244 Iodine in the Mineral Waters of Saratoga, 



or soda, forming the iodate or liydriodale of the alkali, witfi 

 which they are united. As the presence of potassa, in any 

 of its combinations, in these waters, has not been indicated 

 by any of the appropriate tests used for the purpose, it fol- 

 lows that soda is the alkaline base, which retams the acid in 

 question, forming the iodate or hydriodate of soda. To as- 

 certain which of these acids forms the salt in question, 1 pour- 

 ed over a quantity of the dry soluble salts of the water, an 

 ounce of very pure alcohol, which, after standing a short 

 time, was filtered off; this was found to contain the whole 

 of the matter, which indicated the presence of iodine, and as 

 iodate of soda is not soluble in alcohol, I infer that the sub- 

 stance taken up by the alcohol is the hydriodate of soda. 



With a view to illustrate the position still further, and to 

 arrive at the proportion of this salt, contained in a given 

 quantity of the water, I evaporated one gallon of water in 

 a porcelain basin placed in a sand bath, which was kept at 

 the temperature of about 150°, and the evaporation was con- 

 tinued until crystals of muriate of soda began to form on the 

 sides of the basin; it was now removed from the bath, and 

 when cold the whole contents of the basin were thrown on 

 a filter and the residuum, being well washed with recently 

 distilled water, was removed and the filtered liquor again 

 placed on the sand bath in a small basin, and suffered to 

 evaporate to dryness, in a temperature of 150°. 



Alcohol of the specific gravity of .825 was thrown over 

 these salts, and after being frequently stirred, was filtered 

 and the filtered solution evaporated to dryness. The resi- 

 duum weighed, while warm, a trifle over three grains. It 

 consisted principally of the hydriodate of soda, with a very 

 minute quantity of common salt, which the small quantity 

 of water in the alcohol used, and, possibly, the imperfectly 

 dry state of the salts, before the alcohol was added, contrib- 

 uted to render soluble in that menstruum. 



I now dissolved the salts thus obtained in a small quantity, 

 of starch and water and having placed the solution in a Flor- 

 ence flask, over a spirit lamp, added to it a few drops of 

 sulphuric acid ; as it became warm, the blue color of the 

 starch, which had settled to the bottom of the flask, began 

 to disappear, and at the same time the well known purple 

 fumes of iodine, appeared very conspicuous at the neck of 

 the bottle, furnishing the most incontestible evidence of the 

 presence of that highly volatile substance. 



