These letters refer to the exchange of various plants, to botany in general, and to the operation of Kew. There is mention as well of the plants of Halifax, Nova Scotia.

This diary records the individuals and sights that he saw while in England. There are many observations of life in London, e.g. parks, buildings, paintings, food. Outside of London he visited many towns, including Manchester and its cotton mills as well as the steel mills of Birmingham. He relates his visit to Drury Lane and the dramatic performance of Sarah Siddons. Some of the people he met included Sir Joseph Banks, Sir Charles Blagden, Matthew Boulton, Joseph Priestley, William Pitt the Younger, and Benjamin Vaughan. He also visited and described the gardens at Kew. The diary includes several sketches, including the plan of Blenheim Palace, and also a table of distances traveled.

A variety of topics are discussed in these letters, mainly on plant specimens and botanical subjects in relation to England, India, and other parts of the world. The most voluminous correspondence is with Henry Walter Bates, Sir Henry Cole, Sir Richard Strachey, Dawson Turner, and William Crawford Williamson.