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particles of water in a wave had been ascertained by 
observing how the waves broke on a coast, and by looking 
at them through a telescope. 
E. W. Brayley, Esq., F.R.S., F.G.S., &c, of London, 
then delivered a Lecture — 
ON THE ESSENTIAL CONDITIONS OF THE METAMORPHOSES 
OF ROCKS. 
Mr. Brayley, after alluding to the circumstances under 
which he appeared before the Members of the Society at 
the instigation of Mr. Ward, said that he had not had time 
to prepare a paper, but he had selected a subject lately dis- 
cussed by the Geological Society, and which had been ably 
treated by David Forbes, brother to the lamented Professor 
Edward Forbes. 
It was a subject of lamentation that the relations of 
chemistry to geology, and of geology to chemistry, had not 
been properly attended to by scientific men. Mr. Forbes, 
however, had followed up investigations of a combined 
character with respect to the metamorphic rocks of Norway, 
and he had endeavoured to ascertain what changes could be 
effected by using intensely heated iron furnaces. These 
experiments had led to the discussion of this subject. Mr. 
Brayley then proceeded to point out the nature of metamor- 
phic rocks, in which we recognise the joint action of fire and 
water. He then referred to the quarries of Carrara marble 
in Italy, which have been worked between 2,000 and 3,000 
years. This marble was pure carbonate of lime, and if 
burnt well it would become quick lime resembling loaf sugar. 
In one respect this marble resembled the crystalline rocks, 
such as granite, as it contained no indications of organic 
remains, as all sedimentary deposits do. From this circum- 
stance it was supposed that it was a primary formation ; but 
subsequent investigations have changed the views of geologists 
