Benjamin Franklin Papers

From Benjamin Franklin to Thomas Percival, 15 October 1773

To Thomas Percival6

ALS (draft): American Philosophical Society; copy: National Library of Scotland

[London 15 October 17737]

Dear Sir,

I have received here your Favour of September 18th. enclosing your very valuable Paper of the Numeration of Manchester.8 Such Enquiries may be as useful as they are curious, and if once made general would greatly assist in the prudent Government of a State. In China, I have somewhere read, an Account is yearly taken of the Numbers of People, and the Quantities of Provision produc’d. This Account is transmitted to the Emperor, whose Ministers can thence foresee a Scarcity likely to happen in any Province, and from what Province it can best be supply’d in good time. To facilitate the collecting this Account, and prevent the Necessity of entring Houses, and spending time on asking and answering Questions, each House is furnish’d with a little Board to be hung without the Door during a certain time each Year, on which Board, is marked certain Words, against which the Inhabitant is to mark Number or Quantity somewhat in this Manner,9

} Persons 1
} 5
Rice or Wheat 5 Quarters
Flesh 1000 lb.

All under 16 are accounted Children, and all above as Men and Women. Any other Particulars the Government desires Information of, are occasionally mark’d on the same Boards. Thus the Officers appointed to collect the Accounts in each District, have only to pass before the Doors, and enter in their Book what they find marked on the Board without giving the least Trouble to the Family. There is a Penalty on marking falsly, and as Neighbours must know nearly the Truth of each others Account, they dare not expose themselves by a false one to each others Accusation. Perhaps such a Regulation is scarce practicable with us.

The Difference of Deaths, between 1 in 28, at Manchester and 1 in 1201 at Monton, is surprizing. 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.

‘Tis a curious Remark that moist Seasons are the healthiest.2 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 Vapour, 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; Tho’ Air impregnated with Vapours from putrid Marshes is found pernicious, not from the Moisture but the Putridity.3 It seems strange that a Man whose Body is compos’d 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 Importance. But we abound in Absurdity and Inconsistency. Thus, tho’ it is generally agreed that taking the Air is a good Thing, yet what Caution against Air, what stopping of Crevices, what wrapping-up in warm Clothes, what Shutting 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 Hide 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 render’d worse and worse every moment. And this they call taking the Air. From many Years Observations on my self 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 sometimes produce Colds, as in the Influenza: but generally I apprehend they are the Effects of too full Living in proportion to our Exercise.4 Excuse, if you can, my Intruding into your Province, and believe me ever, with sincere Esteem, Dear Sir, Your most obedient humble Servant


Notation: To Thomas Percival.

[Note numbering follows the Franklin Papers source.]

6For the Lancashire physician and scientist see above, XVIII, 104 n.

7The heading of the copy. The letter, so dated, appears in [Edward Percival, ed.,] The Works, Literary, Moral, and Medical, of Thomas Percival, M.D. … (4 vols., Bath and London, 1807), I, xxx–xxxiv. The draft is headed “West Wycomb, in Seat of Lord Le Despencer, Sept. 25. 1773,” and mentions in the first sentence Percival’s favor “of the 18th.” The copy and the printed text, which are almost identical, lack BF’s spelling and punctuation but are otherwise probably closer than the draft to the letter as sent. Although we print the draft we incorporate, and note when significant, changes that we believe BF made in the final version.

8The letter has been lost, but Edward Percival presumably had a copy before him when he compiled the Works. He there remarks, p. XXX, that BF received with the letter “Dr. Percival’s second volume of ‘Essays,’ &c.” The essays were Percival’s Essays Medical and Experimental … (2nd. ed.; 2 vols., London, 1772–73); the “&c.” was either a printed or MS copy of Observations on the State of Population in Manchester … ([Manchester, 1773]), the “very valuable Paper” to which BF refers. For the sequels to it see Percival to BF below, June 21, 1774.

9In the copy and printed text of this letter everything but the left-hand column was deleted. The door cards were less for preventing famine than for tax-collecting, and their use was neither so widespread nor so effective as BF implies. See Ping-ti Ho, Studies on the Population of China, 1368–1953 (Cambridge, Mass., 1959), pp. 39–46.

1Thus in the draft and the printed text. The copy reads 68, which was Percival’s actual figure in the Observations cited above. Monton was a village four miles from Manchester.

2For the remark, borrowed from another writer, see the reprint of the Observations in Percival’s Philosophical, Medical, and Experimental Essays … (London, 1776), pp. 20–1.

3BF’s friends shared this idea that marsh air was dangerous, and one of them had publicized it years before: John Pringle, Observations on the Diseases of the Army (4th ed., London, 1764), especially pp. 84–5, 179–80. Joseph Priestley and Richard Price were investigating the question, and soon supported Pringle’s view in two articles, entitled respectively “On the Noxious Quality of the Effluvia of Putrid Marshes …” and “Farther Proofs of the Insalubrity of Marshy Situations …,” in Phil. Trans., LXIV (1774), part I, 90–8.

4BF’s interest in colds was particularly active this year, as shown in his letters above to Dubourg, March 10 and June 29, to LeRoy, June 22, to Rush, July 14; and in his notes on the subject at the end of this volume.

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