318 ANNUAL OF SCIENTIFIC DISCOVERY. 



thorough revision ; that, when there had been a more careful comparison 

 of well- characterized specimens, European with American, it would be 

 found that the number of species common to the two continents had been 

 much overrated ; that of recent plants, as well as animals, a large number 

 of species were at one time considered common to the two continents ; 

 but more recently constant characters had been observed in most of these 

 species which served to separate the one from the other. In recent Cryp- 

 togamic botany many species which at first sight seemed identical with 

 those of Europe had been found upon careful study to be specifically dis- 

 tinct. His observation, as far as it had extended, prepared him for the 

 same result following a careful examination of our fossil plants. 



He said, that of the new species, of which he now submitted descriptions 

 to the Association, nearly all were from Northern Ohio, which was due to 

 the fact that this region had been most carefully studied by him, and that 

 the specimens from which Brongniart's and Bunbury's descriptions and 

 figures of American fossil plants had been drawn were mostly from the 

 upper part of the series, where, as before stated, the flora was specifically 

 quite different. 



ON THE STRUCTURE OF COAL. 



At the meeting of the British Association, Dr. Redfern presented a 

 communication respecting the structure of coal, especially that of Torbane 

 Hill, Scotland, which resembles the Albert coal of New Brunswick, and, 

 like that, has been the subject of legal dispute as to whether it were indeed 

 true coal, or only asphaltum, or bitumen. He introduced the subject by 

 observing that for all commercial purposes we know sufficiently well what 

 coal is, notwithstanding the difficulty of framing a correct scientific defi- 

 nition of it, and that the popular acceptation of ordinary terms ought 

 never to give way in courts of justice before differences of opinion amongst 

 scientific men. He stated that it was his intention to bring before the 

 Section a number of facts observed by himself, of which he believed many 

 to be new and of great importance, and to show that all the facts ob- 

 tained from geological, chemical, and microscopical investigations point to 

 the same conclusions. He then showed that the Torbane Hill coal is lami- 

 nated, and splits with great ease horizontally, like many Cannel coals, and 

 that, like them, it may be lighted at a candle. In all parts of the bed, 

 stigmaria and other fossil plants occur in greater numbers than in most 

 other coals. They present themselves on all fractured surfaces, either in 

 the form of small angular facets on different planes, or of large surfaces 

 on which very distinct vascular tissue may be easily recognized by a com- 

 mon pocket lens. When the microscopical appearances of a fossil stig- 

 maria are compared with those presented by a section taken in the same 

 direction in any part of the bed, they are found essentially similar ; which, 

 when taken with the fact that Go per cent, of the mass consists of carbon, 

 is good, if not altogether conclusive, evidence that the whole bed is a mass 



