so that what set out to fall from a cloud of many thousand acres, should reach the earth in perhaps a third of that extent, of which I somewhat doubt. In the other cases we have two experiments.

1. A dry glass bottle filled with very cold water, in a warm day, will presently collect from the seemingly dry air that surrounds it a quantity of water, that shall cover its surface and run down its sides; which perhaps is done by the power wherewith the cold water attracts the fluid common fire that had been united with the dissolved water in the air, and drawing the fire through the glass into itself, leaves the water on the outside.

2. An electrified body, left in a room for some time, will be more covered with dust than other bodies in the same room not electrified, which dust seems to be attracted from the circumambient air.

Now we know that the rain, even in our hottest days, comes from a very cold region. Its falling sometimes in the form of ice shows this clearly; and perhaps even the rain is snow or ice, when it first moves downwards, though thawed in falling; and we know that the drops of rain are often electrified. But those causes of addition to each drop of water, or piece of hail, one would think could not long continue to produce the same effect; since the air, through which the drops fall, must soon be stripped of its previously dissolved water, so as to be no longer capable of augmenting them. Indeed very heavy showers, of either, are never of long continuance; but moderate rains often continue so long as to puzzle this hypothesis; so that upon the whole I think, as I intimated before, that we are yet hardly ripe for making one.

B. FRANKLIN.

FROM W. SMALL TO B. FRANKLIN.

Opinions of the Ancient Physicians respecting Catarrhs,

or Colds.

DEAR SIR,

Birmingham, 10 August, 1771.

The reason of your having no sooner received the quotation from Celsus, is, that I wished to employ my very first leisure in looking into several other ancient books for passages to the same purpose, and to send you all together. But Mr. Keir having told me of your desire to see that immediately, you have it almost alone.

In the article "De Tabe" in his third book, treating of the cure, he says, "Cavendæ distillationes, ne, si quid cura levarit, exasperent; et ob id, vitanda cruditas, simulque et sol et frigus." Here indigestion seems to be reckoned the principal cause. If you have not attended to that particular before, you may be surprised to find sunshine among the causes of colds, but such is the doctrine of all the ancients. A passage about the instruments of cure in coughs may perhaps amuse you, "Utilis etiam in omni tussi est peregrinatio, navigatio longa, loca maritima, natationes." +

From several things in Xenophon and in Plato, the prevailing opinion in their time seems to have been, that what we now commonly call colds and catarrhs, arose almost solely from excess and indolence. On this account Xenophon says, that in Persia in the days of Cyrus, to spit or to blow a nose was infamous.

* "Great caution should be observed, when relief is once obtained, lest catarrhs are made worse; indigestion also, as well as exposure to the sun and cold air, ought to be avoided."

"In all coughs it is found beneficial to take long journeys and voyages, to reside on the sea-coast, and to use sea-baths."

Plato often commends simple spare diet, but in one place he says it prevents all catarrhs. Whether he means precisely what we call catarrhs, however, in that passage, may be doubted.

I do not recollect any absolutely express testimony in your favor from Hippocrates. Mucus (of the nose) and saliva he judges to be signs of repletion; and he maintains that persons who drink and eat sparingly are free from diseases occasioned by moisture. Abundance may be found in Galen to your purpose. A modern author, who ought to have understood this subject, for he has written so great a book about catarrhs,* that you had better have twenty colds than read it, is of your opinion. "Illa, illa, inquam, cibi potusque abundantia citat catarrhos. Eosdem abigunt frugalitas et labor. Ut ex luxu et otio nascuntur catarrhi, ita horum medicina est in sobrietate, in continentiâ, in exercitationibus corporis, in mentis tranquillitate. Quotusquisque vero hæc precepta, has leges vivendi custodit? Homo frugi est rara avis, &c. Hinc nemo mortalium fere est sine catarrhis." +

Mr. Boulton will soon present you with one of the boxes with invisible hinges. He has astonished our rural philosophers exceedingly by calming the waves à la Franklin. ‡

I am trying some experiments in relation to the

This book upon the Catarrh is probably that of Schneiderus, consisting of four volumes, 4to.

"Eating and drinking too much is sufficient of itself, I say, to produce catarrhs. Temperance and active pursuits on the contrary drive them away. As catarrhs are produced by luxury and indolence, so the remedy for these is to observe sobriety, continence, exercise of body and tranquillity of mind. How few observe these precepts! Temperance indeed is very rare. Hence very few escape catarrhs."

That is, by means of oil, according to the experiments mentioned in this volume under the date of January 27th, 1773, p. 355.-EDITOR.

improvement of telescopes; should they answer you shall hear of them.

I beg you will make my most respectful compliments to the fellow travellers who were with you here, and believe me to be,

With the highest regard, dear Sir,

Your much obliged and most obedient servant,
W. SMALL.

TO M. LE ROY.

Intended French Voyage to the North Pole. — Mr. West, President of the Royal Society. Messrs. Banks and Solander.

DEAR SIR,

London, 20 April, 1772.

I received your favor of March 5th, by M. Dazeux, and shall be glad of any opportunity of doing him service. It gave me great pleasure to learn by him, that you are well and happily married, on which I give you joy. It is after all the most natural state of man.

Mr. West, our President, concerning whom you make inquiry, is esteemed a good antiquarian, but has not distinguished himself in any other branch of science. He is a member of Parliament, was formerly Secretary to the Treasury, and is very rich.*

I am glad to hear that a voyage is intended from France to the North Pole. The world owes much to the noble spirit with which your nation pursues the

* James West was President of the Royal Society from November, 1768, till his death in July, 1772. He possessed a very extensive library of rare and valuable books, which were sold by auction after his death. His curious collection of manuscripts was sold to the Marquis of Lans. down, of whom they were purchased by Parliament, and they now make a part of the Lansdown Manuscripts in the British Museum. - EDITOR.

CC *

improvement of knowledge, and to the liberality with which you communicate what you acquire to the rest of mankind. I hope your philosophers on this voyage will be able to discover more clearly the cause of the Aurora Borealis, and a passage round the North of America.

I suppose care has been taken to make their ships very strong, that they may bear thumping among the ice. My best wishes will attend them for their success and safe return.

Messrs. Banks and Solander are to sail with two ships in about a fortnight for the South. They expect to be out near four years. They present their compliments, and are pleased with the notice you honor them with in your letter to me. Sir John Pringle continues well, and presents his respectful compliments to you. I am, with the most perfect esteem,

Dear Sir, yours, &c.

B. FRANKLIN.

TO JOSEPH PRIESTLEY.

Electrical Experiments.

Imperfection of the Abbé

Nollet's Electrical Machine. One on an improved Construction sent to M. Le Roy.

DEAR SIR,

London, 4 May, 1772.

I think with you that there cannot be the least occasion for my explaining your method of impregnating water with fixed air to Messrs. Banks and Solander, as they were present, and I suppose are as well acquainted with it as myself; however, I shall readily do it, if they think it necessary. I am glad you intend to improve and publish the process.