Portrait of Charles Bonnet, F.R.S., author of The Contemplation of Nature, surrounded by The Chain of Nature. Engraved by Caldwall.
London: Published by Dr. Thornton. Part of a group of 16 portraits of noted botanists.
Portrait of Johann Lukas Schonlein. He discovered features of purpura rheumatica now known as Schonlein's Disease. "Triangle Volume VI No. 5 April 1964" appears at the head of sheet.