From William Barton
Philada. June 15. 1792
The inclosed Observations on the Hessian Fly, in answer to the Queries published by the Committee of the Philosophical Society, and addressed, to You, were transmitted (under Cover) to me, since the last stated Meeting of the Society.
In the Letter, to me, which covered these Observations, the ingenious Writer—Dr. De Normandie of Burlington—makes mention, that the Magnifier he used on the Occasion, took in the whole Compass of the Fly, and enlarged it to the size of the Yellow wasp. He brought into his Chamber, in their Chrysalis state, some of the Flies, which he had procured from a parcel of damaged Wheat; and provided for them young, growing Wheat, either for them to feed on, or upon which they might deposit their Eggs, neither of which they did. He also placed some of them on the green Wheat: but they instantly deserted it, and flew to the Windows, which by that time he had darkened with the Shutters. This discouraging the Doctor from any further Attempt, and inducing him to decline the investigation in that way, he confined his Attention to their progress in their natural State. From the result, he is inclined to think, they do not couple very soon after they enter their Fly-state; and he supposes, that last Operation of their life—the propagation of their species—is reserved for the Fall of the Year, when the young Grain affords a safe Lodgment for the Egg, and provision for their Worm-state. I have the Honor to be, With great Respect, Sir, Yr. mo. obedt. hble. Servt.
RC (DLC); at foot of text: “The Hon. T. Jefferson, Esqr.”; endorsed by TJ: “Normandie Dr. de.”