From William Jenner   15 October 1864

Balmoral

Octr 15th. 64

My dear Sir

There is no objection to your taking the Chalk1 the urine, not becoming turbid   I should fear stone if the urine continued in that state— Phosphate of Iron is a very useful medicine2—one I often prescribe—but I am inclined to the opinion that it the iron which does the good & that the phosphate of iron is a form in which it can in some be better or more easily taken into the system—& which sits better on the stomach of some—

The Iron if it agrees will certainly improve the vigour & give strength—

So my advice is continue the phosphate ⁠⟨⁠of⁠⟩⁠ I⁠⟨⁠ron⁠⟩⁠   Take C of Magnesia C. of Am. & sp. of HorseRad. & occasionally add the chalk—3

Yours very truly | Wm. Jenner.

P.S. | I am sorry that your letter having had to be forwarded to me has occasioned delay—4 I expect to be home on 27th. Octr.

1
CD had stopped taking chalk for his stomach on Jenner’s advice (see letter from William Jenner, 14 August 1864), but continued to take several other antacids (see n. 3, below). Emma Darwin’s diary (DAR 242) records that CD ‘left off chalk’ on 16 August 1864. CD had formerly thought that the chalk, taken together with other antacids, had significantly improved his health (see letter to J. D. Hooker, 13 April [1864], and letter from Emma Darwin to W. D. Fox, [6 May 1864]).
2
According to Emma Darwin’s diary (DAR 242), CD began taking phosphate of iron on 21 August 1864. Phosphate of iron was prescribed for a number of medical conditions, including rickets, scrofula, bowel problems, and nervous disorders (Beasley 1865, pp. 236–40; Royle and Headland 1865, pp. 155–6).
3
CD had been taking a combination of antacids prescribed by Jenner (see letter from William Jenner, 14 August 1864 and n. 2). Jenner refers to carbonate of magnesia, carbonate of ammonia, and spirit of horseradish (Armoracia rusticana). On the use of these preparations in mid-nineteenth-century medicine, see Royle and Headland 1865, pp. 64–7, 128–30, and 301–2.
4
No letters from CD to William Jenner have been found.

Please cite as “DCP-LETT-4637,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-4637