with Geognoxtical Observations, fyc. 131 



is more and more developed : It occupies towards the south 

 east a great part of the horizon. It commences on the right 

 with Elbrouz, where two summits rise high above the rest of 

 the other mountains, and it terminates on the left with Kas- 

 beck. This chain is more visible, as we advance to near the 

 mineral springs into a plain whose undulating surface rises 

 nowhere so high as to intercept the view of the mountains. 

 We observe, however, even here several insulated cones which 

 vise in front of the snowy crest, and whose sombre colour may 

 be distinguished from it. These are Bechtav and the other 

 trachytic hills which surround the hot springs. At Sablinsky, 

 and at Gheorgievsk, their aspect becomes more and more im- 

 posing : In quitting this last town, the capital of the Cossacks 

 of the line, we enjoy a very agreeable, and at the same time a 

 very instructive view, for we are struck with the relation be- 

 tween the forms of these trachytic cones and the central crest 

 of Caucasus, whilst the chain of mountains which separate them, 

 and whose height is much greater than that of Bechtav, pre- 

 sents a series of elevations whose undulating outlines form a 

 strong contrast with the precipitous rocks of which the central 

 chain is composed. 



Before reaching the hot springs the formations are observ- 

 ed to change : The mineral waters themselves rise from a 

 compact calcareous rock: The Mahouca, a mountain 1000 

 feet above the hot springs, and at the foot of which they have 

 their origin, is entirely composed of this rock : Fossils are 

 rarely found in this limestone : Ammonites and Terebratulites 

 have, however, been discovered. I shall call it the Ammonite 

 limestone, because this kind of fossil particularly characte- 

 rizes it. 



The hot springs which abound with carbonate of lime have 

 deposited a particular sediment filled with impressions of 

 leaves : This deposit is in some places considerably thick. It 

 covers entirely the foot of Mahouca, and rises here and there 

 along the flanks of this mountain, where it sometimes forms 

 small caverns. It is easily distinguished from the limestone 

 of which the Mahouca consists, because is is deposited in the 

 manner of sediment in thin and undulated strata. It is some- 



