132 Geology of the Neighbourhood of the Caspian Sea. 



burning naphtha, but hydrogen gas (probably carbonated hydro- 

 gen), which rises through cracks and openings of the calcareous 

 rocks, and, on the approach of a flame, takes fire, and continues 

 to burn. It never takes fire spontaneously, nor by the approach 

 of red coal, if not burning with flame. The gas, as it escapes 

 from the rock, is without smell — is not sensibly warm — and, on 

 being respired, does not occasion any disagreeable feehng. It 

 burns with a yellowish -white flame, and forms with atmospheric 

 air an exploding gas. 



This perpetual fire, worshipped by the holy Indians of Baku, 

 does not differ from other ephemeral phenomena of the same 

 kind known in other parts of the world. 



Naphtha volcanoes, in a state of activity, occur at Baku and 

 Sallian, as also in several of the islands on the west coast. They 

 agree pretty nearly with the mud volcanoes in the peninsula, 

 Kertsch, and the Isle of Taman, described by Pallas ; and de- 

 serve more the name of naphtha volcanoes than mud volcanoes, 

 as their eruption always terminates with a pouring out of naph- 

 tha. Near to Baku, about one-fourth werst from the perpetual 

 fire, a heat rises out of a fissure of the shell-limestone, which is 

 so strong that the hand can scarcely bear it : hence, from all these 

 circumstances, we can scarcely doubt of the existence of a sub- 

 terranean heating process in the peninsula of Apscheron. 

 (To he concluded in next Nurnber.) 



On the Limit of the Lazv of Symmetry, and the Forces which 

 determine the actual Forms of Inorganic Bodies. Com- 

 municated by the Author. 



A LITTLE observation is sufficient to shew, that when material 

 masses are separating into parts, or, conversely, individual par- 

 ticles aggregating into masses, they have been subjected to some 

 law whose office is to produce symmetry along with individuality. 

 "Whether we look to the animal, the vegetable, or the mineral 

 kingdom, so universal is our expectation of finding symmetrical 

 forms, wherever we find individuals which are the spontaneous 

 produce of nature — and such an expectation can be founded on 



