Ɛpsilon

To T. H. Farrer   18 January 1881

Down, | Beckenham, Kent. (Railway Station | Orpington. S.E.R.)

Jan 18th 1881

My dear Farrer

When you next go to Abinger, if you can spare the time & the weather is decent, will you be so kind as to aid me once more to the many times already.—1

I am perplexed by the amount of residue left on the surface of the chalk here & by the very little on the sloping Downs to the north of your house.— I want you to go to the Downs & select any turf-covered sloping surface & cut with any strong knife or spud a small square hole & to send me about 2 oz. of clean chalk-fragments, immediately beneath the vegetable mould. I want to ascertain the percentage of earthy matter in the chalk. You will not, I imagine, have to dig above 6 inches deep, if so much.— I shd like to hear what the thickness of the vegetable mould is, measured from the upper surface, at the base of the free blades of grass.

Near Winchester I find that much fine earthy matter percolates into the chalk—, from 10 to 13 per cent; whereas the unaltered upper chalk contains only from 1 to 2 per cent.—2

P.S. | Note from Mr Caird agreeing with what you generously proposed in re Torbitt.3

1
Farrer had sent information about worm activity on the Abinger estate (see Correspondence vol. 28, letter from T. H. Farrer, 10 October 1880). See also Earthworms, pp. 186–8.
2
William Erasmus Darwin had collected chalk fragments under sloping turf near Winchester; CD compared the proportion of chalk to earth in these samples with others taken from the downs near Abinger (see Earthworms, pp. 299–300).
3
Farrer and James Caird had agreed to continue support for James Torbitt’s potato experiments, and had asked CD to use the subscription money raised the previous year as needed (see letter from James Caird, 3 January 1881).

Manuscript Alterations and Comments

0.1 (Railway … S.E.R.)] parentheses added
2.1 of the chalk] interl
2.3 with] after del ‘off’
2.4 clean] above del ‘the’
2.6 , I imagine,] interl
2.7 thickness] above del ‘thickness’
2.7 vegetable] after del ‘V’
3.2 upper] interl

Please cite as “DCP-LETT-13016,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-13016