The Online Library of Liberty

A project of Liberty Fund, Inc.

• Of Human Understanding. Part Ii
• Book III.
• Chap. VII.: Of Particles.
• Chap. VIII.: Of Abstract and Concrete Terms.
• Chap. IX.: Of the Imperfection of Words.
• Chap. X.: Of the Abuse of Words.
• Chap. XI.: Of the Remedies of the Foregoing Imperfections and Abuses.
• Book IV.
• Chap. I.: Of Knowledge In General.
• Chap. II.: Of the Degrees of Our Knowledge.
• Chap. III.: Of the Extent of Human Knowledge.
• Chap. IV.: Of the Reality of Knowledge.
• Chap. V.: Of Truth In General.
• Chap. VI.: Of Universal Propositions, Their Truth and Certainty.
• Chap. VII.: Of Maxims.
• Chap. VIII.: Of Trifling Propositions.
• Chap. IX.: Of Our Knowledge of Existence.
• Chap. X.: Of Our Knowledge of the Existence of a God.
• Chap. XI.: Of Our Knowledge of the Existence of Other Things.
• Chap. XII.: Of the Improvement of Our Knowledge.
• Chap. XIII.: Some Farther Considerations Concerning Our Knowledge.
• Chap. XIV.: Of Judgment.
• Chap. XV.: Of Probability.
• Chap. XVI.: Of the Degrees of Assent.
• Chap. XVII.: Of Reason.
• Chap. XVIII.: Of Faith and Reason, and Their Distinct Provinces.
• Chap. XIX.: Of Enthusiasm.
• Chap. XX.: Of Wrong Assent, Or Errour.
• Chap. XXI.: Of the Division of the Sciences.
• A Defence of Mr. Locke’s Opinion Concerning Personal Identity.
• Appendix.
• Of the Conduct of the Understanding.
• Some Thoughts Concerning Reading and Study For a Gentleman.
• Elements of Natural Philosophy.
• Chapter I.: Of Matter and Motion.
• Chap. II.: Of the Universe.
• Chap. III.: Of Our Solar System.
• Chap. IV.: Of the Earth, Considered As a Planet.
• Chap. V.: Of the Air and Atmosphere.
• Chap. VI.: Of Meteors In General.
• Chap. VII.: Of Springs, Rivers, and the Sea.
• Chap. VIII.: Of Several Sorts of Earth, Stones, Metals, Minerals, and Other Fossils.
• Chap. IX.: Of Vegetables, Or Plants.
• Chap. X.: Of Animals.
• Chap. XI.: Of the Five Senses.
• Chap. XII.: Of the Understanding of Man.
• A New Method of a Common-place-book. Translated Out of the French From the Second Volume of the Bibliotheque Universelle.

CHAP. VI.

Of Meteors in general.

Besides the springy particles of pure air, the atmosphere is made up of several steams or minute particles of several sorts, rising from the earth and the waters, and floating in the air, which is a fluid body, and though much finer and thinner, may be considered in respect of its fluidity to be like water, and so capable, like other liquors, of having heterogeneous particles floating in it.

The most remarkable of them are, first, the particles of water raised into the atmosphere, chiefly by the heat of the sun, out of the sea and other waters, and the surface of the earth; from whence it falls in dew, rain, hail, and snow.

Out of the vapours rising from moisture, the clouds are principally made.

Clouds do not consist wholly of watery parts; for, besides the aqueous vapours that are raised into the air, there are also sulphureous and saline particles that are raised up, and in the clouds mixed with the aqueous particles, the effects whereof are sometimes very sensible; as particularly in lightning and thunder, when the sulphureous and nitrous particles firing break out with that violence of light and noise, which is observable in thunder, and very much resembles gunpowder.

That there are nitrous particles raised into the air is evident from the nourishment which rain gives to vegetables more than any other water; and also by the collection of nitre or salt-petre in heaps of earth, out of which it has been extracted, if they be exposed to the air, so as to be kept from rain; not to mention other efforts, wherein the nitrous spirit in the air shows itself.

Clouds are the greatest and most considerable of all the meteors, as furnishing matter and plenty to the earth. They consist of very small drops of water, and are elevated a good distance above the surface of the earth; for a cloud is nothing but a mist flying high in the air, as a mist is nothing but a cloud here below.

How vapours are raised into the air in invisible steams by the heat of the sun out of the sea, and moist parts of the earth, is easily understood; and there is a visible instance of it in ordinary distillations. But how these steams are collected into drops, which bring back the water again, is not so easy to determine.

To those that will carefully observe, perhaps it will appear probable, that it is by that, which the chymists call precipitation; to which it answers in all its parts.

The air may be looked on as a clear and pellucid menstruum, in which the insensible particles of dissolved matter float up and down, without being discerned, or troubling the pellucidity of the air; when on a sudden, as if it were by a precipitation, they gather into the very small but visible misty drops that make clouds.

This may be observed some times in a very clear sky; when, there not appearing any cloud, or any thing opake, in the whole horizon, one may see on a sudden clouds gather, and all the hemisphere overcast; which cannot be from the rising of the new aqueous vapours at that time, but from the precipitation of the moisture, that in invisible particles floated in the air, into very small, but very visible drops, which by a like cause being united into greater drops, they become too heavy to be sustained in the air, and so fall down in rain.

Hail seems to be the drops of rain frozen in their falling.

Snow is the small particles of water frozen before they unite into drops.

The regular figures, which branch out in flakes of snow, seem to show that there are some particles of salt mixed with the water, which makes them unite in certain angles.

The rainbow is reckoned one of the most remarkable meteors, though really it be no meteor at all; but the reflection of the sun-beams from the smallest drops of a cloud or mist, which are placed in a certain angle made by the concurrence of two lines, one drawn from the sun, and the other from the eye to these little drops in the cloud, which reflect the sun-beams; so that two people, looking upon a rainbow at the same time, do not see exactly the same rainbow.