238 Intelligence and Miscellaneous Articles. 



decomposition by mixing solutions of sulphate of chromium and hy- 

 pophosphite of barytes. By evaporation there was obtained an 

 amorphous, cracked mass of a very deep green colour. This salt 

 loses water by drying when it has been heated to 392° Fahr. ; it is 

 not soluble either in water or dilute acids. The formula of this salt 

 is2PH*0 3 , Cr*0 3 +4HO. 



Hypophosphite of Manganese. — The crystals of this salt are of a 

 rose colour, brilliant and unalterable in the air. They do not lose 

 water at 212° Fahr., but at about 302° Fahr. they part with one 

 equivalent. The formula of this salt is PH°- O 3 , MnO + HO. 



Hypophosphite of Cobalt. — This salt forms large crystals of a deep 

 red colour, which effloresce in the air. At 212° Fahr., they lose six 

 equivalents of water of crystallization, and become a pale rose-red 

 powder. The formula of this salt, which agrees with that of M. H. 

 Rose, is PH°~0\ CoO + 6HO. 



Hypophosphite of Nickel. — The crystals of this salt are regular oc- 

 tahedrons, and smaller than those of hypophosphite of cobalt. When 

 the aqueous solution is evaporated at the temperature of 212° Fahr., 

 it is partially reduced to metallic nickel with the disengagement of 

 hydrogen. This reduction takes place perfectly when the crystals 

 of this salt, broken and slightly moistened, are exposed to the air at 

 a temperature of 248° Fahr. The formula of this salt is PH* O 3 , 

 NiO + 6HO. 



Hypophosphite of Copper. — The solution of this salt is readily pre- 

 pared by decomposing sulphate of copper with hypophosphite of ba- 

 rytes. It is not a permanent salt. At about 140° Fahr. it becomes 

 turbid, and deposits hydrate of copper. By evaporating the solution 

 in vacuo, small blue crystals of this salt were once obtained. These 

 crystals decompose quickly, and with projection of the entire mass 

 when heated to 149° Fahr. ; and phosphuret of copper is formed. 

 The formula of this salt is PH' 2 O 3 , CuO. — Ann. de Ch. et de Phys., 

 Fevrier 1846. 



BIELA S COMET. 



The following is an abstract of a letter addressed by Prof. Challis 

 to the editor of the Times : — 



" As I was preparing to observe Biela's comet, on the evening of 

 the 23rd of January, I discovered a smaller comet in its immediate 

 neighbourhood, and ascertained by my observations that evening 

 that the two comets had the same apparent motion. A double 

 comet is a celestial phenomenon which, I believe, has never before 

 been witnessed, and cannot fail to arrest the attention of astrono- 

 mers. It will be a matter of very great scientific interest to deter- 

 mine the relative motions of these two singular bodies, and the na- 

 ture of the influence they mutually exert on each other. The fol- 

 lowing relative positions I have succeeded in obtaining by means of 

 the Northumberland telescope. They are either derived from sepa- 

 rate determinations of the places of the comets, or from direct mea- 

 surements of angles of positions and differences of North Polar di- 

 stance. The smaller comet is north of the other, and precedes it. 



