Proceedings of the IVernerian Society, 401 



to a white heat with pure carbonate of potash, — the same salt cm- 

 ployed in the preceding cases of conversion. A large crucible was 

 worked seven successive times with 9334 grains in all of ferrocyanide 

 of potassium ; and 1240 grains of silicic acid were produced. 



The author added, that, in the course of several of these operations, 

 more especially those of the last section, he found the iron to undergo 

 conversion as well as the carbon ; and in a subsequent paper he pro- 

 poses to state in detail the facts which lead him to the conclusion that 

 this metal is a variety of the same elementary form with rhodium. 



Proceedings of the IVernerian Natural History Sodietyt 

 (Continued from Vol. xxx. p. 441.) 



March 20. 1841. — Dr Traill^ Vice*President, in the Chair. 



A communication was read on the results obtained by Professor 

 F. L. Leuckart of Freiburg, in Baden, from his extensive invcstigationg 

 t)n the intermaxillary bone. A notice was given by Mr Milne, advo- 

 cate, of a black scum which had appeared on Loch Voil in Perthshnc 

 during the last week of February, and of which a quantity had beeil 

 collected sufficient to fill two quart bottles. One of those was exhi- 

 bited. The liquid, when poured out, was of a dark grey colour. It 

 was described as having an oily appearance when on the water, and 

 when disturbed, it formed bubbles on the surface ; when touched, it 

 blackened the fingers. There had been no rain in that part of the 

 country for five or six days previous ; and there being little snow on 

 the hills, the streams were not in the least swollen. On the morning 

 on which the scum was observed, there was a slight frost, and the 

 weather was very calm, A thick fog hung over the lake till noon, 

 when a breeze sprung up which dispersed the scum. Mr Stewart of 

 Ardvorlich, from whom Mr Milne obtained his information, stated that 

 the substance had every appearance of being the same as what covered 

 Loch Earn in February 1837- Mr Milne mentioned, that, on that oc- 

 casion, the substance was proved to have fallen in the atmosphere in 

 the form of a fine powder, and that clothes bleaching were Covered by 

 it. The same phenomenon had been observed in October 1839; 

 throughout the district of Strath earn. Mr Alilne stated, that, in Oc-» 

 tober 1755, a black powder had fallen in great quantity in Zetland* 

 which besmeared the hands, faces, and «iotii%s of workmen in the fields. 



