202 PROCEEDINGS OF METROPOLITAN SOCIETIES. 



penetration of his friend Mr. Lyell, who long previously had enter- 

 tained a suspicion that the chalk had formerly extended over a con- 

 siderable portion of the north-west of Scotland ; for, although this 

 actual stratum had not yet been traced, still the approximation to it 

 afforded by the successive discovery of the immediately subjacent 

 beds, combined with the fact that flints containing chalk fossils 

 occurred abundantly on the summits of many hills, distinctly indicated 

 the denudation that had taken place, some traces of which had also 

 been remarked in Scandinavia. In the conversation which followed, 

 several remarkable identifications of Elgin lchihyolites by M. Agas- 

 siz, who, unaware of the locality whence they were obtained, had 

 assigned them expressly to particular strata of the south of England, 

 were read from a letter received by Mr. Murchison from Mr. Mal- 

 colmson, penned subsequently to the communication of his paper 

 which had been brought forward that evening. 



May 9th. — The business of this meeting commenced with the 

 description of a fine vegetable fossil, a species of Stembergia, par- 

 ticularly interesting as being parasitically attached to what was ad- 

 judged to be a portion of the stem of a Tree-fern. After this, a 

 communication was read from Mr. Williamson, of Scarborough, being 

 a continuation, or resumed description, of the geology of the adjacent 

 part of Yorkshire. Next, a long and very interesting paper, by Mr. 

 Smee, engaged attention for the remainder of the evening, upon the 

 changes which animal matter undergoes in the process of becoming 

 fossilized. In this it was clearly shown, from a variety of direct ob- 

 servations made upon human bones that had been inhumed for a 

 longer or shorter period, and of which the most ancient had been 

 obtained when digging for the foundations of the cathedral of Old 

 Sarum, together with those of different animals, of various degrees of 

 geological antiquity and of petrifaction, also from carefully conducted 

 experiments upon shells and other animal exuviae, that the carboniza- 

 tion of the animal (as distinguished from the earthy) matter which 

 they contain, is superinduced during putrefaction, and accordingly 

 affords no datum for determining the relative age of fossils. After 

 the conversation whicn ensued, Sir Phillip Grey Egerton drew atten- 

 tion to some casts of portions of the cranium of Mastodon longiros- 

 tris which he had laid on the table, and which he suspected to be of 

 the same species as the Mastodon of which teeth had been obtained 

 in the English crag, hitherto referred to M. angustidens, which lat- 

 ter, he had reason to believe, had never been met with out of India. 

 Mr. Charles worth bore testimony to the general similarity of the 



