enumeration of Manchester. Such inquiries may be as useful as they are curious, and if once made general would greatly assist in the prudent government of a State. The difference of deaths between one in twentyeight at Manchester, and one in one hundred and twenty at Morton is surprising. It seems to show the unwholesomeness of the manufacturing life, owing perhaps to the confinement in small, close rooms, or in larger with numbers, or to poverty and want of necessaries, or to drinking, or to all of them. Farmers who manufacture in their own families what they have occasion for and no more, are perhaps the happiest people and the healthiest. It is a curious remark that moist seasons are the healthiest. The gentry of England are remarkably afraid of moisture and of air. But seamen, who live in perpetually moist air, are always healthy, if they have good provisions. The inhabitants of Bermuda St. Helena, and other islands far from continents, surrounded with rocks, against which the waves continually dashing, fill the air with spray and vapor, and where no wind can arrive that does not pass over much sea, and of course bring much moisture; these people are remarkably healthy. And I have long thought that mere moist air has no ill effect on the constitution, though air impregnated with vapors from putrid marshes is found pernicious, not from the moisture, but the putridity. It seems strange that a man, whose body is composed in great part of moist fluids, whose blood and juices are so watery, who can swallow quantities of water and small beer daily without inconvenience, should fancy that a little more or less moisture in the air should be of such But we abound in absurdity and importance. inconsistency. Thus, though it is generally allowed that taking the air is a good thing, yet what caution against air! What stopping of crevices! What wrapping up in warm clothes! What stuffing of doors and windows, even in the midst of summer! Many London families go out once a day to take the air, three or four persons in a coach, one perhaps sick; these go three or four miles, or as many turns in Hyde Park, with the glasses both up close, all breathing over and over again the same air they brought out of town with them in the coach, with the least change possible, and rendered worse and worse every moment. And this they call taking the air. From many years' observations on myself and others, I am persuaded we are on a wrong scent in supposing moist or cold air the causes of that disorder we call a cold. Some unknown quality in the air may perhaps produce colds, as in the influenza, but generally I apprehend that they are the effect of too full living in proportion to our exercise. Excuse, if you can, my intruding into your province, and believe me ever with sincere esteem, dear Your most obedient humble servant, sir, B. FRANKLIN. DXLIV TO JOHN INGENHOUSZ LONDON, 30 September, 1773. MY DEAR FRIEND:-I rejoiced as much as any friend could do at the news we received here from time to time of your success in your profession, and of the safe recovery of your illustrious patients of that most amiable family. But it grieved us all, at the same time, to hear that you did not yourself enjoy health in that country. Surely their known goodness will graciously give you leave of absence, if you have but the courage to request it, and permit you to come and reside in England, which always agreed well with your constitution. All your friends here will be made happy by such an event.1 I had purposed to return to America this last summer, but some events in our colony affairs induced me to stay here another winter. Some time in May or June next I believe I shall leave England. May I hope to see you here once more? I shall be glad to see the work of the Abbé Fontana on that disease of wheat. As yet I have not heard that it is come to England. Sir William Hamilton writes from Naples, that 1 Dr. Ingenhousz was now residing at Vienna, whither he had gone to inoculate for the small-pox the Archduchess Theresa Elizabeth, the only daughter of the emperor, and the Archdukes Ferdinand and Maximilian, the emperor's brothers. He remained in that city several years. He was in England during a large part of the year 1779, when he published his work, entitled, Experiments on Vegetables, etc. In the title-page of that work he styles himself "Counsellor of the Court and Body Physician to their Imperial Majesties."-EDITOR. after many experiments he has not been able to perceive any certain signs of electricity in the torpedo. It is perhaps best that there should be two opinions on this subject, for that may occasion a more thorough examination of it, and finally make us better acquainted with it. It is not difficult to construct a needle, so as to keep pointing to the meridian of any one place, whatever may be the variation in that place. But to point always to the meridian, wherever the needle may be removed, is, I apprehend, not possible. Mr. Nairne has, as you have heard, finished a very fine electric machine. I have seen sparks from the prime conductor thirteen inches in length. He has added a large battery, and produces a discharge from it sufficiently strong to blast growing vegetables, as lightning is supposed to do. From a greater force used, perhaps some more discoveries may be made. I am much pleased with the account you give me of your new machine of white velvet rubbed upon hareskin. Last year the Board of Ordnance applied to the Royal Society here for their opinion of the propriety of erecting conductors to secure the powder magazines at Purfleet. The Society appointed a committee to view the magazines, and report their advice. The members appointed were Messrs. Cavendish, Watson, Delaval, Robertson, Wilson, and myself. We accordingly, after reviewing them, drew up a report, recommending conductors to each, elevated ten feet above the roof, and pointed at the ends. Mr. Delaval did not attend; all the rest agreed in the Report, only Mr. Wilson objected to pointing the rods, asserting that blunt ends or knobs would be better. The work, however, was finished according to our direction. He was displeased that his opinion was not followed, and has written a pamphlet against points. I have not answered it, being averse to disputes. But in a new translation and edition of my book, printed lately at Paris, in two volumes, quarto, you will see some new experiments of mine, with the reasonings upon them, which satisfied the committee. They are not yet printed in English, but will be in a new edition now printing at Oxford, and perhaps they will be in the next Transactions. It has been a fashion to decry Hawkesworth's book; but it does not deserve the treatment it has met with. It acquaints us with new people having new customs, and teaches us a good deal of new knowledge. Captain Phips has returned, not having been able to approach the Pole nearer than eighty-one degrees, the ice preventing. M. Tremont, an ingenious young Italian, who was lately here, gave me a little spy-glass of his making, upon Père Boscovich's principles, the ocular lens being a composition of different glasses instead of the objective. It is indeed a very good one. Sir John Pringle is returned from Scotland, better in health than heretofore. He always speaks of you with respect and affection, as does Dr. Huck and all that knew you. I am ever, with the sincerest esteem, dear sir, |