Ɛpsilon

To John Lubbock   [18 September 1881]1

[Down.]

Sunday evening

My dear L.

Your address has made me think over what have been the great steps in Geology during the last 50 years, & there can be no harm in telling you my impression.2 But it is very odd that I cannot remember what you have said on Geology.— I suppose that the classification of the Silurian & Cambrian formations must be considered as greatest or most important step; for I well remember when all these older rocks were called gray-wacke, & nobody dreamed of classing them; & now we have 3 azoic formations pretty well made out beneath the Cambrian!3 But the most striking step has been the discovery of the Glacial period: you are too young to remember the prodigious effect this produced about the year 1840(?) on all our minds.4 Elie de Beaumont never believed in it to the day of his death!5 The study of the glacial deposits led to the study of the superficial drift, which was formerly never studied & called Diluvium, as I well remember.—6 The study under the microscope of rock sections is another not inconsiderable step.7 So again the making out of Cleavage & the foliation of the Metamorphic rocks—8 But I will not run on, having now eased my mind. Pray do not waste even one minute in acknowledging my horrid scrawls.—

Ever yours | Ch. Darwin

I enjoyed seeing you all this evening, but I was not allowed by my wife to stop & say good bye.—

1
The date is established by the allusion to Lubbock’s presidential address at the 1881 meeting of the British Association for the Advancement of Science (see n. 2, below), and by a reference in a letter from Emma Darwin to H. E. Litchfield, 20 September [1881]: ‘Sir John came on Sunday chiefly to consult F. upon a speech he had to make at University College on the opening of the Medical Class’ (DAR 219.9: 271). The Sunday before 20 September was 18 September. F.: father, i.e. CD.
2
Lubbock had sent CD a copy of his presidential address to the British Association, which included a summary of advances in geology over the past fifty years (see Lubbock 1881a, pp. 16–20).
3
Lubbock credited Adam Sedgwick and Roderick Impey Murchison with establishing the Cambrian, Silurian, and Devonian strata; he also mentioned that new divisions had been proposed for pre-Cambrian strata by Henry Hicks (see H. Hicks 1880 and Lubbock 1881a, p. 17).
4
Lubbock cited an 1837 paper by Louis Agassiz as the first contribution to glacial theory (see L. Agassiz 1837 and Lubbock 1881a, p. 18). Agassiz published further papers outlining his theory in 1840 (see especially L. Agassiz 1840).
6
In his address, Lubbock briefly mentioned the study of drift beds by Joseph Prestwich (see Prestwich 1862a, 1862b, and Lubbock 1881a, p. 17).
7
Lubbock discussed the work of Henry Clifton Sorby in laying the foundation of microscopic petrography in Lubbock 1881a, p. 18.
8
On investigations into the causes of cleavage, see Lubbock 1881a, pp. 17–18.

Manuscript Alterations and Comments

1.2 the] interl
1.5 or most important] interl
1.6 azoic] interl
1.14 on] above del ‘up’
3.1 was] after del ‘di’

Please cite as “DCP-LETT-13308,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-13308