216 



only for specimens of coloured papers formed by the actual mixture 

 of the three primary colours, but also for many valuable suggestions, 

 of which, in the course of this paper, he has fi-eely availed himself. 

 It is the author's wish to be able to obtain a series of coloured 

 enamels complete, according to Mayer's and Lambert's classification. 

 Some he has already obtained from the Vatican Collection (of which 

 he gives a short description), and he hopes to render it more complete. 



3. Verbal Notice of Siliceous Stalactites on Arthur's Seat. 

 By Dr Fleming. 



Dr Fleming began by stating, that a paper of his, " On the Nep- 

 tunian formation of Siliceous Stalactites," was read before the So- 

 ciety, March 7, 1825, and published in " Brewster's Journal of 

 Science," for April of the same year, p. 307. To this paper Dr 

 Hibbert has referred, in his description of the " Limestone of Bur- 

 diehouse," Edin. Phil. Trans., vol. xiii., p. 280, but has misrepre- 

 sented, in an unaccountable manner, the facts which had been stated. 

 Dr Fleming, expressly said, in describing a limestone containing the 

 I'emains of dicotyledonous plants, and consisting of flinty and calcare- 

 ous layers, that it " dips under the great bed of limestone belonging 

 to the coal formation which extends north towards Linlithgow,'' which 

 " encloses the remains of those marine animals which are common in 

 the limestones of the coal formation." Dr Hibbert, on the other 

 hand, confounds the two beds, or rather represents the bed with the 

 vegetable remains as having been viewed as identical with the bed of 

 limestone with marine remains ; for he adds, " Dr Fleming's remark, 

 that this limestone encloses the remains of those marine animals, 

 which are common in the limestones of the coal formation, I con- 

 sider as a mistake.'"' The limestone, however, with vegetable re- 

 mains, had been described as differing in structure, and occupying a 

 lower position, than the limestone with marine remains. 



Dr Fleming then stated that, in the paper referred to, he had de- 

 sci'ibed siliceous stalactites as occurring in the trap-rocks of the north 

 side of Fife (a prolongation of the Ochils), and for some time looked 

 for similar concretions, in vain, in the corresponding rocks of Arthur's 

 Seat. Lately, however, he had detected them, hanging from the 

 under surface of a bed of porphyry interstratified with laminated 

 clay, at the Bog-Crag on the east side of the Hunter's Bog. The 

 aqueous origin of tiie stalactites would not now be disputed, nor, in 

 the present state of chemistry, would their occurrence excite surprise. 



