228 On Labarraque's Disinfecting Soda Liquid. [1827. 



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

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

 rine on the carbonate had taken place in the evaporated por- 

 tion, 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 showed also that there 

 was a gradual reaction of the chlorine and alkali in the fluid 

 preparation, proceeding to a greater extent than in the evapo- 

 rated portion ; for chlorine, equal to five parts, was found by 

 the nitrate of silver to remain. Hence this preparation is one 

 which deteriorates even in the small space of forty-three days. 

 Whether the effect will proceed to any great extent, prolonged 

 experiments only can show. 



17. From an experiment made upon larger quantities of the 

 Labarraque liquor, it would appear that the force of crystal- 

 lization alone is sufficient to exclude the chlorine. A quantity 

 was put into an evaporating basin, and left covered over with 

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

 a few large crystals were found covered over with a dense 

 solution ; the whole had the innocuous odour of Labarraque's 

 fluid, and the fluid the usual acrid, biting taste. The crystals 

 being separated, one of the largest and most perfect was chosen, 

 and being well wiped on the exterior, and pressed between folds 

 of bibulous paper, was rubbed down in water, so as to make a 

 saturated solution. This had no astringent taste like that of 

 Labarraque's fluid, or the mother-liquor, but one purely alka- 

 line; and when applied to turmeric paper, reddened, but did 

 not bleach it. Equal portions of this saturated solution and 

 of the mother-liquor were then compared in bleaching power, 

 acid being added to the former to assist the effect : it was found, 

 notwithstanding that portions of mother-liquor must have ad- 

 hered to the crystal, that its solution had not "^st part the 

 power of the mother-liquor. This, in conjunction with the 

 other experiments, is a striking instance of the manner in which 

 the carbonate of soda acts, as a simple substance, with the 

 chlorine in the solution. The crystal itself had never been in 

 contact with the air : but whether it should be considered as 

 the excess of carbonate of soda only which crystallized; or 

 whether it is essential to the formation of these crystals that 



