These were still days of picturesque dressing, with both men and women. “Jeffersonian simplicity” had not yet come in, in full force. Watson, the annalist, describes Mr. Jefferson, a few years earlier, in “a long-waisted white cloth coat, scarlet breeches and vest, a cocked hat, shoes and buckles, and white silk hose,”--an elegant figure, the life and centre of the group of men gathered together in the society’s rooms on Fifth Street. The great Rittenhouse had, in 1797, set forth upon a wider range among the stars; but Dr. Benjamin Rush was there,--physician, scientist, philanthropist, and statesman, a host in himself. His kindly face and the recollections of his contemporaries tell us that he was a pleasant companion, with all his learning, which cannot always be said of the learned ones of the earth. There also was the Rev. William Smith, first provost of the University of Pennsylvania, a man of science as well as an able divine; Dr. Barton, nephew of Dr. Rittenhouse, an original worker, who contributed largely to the scientific literature of the day, and gave to Americans their first elementary treatise on botany; and Dr. Caspar Wistar, the learned physician and genial companion, who not only enriched the society by his own work and teachings, but by his correspondence with Humboldt and Soemmering in Germany, Camper in Holland, Sylvester in Geneva, Pole and Hope in Great Britain, and many more of that ilk, kept its members _en rapport_ with scientific work abroad. Dr. Wistar succeeded Dr. Rush as President of the Pennsylvania Abolition Society, which early uttered its protest against slavery. Nor was Dr. Wistar solely interested in the cause of the negro; that of the American Indian, which we are wont to regard as one of the latest fads in the philanthropic world, also engaged his attention at this early date. Dr. Wistar was elected president of the Philosophical Society on the resignation of Mr. Jefferson, in 1815. Some years prior to this, Dr. Wistar introduced to its circle the Baron von Humboldt, whom he invited to that smaller coterie of learned men, at his own house, which composed the Wistar Club. A gala day it must have been at the Philosophical Society when it opened its doors to this greatest naturalist of his time, perhaps of any time. The Baron von Humboldt was returning from an extended tour in South America, Mexico, and the West Indies. His young friends Montufar and Bonpland were with him,--the same Bonpland who later gave the Empress Josephine flower-seeds from the West Indies to plant at Malmaison, who became her intendant there, and who stood by her bedside when she was dying.