DEPARTMENT OF MINERALOGY. 163 



The following papers, relative to specimens in the collec- 

 tion, or to mineralogical theory and method, have been 

 published in the *' Mineralogical Magazine and Journal of the 

 Mineralogical Society" or the " Philosophical Magazine," by 

 members of the staff of the Department. 



Dundasite from North Wales : by G. T. Prior, M.A., D.sc, 



F.G.S. 



Phenacite and other minerals from German East Africa : 

 by L. J. Spencer, M.A., f.g.s. 



Paratacamite, a new oxy chloride of copper : by G. F. 

 Herbert Smith, M.A,, F.G.S., with a chemical analysis by 

 G. T. Prior, M.A., D.sc, F.G.S. 



On the method of minimum deviation for the determina- 

 tion of refractive indices, with a diagram : by G. F. Herbert 

 Smith, M.A., F.G.S. ; ; 



The general determination of the optical constants of a 

 crystal by means of refraction through a prism : by G. F. 

 Herbert Smith, M.A., f.g.s. 



Miscellaneous. 



The preparation of slip-catalogues of species, the re- 

 labelling of the specimens, and the entry in the General 

 Register of old specimens hitherto bearing numbers referring 

 only to special catalogues have been continued. For the 

 native elements contained in cases 1 and 2 this work has 

 now been completed, and the exhibited specimens have been 

 entirely re-arranged in the case-tops on re-polished trays. In 

 this connexion the specimens of native iron from Greenland 

 have been weighed, identified, and labelled. A slip index of 

 donations acquired previous to 1837 (when the General 

 Register was commenced) has alsp been prepared. 



The reserve collections of pyrites, marcasite, molybdenite, 

 stibnite, copper-pyrites, fluor,, albite, petalite, anglesite, 

 gypsum, and barytes have been extended and re-arranged in 

 seventeen cubes of new drawers, and in the old drawers thus 

 set free other species have been expanded. 



Several sets of shelves in the chemical laboratory have 

 been converted into cupboards with glazed doors, and the 

 large bookcase in the balance-room has been similarly 

 protected. 



Numerous specimens sent for identification or brought to 

 the Museum by visitors have been examined and named. 



Eighty-six boxes or parcels of mineral specimens have 

 been received, unpacked, and examined ; fifty-eight boxes or 

 parcels have been packed and despatched. 



Two hundred and twenty-one thin slices of rocks and 

 seven of meteorites have been prepared. 



L 2 



