190 Geological Gleanings. 



ceeds 8 or 10, and in bad samples even 15 or 20 per cent. The 

 ash may be argillaceous, argillo-ferruginous, calcareous, or calca- 

 reo-ferruginous. The ferruginous ashes are always more or less 

 red or tawny in color from the presence of sesqui-oxide of iron, 

 derived from the iron pyrites (Fe S 2 ) originally present in the 

 coal. If much pyrites be present, the coal is not available for 

 furnace operations, gas making, engine use, &c, owing to the in- 

 jurious effects of the disengaged sulphur. Calcareous ashes are 

 more common in Secondary and Tertiary coals than in those of 

 the Palaeozoic Age. 



Lower Carboniferous Coal-measures of British America. — A 

 paper by Principal Dawson, giving an account of the present state 

 of knowledge respecting these interesting beds and their fossils, 

 was read before the Geological Society of London, at its meeting 

 of April 28th. The following is from the Abstracts of Proceed- 

 ings of the Society : 



" Deposits indicating the existence of the Coal flora and its asso- 

 ciated freshwater fauna at the beginning of the Carboniferous 

 period, are well developed in Nova Scotia and New Brunswick, 

 with a clearness and fulness of detail capable of throwing much 

 light on the dawn of the terrestrial conditions of the Coal-period, 

 and on the relations of these lower beds to the true coal-measures. 

 This lower series comprises shales and sandstones (destitute of 

 marine remains, but containing fossil plants, fishes, entomostraca, 

 worm-tracks, ripple, and rain marks, sun-cracks, reptilian foot- 

 prints, and erect trees) and great overlying marine limestones and 

 gypsums. These are distinct from the true coal-measures by their 

 position, mineral character, and fossil remains. In the western 

 part of Nova Scotia (Ilorton, Windsor, &c.) the true (or Upper 

 and Middle) Coal-measures are not developed ; and here the 

 Lower Carboniferous marine deposits attain their greatest thick- 

 ness. The lower coal-measures (or Lower Carboniferous fresh- 

 water or estuarine deposits) have here a thickness of about GOO 

 feet. These beds are traceable as far as the Shubenacadie and 

 Stewiacke Rivers. They outcrop also on the south side of the 

 Cobequid Mountains, where the marine portion is very thin, owing 

 perhaps to the fact of these mountains having been land in the 

 coal-period. 



Along the northern side of the Cobequid Range the upper and 

 middle coal-measures and the marine portion of the Lower Car- 

 boniferous series are of great thickness. The freshwater beds 



