41 



that this arose from the experiments on which Hansteen founded his 

 calculation being aflfected by some degree of local attraction, from 

 the confined spaces in which the experiments were made. 



The magnetic intensity, as deduced from the time of 300 vibra- 

 tions in the reporter's experiments with the Society's needles, is, 

 with Hansteen's cylindrical needle — 



At Liverpool, mean of three series = 798". 21 

 At Manchester, from one series . = 798 .82 



With Dollond's flat needle— 



At Liverpool, mean of three series = 1052.83 

 At Manchester, from one series . = 1051.76 



The reporter also stated, that the magnetic dip at Liverpool, as 

 ascertained by several experiments made there by Lieutenant Allen, 

 RN. and himself, >vith a needle furnished by the Board of Admi- 

 ralty, for the late expedition up the Niger, is = 72° 2' 24". • 



The experiments on the dip, as well as two other series on mag- 

 netic intensity with a horizontal needle belonging also to the Admi- 

 ralty, were made on the same spot as those with the Society's needles, 

 viz. an open space in the Botanic Garden at Liverpool, 



3. Description and Analysis of a Mineral from Faroe, not 

 before examined. By Arthur Connell, Esq. 



The mineral in question was put into the author's hands by Mr 

 Rose, mineral-dealer of this city, as a substance supposed to be a 

 variety of mesotype. Mr Rose obtained it from Count Vargas 

 Bedemar of Copenhagen, who had brought it from Faroe. 



It has a pure white colour, with some opalescence and translucence, 

 a glistening vitreous lustre, and somewhat greater hardness than fluor. 

 Its texture is imperfectly fibrous ; but the fibres in some places diverge 

 with considerable regularity, shewing an approach to a crystalline 

 structure. The specific gravity is 2.362 ; it is remarkably tough and 

 difficultly frangible, so as to require much time and labour to separate 

 a mass of it into smaller fragments. 



It gives off water at a red heat ; and is fusible per se before the 

 blow-pipe only on the edges, without any swelling up. With soda it 

 fuses with effervescence into a semi-transparent glass ; with borax and 

 salt of phosphorous, gives colourless glasses ; and, with nitrate of co- 

 balt, presents no alumina reaction. It gelatinizes readily with muria- 

 atic acid when reduced to powder. The analysis was effected by 

 this reagent. After separating silica, the metallic oxides were thrown 

 down by ammonia, and the lime by carbonate of ammonia. The 



