456 ANALYSIS OF THE 



fche evaporation, may be regarded as the just proportion indi- 

 cated by the analysis. 



The resuks, then, by this method, agree very nearly with 

 diose by the other ; being of solid ingredients in a pint of the 

 water, 



45.9 



With a trace of iron. 



With regard to both analyses, a small correction is to be 

 made in the proportion of sulphate of lime. The mode of as- 

 certaining it, by evaporation, being rather imperfect, I after- 

 wards determined it by the more accurate method of precipita- 

 tion by muriate of barytes ; applying this re-agent with a slight 

 excess of acid, so as to prevent any precipitation of carbonate. 

 The quantity of precipitate thrown down from a pint of the 

 water, amounted, after drying at a low red heat, to 6.1 grains, 

 equivalent to 3.5 grains of sulphate of lime. As the portion 

 of sulphate of lime thus obtained, above that obtained by the 

 evaporation, would remain principally mixed with the muriate 

 of soda, the quantity of that ingredient falls to be reduced a 

 little, and may therefore be stated at 24 grains. 



It remained to ascertain the proportion of iron. The quan- 

 tity, however, was evidently so small as to present a difficulty. 

 Succinate of ammonia, and benzoate of soda, produced little 

 or no effect on the water in its natural state. Infusion of galls 

 produced, after some hours, a dark colour, and a precipitate 

 very slowly subsided. This method has been employed to as- 

 certain 



I 



