On (he Occurrence of Carbonate of Manganese in Ireland. 37 



ably great; but shortly afterwards, when the streamers shot 

 up to the zenith, and the arch of light was formed, the great 

 changes of declination took place, the disturbance of horizontal 

 force being at the same period comparatively inconsiderable. 

 After the period represented in the Plate, the disturbances 

 were diminished both in amount and frequency; and after 

 25'^ \2^ they entirely ceased. 



V. Note of the occurrence of a Deposit of native Earthy Cai-- 

 honate of Manganese in Ireland. By Sir Robert Kane*. 



THE place where this substance has been found is in the 

 townland of Glandree, parish of Tulla, in the eastern 

 portion of the county of Clare. The precise locality is near 

 the top of a mountain, about 900 feet above the level of the 

 sea, on the side of a new road connecting ScnrifFwith Gort. 



The rock of the locality is the old red sandstone, from under 

 which the clay-slate rises close by. The surface is, however, 

 very much covered by boulders of sandstone and by bog, and 

 broken into hummocks, separating little basins, in which de- 

 posits of marl, very rich in lime and of much value for agri- 

 cultural purposes, are usually found. The extensive employ- 

 ment of these marls made me very anxious to find additional 

 localities of them ; and I took advantage of a new road being 

 opened through the district during last year by the Board of 

 Works, to have collected for me specimens of all such materials 

 as in any way resembled marl, as could be found in the cut- 

 tings along the line of road. Amongst them, and from the 

 precise locality already stated, was one fawn-coloured earthy 

 matter which effervesced strongly with acids, especially when 

 heated, and which, on more exact examination, turned out to 

 be not carbonate of lime, but carbonate of manganese. 



This substance forms a layer of several inches thick, lying 

 under a stratum of bog of about two feet thick, and resting on 

 the partially decomposed surface of the underlying sandstone 

 and slate rocks. It is of a brownish-fawn colour generally; 

 but the parts that are quite free from admixture of peat are 

 much lighter, and indeed undislinguishable in colour from the 

 carbonate ol manganese artificially prepared. On being dried 

 carefully, it is Ibund not to be quite amorphous, but to consist 

 of nodules of a purer packed in a mass of less pure material; 

 but these nodules are so friable and soft, that few of them now 

 remain in the specimens that have been deposited in our mu- 

 seums. 



The composition of two different specimens oi this mineral 

 was Ibund to be — 



• CoiiiDiimicatccl hy the Author. 



