I was surprised to see yours of Jun. 15th. come to my hands only by last Post. What I then received by it from Dr. Colden, I suppose I owe to you; for which I am sorry I can make no other acknowledgement but thanks. I perceive likewise, that you are desirous (if I am not mistaken), that the small Paper I left with you on the yellow fever should come forth. I was highly delighted to see so good an oppourtunity any one might have to oblige the publick, and promote the arts and Sciences, as your Press affords; better than I expected to have found in our new world. I look upon myself obliged, thro’ gratitude to you, as well as the justice due to your laudable industry and improvements in that way, to encourage your press as much as I can. The Debt likewise which we all owe to the publick, would make me do what I could to discharge it. But for many very good reasons, I can do neither at present. My health is so impaired by this summer and fall, that I am not able to follow my own necessary calling. Since the last of June I have been afflicted with a Diarrhoea several times, a slow hectic, with spitting of Blood, and troublesome Piles: I had no sooner got over these, (when our weather began to break in the fall, with Rains and Easterly winds) than I was seized with an Intermittent fever, the origin and source of all my disorders. With this I was afflicted, when I received yours, and as I kept the house, I have been more prolix in what I have wrote, having nothing else to amuse me; which is the reason, why I have said so little in so many words; which I hope Dr. Colden and you will excuse. I am so farr from being able to come to Philadelphia this fall again, as you kindly invite me, that I was not able to go to the upper parts of our own Countrey, as I had appointed and firmly resolved, to avoid what I expected in the fall, and have accordingly met with. But my bad state of health puts me under a necessity of going to England very soon, or of loosing my life. I shall let you hear from me before I go; which I am afraid will not be before next Spring, but it must be before Summer, or never. What I shall do there or afterwards, I am not determined, nor can I be, ’till I see what my bad State of health is likely to come to.

As for the small piece on the yellow fever in your hands, you know I left it to be transmitted to Dr. Colden, since we were disappointed of seeing him. But lest I might seem to refuse others any benefit that might be reaped from it (if there is any) I consented, that your Physicians might see it. But it is by no means fit to be printed by itself, nor never was intended to be. It contains only a brief account of some things that I thought might be improvements on this Disease, or at least more clearly shown than is common to be met with, Especially the Dissection of the bodies that dyed of it, for which alone it was wrote, as that is not any where to be met with, as far as I know. It was wrote to a Master of the Art (like compendious Institutes, extracted from a much longer account) to whom I thought Explications might be as impertinent, as they are necessary for others, Especially among us. Had I wrote it for (the generality at least of) your Readers, what I have herein left out, would be most necessary to have insisted upon, and what is herein contained ought to be more fully explained. You know very well, this would be necessary all over America, as far as I can perceive at least. My friends in Scotland (to whom I first sent it) desired me to let them print it by itself; but Mr. Monro and Dr. Clarke at Edinburgh were of Opinion, that in that manner it could not miss to perish (which they were pleased to say it was a pity it should) among the many other little pieces of that sort, which daily come out. They desired me to preserve it by a fuller Account of the other things relating to the Disease. But I laid down all thoughts of that, when I first extracted these observations from the others I had made, not out of any discommendable design I hope. My views then were to inform myself, as well as to qualify myself to inform others (if any desired such information, which very few, too few among us, so much as do) of the nature and Cure of our other popular Maladies, as well as this; as well as of the nature and effects of our Climate, minerals, vegetables and animals, &c. With these pursuits I was busied at some times, when this yellow fever came in my way; and I thought it much better to go on with them, than suffer myself to be interrupted with this: hoping I might preserve my account of it in a Natural and Medical History of my Countrey; for which I have kept Journals of Observations for many years, but left them all off, the beginning of this Monthe, and when, or if ever, I shall be able to begin them again, He only knows who disposes of all things. But still I should be glad of your information about any of these things, for which reason I mention them to you and Dr. Colden; and in return you may command any thing from me, hoping you will use it as a friend, as you see I take you to be, by being so very plain with you. I am fond and ambitious of corresponding with all candid and ingenious Persons about these things I here mention, as I find their Information to be necessary, and am as willing and ready to give them the best accounts of things I can, in return. But you must excuse my not publishing any thing yet a while. I think the world is pestered with this Itch of many to appear in print, which makes many so little regarded that do. Authors ought to be Masters not only of the particular subject, but of the whole art, they undertake to instruct the world in; and when they are—Nonum prematur in annum, saies Horace.

What is enclosed suppose wrote equally to yourself as to Dr. Colden, for whom it is directed, and persist to oblige Sir Your very humble Servant