17* 



THE POPULAR SCIENCE MONTHLY. 



ing 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 sci- 

 entific instruction to English-speaking peo- 

 ple in the English language. 



Proceedings at the Inauguration of the 

 Building for the Departments of 

 Arts and of Science in the Univer- 

 sity of Pennsylvania; also Special 

 Announcement of the Organization 

 and Course of Study of the New 

 Department of Science, same Univer- 

 sity. 



The Appendix to the " Proceedings " con- 

 tains two very brief notices of the life and 

 labors of the late John F. Frazer, LL. D., 

 Professor of Natural Philosophy and Chem- 

 istry, and editor of the Journal of the Frank- 

 lin Institute. The new Department of Sci- 

 ence, established in the university, allows 

 the student to make his choice of a profes- 

 sional training between the following four 

 courses : Chemistry and Mineralogy ; Ge- 

 ology and Mining ; Civil Engineering ; and 

 Mechanical Engineering. 



A Popular Treatise on Gems, by Dr. L. 

 Feuchtw anger. New York, 1872. Pub- 

 lished by the author, No. 55 Cedar St. 



This useful work, now in its fourth edi- 

 tion, 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 " Ele- 

 ments," and treats of the forms, physical and 

 chemical properties, and classification, of 

 minerals. The second part treats of gems 

 in general, their composition and geographi- 

 cal 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 vari- 

 ous 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 stu- 

 dent who desires to form an acquaintance 

 with the literature of this branch of miner- 



alogy. 



BOOKS RECEIVED. 



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, Mar- 

 riages, 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. 



MISCELLANY. 



Experiments on Sound. Prof. Mayer, 

 of the Hoboken Technological Institute, 

 N. J., has made some rare and remarka- 

 ble researches on sound, of which he late- 

 ly 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-accept- 

 ed 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 



