26$ Dr. Beck on the Chlorides of Soda, Lime, <§-c. 



We are therefore forced to the conclusion, 



1st, That there are no definite compounds of chlorine and 

 soda, or of chlorine and lime. Analogy would lead us to ex- 

 tend this to all the metallic oxides ; and we might hazard 

 the general assertion that chlorine is not susceptible of com- 

 bination, in definite proportions, with the metallic oxides, at 

 any temperature, or under any circumstances. For it should 

 be recollected that in consequence of the superior attraction 

 of chlorine for the metals, whenever the oxides are highly 

 heated in contact with it, oxygen is evolved, and a chloride 

 of the metal is formed. 



2d, That the bleaching and disinfecting powers of the sup- 

 posed chlorides of soda, lime, &c, depend upon the chlorine 

 held in solution by the water which exists in the hydrated 

 oxides, or in which these oxides are dissolved or suspended ; 

 and that the same explanation will apply to the various sa- 

 line solutions which exhibit these powers. 



Mode of operation. — The first correct views upon this sub- 

 ject were suggested by Gay Lussac in his memoir on chlori- 

 metry, who states that a solution of the bleaching powder, 

 abandoned to the air is gradually decomposed ; a portion of 

 the lime combines with the carbonic acid contained in the 

 atmosphere, and the chlorine is at the same time disengag- 

 ed. He also shows, that this decomposition is retarded by 

 keeping constantly an excess of lime in the solution. These 

 views have been fully confirmed by the experiments of Gaul- 

 tier de Claubry, which may indeed be considered conclusive 

 on this point. 



A solution of well saturated chloride of lime was submitted 

 to the action of carbonic acid gas. After a few moments, 

 there was a disengagement of chlorine, and by continuing 

 the operation for a sufficient time, the whole of this gas was 

 expelled. The liquid no longer exerted any action on col- 

 ors, not even on infusion of litmus. Carbonate of lime was 

 precipitated, which was afterwards redissolved in the excess 

 of carbonic acid. 



Air passed through a solution of potassa, rendered caustic 

 by lime, produced no action on the solution of chloride of 

 lime. But when the latter solution was abandoned to the 

 air for some time, it lost its power of acting on vegetable 

 colors, and a precipitate of lime was produced. 



The following experiments were performed by M. de Clau- 

 bry, to ascertain still more directly what takes place during 



