Annual Report of t]ie Council. li 



Sheffield, and he resigned in order that the Duke of Norfollc 

 might be elected to the presidency. He remained, however, on 

 the governing body of the College, and on the Charter for a 

 University being granted, he was appointed to the Council, was 

 a member of the Committee for the Department of Applied 

 Science, and held both these positions up to his death. 



Dr. Sorby's first research on sulphur and phosphorus in 

 agricultural crops was published in 1847 ; his last paper on 

 geology was written a few months before his death. 



In 1849, I^''- Sorby founded the science of petrography, 

 preparing in that year the first rock section ever examined by 

 transmitted light. His alleged " wild ideas " as to the capabilities 

 of his method were laughed at by the authorities of the period. 

 Indeed, for a young man, not long past his teens, to attempt to 

 upset the generally accepted dictum of de Saussure that moun- 

 tains could not be examined by microscopes, was regarded as 

 bordering on presumption. In the early 'fifties. Dr. Sorby was 

 much engaged on the subjects of the crystalline tetramorphism 

 of carbon and the vexed question of slaty cleavage. In connec- 

 tion with the latter, in spite of rebukes, he persisted in his work, 

 and in 1857 the young man of science disproved both the electric 

 and the 45° theories, by proving that slaty cleavage was due to 

 the fact that lateral pressure on argillaceous rocks compressed 

 them in one direction, elongated them in another, thus setting 

 the small particles with their longest dimensions parallel, and so 

 developing the characteristic structure in a plane perpendicular 

 to the pressure. 



In 1865, Dr. Sorby enunciated his now generally accepted 

 theory that the Cleveland ironstone hills had been originally 

 calcium carbonate, which had been gradually replaced by 

 carbonate of iron derived from associated strata. 



In the organic world Dr. Sorby did much work on colouring 

 matters, and in this connection, for practical value, his micro- 

 spectroscopic examinations of blood perhaps stand first. In 



