Labarraque's Disinfecting Soda Liquid. 89 



in a similar way from carbonate of soda. They were not small 

 and aciciilar, were nearly alike in the three basins, and had 

 effloresced only on a few minute points. A part of one portion, 

 when dissolved, gave a solution, having an alkaline taste, with- 

 out any of the pungency of Labarraque's liquid ; and which, 

 when tested by turmeric paper, reddened, but did not bleach it. 



14. One of these portions that had effloresced least was 

 selected, and being dissolved, was compared in bleaching power 

 upon diluted sulphate of indigo, with one of the portions of solu- 

 tion that had been preserved in bottles. The former had 

 scarcely any visible effect, though sulphuric acid was added to 

 assist the action ; a single measure of the indigo liquor coloured 

 the solution permanently blue, whereas seventy-seven such 

 measures were bleached by the portion from the bottle. Hence 

 the process of slow crystallization had either almost entirely 

 expelled the chlorine, or else had caused it to react upon the 

 alkali, and by entering into strong chemical combination as 

 chloride and chlorate, had rendered it inert as a bleaching or 

 disinfecting agent. 



15. From the appearance of the crystals there was no reason 

 to expect the latter effect ; but to put the question to the proof, 

 one of the evaporated portions, and one of the fluid portions 

 contained in the bottles, were acted upon by sulphuric acid, 

 heat, and a current of air, in the manner already described (11), 

 to separate the chlorine that had not combined as chloride or 

 chlorate. They were then compared with an equal portion of 

 the solution, which retained all its chlorine, nitrate of silver being 

 used as before : the quantity of chloride indicated for the latter 

 portion was 60 parts ; whilst that of the fluid portion deprived 

 of as much free chlorine as could be, by sulphuric acid and 

 blowing, was 6 parts ; and for the evaporated and crystallized 

 portion, similarly cleared of free chlorine, only 1.5 parts. 



16. This result, as compared with the former experiment of 

 a similar kind (11), shewed, that though reaction of the chlo- 

 rine on the carbonate had taken place in the evaporated portion, 

 it was only to a very slight extent, since the chlorine was 

 almost as much separated from it by the process altogether, as 

 it had been from the recent preparation by sulphuric acid, 

 blowing, and heat The experiment shewed also that there 



