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^c^rntrrMiigH nf InthtitH. 



Royal Society of Edinburgh.— On Monday evening, February 6th., 18-54, a paper was read by 

 Professor Bennet, being "Observations on the strueture of the Torbanehill mineral, as com- 

 pared with various kinds of coal." Dr. B. explained the nature of his investigations on this 

 subject, which were chiefly confined to a very careful examination, by the microscope, of the 

 Torbanehill mineral, and of all the different kinds of coal, including those kinds to which the 

 Torbanehill mineral was said to be allied. He was clearly of opinion that the Torbanehill mineral 

 was a substance quite distinct from coal, and not to be confounded with it by any one who paid 

 strict attention to the microscopical characters of the two substances. By the aid of a series «f 

 elegant drawings, he explained the peculiarities of the different kinds of coal, and pointed out 

 the structure by which the Torbanehill mineral is distinguished. Coal he believed to be formed 

 by coniferous wood, and the structure which coal exhibited under the microscope accorded with 

 this idea; but, in the Torbanehill mineral, the wood fibres of ConifersB were not seen. Jle par- 

 ticularly referred to certain bodies of a circular form, which were seen in transverse sections 

 of all true coals, when examined under a high magnifying power. These bodies he considered 

 to form the true mark of coal, and he had never failed to find them in any specimens of true 

 coal. But in the Torbanehill mineral they did not occur, and their absence showed it not to 

 be a kind of coal, but a mineral having a different origin. 



The bodies or appearances in question were considered by Dr. Bennet to be the ends of woody 

 tubes, and in this manner he endeavoured to show that true coal is iiecessarily made up of such, 

 the tubes being in all cases those of coniferous wood. He also directed attention to the characters 

 afforded b}' the presence or absence of tissues in the ashes of coal and substances with wiiich 

 coal was apt to be confounded. In some cases coals did not exhibit their organic structures until 

 they were submitted to partial combustion ; hence in the ashes of coals generally, the wood-cells 

 (Coniferifi,) of which the coal had been formed, could be easily traced. The Torbanehill mineral 

 was remarkably different in this respect, for although its ashes had been very carefully exaniinedj 

 no traces of organized structure could be detected in them; and on this part of the subject, as 

 on several others. Dr. Bennet specially referred to the investigations of Mr. Quekett, as detailed 

 in the "Transactions of the Microscopical Society." Dr. Bennet stated that those bodies which 

 had been called "cells" in the Torbanehill mineral, did not exhibit the character of cells; they 

 were merely spherules of bituminous matter; and the fact that they polarized light was sufficient 

 evidence of their not being vegetable cells. The bituminous matter, moreover, was stated by 

 Dr. Bennet to be the same as that found in Binny quarry, which was there used by the work- 

 men for illumination, and he exhibited a specimen of the substance. He then proceeded to 

 inquire into the nature of the organic structure seen in the Torbanehill mineral. There could 

 be no doubt about the fact that such structures occur in the mineral; namely, the scalariform 

 ducts of cryptogamic plants; but when such a specimen occurred, it was merely accidental, and 

 no more to be regarded as entitling the mineral to be called vegetable, than the occunence of 

 a fossil bone or tooth in a rock entitled it to be called animal. That the scalariform vascular 

 tissue could not belong to Conifers; was proved by the fact, that no Conifera; in this country 

 exhibit cross fibres in their wood cells. Even if it were granted that the yellow bodies in the 

 mineral had the character of vegetable cells, and that the ducts, occasionally found amongst 

 them, were the tissues of the same plants. Dr. Bennet considered it impossible to conceive a 

 plant having such a superabundance of cellular tissue with such a paucity of vessels; for the 

 latter would be quite inadequate for the nourishment of the former, and with such a structure 

 of course, the plant could not exist. It was, therefore, clear that the Torbanehill mineral was 

 not a fossil plant. 



Dr. Bennet exhibited a series of specimens to show the manner in which the Torbanehill 

 mineral was sometimes intermixed with coal, — thin seams or layers of coal running through 

 the mineral, both, however, always retaining their characters unaltered. Such specimens he 

 thought, were likely to give rise to error in observation, as under the microscope an accidental 

 fragment of coal might be looked at instead of the proper mineral. If observers were, in all 

 cases, careful to guard against this source of fallacy, they would have no difficulty in distin- 

 guishing the Torbanehill mineral from coal. For the purpose of showing the view taken of the 



