Darwin, writing from the Cape on 3 June, 1836 to his sister Catherine, looked forward expectantly to the next day: "Tomorrow morning I am going to call with Capt. F[itz] R[oy] on the Sir J. Herschel. I have already seen the house which he has purchased; it is six miles from the town & in a most retired charming situation. I have heard so much about his eccentric but very amiable manners, that I have a high curiosity to see the great Man" .

John Herschel and his family had arrived at the Cape of Good Hope in January 1834 with plans for John to sweep the southern sky to catalogue all of objects of interest, just as he and his father, William Herschel, had done for the northern sky . John Herschel was at that time the best known astronomer in Europe and carried the family name of the man who had become famous for his discovery of the planet Uranus in 1781. John was midway through his sojourn at the Cape and had expanded his interests to include the Cape flora, amassing a collection of bulbs that he planted in systematic order in the garden at his estate of Feldhausen.

The planned visit to Herschel did not materialize on the 4th – on that day Darwin records in his diary that he started on a four day journey to Paarl and Franschhoek – but 15th June has the note "Sir J. Herschel" . The visit is described in his letter to the Cambridge mineralogist and botanist John Stevens Henslow on 9 July 1836:

"At the Cape, Capt Fitz Roy, & myself enjoyed a memorable piece of good fortune in meeting Sir J. Herschel. We dined at his house & saw him a few times besides. He was exceedingly good natured, but his manners, at first, appeared to me, rather awful. He is living in a very comfortable country house, surrounded by fir and oak trees, which alone, in so open a country, give a most charming air of seclusion & comfort. He appears to find time for every thing; he shewed us a pretty garden full of Cape Bulbs of his own collecting; & afterwards I understood, that every thing was the work of his own hands."

He noted in his diary that the meeting "was the most memorable event which, for a long period, I have had the good fortune to enjoy".

Herschel’s diary entry for the day records that "Capt F. & Mr D. came at 4 and we walked together up to Newlands" and that they and other visitors dined at 6. Darwin is not mentioned any further – the main topic of the entry concerns Fitzroy’s report that Dr Smith was to be transferred from Cape Town to Simon’s Town. (Andrew Smith had just returned from a scientific expedition northward in Africa and was very helpful among other things in showing Darwin geological exposures around Cape Town.)

Darwin not only collected natural history specimens at the Cape – he was also alert to social comment. In his autobiography he says "I felt a high reverence for Sir J. Herschel, and was delighted to dine with him at his charming house at the C. of Good Hope and afterwards at his London house. I saw him, also, on a few other occasions. He never talked much, but every word which he uttered was worth listening to. He was very shy and he often had a distressed expression. Lady Caroline (sic – actually Catherine) Bell, at whose house I dined at the C. of Good Hope, admired Herschel much, but said that he always came into a room as if he knew that his hands were dirty, and that he knew that his wife knew that they were dirty".

Darwin’s respect for John Herschel is more understandable when we note other comments. In the entry in his diary for 26 September, 1836, three months after leaving the Cape on the final leg of the return journey to England, he states "… it appears to me that nothing can be more improving to a young naturalist, than a journey in distant countries. It both sharpens and partly also allays that want and craving, which as Sir J. Herschel remarks, a man experiences, although every corporeal sense is fully satisfied." That sentiment comes from Herschel’s "A Preliminary Discourse on the Study of Natural Philosophy", first published in 1830 .

One curious consequence of Darwin’s visit to the Herschels was his first publication. Mellersh, in his biography of Fitzroy , states that this article, entitled "A Letter, containing Remarks on the Moral state of Tahiti, New Zealand &c",which appeared in the South African Christian Recorder for September 1836 signed by Fitzroy and Darwin, was "through the good offices of Sir John Herschel", but in fact it was at the instigation of Margaret Herschel, as the extracts below will illustrate . The article was overlooked until discovered in 1958 .

In a letter to Margaret, sent from the Beagle on 29 June 1836, via a Cape bound passing vessel, Fitzroy says "So tedious is the passage we are now making – I much fear that the paper which is to accompany this letter will not reach your Ladyship until it is supposed to be, by a mistake, on its way to India. Lest such a chance should occur, I will send a duplicate by another ship…. Will you have the kindness to condemn, unsparingly, all that is ‘too much’ or not useful…, I beg that my name, humble as it is, may be added not with that of Mr Darwin, from any foolish personal motives; but because I think anonymous articles in a periodical are less considered than those for whose content some one is accountable…. My only motive for sending more than was suggested by your Ladyship is the hope of doing a little good, and pleasing Sir John Herschel and yourself."

The aim of the article is explained in its opening statement: "A very short stay at the Cape of Good Hope is sufficient to even a passing stranger, that a strong feeling against the Missionaries in South Africa is there very prevalent". This sentiment must have been more widespread for Darwin and Fitzroy make a vigorous defence of the missionaries working in the Pacific and end with the claim that they "thoroughly deserve the warmest support, not only of individuals, but of the British Government".

John Herschel later wrote to Fitzroy, 3 October 1836, "I ought long before this to have replied to yours of the 1st & 8th July besides acknowledging the most interesting notices of the Missionary progress in Otaheite… New Zealand &c. According to your instructions and permission they were at once forwarded to Mr Freeman for instertion in the "Christian Recorder" and printed just as sent them exact from the MS. Herewith I forward copies of the No. in which they are contained for yourself and Mr Darwin with all due acknowledgement on the part of the Editor. I could wish they were in better company for I cannot say that all the contributions to that periodical are to me taste…. Lady H. desires me to add her thanks also for the trouble you and Mr D. have taken at her suggestion".

A possibly seminal influence of John Herschel on Darwin, though it remains speculative, is the coincidence that, only four months before the arrival of the Beagle at the Cape, Herschel had been considering evolution of species. In a long letter to Lyell (who had himself speculated on the origin of species in his 1832 Principles of Geology ) penned from Feldhausen on 20 February, 1836, Herschel wrote

"Of course, I allude to that mystery of mysteries – the replacement of extinct species by others. Many will doubtless think your speculations too bold but it is as well to face the difficulty at once. For my own part – I cannot but think it an inadequate conception of the Creator, to assume it as granted that his combinations are exhausted upon any one of the theatres of this former exercise – though in this as in all his other works we are led by all analogy to suppose that he operates through a series of intermediate causes and that in consequence, the origination of fresh species could it ever come under our cognizance would be found to be a natural in contradistinction to a miraculous process – although we perceive no indications of any process actually in progress which is likely to issue in such a result".

Herschel was led to these thoughts by his bulb collection. He continued "This is a beautiful country for studying the graduation of Botanical species – the families are so rich in species. I am little or nothing of a Botanist – but with one feature it is impossible not to be struck – viz that when you find a species which fills up as you fancy a wanting link between two others – it does not merely fill it, but does so with the superaddition of some new characters – or some analogy with a 3rd species which the others do not offer".

As John Rourke has commented : "The depth of his insight as revealed by these comments is surprising especially when one considers they were conceived several decades before the principles of inheritance were established and 23 years before Darwin’s theory of evolution had been published. Indeed, in terms of the theoretical basis of systematics, observations like these were really only given formal structure with the publications of Hennig [in 1950 and 1966]".

Darwin saw the letter to Lyell: the first sentence of the Introduction of the Origin of Species includes "…that mystery of mysteries, as it has been called by one of our greatest philosophers". Indeed, he refers to it in the notebook on Transmutation of Species that he wrote during late in 1838: "Herschel calls the appearance of new species the mystery of mysteries, & has a grand passage upon the problem! Hurrah – "intermediate causes".

One further extract from the letter to Lyell emphasizes how Herschel was pursuing the logical consequences of species extinction and creation: "Speaking of the destruction of species there is here a very lovely species of plant which seems verging rapidly to extinction – the Disa grandiflora. It grows only on the summit of Table Mountain, and as I am told on no other mountn in the Colony…it may be contended that any given group observed to be confined to a particular district is in fact only the last surviving remnant of the same group universally disseminated, but in course of extinction [;] nor do I see how to distinguish supposing only one individual existed in the whole world – whether that species were just nascent – or just dying out. Perhaps both processes are going on at once – some groupes (sic) may be spreading from their foci others retreating to their last strongholds."

Despite Herschel having "never talked much", if he shared even a few of these thoughts they would surely have taken root in the young Darwin’s mind. Herschel’s letters are known to have had an impact on Lyell’s thinking12. It is a pity that Darwin did not record more definitely the ideas that he received from visiting Herschel at the Cape. The only other written statement, further illustrating Herschel’s then interest in change and evolution, is "Your metaphor of the pebbles of pre-existing languages reminds me that I heard Sir J. Herschel at the Cape say how he wished some one would treat language as you had Geology, and study the existing causes of change, and apply the deduction to old languages".

Brian Warner

Department of Astronomy, University of Cape Town