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piece of the luminous Whiting, and bury it in Ice and Salt, when I call'd for it in less than half an hour after, I found it much stiffen'd by the Cold, and to have no light, that I could discern in a place dark enough. And for fear, that this effect may have proceeded not barely from the operation of the Cold, but also from that of the Salt (for which suspicion you would see reason enough, if I could shew you my Trials about Shining Fish) I caused another time a piece of Whiting to be put in a Pipe of Glass seal'd at one end, and having seen it shine there, I look'd upon it again, after it had stayed but a quarter of an hour, by my estimate, in a frigorifick mixture, which the Glass kept from touching the Fish; and yet neither I, not a Youth that I employed to look on it, could perceive in a dark place, that it retained any light; which whether the Cold had deprived it of by that great change of Texture, that the Congelation of the Aqueous Juice of the Fish (which I have several times observed to be luminous) may be supposed to have made in the Body invaded by it; or whether the effect depend more principally on some other cause, I shall not now examine.
Differences.
1. The first difference I observed betwixt a Live Coal, and Shining Wood, is, That whereas the light of the former if readily extinguishable by Compression (as is obvious in the practice of suddenly extinguishing a piece of Coal by treading upon it) I could not find that such a Compression, so I could conveniently give, without losing sight of its operation, would put out, or much injure the light, even of small fragments of Shining Wood. One of my Trials about which I find thus set down among my Notes about Light.
I took a piece of Shining Wood, and having press'd it between two pieces of clear Glass (whereof the one was pretty flat, and the other convex) so that I could clearly see the Wood through the Glass, I could not perceive, that the compression, though it sometimes broke the Wood into
