1S27.] On Labarraque's Disinfecting Soda Liquid. 227 



stoppered bottles, two were put into basins and covered over 

 with bibulous paper, and one was put into a basin and left 

 open; all were set aside in an obscure place, and remained 

 from July 16th to August 28th. Being then examined, the 

 portions in the basins were found crystallized and dry; the 

 crystals were large and flat, striated and imperfect, resembling 

 those formed in a similar way from carbonate of soda. They 

 were not small and acicular, 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, without any of the pungency of Labarraque's 

 liquid ; and when tested by turmeric paper, it reddened, but 

 did not bleach it. 



14. One of these portions, that had effloresced least, was se- 

 lected, and being dissolved, was compared in bleaching power 

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

 solution 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 part. 



