1826 J On a peculiar Substance contained in Sea Water, 381 



Article XIII. 



Memoir on a peculiar Substance contained in Sea Water, By 

 M. Balard, Apothecary and Chemist to the Faculty of Sci- 

 ences, at Montpelier.^ 



I HAD repeatedly observed, upon treating the washings of 

 the ashes of the fucus which contain iodine, with an aqueous 

 solution of chlorine, that after having added a solution of 

 starch, there was not only a blue colour, occasioned by the 

 iodine, but also a little above it, a yellowish colour of consider- 

 able intensity. 



This orange yellow colour was also apparent when the mother 

 water of our salt-works was treated in the same manner; and 

 the tint was strong in proportion to the concentration of the 

 liquid. The production of this colour is accompanied with a 

 peculiar penetrating smell. 



I examined the nature of this colouring principle, and my 

 first attempts led me to the following observations : 



1. The mother water of the salt works, treated with chlorine, 

 loses its colour and characteristic odour when it is exposed for 

 a day or two to the air, and chlorine does not afterwards repro- 

 duce the same phenomenon. 



2. If it be treated with the alkalies or their sub-carbonates, 

 the smell and colour are also lost. 



3. The same effects are produced when any reagent is added 

 to the coloured fluid, which yields it hydrogen, either directly 

 or by the intervention of water. 



These effects are produced by sulphurous acid, ammonia, 

 sulphuretted hydrogen, the hydrosulphurets, but especially by a 

 mixture of zinc and sulphuric acid, which presents nascent hy- 

 drogen to the fluid. 



4. When the fluid has been decolorized by the alkalies or 

 bodies containing hydrogen, the addition of chlorine restores 

 the originarcolour. 



Two explanations naturally present themselves to account for 

 these various phenomena ; in the first place, it may be supposed 

 that the yellow matter is a compound of chlorine with some 

 substance contained in the mother water of the salt-works ; in 

 the second place, it may be imagined that the colouring matter 

 had been evolved from some of its combinations, by the chlo- 

 rine, and that this had taken its place. 



To determine which opinion to adopt, it was requisite to obtain 

 the colouring matter in a separate state ; its volatility afforded 

 some hope that distillation would be sufficient to separate it 

 from the liquid, and I had recourse to this process. 



* From the Annales jdeChemie and de Physique, xxxii. p* 337. 



