30 Dr. Thomson's Analysis of a Specimen of Water. [July, 



did not, previous to the analysis, exist as such in the water ; for 

 the sulphate of soda was converted into muriate of soda, and 

 existed as such in the 21 '58 gr. of common salt. Now 0-304 gr. 

 of soda require 0*352 gr. of muriatic acid to convert it into 

 common salt ; so that the common salt which must be subtracted 

 from the residue amounts to 0*656 gr. Hence the common salt 

 contained in 500 gr. of the water amounts to 20*924 gr. 



Thus the anhydrous salts contained in 500 gr. of the water 

 from the boiling spring are the following : 



Grains. 



Common salt 20*924 



Miniate of lime 3*505 



Sulphate of soda 0*684 



25*113 



Upon comparing the quantity obtained by the analysis with 

 the weight of salts as deduced from the direct evaporation of a 

 portion of the water, it will be seen that the analytical result 

 exceeds the other by 2*453 gr. This difference is probably 

 owing in part to the too rapid evaporation of the water in an open 

 vessel, which doubtless occasions a loss ; but I think it not 

 improbable that a portion of the muriate of lime might have been 

 decomposed or carried off by the sudden application of a strong 

 heat to the salt. In the analytical processes, the heat was 

 applied much more slowly, and, therefore, the results are more 

 to be depended on. 



The saline constituents of this water differ in several respects 

 from those of sea water. They are more abundant, amounting 

 to live per cent, whereas those in sea water do not exceed 4*5 

 per cent. This difference is indicated by the specific gravity of 

 the water which is considerably greater than that of sea water. 

 Another remarkable difference is the absence of the magnesran 

 salts, which constitute so remarkable a constituent in sea water. 

 The proportion of sulphate of soda is also considerably less, and 

 that of muriate of lime considerably greater than in sea water. 



These circumstances, together with the presence of sulphuret- 

 ted hydrogen gas, can leave no doubt that the boiling spring, 

 whose analysis I have given in this paper, is quite different from 

 sea water. 



I regret that I cannot lay before my readers any informa- 

 tion respecting the nature of the island in which the spring 

 occurs. Tournefort mentions boiling springs in the harbour of 

 Milo, and describes the island as abounding in sulphur and iron 

 mines ; but T presume Milto is a different island from Milo, 

 though Tournefort takes no notice of it. 



