JDH writes that he is glad to hear of Sir William Turner Thiselton-Dyer's [WTTD's] appointment to the Dublin chair [of the Royal College of Science for Ireland, Dublin]. Has seen Dr [Edward Percival] Wright who is happy for WTTD to have access to, & make use of, the T[rinity] C[ollege] Herbarium. However, Wright wishes WTTD to wait a little before taking a more prominent position than himself so that 'matters will arrange themselves'. Wright is talking of getting leave for 2 years & going abroad, leaving WTTD in charge. JDH says that the vegetable products museum should be attached to the Botanic Garden, along with a Herbarium & Library, without which the garden will be useless. JDH cannot supply structural specimens of plants from the RBG Kew museum as all duplicates are sent to places which give things in return. Will be happy to give advice about Cape Flora & thinks it is a worthy endeavour to finish it. Notes that WTTD will probably not be ready to embark on the descriptive part of the flora, & therefore need the herbarium, before Wright leaves anyway.

JDH compliments Sir William Turner Thiselton-Dyer [WTTD] on his paper on 'Spontaneous Generation & Evolution' & hopes that it is a prelude to further research into the chemistry of vegetation as JDH believes there is no better man to do it. JDH is currently reading John Tyndall's paper 'On the Actions of Rays of High Refrangibility upon Gaseous Matter' in PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON & he is struck by Tyndall's remarks on the decomposition of carbonic acid, by solar rays, in the leaves of plants. JDH says that he had thought about this independently & believes it would make a good research subject. Has heard that Dr P[ercival] Wright it going to Algeria for the winter. JDH hopes that he has left the key to the [Trinity College] Herbarium for them.