Labarraque'* Disinfecting Soda Liquid. 91 



substance apparently quite dry may be obtained, which yet 

 possesses strong bleaching power. In one experiment, where, 

 of two equal portions, one had been evaporated in the course 

 of twenty-four hours to dryness upon the warm part of a sand- 

 bath, when compared with the former, it had not lost more 

 than one- third of its bleaching power. 



19. With the desire of knowing what effect carbonic acid 

 would have on Labarraque's fluid, and whether it possessed 

 in a greater or smaller degree the power of ordinary acids 

 to expel the chlorine, portions of the solution were put into 

 two Woulfe's bottles, and a current of carbonic acid gas passed 

 through them. The gas was obtained from sulphuric acid 

 and whitening in a soda-water apparatus, and was well weished 

 in water. The stream of gas brought away small portions 

 of chlorine with it, but they were not sensible to the smell, 

 and could only be detected by putting litmus paper into 

 the current. An immense quantity of gas, equal to nearly 

 1300 times the volume of the fluid, was sent through ; but yet 

 very little chlorine was removed, and the bleaching powers of 

 the fluid were but little diminished, though it no longer appeared 

 alkaline to turmeric paper. Air was then passed through the 

 solution in large quantity ; it also removed chlorine, but appa- 

 rently not quite so much as carbonic acid. 



20. One other experiment was made upon the degree in 

 which the carbonate of soda in Labarraque's liquor resisted 

 decomposition by the chlorine, even at high temperature. Two 

 equal portions of the fluid were taken, and one of them boiled 

 rapidly for fifl:een minutes ; both were then acted upon by 

 sulphuric acid, blowing, and heat, as described (11), and the 

 two were then tested by nitrate of silver, to ascertain the quan- 

 tity of chlorine remaining : it was nearly three times as much 

 m the boiled as in the unboiled portion ; and by comparing 

 this with the results before obtained (11), it will be seen that, 

 after boiling for a quarter of an hour, not more than a twentieth 

 part of the chlorine had acted upon the alkali, to form chbride 

 and chlorate. 



21. It would seem as if I were unacquainted with Dr. Gran- 

 ville's paper upon this subject, published in the last volume of 

 this Journal, p. 371, were I to close my remarks without taking 



