Souther n Indict, the origiji of Ike Kimkcr, 3,-c. 529 



and plants is tar more siliceous; so much so, indeed, as to re- 

 semble in some parts the siliceous tufa deposited by the hot 

 springs of Iceland, more than the common calcareous kunker 

 of India. 



The natives declare, that both the volume and heat of these 

 thermal springs (of which I have within the last two years 

 discovered several in the diamond formation) are on the de- 

 crease. There is no question that the spring under descrip- 

 tion is fast drying up, for the Redely of the village pointed out 

 to me land, now waste, which within the last fort}' years had 

 been irrigated by it. It now yields but a scant supply to the 

 cattle and the beasts of the forest. The traditionally accounts 

 of diminishing temperature are by no means so satisfactor}', 

 since the Hindoos had no means of measuring warmth or 

 cold. 



However, the examination of the deposits in and around 

 the mouth of this spring goes to support what the natives say, 

 assuming that the more siliceous deposit containing the fossils 

 is of an older date than the two at the bottom of the spring, 

 and formed when the spring was more abundant, and its water 

 hot enough to hold a considerable quantity of silica as well as 

 lime in solution, possibly combined. As the heat decreased, 

 the water would lose most of its silica, but still retain the lime; 

 at this period it may be inferred that the kunker was preci- 

 pitated as the water cooled on the earth's surface. As the 

 heat still diminished, the portion of lime brought up in solu- 

 tion decreased to the state in which we now see it. That such 

 is the fact, appears from the circumstance of the water of two 

 other and warmer springs, which I have since discovered in 

 the same formation, holding considerably more lime in solu- 

 tion than this. 



The waters of two other thermal springs in the same for- 

 mation still deposit lime as a kunkrous incrustation on their 

 sides and on the rocks in their course. 



These had a higher temperature, viz. 90° and 91° 3'; the 

 minerals held in solution are similar, but the proportion of 

 lime is greater. One fact is worthy of note, that they were 

 all slightly alkaline, and contained no perceptible free car- 

 bonic acid. 



In order to ascertain the interesting problem, as indicated 

 by the traditions of natives, and the difference between the 

 quantity and quality of the present and ancient deposits, viz. 

 that the heat of this part of the interior of the globe is de- 

 creasing, it would be desirable to keep a register not only of 

 the thermal springs of Southern India, but of those far hotter 

 fountains that gush from the great southern line of dislocation 



PhiL Mag. S. 3. Vol. 26. No. 175. Jime 184.5. 2 N 



