer all the purposes of essential oils as solvents. 



Part of this fluid is very volatile, causing the appearance of ebullition at 

 temperatures of 50° or 60°, other parts are more fixed, requiring even 250° 

 or more for ebullition. By repeated distillations, a series of products were 

 obtained from the most to the least volatile, the most abundant being sucli 

 as occurred from 170° to 200°. On subjecting, these, after numerous rec- 

 tifications, to a low temperature, it was found that some of them concreted 

 into a crystalline mass, and ultimately a substance was obtained from 

 them, principally by pressure at low temperatures, which, upon examina- 

 tion, proved to be a new compound of carbon and hydrogen. At com- 



