I communicated your Piece on Fluxions to Mr. Logan, and being at his House a few Days after, he told me, he had read it cursorily, that he thought you had not fully hit the Matter, and (I think) that Berkley’s Objections were well founded: but said he would read it over more attentively. Since that, he tells me there are several Mistakes in it, two of which he has mark’d in Page 10. He says, xx is by no Means=x+x, nor is the Sq. of 10+1=10:2:01 but=100+20+1 and that the Method of Shewing what Fluxions are, by squaring them, is entirely wrong. I suppose the Mistakes he mention’d, if they are such, may have been Slips of the Pen in transcribing. The other Piece, of the several Species of Matter, he gave me his Opinion of in these Words, “It must necessarily have some further Meaning in it than the Language itself imports, otherwise I can by no means conceive the Service of it.” At the same time, he express’d a high regard for you, as the ablest Thinker (so he express’d it) in this part of the World. I purpose to write to you from N York next Week, and till then must defer saying any further on the last mention’d Piece. Enclos’d I send you a Piece of Dr. Mitchel’s (of Virginia) which I caus’d to be transcrib’d while he was here. He desires your Sentiments of it, and to be favour’d with any other Observations you have made on the same Distemper (the Yellow Fever). When you have perus’d it, please to return it. I am, Sir Your most humble Servant