Scientific American Supplement, No. 613, October 1, 1887 by Various
page 18 of 148 (12%)
page 18 of 148 (12%)
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hand all truth, and in his left hand the ever-active desire to seek
truth, though with the condition of perpetual error, I would humbly ask for the contents of the left hand, saying, 'Father, give me this; pure truth is only for thee.'" At the close of his address a vote of thanks was passed to the president, on the motion of the Mayor of Manchester, seconded by Professor Asa Gray, of Harvard College. The president mentioned that the number of members is already larger than at any previous annual meeting, namely, 3,568, including eighty foreigners. * * * * * THE CRIMSON LINE OF PHOSPHORESCENT ALUMINA. Crookes has presented to the Royal Society a paper on the color emitted by pure alumina when submitted to the electric discharge _in vacuo_, in answer to the statements of De Boisbaudran. In 1879 he had stated that "next to the diamond, alumina, in the form of ruby, is perhaps the most strikingly phosphorescent stone I have examined. It glows with a rich, full red; and a remarkable feature is that it is of little consequence what degree of color the earth or stone possesses naturally, the color of the phosphorescence is nearly the same in all cases; chemically precipitated amorphous alumina, rubies of a pale reddish yellow, and gems of the prized 'pigeon's blood' color glowing alike in the vacuum." These results, as well as the spectra obtained, |
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