162 ACCOUNTS, ETC., OF THE BRITISH MUSEUM. 



Department of Mineralogy. 

 Research. 



In the course of the systematic crystallographic and 

 chemical investigation of the Mineral Collection during the 

 past year, the morphological and optical examination of the 

 new red silver minerals from the Binnenthal has been con- 

 tinued, crystals of zirkelite and baddeleyite from Ceylon and 

 of ilmenite from Brazil have been measured and described, 

 and a new mineral from Italy containing tantalum, niobium, 

 and titanium has been analysed. Collections of minerals 

 from German East Africa, Bolivia, and Spain have also been 

 examined and described. 



Crystallographic measurements have been incidentally 

 made on various other species, including apatite, atacamite, 

 calamine, caracolite, chrysoberyl, corundum, dyscrasite, 

 hausmannite, marrite, mispickel, phosgenite, prehnite, quartz, 

 vivianite, and zircon. 



The whole of the collection of faceted gem-stones has 

 been reviewed, and the refractivity, double refraction, 

 pleochroism, and dispersion of many of them have been 

 studied. 



A diagram has been drawn in order to facilitate the 

 determination of refractive indices by the method of minimum 

 deviation. 



The petrographical and chemical investigation of the 

 rock- specimens collected by the "Discovery " Antarctic Ex- 

 pedition has been completed, in which connexion seven 

 quantitative chemical analyses of rocks have been made, the 

 series of over 300 thin slices has been re-examined, and a 

 detailed report has been prepared. The manuscript of 

 Mr. H. T. Ferrar's report on the Field-geology has also been 

 revised. The work of preparing for the printer these two 

 reports, which are illustrated by 72 text figures and 

 10 plates, has been completed. 



In the chemical laboratory complete quantitative analyses 

 have been made of seven rock-specimens from Antarctic 

 regions, a new mineral containing rare earths from Italy, a 

 specimen of binnite from the Binnenthal containing a large 

 percentage of zinc, and a specimen of semseyite from Bolivia. 

 Further many doubtful minerals have been qualitatively 

 analysed. 



Puhlications. 



New editions of the " Introduction to the Study of 

 Minerals" and of the " Guide to the Mineral Gallery" have 

 been completed and passed through the press. 



