■ 



366 /. Lawrence Smith on the Thermal Waters of Asia Minor. 



J 



HoLighite rather favor the ratio 1 : 1 J. The approximation shows 

 at least the close relation of the two minerals. As part of the 

 water of constitution was evidently driven off by excessive heat 

 in drying, the per-centage of this ingredient is yet to be ascer- 

 tained. The grayish mineral forming the interior of the masses 

 is not foliated like Volknerite^ but this structure may not be 

 more essential here than it is in gypsum- The nodules are often 

 somewhat fibrous radiated. The presence of carbonic acid in 

 the exterior of the nodules is apparently due to an alteration of 

 the true hydrous mineral, from the action of the carbonic acid 

 of infihrated waters or the atmosphere. The hydrotalcite of 

 Hochstetter, which Hermann refers to YolkneritCj afforded 10-54 

 p. c, of carbonic acid.* 



The mineral has probably resulted from the alteration of spinel, 

 judging from the many specimens the writer has seen. There 

 is a passage from the perfect octahedrons with sharp edges, to 

 those that are uneven and rounded as if by corrosion from 

 chemical action, and from these to the flattened nodule ; and the 

 nodules are such forms as would result from a softening and 

 pressure accompanying the metamorphic change, together with 

 the crystallizing or semi-crystallization of the new mineral. 



J. 



D. D.] 



Akt. XXXYIII.— 0/i some of the Thermal Waters of Asia Mi- 

 nor; by Dr. J. Lawrence Smith, of New Orleans, Prof Chem. 

 in the University of Louisiana. — Part IL Waters of Yalova^ 

 Hierajpolisy Eski-shehTy Troy^ Mitylene and Tiberias, 



Thermal Waters of Yalova,\ 



The shortest way of reaching the springs of Yalova is by land- 

 ing on the south side of the Gulf of Nicomedia, near to Angori, 

 (three hours distant from Constantinople by steamer,) and proceed- 

 ing along a beautiful plain, that gradually narrows until termina- 

 ting in a valley closely shut in by hills. The springs in question 

 are situated in this valley, about six miles from the sea; they 

 are at the foot of a hill, which on the southwest closes in the 

 valley of Yalova and are known in the country by various names, 



as Couri-Hamam^ Dagh-Hamam, &c. 



On the road that approaches the springs, there are extensive re- 

 mains of the foundations of old Roman and Grecian buildings, and 

 still nearer, the remains are more perfect, in the form of arches, 



* See Dana's Mineralogy-, p. 201. 



f Tlie locaiity^ of these waters is described very fully as it is but little knovn, 

 being seldom visited by travellers. 



