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378  seen the original German of the two papers which make up the second number of this serial, we are not prepared to say whether they contain any thing novel or interesting about the matters they treat of. On the whole, it were better to convey scientific instruction to English-speaking people in the English language.

Appendix to the "Proceedings" contains two very brief notices of the life and labors of the late John F. Frazer, LL. D., Professor of Natural Philosophy and Chemistry, and editor of the Journal of the Franklin Institute. The new Department of Science, established in the university, allows the student to make his choice of a professional training between the following four courses: Chemistry and Mineralogy; Geology and Mining; Civil Engineering; and Mechanical Engineering.

useful work, now in its fourth edition, is intended as a guide for the teacher of natural science, the lapidary, jeweller, and amateur. It is, in the best sense of the term, a popular treatise, explaining the chemical constitution and properties, and the geological character, of all the substances known as gems, in such a manner as to be understood by the untechnical student. The first part, which treats of mineralogy in general, is based on Nichols's "Elements," and treats of the forms, physical and chemical properties, and classification, of minerals. The second part treats of gems in general, their composition and geographical distribution, and describes the various ways of grinding, polishing, and setting them, as also the methods of producing gems artificially. The third and last part is devoted to the consideration of the various species of gems, in the order of their commercial value. The Appendix contains a full chronological list of works on gems, which will be of great service to the student who desires to form an acquaintance with the literature of this branch of mineralogy.

Annual Report of the Board of Health, to the General Assembly of Louisiana. New Orleans, 1872.

Proceedings of the Agassiz Institute, Sacramento, Cal. With the Constitution and By-Laws. Sacramento, 1872.

Fourth Annual Report of the Secretary of State, of the State of Michigan, relating to the Registry and Return of Births, Marriages, and Deaths. For the Year 1860. Lansing, Mich., 1872.

Popular Address on Organic Reform, delivered before the Illinois State Medical Society, at Rock Island, for the Session of 1872. By A. L. McArthur, M. D. Chicago, 1872.

New Theory of the Origin of Species. By B. G. Ferris. New Haven, 1872.

On a Method of detecting the Phases of Vibration in the Air surrounding a Sounding Body. By Alfred M. Mayer, Ph. D.



Experiments on Sound.—Prof. Mayer, of the Hoboken Technological Institute, N. J., has made some rare and remarkable researches on sound, of which he lately gave an account before the Lyceum of Natural History, New York. The following is a summary of the views he presented: That sound reaches the ear by a series of waves or undulations, is a generally-accepted fact. But, although so accepted, it may well be doubted whether many persons, even among those of considerable general culture, are possessed of a clear view of the nature of these waves. To obtain this, it is necessary to bear in mind that the waves of sound which take place within a gaseous medium are in no wise similar to those waves which undulate on the surface of water or other liquids. The latter form around their point of origin in concentric