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Darwin Correspondence Project

From William Jenner   9 November 1864

8 Harley St.

Novr 9th. 1864

My dear Sir

The preparation to which you refer is “Syrup of Phosphate of Iron”—1 I think that as the turbidity continues you may find benefit from taking after each pill—10 drops of dilute phosphoric acid in water—2

I would not advis〈e〉 〈    〉 to drink more water3 〈    〉   The Phosphoric acid (if 〈as〉 I suppose the turbidity of urine is as it was when I last saw it)4 will diminish & not produce the deposit.

I think you had better let me have a bottle of the urine & I will have it analysed—5

Yours very truly | Wm. Jenner.

〈Co〉ntinue the phosphate 〈of〉 Iron.

Is the urine alkaline when passed? if so you must omit the potash from magn. soda & potash powder—6

Your last was address 8 Gower St.7


No letter from CD to Jenner on syrup of phosphate of iron has been found; however, CD had recently learned from Mary Elizabeth Lyell that dyspeptic symptoms might be relieved by the preparation (see letter to Asa Gray, 29 October [1864]). On syrup of phosphate of iron, see British pharmacopœia 1864, pp. 334–5, and Royle and Headland 1865, p. 156. For Jenner’s discussion of CD’s use of phosphate of iron, see the letter from William Jenner, 15 October and n. 2.
CD evidently took phosphate of iron in pill form.
Jenner had advised CD to drink little water when he first began treating him in March (see letter to J. D. Hooker, 13 April [1864] and n. 6).
For Jenner’s last recorded examination of CD’s urine, see the letter from William Jenner, 14 August 1864.
Jenner had prescribed a combination of antacids, including chalk, magnesia, and carbonate of ammonia, in March (see letter to J. D. Hooker, 13 April [1864] and n. 6). Potash was an alkali used in the treatment of dyspepsia and gastric acidity (see Beasley 1865, pp. 392–7, and O. D. Owen 1868, p. 538).
Jenner resided at 8 Harley Street, Cavendish Square, London (Post Office London directory 1865).


Beasley, Henry. 1865. The book of prescriptions, containing more than 3000 prescriptions, collected from the practice of the most eminent physicians and surgeons, English and foreign. 3d edition. London: John Churchill and Sons.

British pharmacopœia. London: Spottiswoode & Co. 1864.

Owen, O. Davies. 1868. Conspectus; or tabular synopsis of the British Pharmacopœia, 1867. 2d edition. London: Longmans, Green, Reader, and Dyer.

Post Office London directory: Post-Office annual directory. … A list of the principal merchants, traders of eminence, &c. in the cities of London and Westminster, the borough of Southwark, and parts adjacent … general and special information relating to the Post Office. Post Office London directory. London: His Majesty’s Postmaster-General [and others]. 1802–1967.


Prescribes "syrup of phosphate of iron". Requests a urine sample.

Letter details

Letter no.
William Jenner
Charles Robert Darwin
Sent from
London, Harley St, 8
Source of text
DAR 168: 52
Physical description
3pp damaged

Please cite as

Darwin Correspondence Project, “Letter no. 4666,” accessed on 18 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 12