152 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



gy, and the appearance of a mineralogical treatise by Pisani 

 in Paris, arc also deserving of mention. 



In this country there has appeared a second "Report of the 

 Mineralogy of Pennsylvania," by Dr. F. A. Genth ; also Dana's 

 " Text-book of Mineralogy," a work of about five hundred 

 pages; and a new edition of Weisbach's Tables edited by 

 Professor Frazer. 



The new journal (Zeitschrift fi'ir Krystallo graphic) pub- 

 lished by Professor Groth in Strasburg has now completed 

 its first year, and has more than fulfilled the promises of the 

 prospectus alluded to in the last volume of the Record. The 

 first volume, in six numbers, covers about six hundred and 

 fifty pages, with a large number of plates. It contains many 

 valuable papers, as would be expected ; but, perhaps more 

 important than these, it includes also abstracts of most of 

 the mineralogical memoirs published during the year, not 

 only in other German periodicals, but also in English, Amer- 

 ican, French, Italian, Spanish, and Swedish journals. It thus 

 furnishes a quite complete record of the progress of the sci- 

 ence during the year. 



The Mineralogical Society of Great Britain and Ireland 

 has now issued six numbers, containing the records of its 

 meetings, and also a number of original contributions. 



FOREIGN RESEARCHES. 



Of the many foreign mineralogical memoirs, mention can 

 be made only of a very few ; reference must rather be made 

 for them to the journals that have been spoken of, as well as 

 to the many other older and well-known publications. A list 

 of the new species which have been described is <nven on a 

 following page. 



Mr. II. C. Sorby has added to his many important memoirs 

 a most valuable research "On the Determination of the Chief 

 Optical Constants of Minerals by Means of a New Class of 

 Optical Properties." It is published in No. G of the Miner- 

 alogical Magazine. The method consists in the determina- 

 tion, in thin sections of minerals, of their mean refractive 

 index by simple observations with the microscope. Briefly 

 described, this is done by measuring the amount of displace- 

 ment which the focus of a certain object, as a set of finely 

 ruled parallel lines on glass, suffers when a highly refractive 



