From Bernard Peirce Brent   15 July 1862

Dallington | nr. Robertsbridge | Sussex

July 15th. 1862

My dear Sir,

Ever since I last wrote I have been endeavouring to repeat the experiment with the Guinea Pigs, only one has bred, the same Sow that, was kept out of doors last spring went to the Boar this year on the afternoon of Friday May the second— I placed her in a hutch and kept her by the kitchen fire until the 10th. of July when I removed her not wishing her to have young before the children, Saturday morning July the 12th. I found she had kindled being exactly the same time namely a few hours over the ten weeks which she went when exposed to the cold and I hope you will consider this quite conclusive1   her young two in number were dead   one apparently had been long dead   the other died at the birth.

I think we may set down the period of gestation as ten weeks and that warmth has no influence   I wish to part with the Guinea Pigs   shall I send them to you? there is the Boar and one Sow that Messrs. Baker sent,2 an old Sow I got here, and a young one bred last year   four in all, and though I have watched them closely I have not seen any desire in the other Sows to breed

I have a Rat’s tooth that forms a complete circle   the rat was blind and very thin   both the upper teeth, had grown in a circle the points growing into the roof of the mouth and almost touching the roots. one was broken by the dog killing the rat   the other is perfect and at your service if you think it worth acceptance,

I have also the skull of my old dog a bull terrier 12 years old, would you like it,? I have not yet seen any notice of your work on Variation under domestication so I conclude it is not yet published3   I trust that your health and also your daughters has improved since I last heard,4 I do not call to mind that I have anything else to communicate,

I am sorry to say I am not yet free from my law suit   I hope however for the final settlement in November unless any unforseen hinderance prevents,5

With best wishes believe me | My dear Sir | Your’s truly | B P Brent

To C Darwin Esqre

CD annotations

2.3 there is … sent,] scored brown crayon !alignleft!3.1 I have … published 4.3] scored brown crayon
5.1 I am … suit] scored brown crayon
1
In 1861, CD had apparently asked Brent to examine the effect of temperature on the gestation period in guinea-pigs (see Correspondence vol. 9, letter from B. P. Brent, 15 June 1861).
2
Brent may refer to Samuel C. and Charles N. Baker, dealers in birds and live animals, with premises in London and Paris (Post Office London directory 1861).
3
Variation was published in 1868.
4
Henrietta Emma Darwin was seriously ill throughout 1861 (see Correspondence vol. 9).
5
Files concerning Brent’s lawsuit in Chancery are available at the National Archives (C 15/359/B255, cause no. 1857 B255 (Brent v Boyton) and C 15/360/B287, cause no. 1857 B287 (Brent v Briggs)). The lawsuit came to an end in 1864, with expenses of over £900. Brent subsequently told CD: ‘had I not defended myself I have no doubt I should have lost everything’ (letter from B. P. Brent, 2 September 1864 (Calendar no. 4607)).

Please cite as “DCP-LETT-3660,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-3660