416 M, Roseonthe Compoutids of [Dec. 



It came into view Aug. 18, 12'* 



Disappeared Aug. 3, 9 



It was invisible during 15 3 



This spot first came into view . . July 21, 20'^ 

 Returned after one revolution . . Aug. 18, 12 



Therefore 27 IG is the time 



of a revolution. 



The spot which disappeared . . July 22, 0'* 

 Disappeared after a revolution, Aug. 17, 22 



26 22 



Hence this spot has had a considerable motion on the sun's 

 disc, which accords with the observations. Sheiner first took 

 notice of this proper motion which the maculae often have; 

 many other astronomers have confirmed his statements : indeed 

 there is nothing more common than to see the spots of a cluster 

 change their relative places very considerably, even in the space 

 of a few hours, Mr. Wollaston once saw a spot suddenly divided, 

 and the parts fly off/rom each other very rapidly. 



*f6r '^o l^ioffqlri? Ilii ^i,\\ 



Article III. 



On the Compounds of Antimony with Chlorine and Sulphur, 

 ByM.H.Rose.* 



I. Compounds of Antimony and Chlorine. 



It is known that a solid compound of antimony and chlorine, 

 fusible at a very moderate heat, is obtained by distilling pulve- 

 rised antimony with an excess of corrosive sublimate. It deli- 

 quesces by exposure to the air, and is converted into a liquid 

 resembling an emulsion.f When treated with water it changes, 

 without the evolution of heat, into hydrochloric acid, and a 

 compound of the oxide and chloride of antimony. This white 

 powder, which is precipitated by mixing the chloride with water, 

 is wholly volatilized when heated in a little matrass by the blow- 

 pipe ; consequently it contains neither antimonious nor anti- 

 monic acid. But since this chloride of antimony is converted 

 by water into hydrochloric acid and oxide of antimony, its com- 



• From the Annales dc Chimie. 



+ The common butter of antimony of the shops, which forms a clear liquid, is not a 

 solution of the solid chloride of antimony in a small quantity of water, but in muriatic 

 acid ; for the Pharmacopoeias order it to be prepared with a larger quantity of add than 

 is necessary to form the ^>olid chloride. 



