[dateline] Hague 25 July 1782
[salute] My dearest Friend
In this Country, as in all others, Men are much Addicted to “Hobby Horses.” These Nags are called in the Language of the Dutch “Liefhebbery,” as they are called in French “Marotte.” I had rather ride a Dutch Hobby Horse than an English one or a French. It is the wholesomest Exercise in the World. They live to great Ages by the Strength of it.
My Meaning is this. They pitch in early Life upon some domestick Amusement, which they follow all their days at Leisure hours. I shall give you the History of several.
I Yesterday made a Visit to one, a Mr. Lionet, a venerable old Man of 75, in full Health, Strength and Vivacity, respectable for several Offices which he holds, but more so for vast learning in various Kinds, and great Ingenuity. His Hobby Horse has been natural Knowledge. We went to see a Collection of marine Shells. We were two hours, and had not got half through. The infinite Variety of Figures and Coulours, is astonishing.
But his Curiosity has not been confined to Shells. It has extended to Insects, and he has had it in Contemplation to write as full an Account of these as Buffon has written of Birds, Beasts and Fishes. But beginning with Caterpillars, he has filled a Folio upon that Species—and drew, and engraved the Plates himself.
Thus he rode his Hobby Horse and lived. Without it, he would have died fifty Years ago.
Have you an Inclination to read and inspect Cutts of the Anatomy of Caterpillars—their Nerves, Blood, Juices, Bones, Hair, Senses,
Intellects &c. &c.—Their moral Sense, their Laws, Government, Manners and Customs.
I dont know whether he teaches the manner of destroying them, and Saving the Apple tree.
I doubt not the Book is worth studying. All Nature is so.—But I have too much to do, to Study Men, and their mischievous Designs upon Apple Trees and other Things, ever to be very intimate with Mr. Lionet, (whom I respect very much however) or his Book. Adieu.1