Kew - JDH had not read WW's 'History' [The History of the Inductive Sciences, from the Earliest to the Present Time, 1837] for upwards of five years: 'I am surprised to find how little there is to add, and nothing that affects the general purport of the work' [WW is bringing out the third edition]. The only two subjects to require touching up are Cryptogamia and Geographical Botany. If WW wants to follow up developments on the former he will send him 'Berkeley's Intro. to Crypt. Bot': - [Miles J. Berkeley, Introduction to Cryptogamic Botany, 1857] Henfrey's [Arthur Henfrey] Report to Brit. Assn. [BAAS] - and a German pamphlet or two'. With regard to geographical Botany, he agrees with WW that in the strict sense it belongs to Paleontology: 'I am puzzled what to say about about it - my own opinion being, that in the present state of our knowledge, we are quite in the dark as to the philosophy of distribution. This subject however occupies so much of the attention of Botanists and Geologists, that it can scarcely be avoided'. Charles Lyell's views are the 'most able and original, and as developed by Edward Forbes have thrown a new light'. We must 'draw upon our imaginations, as to assume that species are created as such, and in one place only'. WW will find it worth while looking at JDH's recent review of Augustin Pyrame de Candolle's work upon Geographical Botany: 'I appear (to myself) however there to favor the doctrine of transmutation more than I really do...My views of progression in Fossil Botany are directly opposed to the prevalent ones; - those I mean which Hugh Miller advocates so strongly'. JDH will also send WW 'another Introductory Essay, and contains some observations upon the study of Systematic Botany; whatever may be good in this attempt is as you will see due in a great measure to the influence of the 'History of the Inductive Sciences' upon the author'. JDH gives a few suggestions on certain other details. The foundations of the natural system were laid by Carl Linnaeus, to a greater extent than most botanists are aware of. 'Brown's [Robert Brown] discovery of gymnosperm is the only real advance hitherto made in the right direction'.