M, Balard on the Nature of the [Oct. 



of Chimborazo that I separated from Colonel Hall During 

 my residence in the province of Quito, I had enjoyed his 

 confidence and friendship. His perfect knowledge of the 

 topography was of the greatest utility to me, and I had 

 found him an excellent and indefatigable travelling com- 

 panion. Both of us had served for a long time in the cause 

 of independence. Our farewell was affecting : Something 

 seemed to tell us that we should never meet again. This 

 sad presentiment was too well founded. Some months 

 afterwards my unfortunate friend was assassinated in one 

 of the streets of Quito. 



Article III. 



Researches into the Nature of the Decolourizing Combinations 

 of Chlorine, By A. J. Balard.* 



Among the remarkable properties which chlorine possesses, 

 there is one to which manufactures have been much indebted 

 ever since its discovery, viz. its powerful action upon co- 

 louring matter. 



Scheele first pointed out this character, but it was Ber- 

 thollet who introduced it as the foundation of a new art. 

 It was first employed in the gaseous form, then in an aque- 

 ous solution ; but in both of these states it was observed to 

 produce noxious efi'ects upon the workmen employed in the 

 bleaching operations. Berthollet strove to overcome this 

 objection, and ascertained that, by the addition of a little 

 alkali, as quick-lime, and even carbonate of lime, or mag- 

 nesia, the pungent odour of chlorine might be removed from 

 its aqueous solution without injuring its bleaching proper- 

 ties. This important observation led him to recommend a 

 still more convenient method. He observed that, if, in 

 place of dissolving the alkali in an aqueous solution of 

 chlorine, a current of the gas was passed through an alka- 

 line solution, a much greater quantity would be dissolved,' 

 and the liquid would also possess a stronger bleaching 

 power. These new compounds were speedily introduced 

 into the arts ; and, as the first trials were made in 1789, in 



• From the Ann. de Chim. Ivii. '225. 



