"With sentiments of the greatest esteem and regard, "I am, sir, "Your most obedient humble servant, "MATTH. CLARKSON. _"Philadelphia, Oct. 17, 1793._ _"Richard Varick, mayor of the city of New-York."_ It is no new thing for bilious fevers, of every description, to be checked or subdued by _wet_ and _cold_ weather. The yellow fever which raged in Philadelphia in 1699, and which is taken notice of by Thomas Story in his journal, ceased about the latter end of October, or the beginning of November. Of this there are satisfactory proofs, in the register of the interments in the friends' burying-ground, and in a letter, dated November 9th, old style, 1699, from Isaac Norris to one of his correspondents, which his grandson, Mr. Joseph P. Norris, politely put into my hands, with several others, which mention the disease, and all written in that memorable year in Philadelphia. The letter says, "It has pleased God to put a stop to our sore visitation, and town and country are now generally healthy." The same disease was checked by wet and cold weather in the year 1741. Of this there is a proof in a letter from Dr. Franklin to one of his brothers, who stopped at Burlington, on his way from Boston to Philadelphia, on account of the fever, until he was assured by the doctor, that a thunder gust, which had cooled the air, had rendered it safe for him to come into the city[57]. Mr. Lynford Lardner, in a letter to one of his English friends, dated September 24, 1747, old style, after mentioning the prevalence of the fever in the city, says, "the weather is now much cooler, and those under the disorder revive. The symptoms are less violent, and the fever gradually abates." [57] From a short note in the register of the interments in the friends' burying-ground, it appears that the fever this year made its first appearance in the month of June. The following is a copy of that note: "12th of the 6th month (O. S.), 1741, a malignant yellow fever now spreads much." Besides that note, there is the following: "25th of the 7th month (O. S.), 1741, many who died of the above distemper were persons lively, and strong, and in the prime of their time." I have in vain attempted to procure an account of the time of the commencement of cold weather in the autumn of 1762. In the short history of the fever of that year, which I have inserted from my note book, I have said that it continued to prevail in the months of November and December. The register of the interments in the friends' burying-ground in those months confirms that account. They were nearly as numerous in November and December as in September and October, viz. in September 22, in October 27, in November 19, and in December 26. The bilious remitting fever of 1780 yielded to cool weather, accompanied by rain and an easterly wind[58].