170 Foreign Literature and Science. 



The carbonate of lime obtained from the decomposition 

 of the chloride of lime, retains no trace of chlorine. The chlo- 

 ride of soda is decomposed by carbonic acid like chloride of 

 lime only more slowly, because it does not form an insoluble 

 salt. 



It is difficult to obtain chloride of lime entirely free from 

 hydrochlorate. I found the quantity of hydrochloric acid 

 to be exactly the same after the action of the carbonic acid 

 as before. To determine the quantity of hydrochloric acid 

 in the chloride before decomposition, I treated the chloride 

 with acetic acid, and precipitated with nitrate of silver. 



Simple exposure to the air likewise decomposes the solu- 

 tion of chloride of lime. A filtered solution was exposed on 

 the 13th of August, and on the 10th of October, it would 

 not discolor turnsol ; the precipitate when washed, was found 

 to be carbonate of lime. These experiments show clearly 

 enough what takes place when a chloride is exposed to the 

 action of air containing miasmatic impregnations ; it appear- 

 ed to us however that a few direct experiments would not be 

 useless. 



Some air was blown through a quantity of blood, which 

 had been abandoned to putrefaction during a week and 

 which emitted an unsupportable odour. The infected air 

 was then passed through chloride of lime ; carbonate of lime 

 was formed and the air remained entirely free from smell and 

 completely purified by the chloride. 



The experiment was repeated by substituting a solution of 

 caustic potash for the chloride. The air issued from it with a 

 very fetid odour. 



Air which had been left twenty four hours in contact with 

 trie putrefied blood, was placed in contact with the chloride; 

 the disinfection was complete in a few moments, and carbo- 

 nate of lime was formed. Another portion was treated with 

 caustic potash, and afterwards with the chloride ; but it pre- 

 served its insupportable odour ! 



It appears to us that nothing is at present to be desired 

 with respect to the action of alkaline chlorides as disinfec- 

 ting agents ; the carbonic acid of the air decomposes the 

 chloride, and sets the chlorine at liberty, which then re-acts 

 as if it had been directly employed. 



It is thus easy to explain the preference to be given to 

 chlorides as disinfecting substances, over fumigations of chlo- 

 rine. The carbonic acid in the air, or that which arises from 



