Croonian lectures on matter and force: given at the Royal College of Physicians in 1868 / by Henry Bence Jones.

  • Frankland Edward, Sir, 1825-1899.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: Croonian lectures on matter and force: given at the Royal College of Physicians in 1868 / by Henry Bence Jones. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    ]iropagation of light, and of the way iu which different rays interfere with one another, and the laws so deduced are abundantly confirmed by experiment. But here also science kicks down the ladder by which she has risen. In order to explain the phenomena of light, it is not necessary to assume anything more than a periodical oscillation between two states at any given point of space. What the two states are nobody knows, and the only thing we can assert with any degree of probability is that they are not states of merely mechanical displacement, like the tremor of a jelly, for the phenomena of fluorescence appear to negative this supposition. Of the existence of this asther, spectrum analysis has given us no evidence, yet this most sensitive test has proved that some of the substances that are on our earth exist also in the stars, nebulae, and comets. As yet no great opportunity for analysing the matter of comets has occurred. It is probable that nitrogen and the aerolitic metals exist in them. When we are told that the tail of the comet of 1811 extended 112 million miles through space, and that the nature of the matter composing it may
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