Twelve days after receiving your most gracious letter I was overtaken by blind hemorrhoids, which have tormented me fiercely for three months and a half. Hence it is only now, as I begin to feel some relief from them, that I am able to thank both the Royal Society and you for the condescension you showed towards my endeavors whatever [they may be worth], and this I think I cannot do in a better manner than by continuing my experiments. In keeping with this goal, I am enclosing a few pages of experiments I had carried out before I fell sick. Among them you will find an improved and augmented table of my first experiments. Should the Royal Society like to have the abovesaid pages as well, it seems to me that the first experiments could be printed, omitting the whole table, and starting again with the Theorem. However, the number of the Transactions where the table is to be printed, such as I am sending it now, ought to be quoted. I do not know whether Mr. Maty has communicated to you a postscript I had added to those first experiments. It should read as follows:

“I am adding an experiment, as it will be seen, which is elegant, easy, and not hard to explain: I wrap a band of velvety black silk cloth around a glass cylinder which is rubbed in an electric machine; I distend it, sew it, rub it against the hair of the skin of a wild animal (the very long hair of a wildcat does much better than that of a hare). By such a not-so-strong friction there appears in the chain electricity [that is] more vehement than that appearing through the ordinary friction of glass, but is opposite to it. Moderate friction offers easiness in experimenting. The vehemence of the electricity both increases the easiness of experimenting and increases the effects of the experiments. The contrast in the vehemence of the electricity defines the question. Thus as a matter of fact, I see that those who denied the electricity of resin opposite to the electricity of glass were deceived by the weakness of its electricity.”

Mr. Maty, in replying to my first letter, told me that you were very much occupied with American affairs. This is the only reason why, since I expected no reply from you, I addressed to Mr. Wilson other additional pages of mine concerning the electricity of glasses. If I had hoped for the honor of correspondence from you, I would have addressed myself to you and would have explained more openly my theoretical impressions concerning those experiments, which I think detract nothing from your theory but only add something. As I gain strength I shall endeavor to support those impressions with additional facts and shall write you about them if you care for it. I am enclosing the printed copy (a) of those pages of mine, sent to Mr. Wilson, which I beg you to look at and to write me something about them. For the time being I shall only point out: first, that the more the glasses are heated by fire, the less they show the effects preceding the discharge, and the discharge itself also is less, but they show greater effects following the discharge; second, that when I want to see the colored areas, I apply glasses that overlap in their two naked, most polished surfaces, which have been exposed to fire; third, that whether the glasses are charged in the chain as usual, or are charged by laying them over some body and rubbing them, one must always distinguish the two electricities, for if immediately after rubbing the surface of one of two united glasses, I separate them, the one which was rubbed appears electric by excess, the other by defect. Only after some time do these electricities reverse themselves. I should like these three remarks to be added as footnotes to those experiments. Here in Turin, Cigna, the physician, a student of mine a few years ago, sent me on 23 February of this year a printed copy of a pamphlet of his, where, among other things, he deals with the rubbing of ribbons and with the electricity of glasses. I think you will have received such a pamphlet from Mr. La Grange, a companion and great friend of the said Cigna. I was uncertain whether I ought to mention that pamphlet as I was dealing with glasses and ribbons. I decided not to do it, considering that such a quotation might look like a reproach, since my experiments concerning ribbons show the experiments of Cigna to be wrong in that part where they would coincide with mine; and you will see that the same is true in Cigna’s experiments concerning glasses, because, among other things, he does not in any way distinguish the electricity before a discharge from that after the discharge. At any rate, Cigna could have made out a more ingenious pamphlet if he had less indulged his inclination to innovate and contradict.

Should you not have that pamphlet, I will send it to you. Likewise, I beg you to continue [sending] me the news of discoveries that happen there and I am awaiting with great eagerness the new and enlarged edition of your most original letters, of which the meteorological observations you have most courteously favored me with are a most worthy accompaniment. On the other hand, in regard to waterspouts I have two observations of my own, one of 12 September of last year, the other of the last day of Whitsuntide of this year, which I shall make bold to offer you, if it pleases you, so that you may decide by yourself whether the circumstances I observed prove that some of the phenomena included under the name of waterspouts are produced by electric fire, as I have suggested. Meanwhile with full gratitude, respect and esteem, I am