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HUGHES : ADAM SEDGWICK. 
Cambridg-e, in 1818, he modestly said he knew nothing- about geology. 
He had not paid special attention to the subject. His studies had 
been classics and mathematics, in both of which he was among the 
first few men of his year. But we know from many sources, that 
he had long- been an intelligent observer of geological phoenomena. 
As he wandered with his gun, or fishing- rod, among- the crags and 
up the streams of his native Yorkshire, he noticed the lie of the 
rocks and the occurrence of fossils. 
It was not long, therefore, before he attacked the most difficult 
questions relating to the physical structure of various parts of 
England. He read papers on the Lizard district, before the Cam- 
bridge Philosophical Society, in 1820 and 1821, in which, among 
other things, we find the Metamorphic origin of the Serpentine 
suggested. 
He published in the Annals of Philosophy a letter dated March 
17, 1822, on the Geology of the Isle of Wight, in which he confirms 
the views of Webster where opposed to those of Sowerby. 
In speaking of the green sand and chalk formation, he points 
out that " when the salt in the vicinity of Cambridge is perforated 
for the purpose of obtaining water, the first discharge forces up a 
quantity of green sand, a fact which indicates the existence of the 
green sand formation beloAv the salt. This sand he identifies with 
that seen passing under the salt in Bedfordshire ; points out the 
mixed character of the fossils in our upper green sand, and forms the 
classification and nomenclature of the beds round Cambridge which is 
still in use. 
The year 1822 is a very long time ago, and many genera and 
species have been re-named and re-arranged since then. 
In a syllabus published in 1821, for the use of his Geological 
class, he gives a classification of the sedimentary rocks, which holds 
good on all the chief points. Of course the older Palaeozoic rocks 
had not yet been worked out. He was, himself, the first to put 
them in order some ten years later. In those early days the Wer- 
nerian and Iluttonian theories were still subjects for difference of 
opinion, and many years later, referring to the Aqueous and Igneous 
theoi-ies, he said playfully, that for a long time he had been troubled 
