Kin ah an — On Irish Metal Mining. 263 



in the continental minerals, by all known processes, there is a loss 

 of from 6 to 8 per cent, that cannot be abstracted ; on this 

 account the Irish clays compare much more favourably with the 

 continental than the Table suggests. Many of the beauxytes and 

 woeheinytes contain much more iron than the above, iron having 

 been made from a variety of the latter. Of beauxyte Dana gives 

 three analyses ; containing of iron respectively, 27*6, 3'0, and 349 

 per cent. The Irish clays contain much more silica than is found 

 in the French or German. The Beauxyte, however, which gave 

 30 Iron is white in colour and gives 21*7 of silica. 



The Canizoic (Eocene ?) iron-ore trade is also of recent develop- 

 ment. In 1609 Chichester mentions ore, while in 1683 Dobbs 

 uggested that it existed in Island Magee ; but it would appear 

 that it was not generally known before 1861, when Dr. Ritchie 

 specially directed public attention to those iron-ores. Afterwards 

 they were successfully worked, until the slack in the iron trade, 

 since which time, although not as successful as previously, there 

 is a sufficient demand for the ore to keep some of the workings still 

 going. 1 The occurrence of the pisolitic-ore is peculiar ; for, although 

 it appears as if bedded, its genesis probably was long subsequent to 

 the formation of the associated rocks. The pisolitic iron- ores fill 

 horizontal shrinkage fissures, the accumulations having characters 

 more or less analogous to those of standing lodes. — (See Seien. 

 Proc, R. D. S„ vol. iv., 1884, p. 312.) 



The steatyte at the path to the Gobbins Island Magee was 

 formerly worked as " French chalk." 



In places the doleryte is decomposed into a rich ochre. Of 

 ochre found at Mr. M' Arthurs, near Ballymena, Apjohn writes : 

 " The silex of the basaltic ochre is at present in a state of 

 extreme division ; and from this circumstance, and the great depth 

 and beauty of its colour, it appears well suited to the purpose of a 

 red paint for gates, railings, and other descriptions of outdoor 

 work. 



The Jurassic beds (Lias) are very sparingly represented ; but in 

 them are apatitic nodules (phosphates). These, however, have not 

 been found in sufficient quantity to be utilized. 



1 Quite recently (1885) arrangements have been mad* to work an accumulation 

 found in Rathlin Island. 



