It may be asked—What is the difference between ponderable and imponderable matter, and why are the atoms of ether imponderable? To this query a satisfactory answer is given; but I must refer the reader to the book for it. Were I to enter upon any demonstrations an entire number of this Journal would not contain half that could be said.
I have proved in an independent manner, and different from that of Père Leray, that two equal, penetrable spheres of ponderable matter, existing in space at a distance apart which is large in proportion to their diameters, will be impelled towards each other by the impact of ethereal matters, according to a law which is approximately that of the inverse square of the distance. When the spheres are brought to within a much shorter distance of each other the law ceases to be approximately true. The law of gravitation may, therefore, be only approximately true for particles of matter at a great distance apart in proportion to their diameters. The only observations which appear to confirm the law are those which have been made upon the heavenly bodies; and here we have a case of a distance apart many times the diameters of the bodies, even between satellites and their primaries.
But before any one can seriously accept this new hypothesis a vast deal more thought and study must be bestowed upon it than I have yet had time to give it.
I will send the demonstration referred to for insertion in a future number of this Journal if our Editors think fit. The subject is not foreign to photography, but intimately connected with it as a science.
According to the new hypothesis, new definitions must be given of MASS and DENSITY. According to M. Leray, “the mass of an atom is equal to its volume, and the mass of a body is equal to the sum of the volumes of its atoms.”
“If we call M the mass of a body, and V its apparent volume, the fraction M/V is the absolute density of the body. The absolute density is, therefore, unity for an atom, and varies from 0 to 1 for all bodies.”
If two bodies have the same apparent volume, their densities are proportional to their masses.
I have been looking through a capital French work on Chemistry, published in 1870, by M. Alfred Riche, lecturer at the Polytechnic School at Paris. He uses the old notation and table of equivalents; but strongly advises a change to the new, which he explains very nicely, and pretty much as our lecturer has done. Whenever the atomic weight of an element is given according to the new table its symbol has a bar drawn across it. Something of this sort should always be observed, in order to avoid confusion between the old and new formulæ.
