Pitt's experiments with leaves

Humphry Repton, a well-known late 18th and early 19th century landscape gardener, spent some time at Pitt’s country villa Holwood in Kent. Writing later about one such occasion, he describes a conversation he had with Mr. Pitt upon the relative opaqueness or transparency of leaves. Pitt was a great lover of the beauties of nature and the countryside, and he savoured every opportunity to go down from London to his favourite retreat of Holwood.
I relate Repton’s recollection of this conversation:
"Having one day, when at Holwood, pointed this out to Mr. Pitt, as a source of the delight we experience in a sunny day, from an open trellis of vines overhead, or the foliage in the roof of a conservatory, he was so forcibly struck with the remark, that he made several experiments with leaves of different shapes and tints, some of which, from the opaquer ramification of their fibres, or other circumstances of texture, &c. became new objects of delight to a mind like his, capable of resorting to the beauties of nature as a relief from the severer duties of his arduous situation."
Run-on sentence, much? Still, I’m constantly amazed by the brilliancy of Pitt’s mind.

Source:
Repton, H. and John Claudius Loudon (1840) The landscape gardening and landscape architecture of the late Humphry Repton, Esq. London: Longman & Co., pg. 494.