266 ANNUAL OF SCIENTIFIC DISCOVERY. 



mation of this chromate. It is well known that serpentine contains 

 all the elements of chromate of iron, which, during the consolidation 

 of this rock, might separate themselves by the force of segregation, 

 so well known to operate in many geological phenomena. Two 

 facts, which seem to confirm this supposition, are, first, the existence 

 of the chromate of iron in masses and not in veins, and secondly, 

 the pale color of the serpentine associated with the chromate. One 

 small specimen, which I have, consists of white rock, principally 

 composed of carbonate of magnesia, in which chromate of iron in 

 small specks is visible. It is possible that this carbonate is the result 

 of the decomposition of the serpentine at the surface, by the action 

 of water containing carbonic acid. The chromate of iron occurs, 

 however, abundantly, and is disseminated in the rocks over a consid- 

 erable extent of territory. 



" In quitting the locality of the chrome, and going northeast, I trav- 

 ersed in several places the serpentine containing veins of carbonate 

 of magnesia, quite pure ; and this occurs until we arrive at the plains 

 of Eskihi-sher. It is from different parts of this plain that the 

 meerschaum, most esteemed in the arts, comes. The plain is a de- 

 posit of drift, being a valley filled up with the debris of the neigh- 

 boring mountains, consolidated by lime containing no fossils. The 

 meerschaum is found in this drift in masses more or less rounded, the 

 other pebbles being fragments of hornblende and magnesian rocks. 

 I have examined with care the neighboring mountains, which sur- 

 round the plain, and have found that the rocks are of the same nature 

 as the pebbles in the plain, except those of the meerschaum ; but, on 

 the other hand, I found carbonate of magnesia in the mountains, 

 which is not to be found in the plains. And this makes me suppose 

 that the meerschaum owes its origin to the carbonate of magnesia in 

 the mountains, decomposed after its separation by water containing 

 silica. In confirmation of this supposition, the meerschaum, which 

 has not been completely changed, has been found to contain carbon- 

 ate of magnesia. Another proof that the meerschaum owes its ori- 

 gin to the carbonate of magnesia is, that serpentine, similar to that 

 found in contact with the carbonate of magnesia in the mountains, 

 often adheres to the meerschaum of the plain." Sittimaii's Journal, 

 March. 



COAL FORMATIONS ON THE PACIFIC. 



MR. WILLIAM RIDLEY, of New York, in a report on the Isth- 

 mus of Panama, states that he has recently discovered near Costa 

 Rica, on the Pacific, a " deposit of bituminous coal of such excel- 

 lent quality, and in such abundance, as to realise every expectation. 

 The coal, as proved on the spot, although taken from an upper seam 

 and exposed for centuries to the action of sea-water, is highly bitu- 

 minous, igniting freely in the flame of a candle, emitting a fierce 

 flame, and leaving little residuum. In this respect it is fully equal to 

 the upper seams of the best Newcastle or Scotch coals, which are 

 generally considered superior for generating steam. 



