2 ON THE COMPOSITION OF PURTON SALINE WATER. 



These constituents arranged into compounds give the following 

 results : 



Grains 

 per imp. gal. 



Organic matter and water of combination (loss on 



drying residue at 320F) . . . . . . 8' 750 



Sulphate of soda .. ... 112-239 



Sulphate of magnesia . . . . . . 77*208 



Bromide of magnesium . . . . . . '092 



Iodide of sodium . . . . . . . . '066 



Chloride of sodium .. .. .. .. 34-297 



Sulphate of lime . . . . . . . . 83*873 



Sulphate of potash . . . . . . . . 1'916 



Carbonate of potash . . . . . . . . 28'880 



Oxides of iron and alumina with traces of phosphoric 



acid .. .. .. .. .. '280 



Silica 1'280 



Solid residue, dried at 320F per imperial gallon 348-881 

 Free carbonic acid . . . . . . 23'820 



Dr. Noad has communicated his results to me. They differ 

 materially from mine. But the fact that the water analysed by 

 Dr. Noad contains a great deal more solid matter than the water 

 analysed by me, shows sufficiently that we examined two different 

 specimens of Purton water. I have determined at various times 

 the amount of residue which is left on evaporation, and find great 

 differences in the total amount of total saline matters. Probably 

 the composition of the saline residue varies at different seasons, 

 and the water, like other saline waters obtained only in limited 

 quantities, is not always of the same composition. 



With respect to the arrangement of the direct results of the 

 analysis into compounds, I beg to observe that I have purposely 

 united carbonic acid with potash and not with lime. In his 

 arrangement of results, Dr. Noad does not give any alkaline 

 carbonates. "The Purton water, which I examined, however, con- 

 tains alkaline carbonates, for it exhibits a strong alkaline reaction 

 to litmus paper, even before evaporation. 



It is of course impossible to say what proportions of the carbonic 

 acid and sulphuric acid are united with lime and the alkalies, and 

 I have deviated from the ordinary mode of uniting acids and bases 

 together, because the Purton water in its natural condition really 

 contains alkaline carbonates. 



