374 DR. R. D. THOMSON ON" MINERAL WATERS. Appendix B. 



B. 



ON THE MINERAL CONSTITUENTS AND ALG^E OF THE HOT-SPRINGS 

 OF BEHAR, THE HIMALAYA, AND OTHER PARTS OF INDIA, ETC., 

 INCLUDING NOTES ON THE FUNGI OF THE HIMALAYA. 



(By Dr. R. D. Thomson and the Rev. M. J. Berkeley, M.A., F.L.S.) 



The following remarks, for which I am indebted to the kindness 

 of the able chemist and naturalist mentioned above, will be highly- 

 valued, both by those who are interested in the many curious 

 physiological questions involved in the association of the most 

 obscure forms of vegetable life with the remarkable phenomena of 

 mineral springs ; or in the exquisitely beautiful microscopic structure 

 of the lower Alga?, which has thrown so much light upon a branch 

 of natural history, whose domain, like that of astronomy, lies to a 

 great extent beyond the reach of the unassisted eye. — J. D. H. 



1. Mineral water, Soorujkoond, Behar (vol. i., p. 27), contains 

 chloride of sodium and sulphate of soda. 



2. Mineral water, hot springs, Yeumtong, altitude 11,730 feet 

 (see vol. ii., p. 117) . Disengages sulphuretted hydrogen when fresh. — 

 This water was inodorous when the bottle was opened. The saline 

 matter in solution was considerably less than in the Soorujkoond 

 water, but like that consisted of chloride of sodium and sulphate of 

 soda. Its alkaline character suggests the probability of its con- 

 taining carbonate of soda, but none was detected. 



The rocks decomposed by the waters of the spring consist of 

 granite impregnated with sulphate of alumina. It appears that in 

 this case the sulphurous waters of Yeumtong became impregnated 

 in the air with sulphuric acid, which decomposed the felspar,* 

 and united with its alumina. I found traces only of potash in 

 the salt. 



Sulphuretted hydrogen waters appear to give origin to sulphuric 

 acid, when the water impregnated with the gas reaches the surface; 



I have, in my journal, particularly alluded to the garnets (an aluminous 

 mineral) being thus entirely decomposed. — J. D. H. 



