EXPERIMENTS ON ELECTRICITY. 193 



A curious obfervation of Cit. Le Blanc, which has already Solutions are 

 keen recorded in the Journal de Phyfique, proves that the^g^^jjep^, 

 fame folution left to itfelf, is not equally faturated in all its 

 parts. U we fufpend cryftals at different heights in a folu- 

 tion, the loweft cryftals increafe more rapidly than the higher 

 ones ; and it (bmetimes happens that thefe diflblve whilft the 

 lower ftill continne to grow. Citizen Le Blanc adverts to 

 the analogy that fubftfts between this obfervation, and that of 

 the more complete faturation of the water of the fea at great 

 depths. 



Cit. Le Blanc informs us, that by adding fulphate of cop- 

 per which cryftallizes in oblique prifms, to fulphate of copper 

 which cryftallizes in the octahedral form, rhomboids are eori- 

 ftantly obtained *. 



. VII. 



Accounts of the New Planet Ceres t. 



'N the 4th of February a letter from Dr. Mafkelyne was Letters to the 

 read before the Royal Society, announcing that he had ob- ^^ Societ £ 



J J i announcing ob- 



lerved the new planet of Mr. Piazzi paffing the meridian be- fervations of 



I ween three and four o'clock in the morning, having about * he " e ^j >, ^ et 



188° 43' right afceniion, and 12° 38' north declination, ap-j yn e, Mr. von, 



pearing like a ftar of the eighth magnitude. Zach, and A. 



Another letter from Mr. vpn Zach was read, informing the ' 



Society that he had obferved this planet at Sceberg on the 



7th of Deeember, within half a degree of the place before 



cient to feparate it. Thefe cryftals are accordingly opaque : betides, 

 the fame chemift has obtained cubic ?nd transparent cryftals from 

 acidulous fulphate of alumine. (Note of the Editors). 



* We muft obferve that the primitive form of the fulphate of iron 

 is the rhomboid, and that the irregular octahedron which it preients 

 is a fecondary form. Cit. Hauy has examined one of thefe cryftals 

 refusing from a mixture of a folution of fulphate of copper with a 

 folution of fulphate of iron. The rhomboid which he examined 

 differed in no refpect from the primitive rhomboid of the fulphate of 

 iron. (Note of the Editors.) 



f This whole article is taken verbatim from the Journal of the 

 R oyal Inftitution. 



Vol. I f — March, O determined 



