h OVUM ORGANUAf. 353 



doubt about this), while it remains above the magnet, will leave the 

 poles of the world, and turn itself towards the poles of the magnet. 

 Therefore, as long as it remains there it will point east and west. UiK 

 if it be found that the needle, when removed from the magnet and 

 placed on a pivot, immediately places itself north and south, or even 

 takes that direction by degrees, then the presence of the earth must 

 be taken as the cause ; but if it points (as before) east and west, or 

 loses its polaiity, this cause must be regarded as suspicious, and 

 further inquiry must be made. 



In like manner let the Nature inquired into be the Corporeal Sub 

 stance of the Moon, whether it be rare, consisting of flame or air, as 

 very many of the old philosophers thought, or solid and dense, as 

 (Gilbert and many moderns, together with some of the ancients, hold. 

 The reasons for this latter opinion arc founded principally on the fact 

 that the moon reflects the rays of the sun ; and there does not seem to 

 be any reflection of light except from solid bodies. 



Therefore the Instances of (he Cross on this subject (if any there be) 

 will be such as prove that reflection docs take place from a rare body, 

 such as flame, if it be of sufficient thickness. Certainly one cause of 

 twilight, amongst others, is the reflection of the rays of the sun from 

 the higher regions of the air. Also, we sometimes see the rays of the 

 sun reflected, on fine evenings, from the fringes of dense clouds, with 

 a splendour equal to, or rather brighter and more glorious than, that 

 reflected from the body of the moon ; and yet there is no proof that 

 these clouds have collected into a dense body of water. Also, we see 

 the dark air behind windows reflect the light of a candle no less than 

 a dense body would. We should also try the experiment of trans 

 mitting the rays of the sun through an opening upon any dusky blue 

 flame. Indeed, the open rays of the sun falling on obscure flames 

 appear, as it were, to deaden them, and make them seem more like 

 white smoke than flame. These are what occur to us at present as 

 Instances of the Cross with regard to this matter, and better may per 

 haps be found. But we must always observe that reflection from flame 

 is not to be expected except from a flame of some depth, for otherwise 

 it verges upon transparency. This, however, must be set down as 

 certain, that light on an even body is always either taken up and 

 transmitted, or else reflected. 



In like manner let the Nature investigated be the Motion of Missiles, 

 such as darts, arrows, shells, c., through the air. This motion the 

 School (after their usual fashion) explained in a very slovenly manner, 

 thinking it enough to call it a violent motion, as distinguished from 

 what they call natural motion ; and to account for the first percussion 

 or impulse by stating that two bodies cannot occupy the same place, 

 owing to the impenetrability of matter ; and caring nothing how the 

 motion progresses subsequently. Now, about this Nature, two ways 

 meet after this fashion. Either that motion is caused by the air carry 

 ing on the projected body and collecting behind it, as the stream acts 

 upon a boat, or the wind upon straws ; or by the parts of the body 

 itself not being able to sustain the impression, but advancing in sue- 



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