In the mid-1990s I spent a month doing research at Aberdeen University. During the week I sat transcribing letters in the library. On the weekends, I explored the coast and countryside in a borrowed van. One warm(ish) day in June, I visited Crathes Castle near Banchory. The castle dates from the 16th century, but what I mostly remember from my visit was the gardens, particularly the tall yew hedges that walled in the different spaces. Yew grows to a great age, and these hedges, well over 9 feet tall, date from the beginning of the 18th century.
The day I was there, a gardener was trimming the hedges. Balanced on a ladder, a good 8 to 9 feet above me, he was carefully saving all the clippings in a plastic garbage bag. The work looked precarious, and I asked him why he was taking so much trouble to save the trimmings. He told me they were parcelled up and sent to the Pasteur Institute in Paris, where scientists were working on a cure for cancer.