Dr. Beck on the Chlorides of Soda, Lime, $c. 255 



an established law, that they are not susceptible of combina- 

 tion with chlorine at ordinary temperatures, when both are 

 completely deprived of water. When these oxides are ex- 

 posed to a high heat, chlorine effects their decomposition ; 

 — oxygen being disengaged, the chlorine combines with their 

 metallic bases. But these compounds of chlorine and the 

 metals do not possess any bleaching or disinfecting powers. 



If instead of employing the dry oxides of sodium, calcium, 

 &-c. we take the hydrates of these oxides, or their solutions, 

 and pass through these a stream of chlorine gas, their weight 

 will in every case be increased, and we shall obtain com- 

 pounds possessed of bleaching and disinfecting properties. 



To what then shall we ascribe the difference in the results 

 obtained ? The presence of water is the only circumstance 

 in which the cases are not parallel, and we must therefore 

 look to this as influencing, in a great measure, the formation 

 of these compounds. 



Another fact worthy of notice, is, that chlorine, when per- 

 fectly dry, exerts no action upon vegetable colors, and proba- 

 bly not upon putrid substances, though I am not aware that 

 the latter has been settled by experiment. But water at low 

 temperatures, dissolves or absorbs chlorine in considerable 

 quantity, and this solution has the property of discharging 

 vegetable colors, and was indeed for a long time employed 

 exclusively in the process of bleaching. This solution, if kept 

 in well stopped bottles, will retain its powers for a great length 

 of time ; but if it is exposed to the air, or if its temperature is 

 raised, chlorine is evolved and with it all the bleaching pow- 

 ers of the solution are lost. 



Having premised these remarks, I shall first notice the 

 combination of chlorine with solution of soda. 



When a stream of chlorine gas is passed through a solu- 

 tion of soda, after the manner directed by M. Labarraque, 

 the chlorine is absorbed, and as it is said, a chloride of 

 soda is formed. But if additional quantities of chlorine 

 are transmitted through the solution after variable periods 

 of time, decompositions take place and new definite com- 

 pounds are produced, which are permanent and can be 

 obtained in a separate state by subsequent analysis. These 

 changes consist in the decomposition of water, the formation 

 of chloric and muriatic acids, and the combination of these 

 with the soda, forming the chlorate and the muriate of that 

 alkali. In whatever manner these changes are effected, the 



