The _light_ proceeding from _diamonds_ &c. seems to be easily accounted for from the _motion_ of the _airs_; that there is a _perpetual motion_ of the _airs_, may be proved by the following experiment. In a still place, suppose a close darkened room, illuminated only by one small hole in the window shutter; where, if a person at rest views the enlightened current of air sideways, as it extends along the room, he will perceive a _surprising motion_ of the dusty atoms therein, _perpetually rolling and tossing_ about _with great rapidity_. This _motion_ must be very _considerable_, as it is _perpetual_, and pushed on with the power of _gravity_ in the air equal to a column of water 33 feet high. By this _action_ on _diamonds_, whose _pores_ are very _small_, and the bodies themselves of such a _make_ and _hardness_, as that, when the air is pressed on them with so great a _force_ as that of the _incumbent atmosphere_, the air is _broke exceedingly small_, and, by the continuance of the _pressure_, is sent off from the body in form of _light_. We likewise find from experiments, that where _diamonds_, or other bodies of that kind, have not their outward parts of a proper _make_, or their _substance_ of a _sufficient hardness_ or _closeness of parts_, to emit _light_ with no greater _force_, than the pressure of the _atmosphere_ only, then this deficiency may be supplied by _rubbing_; by which means the air is _ground_ to pieces, and emitted in form of _light_, as is shewn in all electrical experiments. One great property of _light_, or, as it is commonly called the _electrical effluvia_, is (as Mr. _Hauksbee_ has proved from many experiments,) that it passes _through glass_, as water does through a sieve, or as if no body of matter interposed. This _light_ of itself, when _pure_, or _simple_, hurts or destroys no material bodies; but when _pushed_ on by the following air with _great violence_, and _meeting_ with a _great resistance_ from an impeding body, the _conflict_ is so great, that if the following air _presses_ on with _sufficient violence_, it _dissolves_ or _destroys_ the _solidity_ of any material body. As all bodies become _solid_ according to the _temperature_ of the surrounding air; some retaining their _solidity_ in such a degree of _heat_, as _metals_ of most kinds; whilst others require a particular degree of _cold_ before they become _solid_, as _water_ &c. which when froze is as much a _solid_ as any thing else--this proves that the _solidity_ of bodies depends on the _temperature_ of the air, as will be more fully proved hereafter. The glass globe, with the electrical experiments, seems to give a very clear idea in what manner the _sun_ is _supported_, how this _terraqueous globe_ and the rest of the _planets_ are made to _move_, and _continued in motion_; and also, what is the cause of the _attraction_ of the _sun_, _earth_, _moon_ and the rest of the _planets_.