Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/265

1869.] occasion of the reading of the Duke of Argyll's paper on the " Leafbeds of the Isle of Mull." The plant-remains were obtained on the shores of Lough Neagh, near Shane's Castle, and opposite Ram's Island, on the east shore of the Lough. These and other species additional to those enumerated by Mr. Baily from the Antrim basalt concur to fix the period of their growth on the horizon of the Upper Miocene, and to establish a contemporaneity with the florula of the Basalts of Mull.

Amongst the plant-remains from the ash-beds on the shore of Lough Neagh, collected by Dr. Bryce, we recognize Platanus aceroides, Sequoia Langsdorfi, species of Juglans, Fagus, Laurus, &c. And from the sedimentary ochreous beds at Ballypalidy we have collected the following unrecorded forms : — Eucalyptus oceanica, Ung., Hakea, sp., Celastrus, sp., Daphnogene Kanii, Heer ?, Graminites, sp., &c.

V. Economics and mineral Statistics.

The Antrim iron-ore, though of but recent introduction, has already attracted some attention among the iron-masters in England. Its freedom from deleterious substances, such as phosphorus and sulphur, and from any qualities injurious to the production of superior iron, commends it highly, while the presence of titanic acid in the pisolite-bed adds much to its value for the production of steel. But it is the high percentage of alumina that claims for this ore peculiar importance.

Mr. S. Evans, who has introduced much of this ore into England, informs us that its value as a flux is becoming more and more appreciated, and that the furnaces of Cumberland and Lancashire are now supplied with large quantities for mixing with the siliceous haematites of that district. The effect of combining these two ores in the furnace is to soften the slag and to produce what is called a " loose load," which allows the metal to pass through with facility, and at the same time acts as a protection to the inner casing of the furnace. But, in addition to these valuable properties, the alumina determines the separation of the silica from the haematite-ores, thereby producing from a given quantity a larger percentage of metallic iron than could otherwise be obtained.

The great difficulty hitherto has been to produce an iron free from silica for the Bessemer process of steel-iron making. The Cumberland ore has been found well adapted for producing this steel ; but the contained silica has always been a drawback, injurious and difficult to remove. The great demand is for an iron free from silica ; and since the Antrim ore has entered the market this desideratum has been accomplished : it contains little or nothing deleterious, and yet has within itself the essential properties for making a superior steel-iron, while the large excess of alumina acts as a purifier to the richer ferruginous ores, and has thus enabled the Cumberland and Lancashire furnaces to stand first in producing the most suitable iron for Bessemer's process.

It is not difficult to discern that other districts will soon learn the