Relieved that JH has returned safely from his European tour.

Sending the fourth volume of his own Mécanique céleste; comments on various parts. Work is being done on the figure of the earth.

Encloses differences determined through indications of portable barometer, standard, thermometer, and various other instruments.

JH carried portable barometer by Edward Troughton and thermometer by Mr. Newman to Europe and compared these to instruments used by individual scientists and observatories. Reports results to Board of Longitude.

Has heard that JH has arrived back in England. Sends one of his own papers for his library. Regrets that JH did not call at Paris on his travels. Sends a parcel from P. S. Laplace. Remember him to Charles Babbage.

Settles accounts with Smith, including from Gurney and [John] Latham. Smith will have to reduce 'Tilia' to three species, as Bicheno has found 'T. grandifolia', 'T. parvifolia', and 'T. europaea' in Stokenchurch Woods, proving duplication of species has occured in other works, including Ray and Dillenius; observations. Discussion of 'Rubus rhamnifolius'; glad Smith found [Robert] Brown "so correct", he has just returned from his trip to Italy "much pleased". [Alexander] Macleay is returned from Caithness with his lame son, fears he will always be a "cripple".

[Note in Bicheno's hand] confirms Forster's account of his discovery of three 'Tilia' species in Stokenchurch Woods.

Has just returned from abroad and found his letter of April awaiting him. Hoped to visit Vienna when abroad. Has received money for the clock. Hopes to send his own paper on double stars later. Encloses some papers for distribution. Measured height of Etna when in Italy. Met Josef Fraunhofer and had an instructive discussion with him.

Charles Babbage communicated [Edward] Smedley's note requesting JH to write an article on 'Heat' and an Introduction to Physical Science. Appears to be some misunderstanding as JH does not wish to write on Heat, no interest in the subject, but is prepared to write on Physical Optics. When will the latter article be required?

Repeat computation for Jupiter's satellite IV [see TY's 1824-4]. Explains W. H. Wollaston's 'blue bow.' See figure 422 of TY's [Lectures on Natural Philosophy].

Thanks TY for books and for taking charge of [G. A. A.] Plana's plates. JH mentioned Eilhard Mitscherlich only when no other proposals came forth. Matter was left hanging. Assures TY that JH was not offended [see TY's 1824-11-21, i.e., #1075]. Regrets 'dilapidated state of scientific matters' in R.S.L.

As R.S.L. vice president, JH should reconsider his report favoring Eilhard Mitscherlich over W. H. Wollaston. This may be last opportunity to pay Wollaston a 'just compliment.' Agrees with JH that much in R.S.L. 'nicknamed science [is] sleight of hand,' and that 'great injustice is done to men of science.' But TY expects a short life and tries not to be concerned about approval of others.

TY would rather have JH's labor made useful another year. W. H. Wollaston does not want [Royal] medal, but medal wants Wollaston. One council member felt that TY's remarks offended JH. Assures JH it was not intended.

Math is flimsy in John Dalton's theory of vapor dispersion, but physical grounds are firm. Sends copy of TY's volume on sound. Modules of elasticity and tension are analogies to explain TY's doctrine. Presently studying modules of elasticity that do not apply to chimney pipes investigated by Daniel Bernoulli and J. H. Lambert.

School at Sedbergh is vacant; please let him know if he wishes to become a candidate. [Miles?] Bland is candidate for a valuable living in Cheshire.

Praises old Edinburgh Philosophical Journal. Promises to send DB some materials for publication.

Reports on the reception of WW's crystallography paper at the R.S.L. Asks WW to add a comment on the paper's relation to a paper in David Brewster's journal. Asks WW to contact George Peacock.

Unable to provide Smith with specimens of the red-twigged lime, the original Kew plant of Smith's reference being dead some years and the substitute, having produced no fruit, is of doubtful accuracy, and herbariums of [Robert] Teesdale and the Gardens provide no examples. Sends specimens of New Holland plants collected by [Allan] Cunningham [(1791-1839), botanist and explorer] and parcel for Lady [Pleasance] Smith.

Sending papers published by their Academy. Will be pleased to help in any way.

Sorry Sir James [Edward Smith] could not visit him in Bury following his own visit to Smith in Saxmundham; hopes his health is recovering. Lady Cullum's trip to Brighton did not revive her health; she is now taking ass's milk to prevent "an irregular & teazing intermittent fever". His son and daughter-in-law staying in Pisa so she can treated by the "celebrated Dr Vacca", but as the baths of Barèges, [France], and Sorrento, [Italy], doubts the worth of this. Death of Sir William Watson [(1744-1824), physician and naturalist]; recalls that when he stayed in Bath he would meet at Governor Pounal's house with Sir William, Dr Parry, [Thomas] Velley, [John] Stackhouse, Sir Thomas Frankland, Archbishop of York [William Markham (1719-1807)], and Dr Falkner, reminded of death of Sir Joseph Banks and the loss of a place where so many friends would meet together.

Thanks for botanical information in Smith's last letter, and for Smith's "friendly & affectionate manners". Unsure of [Joseph] Sabine's intentions in erroneously reporting John Lindley's [(1799-1865)] involvement in "Flora Scotia".

Discusses his proposed "Species plantarum" in English, which will neither be a translation of Candolle's "Prodromus" nor an entirely original work; details; will be able to profit from consulting Smith's "English Flora"; queries on terminology; encloses a specimen of the work; will not commence printing until his return from London and Paris in March.

Has not received Nepalese plants from [Nathaniel] Wallich except one collection sent 5 years ago, and now understands that the East India Company requires that they have the distribution of all the specimens, but he continues to receive mosses from Wallich. Pleased the Company sent Smith "so fine a parcel of ferns", thanks the 'Darea' from it, which he wishes to figure in his "Exotic flora". Encloses a "fern-like plant"; observations; wishes to name the genus after its discoverer, Mr Parker; asks if 'Pteris thalictroides' or 'Pteris cornuta' belong to same genus. He has established botanical correspondence with Demerara and St Vincent's; has mosses to send Smith; wishes to consult him about 'Orchideae', of which every new species forms a new genus.

Lists plants for his "Exotic flora", including 'Marcgravia umbellata', 'Cassytha filiformis', 'Cytinus hypocistus'; has two plates engraved of the nutmeg and two new 'Tillandsiae'; about to figure 'Artocarpus incisa' and 'A. integrifolia'. Discusses 'Lepraria iolithos'. Expects "great things" from the unexplored parts of North America, having sent two botanists to the north-west coast; one is to join Captain Franklin and return overland with him, and the other to explore the vicinity of the Columbia [River]; appointing a third to go with Captain Franklin and Dr Richardson on their expedition as far as Saskatchewan and to remain their two years; further details. [Francis] Hamilton and [Francis] Boott both enquired after Smith.