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Darwin Correspondence Project

From John Crawfurd to E. A. Darwin   7 August 1863

The Athenæum

August 7th. 1863.

My dear Darwin/

I was requested by Archdeacon Sinclair to send the enclosed to your brother.1 It contains a remarkable prophecy of your grandfather which long anticipated the opinion of Libig & well deserves attention.2

Will you forward with my kind regards | very sinly yours | J Crawfurd

Erasmus Darwin Esq


Nor did the Board confine their efforts to the Collection & diffusion of agricultural Knowledge;3 they endeavoured also to arrange it—to connect husbandry with philosophy or as the Founder of the institution frequently expressed himself “to raise agriculture from the level of an art to the dignity of a science.” They wished its process no longer to be carried on blindly or empirically, but to be formed into a regular system & conducted upon rational & experimental principles. The two branches of science from which the greatest aid might be expected were vegetable physiology & chemistry; the Board therefore endeavoured to prevail on men of eminence in these departments to employ their scientific attainments in arranging & combining theoretically the miscellaneous facts & loose notions of which agricultural knowledge at that time exclusively consisted. Among the most valuable results were Darwin’s Phytologia & Davy’s Lectures on Agricultural Chemistry.4

The Phytologia or Philosophy of Agriculture & Gardening was dedicated by the Author in the most cordial terms of friendship & esteem to Sir John Sinclair as a work “begun at his instigation, & forwarded by his encouragement.” Dr Darwin entered warmly into Sir John’s feeling of indignation that husbandry had till then been so much neglected by the learned, & that at a time when many branches of knowledge far inferior in importance had been carefully arranged & digested into sciences agriculture & gardening though of such great utility in producing the nutriment of mankind continued to be only arts. The work comprises three parts of which the first explains the physiology of vegetation; the second describes the economy of vegetation & the third applies the principles thus established to agricultural & horticultural productions. Among the casual discoveries which this ingenious work had the merit of bringing forward was the use of bone dust as a manure. Having mentioned phosphorus as an element under different forms, existing universally in vegetables, & not before sufficiently attended to, the Doctor specifies the different substances from which this essential food of plants may be obtained & which therefore might be advantageously employed as manure; he then proceeds— “and, lastly, the use of recent shells, or bones ground into powder, or of bone ashes may be deduced as they consist almost entirely of phosphorus & calcareous earth.”5 The fertilizing properties of this manure had been previously noticed by Hunter,6 but they were first theoretically explained & brought forward with authority by Dr. Darwin. Perhaps no modern discovery has contributed so powerfully to improve the fertility & increase the produce of the soil, as the use of bone dust.7 Nothing but experience would render credible the strong & lasting effects produced by even small quantities of this active Substance.—

Life of Sir John Sinclair Bart. | vol II. p. 83–5.


The reference is to John Sinclair, archdeacon of Middlesex and vicar of Kensington. The enclosure was a handwritten extract from a book by Sinclair about the life of his father, John Sinclair (Sinclair 1837, 2: 83–5); it included a tribute to CD’s grandfather, Erasmus Darwin.
The enclosure discusses points in Erasmus Darwin’s Phytologia (E. Darwin 1800) that the author thought predated Justus von Liebig’s conclusions regarding agricultural fertiliser. Liebig had noted that fields required the replacement of essential minerals in order to maintain a constant state of fertility (Liebig 1840, p. 182). He recommended bone as a rich source of calcium and magnesium phosphates and further observed that the waste materials of the glue industry represented an untapped source of valuable minerals in a form particularly suitable for agricultural use (ibid., p.185). For an analysis of Liebig’s role in the development of agricultural chemistry, particularly in the analysis and development of artificial fertilisers, see Brock 1997, pp. 145–82.
The reference is to the Board of Agriculture, founded in 1793 at the instigation of John Sinclair Sr, who became its first president (E. J. Russell 1966, pp. 54, 67).
E. Darwin 1800 and H. Davy 1813. For a discussion of Erasmus Darwin’s Phytologia, and his anticipation of later discoveries in agriculture and plant biology, see King-Hele 1999, pp. 333–8. Humphry Davy’s Elements of agricultural chemistry is discussed in Russell 1966, pp. 67–76.
The quotation is from E. Darwin 1800, p. 211.
Sinclair refers to a remark on the use of ash as a fertiliser Hunter 1777, pp. 382–3.
In his biography of his grandfather, CD quoted this sentence, adding in a note that he was ‘indebted to Dr Dowson’s Life of Erasmus Darwin, for the reference to the Life and Works of Sir J. Sinclair’ (Erasmus Darwin, p. 113); the quoted sentence appears in Dowson 1861, p. 56.


Brock, William Hodson. 1997. Justus von Liebig: the chemical gatekeeper. Cambridge: Cambridge University Press.

Darwin, Erasmus. 1800. Phytologia, or the philosophy of agriculture and gardening. With the theory of draining morasses and with an improved construction of the drill plough. London: J. Johnson.

Davy, Humphry. 1813. Elements of agricultural chemistry: in a course of lectures for the Board of Agriculture. London and Edinburgh: Longman, Hurst, Rees, Orme, and Brown.

Dowson, John. 1861. Erasmus Darwin: philosopher, poet, and physician. A lecture to the Literary and Philosophical Society of Whitby. London: H. K. Lewis.

Hunter, Alexander. 1777. Georgical essays. York: J. Dodsley [and others]. London: T. Durham. Edinburgh: W. Creech.

King-Hele, Desmond. 1999. Erasmus Darwin. A life of unequalled achievement. London: Giles de la Mare Publishers.

Russell, Edward John. 1966. A history of agricultural science in Great Britain. 1620–1954. London: George Allen & Unwin Ltd.

Sinclair, John. 1837. Memoirs of the life and works of the late right honourable Sir John Sinclair, bart. 2 vols. Edinburgh: William Blackwood and Sons. London: T. Cadell.


Forwards an enclosure for CD, at Archdeacon John Sinclair’s request [extract from J. Sinclair’s Life and works of Sir John Sinclair (1837) 2: 83–5], showing how Dr Erasmus Darwin anticipated Justus von Liebig [in recognising the importance of phosphorus-rich manures].

Letter details

Letter no.
John Crawfurd
Erasmus Alvey Darwin
Sent from
Athenaeum Club
Source of text
DAR 161: 237, 237/1
Physical description
ALS 1p, encl 2pp

Please cite as

Darwin Correspondence Project, “Letter no. 4880,” accessed on 29 May 2023,

Also published in The Correspondence of Charles Darwin, vol. 13 (Supplement)