I just learned, my illustrious doctor, that there is a packet-boat leaving Le Havre and I don't want to miss this occasion to have the honor of writing to you. First of all, I owe you many thanks for your kindness in sending me the Diploma for my association with your learned Society. I hope you will please express my heartfelt gratitude to them. In a letter which I had the honor of writing to you already a few months ago, I told you that there was nothing new happening here in the sciences. Our chemists are still strongly divided, and there is every reason to believe that it will only be after a few years, as I think I told you already, that we will be able to make up our minds about the new principles introduced in this science. M. de Fourcroy, a doctor and chemist, and one of our colleagues, published a work in four volumes on chemistry and natural history, in which these new principles are found, but everything is done there a little too generally. I plan to send you another book in a while, in which these ideas will be more interrelated. I gave M. Grand the committee's report regarding the Hôtel-Dieu, and I imagine that you must have received it, but these days we are like the English at Parliament time, when they argue over great questions: the Assembly of Notables gets all the attention, and everyone talks of nothing but their deliberations, their resolutions, etc.

The balloons are almost forgotten, and without Blanchard, who continues to uphold their honor, one would believe they never existed. He is to leave from Valenciennes next Monday, but with a new arrangement: his basket will be carried by three balloons. I will have the honor of letting you know the results of the aerial expedition.

I don't know what will become of the poor people of Javelle, whose crossing of the Seine you immortalized in the letter which you did my brother the honor of writing; just now, their leader, M. Bourboulon, is in fraudulent bankruptcy, and he is on the run, never to return. My brother was planning, my illustrious doctor, to send you by the packet-boat a published copy of the translation that I made of your letter, but unfortunately it is not ready yet. He had to put it off and delay sending it to you.

When I told you that we had no news in the sciences, I meant on the continent, for surely you have learned by the Gazettes the news of the brilliant and extraordinary discovery that M. Hirschel [Herschel] made, of the planet's [Uranus's] two satellites. Doubtless you also know that he did it by changing the mechanism of his telescope (which is still a reflector). This change consists in removing the small mirror, in a slight indentation given to the large mirror, and in the position of the eyepieces at the end of the tube, which are fitted for this tube. The sketch below will permit you to easily understand the arrangement [figure]

M. Hirschel [Herschel] calls this new way of using the reflector telescope, The Front View. Adieu my illustrious doctor. I learned with great pleasure that your health is still holding up well. It seems that the pains you were suffering here have been greatly eased. M. de Buffon is not so lucky as you, as he continues to suffer fairly often, especially at night. Continue to enjoy a state of health which is so precious to your friends; no one, I assure you, wishes more sincerely than I, that you will enjoy this health up until the age of Nestor, and that it be said that you are, all in all, an extraordinary phenomenon for future generations