276 Mr Hardie 07i the Geology of the 



cult or of an unknown nature. ' If, in this spirit, we speculate on 

 the origin of kunkur, our attention will naturally be directed to 

 the great deposits of travertin and tufFaceous limestone, the pro- 

 duce of calcareous springs. The texture of the kunkurs, the 

 spheroidal, concentric laminar, and oolite forms which it assumes, 

 are characteristic of many of the travertins, which owe their origin 

 to the calcareous springs of Italy and other countries, while the 

 appearance of the kunkur beds, and their mode of distribution, 

 would all point to a similar origin. There seems no limit to the 

 power of production of such springs, and we need be under no 

 apprehension that the cause is not proportionate to the effect : 

 they issue from all kinds of rock, from the most ancient to the 

 most recent, and have been discovered to a greater or less ex- 

 tent in almost every country hitherto explored. 



My attention was first forcibly directed to the subject, on wit- 

 nessing the calcareous brine-springs of the volcanic island of 

 Java, and I was much struck by the great similarity between 

 several of the Javan tuffaceous limestones and the Indian kun- 

 kur-beds. The facts of this paper are copied without addition, 

 from notes taken previous to my visit to Java, and at a period 

 when I was rather inclined to take a different view of the origin 

 of kunkur, so that there is every security that I was not biassed 

 in making my observations by preconceived theory. 



The description which Lyell has given of the calcareo-mag- 

 nesian travertins of the baths of San Philippo, and other de- 

 posits of a similar nature, exhibits many points of analogy with 

 the account which I have given of the kunkur. Mr Lyell also 

 points out the striking analogy between the concentric structure 

 of the travertins and the spheroidal forms of the English mag- 

 nesian limestone of Sunderland, which last he supposes to have 

 been formed under " circumstances perfectly analogous**' to the 

 travertins of mineral springs. 



Mineral springs, both cold and thermal, rise up beneath the 

 waters of lakes and seas ; and the mineral substances to which 

 they gave birth, must be modified by the circumstances under 

 which the deposition takes place. Many of the Javan calcareous 

 tuffas have obviously been formed in this manner *, and the 



• The Javan beds include numerous remains of marine shells, which have 

 iu general a strong resemblance to shells of the present day. Mr J. D. E. 



