156 accounts, etc., of the british museum. 



Department of Mineralogy. 



Research. 



During the past year the morphological, optical, and chemical 

 investigation of specimens belonging to various species has been 

 continued. In the Sulphide Division, a chemical examination 

 has been made of seligmannite, a rare mineral from the 

 Binnenthal, and its chemical composition has been for the first 

 time determined. In the Haloid Division, a crystallographic, 

 optical, and chemical examination has been made of schwartz- 

 embergite. The " light-figures " displayed by the crystals of 

 this mineral were so complex that for their reproduction a new 

 form of camera lucida had to be designed. In the Silicate 

 Division, chemical investigations have been made of fuchsite 

 from the Binnenthal, and of the extremely rare mineral 

 guarinite, the result of the latter being to establish its specific 

 identity with hiortdahlite. 



The investigations of the new phosphates of zinc and other 

 minerals from the Broken Hill mines of Rhodesia, and of the 

 minerals striiverite and ilmenorutile, which were in progress 

 last year, have been completed. 



Crystallographic measurements have been incidentally made 

 on various other species, including anglesite, barytes, beryl, 

 carminite, chalybite, cotunnite, olivine, paralaurionite, pyro- 

 morphite, and zircon. 



Microscopic examinations have been made of collections of 

 rocks from Natal and Zululand, Persia, Sweden, and South 

 America. 



In the chemical laboratory, two quantitative analyses have 

 been made of schwartzembergite, two of seligmannite, one of 

 fuchsite, and three of rocks from Zululand, and many doubtful 

 minerals have been qualitatively analysed. 



Publications. 

 New editions of the Introduction to the Study of Minerals, 

 the Introduction to the Study of Meteorites, the Student's 

 Index, and the Guide to the Mineral Gallery, have been pre- 

 pared and published ; the preparation of a new edition of the 

 Introduction to the Study of Rocks has been in hand. 



Independent Publications. 



Apart from the oflScial publications issued by the trustees 

 the following papers, relative to specimens in the collection, 

 have been published during the year by members of the staff 

 of the Department : — 



On the possible existence of a nickel-iron constituent 

 (FcsNis) in both the meteoric iron of Youndegin and the 

 meteoric stone of Zomba : by L. Fletcher, m.a., f.r.s. 



