276 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ing, and contains an enumeration of a large number of new 

 planes. Another is by Beoke on Cassiterite. Still another 

 by J. McD'Irby on the forms of calcite, in which the subject 

 is most exhaustively treated. Schrauf has given a memoir 

 on the crystallized tellurium minerals of Transylvania; and 

 Vom Rath and Bauer have described independently some 

 remarkably perfect crystals of cyanite, a species never be- 

 fore obtained in satisfactorily terminated crystals. 



RESEARCHES IN CHEMICAL MINERALOGY. 



The discovery of the rare species samarskite was an- 

 nounced in the Annual Record several years since. During 

 the past year this mineral has had attention called to it 

 anew. The presence in it of the rare metal erbium was first 

 made certain by the analysis of Hammelsberg ; later Dela- 

 fosse showed that the metal terbium an element of so 

 doubtful a character that its existence has not generally 

 been granted was also present. Since then Dr. J. L.Smith, 

 who had previously published an analysis of the mineral, has 

 announced the existence in it of a new element, which he 

 calls mosandrum. Delafosse has followed by claiming to 

 have discovered two new elements, which he names ph'dUp- 

 ium and decipium, while he states that the mosandrum of 

 Smith is not a new metal, but, in fact, a substance identical 

 with terbium. Marignac, of Geneva, has published an article 

 on the subject in which he also throws doubt upon the real 

 existence of the mosandrum. He was not, however, at that 

 time in possession of all the facts. At present it is impossi- 

 ble to decide how far these three new names will be accept- 

 ed among chemists. 



A discovery of a character similar to the above has been 

 announced by Marignac ; he claims to have found a new ele- 

 ment in the gadolinite of Ytterby, to which the name of Yt- 

 terbium is given. 



Among other important papers upon chemical mineralogy 

 may be mentioned that of Tschermak upon the mica group; 

 it is in fact the second part of the memoir referred to in the 

 last volume of the Record. He gives new and very carefully 

 made analyses of many of the species of the mica group, and 

 bases upon them an ingenious but somewhat artificial ex- 

 planation of their variations in composition. It is impossi- 



