There may possibly seem a want of due consideration in sending this letter, and what accompanies it, to draw the attention of the President of the United States from the important concerns of our nation to a subject more nearly allied to medicine, than to the affairs of state.

On this account, I should have hesitated still longer, were I not constantly receiving letters from unknown persons, in different parts of Virginia, entreating me to send them the vaccine matter, with instructions for carrying on the kine-pock inoculation. From one, received very lately, I learn that the small-pox is unknown to half the inhabitants of your extensive and populous state; that in some quarters of it, the very name of small-pox excites terror; and that your laws are full as severe as those of Massachusetts and Rhode Island, respecting its introduction by inoculation. From these letters I am convinced that there is, perhaps, no state in the Union more deeply interested in the adoption of this new inoculation than Virginia. By letters from Norfolk, I find, that the inoculation for the kine-pock has been attempted there, but that the subjects of it did not resist the small-pox. Such failures may bring this admirable discovery into disrepute, and deprive you, for a time, of its blessings; nay, what is very serious, such accidents may be the means of spreading the small-pox among you, as it has in some places among us. Not merely ignorance, but avarice, rivalship, and some other unworthy passions, have cast a temporary shade over this important discovery, in some of the towns in this Commonwealth; and I suspect you have experienced something similar, though not from the same causes.

I presume you will think with me, that too much care and attention cannot be exercised in the introduction of this valuable but delicate remedy among you. I will do all in my power for its establishment, provided I can obtain the countenance of men of more consequence than myself. Amidst the pelting storm of his adversaries, Dr. Jenner had the countenance of his Sovereign; and the Duke of York is the patron of the London Vaccine Institution. Bonaparte took a lively interest in the diffusion of vaccinism in France; and so did the German nobility at the court of Vienna. Under such patronage, people in the inferior walks of life embraced the doctrines of this new discovery with entire confidence.

Having no personal acquaintance with any medical man in Virginia (some of my own pupils excepted, to whose inexperience I should hardly venture to commit this delicate business) I cannot see my way clear to transmit the matter to I know not whom. After much thought, and some advice, I have concluded to send it to President Jefferson, together with such books and descriptions as may enable a physician experienced in exanthematous diseases, to conduct the process with certainty.

My view is this:—The President can at once fix his eye on some proper medical character, to whom the first experiments may be entrusted; some cautious discerning person, perhaps his own family physician. A series of experiments may be directly instituted by him; and when the distemper has proceeded according to the description herewith sent, the subjects of them, may afterwards be submitted to the test of the small-pox inoculation, just as was done at Paris, under direction of the National medical school.

As your domestics are principally blacks, I have taken no small pains to procure a picture of the disease, as it appeared on their skins (see fig. xii). Besides being of vast importance to the state at large, I conceive that an exertion to preserve this wretched people from the horrors of the small-pox, cannot but be agreeable to that beneficent Ens Entium, who has seen fit to make that enviable distinction between the situation and faculties of this helpless race and us!

By causing this inoculation to pass through the respectable channel here contemplated, Virginia, and of course, the other southern States, will insure to themselves the blessings of this invaluable discovery, and the serious evils that have arisen in some places, will be avoided. Young and unexperienced practitioners are most forward in this business; yet such can neither excite attention, nor inspire confidence; whereas, if it came from Mr. Jefferson, it would make, like a body falling from a great height, a deep impression. Need I then, make any further apology for sending the matter first to you, encumbered, as I know you must be, with other concerns?

I here send a little book, compiled by Mr. Aikin, Surgeon of London; being perhaps, the best manuel for the inoculator, extant. I have it in contemplation to publish something of the kind, more adapted to this country, and containing some letters of Dr. Jenner to me, on the best mode of conducting this inoculation. I also transmit for your acceptance, exact pictures of the kine-pock pustule, in all its stages, from the third day to its final termination, painted with surprising justness, together with similar representations for the small-pox, on corresponding days. The dark coloured picture, (fig. 12) is a representation of the kine-pock on the skin of the negro. I have never inoculated but three of this colour; but, as far as I can remember, it is equally accurate. The graphic art never, perhaps, received a greater honour. I likewise send some fresh infected thread, confined between two thin plates of talc, and inclosed in the laminæ of a card; the whole pasted up so as to exclude entirely the external air. In this way, I conjecture, it may be sent to the Cape of Good Hope, the Isle of France, or the hot regions of India, without losing its efficacy.* The red thread marks the place where it is to be opened.

I would advise the inoculator, when he makes the incision, or rather scratch, in the arm, not to draw blood, if he can help it. If this should be unavoidable, it is best to wait a moment until the exudation ceases, lest the blood should dilute the virus too much, and so weaken its power. The thread is then to be covered with a piece of gold beaters skin, which I generally take off in 24 hours. But the fifth or sixth day, the inoculator may expect to see the effects of his operation. By the eighth the vesicle will be found to contain a small quantity of pellucid fluid, but in no degree resembling matter, or pus; on the contrary, as limped as the dew drop on flowers, at this season. And this is the exact period, and proper condition of the vaccine fluid, for I will not call it matter, for the purpose of inoculation. It may be taken on the ninth day, but seldom or never later. The want of strict attention to this important point, has produced all the disasters that have occurred in this inoculation in Europe and America, and therefore, this rule cannot be too emphatically urged. The virus should never be taken after the efflorescence has come on, much less during the febrile symptons. Mr. Aikin allows too much latitude. Some give a still wider license, and assert that the genuine virus is found in a pustule on the twelfth or thirteenth day; but Jenner and experience say otherwise. “I wish you to consider, says Dr. Jenner, in one of his letters to me, this Efflorescence as a “sacred boundary, over which the lancet should never pass.” I cannot then but reiterate the injunction, to take the vaccine fluid on the seventh, eighth or ninth day, and not on the tenth, eleventh, or twelfth. For want of this knowledge, spurious cases have arisen, and multiplied in our country. It is the most important point in the whole process, the fulcrum on which the whole business turns; and yet no writer, but the celebrated Jenner, appears to be impressed with its importance. It is natural, say some, to conclude that it is best to take the fluid for inoculation, at the very height of the disorder, that is, of the efflorescence. But I am doubtful whether this be the voice even of a legitimate theory. When the inflammation, or efflorescence of the inoculated part commences, it indicates that absorption has already begun; and after absorption has commenced, the quantum, or force of the virus in the vesicle, pustule, or inoculated part, denominate it which you will, is diminished. To note the progress and aspect of the pustule, is of prime importance in the commencement of this practice. “One of the first objects of this pursuit, says Dr. Jenner, should be to learn how to distinguish with accuracy, between that pustule which is the true cow-pox, and that which is spurious. Until experience has determined this, we view our object through a mist.” My insulated situation, and remoteness from all correct information on this head, has compelled me to the closest observation of the progress of the pustule, even from hour to hour, with the microscope; and I am convinced of the importance of Dr. Jenner’s injunctions to me; nay more, I am convinced by my own blunders.

In people of weak circulation, I have found the progress of this disease more backward, than is here represented: that is to say, the efflorescence described around the pustule on the ninth day, did not make its appearance until the tenth or eleventh, and continued thus backward through the whole progress. I suspect that this may oftener occur in the southern States, than in the colder regions of the north. I have just inoculated a family from Natchez, where this variation was remarkable. In such cases, I take the fluid for inoculation on the ninth, tenth, and even eleventh day. Should the physician, or physicians, to whom you would think proper to confide this matter, wish for any further information from me, they cannot be more ready to ask, than I shall be to communicate what little I know on this subject.

It is perhaps unnecessary for me to say, that it is found, from the most incontestable experiments,

I.	That the kine-pock is not contagious.
II.	That it never has been fatal.
III.	That it completely prevents the small-pox.
IV.	That it conveys no constitutional disease. And
V.	That it creates no blemish, or mark, on the human frame.

These properties make this vicarious distemper, one of the most precious gifts of Providence to afflicted man. That it actually possesses them all, we are assured by the united testimony of the first physicians in London, which is saying the first physicians in the world.

Besides England, this new inoculation now prospers in France, Germany, and at Geneva. The physicians at Geneva had many spurious cases, and some perplexity, until Dr. Jenner sent them, as he did me, fresh matter, and clearer instructions. It has taken the place of the small-pox inoculation in the British army and navy, and is spoken of by the surgeons of the latter, as one of the greatest blessings ever extended to it.* By a Madrid gazette, just come to my hands, I find that it is introduced there from Gibraltar, by permission of both the British and Spanish governments. Nay more, Lord Elgin has planted it in Constantinople, just about eighty-six years after the Turks helped us to the practice of the variolous inoculation. In no place has the vaccine inoculation been received with more prudence, than at Paris, under the conduct of the National medical school. The report of the committee may be seen in the 4th volume of the Medical and Physical Journal; where it will appear, that they made themselves sure of every inch of ground they passed over.

As to the progress of the inoculation in this quarter, it is very satisfactory. Last autumn we were pestered with spurious cases, and absolutely lost the genuine virus. The most eminent physicians in this region, as well as the most distinguished characters, in the two other learned professions, are advocates for this inoculation; not that I would insinuate, that this new practice is destitute of the advantage of having adversaries, even among the faculty.

It is in such a prosperous state of the business, that I am desirous of transmitting the blessings of this new discovery to my brethren of the southern States; and in order to ensure it success, I wish it may pass from your hands to them.

Should I be the means of introducing this disease, or rather remedy, not merely into Virginia, but into the vast region of the southern States, I should1 indeed rejoice in its recollection to the end of life.*

With the highest respect, I remain, &c.