I have lately received a letter from General Clarke. He has employed ten laborers several weeks, at the Big-bone Lick, and has shipped the result, in three large boxes, down the Ohio, via New Orleans, for this place, where they are daily expected. He has sent, 1st, of the Mammoth, as he calls it, frontals, jaw-bones, tusks, teeth, ribs, a thigh, and a leg, and some bones of the paw; 2d, of what he calls the Elephant, a jaw-bone, tusks, teeth, ribs; 3d, of something of the Buffalo species, a head and some other bones unknown. My intention, in having this research thoroughly made, was to procure for the society as complete a supplement to what is already possessed as that lick can furnish at this day, and to serve them first with whatever they wish to possess of it. There is a tusk and a femur which General Clarke procured particularly at my request, for a special kind of Cabinet I have at Monticello. But the great mass of the collection are mere duplicates of what you possess at Philadelphia, of which I would wish to make a donation to the National Institute of France, which I believe has scarcely any specimens of the remains of these animals. But how to make the selection without the danger of sending away something which might be useful to our own society? Indeed, my friend, you must give a week to this object. You cannot but have some wish to see Washington for its site, and some of its edifices, which will give you pleasure. You will see one room especially, to which Europe can show nothing superior. Baltimore, too, is an object. Take your lodgings at the tavern close by us. Mess with me every day, and in the intervals of your perlustrations of the city, Navy Yard, Capitol, &c., examine these bones, and set apart what you would wish for the society. I will give you notice when they arrive here, and then you will select a time when you can best absent yourself for a week from Philadelphia. I hope you will not deny us this great service, and I salute you with friendship and respect. TO GEN. WILLIAM CLARKE. WASHINGTON, December 19, 1807. DEAR SIR,--I have duly received your two favors of September 20th, and November 10th, and am greatly obliged, indeed, by the trouble you have been so good as to take in procuring for me as thorough a supplement to the bones of the Mammoth as can now be had. I expect daily to receive your bill for all the expenses, which shall be honored with thanks.