Dr. Beck on the Chlorides of Soda, Lime, fyc. 263 



the action of a compound of chlorine on air impregnated with 

 putrid miasmata. 



" Air blown through blood which had been left for eight 

 days to putrefaction, and which disengaged an insupporta- 

 ble odor, was afterwards made to pass through a solution 

 of chloride of lime ; carbonate of lime was formed, and the 

 air came out without smell, and completely purified by the 

 chlorine. 



" The same operation was again commenced, by making 

 the air pass through a solution of caustic potassa, before 

 sending it through the chloride ; the air came out with a very 

 fetid odor. 



" Air was left for twenty-four hours in contact with some 

 of the blood used in the preceding experiment. A portion 

 having been put in contact with some chloride, the disinfec- 

 tion was complete in a few moments, and carbonate of lime 

 was formed. The other part of the air was treated by caus- 

 tic potash, and afterwards by chlorine ; but it retained an in- 

 supportable odor."* 



From these decisive experiments, it appears, that the car- 

 bonic acid given out by the putrid substance effects the evo- 

 lution of chlorine ; which last combines with the constituents 

 of the miasmata, and neutralizes them in some hitherto un- 

 known manner.! 



An attentive examination of the manner in which carbonic 

 acid causes the evolution of chlorine will perhaps throw ad- 

 ditional light upon the chemical history of these disinfecting 

 compounds. 



It has just been stated that a solution of the supposed chlo- 

 ride of lime, when abandoned to the air, loses its chlorine, 

 and there is produced a precipitate of carbonate of lime. 

 This process, however, requires nearly two months exposure. 

 But the same thing also takes place when we expose two 

 separate vessels to the air, in one of which is lime water, and 

 in the other a simple solution of chlorine. At the end of 

 several days, the chlorine of the latter will be completely 

 disengaged, and the lime of the former is converted into a 



* Ann. de Chimie, Vol. 33. 



t It is difficult to reconcile with this view of the subject, the fact stated by- 

 Mr. Faraday, in the volume of Brande's Journal to which I have referred, viz : 

 That when carbonic acid was passed through Labarraque's liquor of soda, equal 

 to nearly 1300 times the volume of the fluid, very little chlorine was removed, 

 and the bleaching powers of the fluid were but little diminished, though it no 

 longer appeared alkaline to turmeric paper ; — unless we adopt the opinion sug- 

 gested at the close of this essay. 



