May 14. Fryday.
On Board all day, ill of a Cold. Many Gentlemen came on board to visit me. A Dr. Brooks, Surgeon to the Poor Richard, drank Tea with me. He seems to be well acquainted with Philosophical Experiments. I led him to talk upon this subject. He had much to say about Phlogiston, fixed Air, Gas &c. About absolute and sensible Heat, Experiments with the Thermometer, to shew the absolute and sensible Heat in Water, Air, Blood &c.
Finding he had Ideas of these Things, I led him to talk of the Ascent of Vapours in the Atmosphere, and I found he had considered this subject.
He mentioned a natural History of N. and S. Carolina, by Catesby in 4 Volumes folio with Stamps of all the Plants and Animals. Price 25 Guineas. He mentioned a Dr. Erving  and a Dr. Black of Glasgow, as great Philosophers, whose Hints Priestly had taken.
This Dr. Brooks is a Gentleman of Family, whose father has a great Fortune and good Character in Virginia. Mr. Dick, Captain of Marines, on Board of Jones, is also of good family and handsome fortune in Virginia.
Mr. Gimaet came on board to visit me, Aid de Camp of the Marquis de la Fayette.1
1. Jean Joseph Sourbader de Gimat had accompanied Lafayette to America in the Victoire in 1777, returned there again in 1780, and achieved a distinguished military record (Lasseray, Les français sous les treize étoiles description begins André Lasseray, Les français sous les treize étoiles (1775–1783), Macon and Paris, 1935; 2 vols. description ends , 2:418–420).