From G. H. Darwin   [after 6 April 1864?]1

1 milligramme = .0154 English grains 1 English grain = 1/.0154 milligrammes

= 64.9 milligrammes2

For .0154) 1.000 (64.93

924

—

760

616

—

1440

1386 3 4 —

540

462

–

78

–

To Mama

Could you send a large fruit tart. I should rather like 12 napkins, I’ll see that they are brought back Safe.—3

CD annotations

64.93] ‘say 65’4
Bottom of first page: ‘Decigramme is [found thus] in [end] to be 1.543’ ink, crossed ink; ‘gramme = 15.432’ ink, crossed ink
1
The date is conjectured from the relationship between this letter and the letter to G. H. Darwin, [after 5 April 1864?].
2
For his work with Clematis, CD had asked George how many milligrams were in one English grain (see letter to G. H. Darwin, [after 5 April 1864?] and n. 3).
3
The note to Emma Darwin, written on the back of the calculations, could have been written by George, or by one of the Darwins’ other sons, Leonard or Francis, who were also attending Clapham school.
4
In his discussion of Clematis species in ‘Climbing plants’, p. 27 n., CD wrote: ‘Our English grain equals nearly 65 milligrammes.’

Please cite as “DCP-LETT-4453F,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-4453F