1829.] 
Expansion of Mercury. 
359 
its surface, were numerous pieces of siliceous stone, containing shells of the genera 
Turbo and Cyclostoma ; the specific gravity of the stone varied from 2,0 to 2,5. the 
shells did not effervesce in acids, although some of them preserved their external 
polish, fnternallv, some of the stones appeared to pass into flint, particularly 
those of small specific gravity, whilst their external surface effervesced in acids. 
Some of the small shells were completely changed into calced ny. Specimens of 
these shells are lodged with the Asiatic Society. 
It is a remarkable fact, that the only remains of animals, hitherto discovered in 
India, should be found in trap-rocks, and under quite peculiar circumstances. 
1st. They are found in situations where th«re are no indications of the former 
existence of lakes. 2d]y, Both the shells and matrix arc destitute of carbonic acid. 
3dly, The former are in many instances squeezed flat without fracture, and, in 
some cases, completely commixing with their matrix. 
These effects conld onlv have been produced by the agency of heat, an d conse- 
quently, the modern theory of sub-marine or sub-aqueous volcanoes, will best serve 
to explain the phenomena. These shells were deposited in the stratum of clay in 
which they are now found, and when forced up by the mass of wacken beneath, they 
were, most probably at the same time, covered by the nodular basalt. Thus we have 
heat to drive off the carbonic acid, and soften the shells under a pressure, which as- 
sisted the process, and at the same time flattened them. 
I have too numerous collateral proofs of the intrusion of the trap-rocks in this 
district, amongst the gneiss, to allow' me to doubt of their volcanic origin. I shall 
take an early opportunity of completing the history' of the trap-rocks of India, for 
which I have collected materials for several years past. 
III. On the Measure of Temperature and the Laws which regulate the 
Communication of Heat. By M.M. Dulong and Petit. With a plate. 
[From the Journal de 1’ Ecole Royale Polytechnique, T. xi ] 
§ 2. On the expansion of Mercury. 
Expansion of Mercury from 0° to 100°. 
Hallstroem, 
65 
of every desirable accuracy . 
