1870-1871 ILLNESS OF MURCHISON 307 



and he discussed the subject in two papers communi- 

 cated in January and March 1871 to the Geological 

 Society. One of these dealt with the red rocks of 

 Palaeozoic age, and the other with those of later date. 

 He was likewise turning his thoughts more frequently 

 and earnestly to the history of topography, and espe- 

 cially to the origin of river-valleys. He gave a series 

 of lectures on that subject during this year, and after- 

 wards condensed the substance of one or two of them 

 into a paper on the ' River- courses of England and 

 Wales,' which was read before the Geological Society 

 on the 7th February 1872. 



Much anxiety was felt during the year 1871 as 

 to the health of the distinguished Director- General 

 of the Geological Survey. On the 3<Dth November 

 1870 he had a stroke of paralysis, which at the time 

 deprived him of the use of his left side. But he 

 rallied so far as to be able to take carriage exercise, 

 and to attend to a good deal of business. It was 

 evident, however, that he would never again be fit 

 to resume his place in the scientific world, though he 

 might possibly linger long. Trenham Reeks, his faith- 

 ful secretary, and Registrar of the School of Mines, 

 used to see him at his house daily, bring official and 

 other letters, arrange about the answering of them, 

 and despatch frequent bulletins to members of the staff 

 as to the condition of the chief. Murchison never 

 again set foot in the Museum in Jermyn Street. 



But as there was no immediate prospect of serious 

 change in Sir Roderick's condition, Ramsay took the 

 field among his men in the spring of 1871. Some 

 further letters from him show what he was doing 

 and thinking about during the summer and autumn 

 of this year. 



