334 On the occurrence of Metallic Iron in Fossil Wood. 



iron has been really deposited in the metallic state, and that the 

 singular mineral submitted to his examination presents the fii'st 

 well-established instance of the occurrence of terrestrial native 

 iron. 



Among the points on which M. Bahr bases his opinion, may 

 be cited the following : — 



The specimen of fossil wood in question was detached on the 

 28th of August 1798 from the thick end of the trunk of a tree 

 that was met with on the floating island in the lake of Ralang 

 in Smaland. This island, after being submerged for four years, 

 had risen to the surface the evening before. At the end of the 

 trunk there were two plates of copper, bearing an inscription 

 commemorative of the date when Gustavus III. visited this sin- 

 gular island, which appears in its origin to have formed a tongue 

 of land boarded ovei', which became detached from the mainland 

 by the action of the waters of the lake. It is usually submerged, 

 but from time to time it rises to the surface for a few days, most 

 commonly in the months of August and September. 



M. Bahr had submitted to him two specimens of this fossil 

 wood, which in its external appearance very much resembled a 

 fragment of limonite. The specific gravity of one of these frag- 

 ments was 3 "85, of the other only 2*94. When the surface was 

 brushed with the feathery part of a quill, metallic iron was ren- 

 dered visible, penetrating the general mass of the wood in a pul- 

 verulent form, or in the state of scales and angular and rounded 

 grains. This structure was more clearly seen by means of a 

 magnifying glass or of a microscope, which showed the fibres of 

 the wood separated by the pulverulent iron. Here and there 

 these grains of iron were of an appreciable magnitude, and were 

 joined together like beads in a rosary. A gi^wp of five such 

 grains was about a millimetre in length. In other portions of 

 the specimen they might be detached, leaving cavities resembling 

 the organic cellules. The specific gravity of this iron (in con- 

 sequence, probably, of its admixture with organic matters) is 

 very inconsiderable. In two trials it was found to be 6'248 and 

 6*4972 ; in a third and last experiment instituted with a grain 

 of iron flattened by the blow of a hammer, it was found to be 

 6-6255. 



M. Bahr analysed these grains of iron, having first freed them 

 as much as possible from all organic substances, and the results 

 that he obtained are stated below. The solution was efi'ected by 

 means of very dilute nitric acid, and the portion thus dissolved 

 amounted to 80"16 per cent, of the total weight of the grains, 

 and contained the following substances calculated in the form of 

 oxides : — 



