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242 contents of Prof. Dana's volume, but mean to do so in a future number; yet we cannot forbear quoting a pleasant passage referring to a man of whom much is now vehemently said, both in praise and disparagement:

"Our cruise led us partly along the course followed by Mr. during the years 1831 to 1836, in the voyage of the Beagle, under Captain Fitzroy; and, where it diverged from his route, it took us over scenes, similar to his, of coral and volcanic islands. Soon after reaching Sydney, Australia, in 1839, a brief statement was found in the papers of Mr. Darwin's theory with respect to the origin of the atoll and barrier forms of reefs. The paragraph threw a flood of light over the subject, and called forth feelings of peculiar satisfaction, and of gratefulness to Mr. Darwin, which still come up afresh whenever the subject of coral islands is mentioned. The Gambier Islands in the Paumotus [sic], which gave him the key to the theory, I had not seen; but on reaching the Feejees [sic], six months later, in 1840, I found there similar facts on a still grander scale and of more diversified character, so that I was afterward enabled to speak of his theory as established with more positiveness than he himself, in his philosophic caution, had been ready to adopt."

his late work on the sun, Mr. R. A. Proctor, author of “Other Worlds than Ours,” says: “The reader is referred, for fuller details than there is here space for, to Dr. Schellen's work on ‘Spectrum Analysis,’ the English edition of which is now preparing for publication under the able supervision of Dr. Huggins. This work will be specially worthy of very careful study in all matters relating to the spectral Analysis of the sun.” This long-expected work, which has been so eagerly looked fofor [sic] by those who desire a popular and authoritative exposition of this beautiful subject has now appeared, and is republished in this country at half the English price. An able writer in the London Spectator thus speaks of it:

In the whole history of science there is nothing more wonderful than the discovery or invention (it would be difficult to say which is the more correct term) of spectrum analysis, and the sudden advance of the new method of research into a foremost position, among all the modes of scientific inquiry. If we take up at random any recent scientific work, whether on astronomy, or chemistry, or meteorology—nay, even though it treat of subjects like entomology, botany, and conchology, which seem as far as possible removed from optical problems—we cannot turn over its pages without finding more or less copious reference to the prismatic analysis of light. Yet, thirteen years ago, spectrum analysis had no existence whatever as a mode of scientific inquiry. It was a subject for research, not a method of research, and there were not a few who regarded it as a subject altogether intractable, while scarcely any believed that it would become the means of advancing our knowledge to any important extent.

The history of the sudden advance of this great problem into the position of a great solver of problems is full of interest. Not five years had passed from the day when Kirchhoff announced the true meaning of the dark lines in the solar spectrum, before Huggins and Miller were telling astronomers of the terrestrial elements existing in the stars. Then the great secret of the gaseous nebulas was revealed by Huggins, and soon after the structure of comets began to be interpreted. Nor had chemists been idle in the mean time. In 1861, Bunsen and Crookes, by means of the new analysis, had detected three hitherto unknown elements, cæsium, rubidium, and thallium, and, in 1863, Reich and Richter had discovered a fourth new element, indium. The importance of the new mode, of research in all problems of chemical analysis, as a delicate test for determining the presence of poisons, as a means of