In 1877 and his 69th year, Darwin remained remarkably productive at Down House and was happiest when at work on topics requiring careful observation and experiment. These are copies of the hand-written notes by Charles Darwin in which he is describing using Backhouse Purple Sprouting Broccoli in his research in to bloom using drip tests and susceptibility to insect bites. This research lasted decades and he was assisted by his son Francis.
Darwin wrote on Sept 5th 1877 to William Turner Thiselton-Dyer assistant director at Kew, “As it is we have made out clearly that with some plants (chiefly succulent) the bloom checks evaporation.— with some certainly prevents attacks of insects— with some sea-shore plants prevents injury from salt-water—& I believe with a few prevents injury from pure water resting on leaves”.
Francis reported “through the kindness of Sir J.D Hooker I was enabled to carry out the work in the Jodrell Laboratory in the Royal Gardens at Kew. I was this enabled to obtain a large supply of fresh material…”. Francis wrote up his own and Darwin’s work in 1886, noting “With regard to the kind of wetting which is prevented by the bloom on leaves, it is probable that it is more effective against rain than against dew, since at least some bloom-protected leaves are easily covered with a coating of dew in very finely divided drops. It is curious to observe the effect of immersion on such a leaf – which may be plunged into water still retaining its coating of dew, and will be found to be perfectly dry on being removed from the water – so that the readiest way of drying such a leaf is to dip it into water.”
One of Caroline’s 4th Great Uncle achievements was a fine range of Broccoli available in his catalogues, also shown here. Today we celebrate his achievement in the Café where we serve a traditional broccoli soup from a Backhouse Family Recipe.