other Writers of the same Kind, may be used on these Occasions to decide their Disputes. Publick Disputes warm the Imagination, whet the Industry, and strengthen the natural Abilities.

When Youth are told, that the Great Men whose Lives and Actions they read in History, spoke two of the best Languages that ever were, the most expressive, copious, beautiful; and that the finest Writings, the most correct Compositions, the most perfect Productions of human Wit and Wisdom, are in those Languages, which have endured Ages, and will endure while there are Men; that no Translation can do them Justice, or give the Pleasure found in Reading the Originals; that those Languages contain all Science; that one of them is become almost universal, being the Language of Learned Men in all Countries; that to understand them is a distinguishing Ornament, &c. they may be thereby made desirous of learning those Languages, and their Industry sharpen'd in the Acquisition of them. All intended for Divinity, should be taught the Latin and Greek; for Physick, the Latin, Greek, and French; for Law, the Latin and French; Merchants, the French, German, and Spanish: And though all should not be compell'd to learn Latin, Greek, or the modern foreign Languages; yet none that have an ardent Desire to learn them should be refused; their English, Arithmetick and other Studies absolutely necessary, being at the same Time not neglected.

If the new Universal History were also read, it would give a connected Idea of human Affairs, so far as it goes, which should be follow'd by the best modern Histories, particularly of our Mother Country; then of these Colonies; which should be accompanied with Observations on their Rise,

Encrease, Use to Great Britain, Encouragements, Discouragements, etc. the Means to make them flourish, secure their Liberties, &c.

With the History of Men, Times, and Nations, should be read at proper Hours or Days, some of the best Histories of Nature, which would not only be delightful to Youth, and furnish them with Matter for their Letters, &c. as well as other History; but afterwards of great Use to them, whether they are Merchants, Handicrafts, or Divines; enabling the first the better to understand many Commodities, Drugs, &c.; the second to improve his Trade or Handicraft by new Mixtures, Materials, &c., and the last to adorn his Discourses by beautiful Comparisons, and strengthen them by new Proofs of Divine Providence. The Conversation of all will be improved by it, as Occasions frequently occur of making Natural Observations, which are instructive, agreeable, and entertaining in almost all Companies. Natural History will also afford Opportunities of introducing many Observations, relating to the Preservation of Health, which may be afterwards of great Use. Arbuthnot on Air and Aliment, Sanctorius on Perspiration, Lemery on Foods, and some others, may now be read, and a very little Explanation will make them sufficiently intelligible to Youth.

While they are reading Natural History, might not a little Gardening, Planting, Grafting, Inoculating, etc., be taught and practised; and now and then Excursions made to the neighbouring Plantations of the best Farmers, their Methods observ'd and reason'd upon for the Information of Youth? The Improvement of Agriculture being useful to all, and Skill in it no Disparagement to any.

The History of Commerce, of the Invention of Arts, Rise

of Manufactures, Progress of Trade, Change of its Seats, with the Reasons, Causes, &c., may also be made entertaining to Youth, and will be useful to all. And this, with the Accounts in other History of the prodigious Force and Effect of Engines and Machines used in War, will naturally introduce a Desire to be instructed in Mechanicks, and to be inform'd of the Principles of that Art by which weak Men perform such Wonders, Labour is sav'd, Manufactures expedited, &c. This will be the Time to show them Prints of antient and modern Machines, to explain them, to let them be copied, and to give Lectures in Mechanical Philosophy.

With the whole should be constantly inculcated and cultivated, that Benignity of Mind, which shows itself in searching for and seizing every Opportunity to serve and to oblige; and is the Foundation of what is called GOOD BREEDING; highly useful to the Possessor, and most agreeable to all.

The Idea of what is true Merit should also be often presented to Youth, explain'd and impress'd on their Minds, as consisting in an Inclination join'd with an Ability to serve Mankind, one's Country, Friends and Family; which Ability is (with the Blessing of God) to be acquir'd or greatly encreas'd by true Learning; and should indeed be the great Aim and End of all Learning.

SIR,

93. TO PETER COLLINSON1

[Philadelphia,] 1748.

§ 1. There will be the same explosion and shock if the electrified phial is held in one hand by the hook, and the 1 From "Experiments and Observations on Electricity," London, 1769, p. 21.

coating touch'd with the other, as when held by the coating, and touch'd at the hook.

2. To take the charg'd phial safely by the hook, and not at the same time diminish its force, it must first be set down on an electric per se.

3. The phial will be electrified as strongly, if held by the hook, and the coating apply'd to the globe or tube; as when held by the coating, and the hook apply'd.1

4. But the direction of the electrical fire, being different in the charging, will also be different in the explosion. The bottle charged through the hook, will be discharged through the hook; the bottle charged through the coating, will be discharged through the coating; and not otherways; for the fire must come out the same way it went in.

5. To prove this, take two bottles that were equally charged through the hooks, one in each hand; bring their hooks near each other, and no spark or shock will follow; because each hook is disposed to give fire, and neither to receive it. Set one of the bottles down on glass, take it up by the hook, and apply its coating to the hook of the other; then there will be an explosion and shock, and both bottles will be discharged.

6. Vary the experiment, by charging two phials equally, one through the hook, the other through the coating; hold that by the coating which was charged through the hook; and that by the hook which was charged through the coating; apply the hook of the first to the coating of the other, and there will be no shock or spark. Set that down on glass which you held by the hook, take it up by the coating, and

1 This was a Discovery of the very ingenious Mr. Kinnersley's, and by him communicated to me.-F.

bring the two hooks together: a spark and shock will follow, and both phials be discharged.

In this experiment the bottles are totally discharged, or the equilibrium within them restored. The abounding of fire in one of the hooks (or rather in the internal surface of one bottle) being exactly equal to the wanting of the other; and therefore, as each bottle has in itself the abounding as well as the wanting, the wanting and abounding must be equal in each bottle. See § 8, 9, 10, 11. But if a man holds in his hands two bottles, one fully electrified, the other not at all, and brings their hooks together, he has but half a shock, and the bottles will both remain half electrified, the one being half discharged, and the other half charged.

7. Place two phials equally charged on a table, at five or six inches distance. Let a cork ball, suspended by a silk thread, hang between them. If the phials were both charged through their hooks, the cork, when it has been attracted and repelled by the one, will not be attracted, but equally repelled by the other. But, if the phials were charged, the one through the hook, and the other through the coating,' the ball, when it is repelled from one hook, will be as strongly attracted by the other, and play vigorously between them [fetching the electric fluid from the one, and delivering it to the other—1774] till both phials are nearly discharged.

8. When we use the terms of charging and discharging the phial, it is in compliance with custom, and for want of

1 To charge a bottle commodiously through the coating, place it on a glass stand; form a communication from the prime conductor to the coating, and another from the hook to the wall or floor. When it is charged, remove the latter communication before you take hold of the bottle, otherwise great part of the fire will escape by it.-F.