224* On Labarraque's Disinfecting Soda Liquid. [1827. 



as the saturated solutions of carbonated soda ; they were of a 

 bright greenish yellow colour, and had an insupportable odour 

 of chlorine. 



5. The saturated solution (4) was then examined as to the 

 change which had been occasioned by the action of the chlo- 

 rine. It bleached powerfully, and apparently contained no 

 carbonated alkali ; but when a glass rod was dipped into it 

 and dried in a warm current of air, the saline matter left, when 

 applied to moistened turmeric paper, reddened it considerably 

 at first, and then bleached it ; and this piece of paper being 

 dried and afterwards moistened upon the bleached part, gave 

 indications of alkali to fresh turmeric paper. 



6. A portion of the saturated solution (4) being warmed, 

 instantly evolved chlorine gas, then assumed a dingy appear- 

 ance, and ultimately became nearly colourless ; after which it 

 had an astringent and saline taste. Being evaporated to dry- 

 ness at a very moderate temperature, it left a saline mass con- 

 sisting of much common salt, a considerable quantity of chlorate 

 of soda, and a trace of carbonate of soda. This mixture had 

 no bleaching powers. The dingy appearance, assumed in the 

 first instance, was found to be occasioned by a little manganese 

 which had passed over into the solutions, notwithstanding the 

 care taken in evolving and washing the gas. 



7. From these experiments it was evident that when chlorine 

 was passed in excess into a solution of carbonate of soda (3), 

 the carbonic acid was expelled, and the soda acted upon as if 

 it were caustic, a mixture of chloride of sodium and chlorate 

 of soda being produced ; with the exception of the small por- 

 tion of carbonate of soda which, it appears, may remain for 

 some time in the solution in contact with the excess of chlorine 

 at common temperatures, without undergoing this change. 

 The quantities of chloride of sodium and chlorate of soda were 

 not ascertained, no doubt being entertained that they were in 

 the well-known proportions which occur when caustic soda is 

 used. 



8. The Labarraque's soda liquor which had been prepared 

 as described (2), was now examined relative to the part the 

 chlorine played in it, or the change the alkali had undergone, 

 and was soon found to be very different to that which has just 

 been described, as indeed the experiments I had seen made 



