260 Dr. Beck on the Chlorides of Soda, Lime, fyc. 



Passing now to the supposed chemical compound of chlo- 

 rine and lime, it will be found that the explanations above 

 given, and the arguments employed, will also apply. 



It has been stated that dry lime in fine powder, though 

 exposed to a copious stream of chlorine for several days, 

 does not sensibly increase in weight. It may now be added, 

 that when chlorine gas is transmitted through the proto-hy- 

 drate of lime, there is an increase of weight in the proportion 

 of fifty to sixty per cent. It is, however, important to re- 

 mark, that this increase is by no means definite, but varies 

 according to circumstances, depending chiefly upon the skill 

 of the manufacturer. 



The proto-hydrate of lime is supposed to be composed of 

 one proportional of pure lime, and one proportional of water. 

 This, when exposed to an atmosphere of chlorine, is con- 

 verted, according to Welter, into a sub chloride, which, ac- 

 cording to him, is composed of 



2 proportionals of lime, 

 2 " of water^ 



1 " of chlorine. 



The same chemist asserts, that when the above is mixed 

 with water, it is immediately decomposed ; one half of the 

 lime is precipitated, and the other half remains in solution, 

 combined with the whole of the chlorine, and consequently 

 forming a neutral chloride. The sub chloride is obtained by 

 saturating hydrate of lime with chlorine, and the neutral 

 chloride by dissolving the sub chloride in water, or by sat- 

 urating lime dispersed through water, with chlorine. 



The experiments of Dr. Ure are at variance with these 

 ideas. He found that the solid residuum of a portion of the 

 powder, (sub chloride of lime) left on the filter after two suc- 

 cessive solutions, contained a notable quantity of chlorine, 

 from which he infers, that the chloride is but sparingly solu- 

 ble in water. And he remarks that he could never observe 

 that partition occasioned by water in the elements of the 

 powder of which Mr. Dalton, and M. Welter speak.* 



It appears, therefore, that no certain evidence exists, that 

 there is, in the above case, a definite compound of chlorine 

 and lime. All the phenomena presented by this powder can 



* Chsmical Dictionary, 2d edition. The existence of the sub chloride of lime 

 is also disputed by M. Houton Labillardiere. See Tlienard, 5th ed. vol. 2, p. 

 474. 



