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ChemReference: Periodic Table and Chemistry Reference. The Elements by Theodore Gray. Praise for The Elements The printing quality of this book is truly extraordinary.

The Elements by Theodore Gray

The pictures leap out from a deep black background, just as brightly as they do on the computer screen. (And the metalized cover is pretty nifty!) If you don't believe me how packed this book is with elements, take a look at this complete catalog of the pages in the book. THE ANIMATE AND THE INANIMATE, Chapter 1. Home Contents Next Among the physical laws it is a general characteristic that there is reversibility in time; that is, should the whole universe trace back the various positions that bodies in it have passed through in a given interval of time, but in the reverse order to that in which these positions actually occurred, then the universe, in this imaginary case, would still obey the same laws.


To test reversibility, we may imagine what we may call "the reverse universe," that is to say, another, an imaginary universe, in which the positions of all bodies at various moments of time are the same as in our real universe, in which those positions occur at the same respective intervals of time but in the reverse order. With this auxiliary, imaginary universe, our test of the reversibility of any given physical law or process would be, whether that law holds good, whether that process still subsists in the reverse universe.

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