Antoine-Joseph Pernety
Published: 2013-09
Total Pages: 66
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 edition. Excerpt: ... "It is also the cause of the movement of Light which acts on our Ether, and which conus principally and most efficaciously from the sun." This vehicle is not, even according to him, a being multiplied without necessity. He distinguishes Fire from Light, and notes their differences; but after having said that Light produces brightness, he here confounds the latter with the luminous principle, as one may conclude from the instances which he relates. I would have concluded from them that there is a Fire and a Light which do not burn, that is to say, which do not destroy the bodies in which they are adherent; but not that there is f a Light without Fire. This lack of distinction between the principle, or cause of the splendour and brightness, and the effect of this cause, is the source of an infinite number of errors in regard to this matter. Perhaps it is only the mistake of the translator who may have employed the terms Light and brightness, indifferently as being synonymous. I would be much inclined to believe this, since Mr. Pott, immediately after having related the different phenomena of phosphorescent substances, rotten wood, glow worms, burned clay rubbed, etc, says, that the substance of Light in its purity, or separated from every other body, does not permit itself to be perceived; that we treat it surrounded by an envelope, and that we know its presence only by induction. This is to distinguish Light, properly speaking, from the brightness which is the effect of it. With this distinction it is easy to explain a great number of phenomena which would remain incomprehensible without it. Heat, although the effect of movement, is, we may say, identified with it. Light being the principle of Fire, is the principle of movement...