HBPORT ON MINERAL AND THERMAL WATERS. 15 



springs of Lucca by Sir H. Davy*; the body combined with it 

 being, not the cra-bonic or sulphuric acid, but silica. 



Sir Humphry suggests, that the ochreous deposit so frequent 

 in hot springs, as at Mont Dor, Bath, &c., may be a similar 

 chemical compound, tlie iron originally existing in the state of 

 a protoxide, but passing into that of a peroxide upon exposure 

 to air. 



Though the iron however is thrown down from the water in 

 this condition, it does not follow that it exists there in the same, 

 since, in proportion as the carbonic acid which had upheld it 

 escaped, the silica present in the water might begin to exert its 

 affinity, and be carried down along with the metal. 



Iron has also been found by Dr. Thomson combined with iron with 

 muriatic acid in the mineral water of Mitchill in the parish of ^^"^"'"'^ 

 Nielstont, near Glasgow, and by Lachmund in the aluminous 

 ■water of Buckowine in Lower Silesia J. 



Manganese was discovered many years ago by Becher in the Manganese. 

 springs of Cai'lsbad ; and recent observations have shown that 

 it is by no means uncommon either in cold or in thermal waters. 

 Thus it has been found in the chalybeates of Pyrmont§, Ma- 

 rienbad. Seltzers, and Fachingen ; at Luxeuil near Paris || ; at 

 Adolphsberg in Sweden; and in several springs in Russia. Also 

 in the thermal waters of Carlsbad and Ems ; the sulphiu'eous 

 ones of Neundorf and Eilsen ; the aperient ones of Seidschutz ; 

 and the brine springs of Kreutznach. 



It has likewise been met with as a deposit from the thermal 

 water of Popayan in the Andes *^. 



Zinc combined v.ith sulphuric acid has been found by Berze- Zinc. 

 lius in small quantities in a mineral water at Ronneby in Swe- 

 den**, probably under circumstances similar to those, under 

 which copper is occasionally met with in streams flowing 

 through beds of copper pyrites. 



Strontian lias been detected in the chalybeates of Seltzer ff strontian. 

 and Pyrmont JJ, and in the thermal waters of Carlsbad, Konig- 

 worth, Aix la Chapelle, and Borset§§. It seen:is also to exist in 

 small qnantities in the springs of Bristol, it having been found, 

 as I am informed, in a stalag'iiitical deposit incrusting the pipes 

 that convey water to that city. 



* Anuales de Chimie, vol. xix. from the " Memoirs of the Academy of 

 Naples." 



f Records of Science, \o\. iii. p. 418. + Bley> Taschenbiich. 



§ See Bley, Taschenbuch for the German springs. 



II Annules de Chimie, 1821. If Boussingault, Annales de Chimie, 1833. 



** Brandes' Archiv, b. xiii. as quoted by Osann. 



++ Struve, Kunstlich Miner. XX Brandes' Pyrmonfs HeilqucUen, 



§§ Bley's Taschenbvch. 



