3S0 NOTES ON THE GEOLOGY 



I am indebted for the specimen of this water, No. 555, to the Prin- 

 cipal of the Mount Holyoke Female Seminary, who received it 

 from Rev. Mr. Sherman, American missionary at Jerusalem. 



Tlie taste of this specimen is decidedly acid, somewhat hke 

 weak vinegar. On mixing it wilh a delicate purple infusion of 

 the blue petals of a flower, it changed the color to red ; and this 

 remained unchanged for several days, precisely like a test exper- 

 iment with nilric acid. It is impossible, therefore, that the acid 

 should be the carbonic. It may, indeed, be a metallic salt, and 

 not a free acid, which gives it its acid taste. But so decidedly acid 

 is the taste, that I could not but suspect the specimen may have 

 been accidentally put into a vessel containing an acid ; and yet 

 this is not probable. I regret that the small quantity of water in 

 my possession has not allowed me to do any thing more towards 

 its analysis, than to make a few tentative processes ; and even 

 those could not be repeated. I should not state them at aU, so 

 imperfect are they, had I ever met with any account of the ingre- 

 dients in this very interesting water. I operated upon only fifty 

 grains of the water with each reagent, and obtained the following 

 results by a single ti'ial. 



In five hundred grains I find. 



Sulphuric acid 0.78 grains. 



Chlorine, 0.49 " 



Magnesia, 0.04 " 



Lime, a very distinct trace. 

 The ferro-cyanuret of potassium gave a green color to the water, 

 and, in flic course of a few hours, a blue precipitate, whence I 

 infer, that the water is ferruginous and alkaline. {TraiU de 

 Chimlc par Berzelius, Tome Hidtieme, p. 85. Bruxellcs, 1840.) 

 Though little dependence can be placed upon the preceding 

 results as to the proportion of the ingredients, yet fliey indicate, 

 clearly enough, that Siloam must be a rather powerful mineral 

 water. Indeed, Dr. Robinson states, that when flie pool is low 

 it is unfit for common purposes. It is much to be desired that it 

 should receive a thorough analysis. 



The second division of countries to which I wish to call the 

 attention of the Association, embraces a few islands in the Gre- 



