DEPARTMENT OF MINERALOGY. 191 



Two hundred and thirty thin-slices of rocks have been 

 microscopically examined, and have been entered in the slip- 

 catalogue. 



Four hundred and forty-six locality, species, and variety 

 labels have been prepared, printed, and placed in the exhibition 

 cases, and the corresponding entries have been made in the 

 alphabetical and topographical indexes of localities. 



Five thousand four hundred and twenty thin-slices of rocks 

 have been cleaned, and the register-numbers have been written 

 on them with a diamond. 



III. — Preparation. 



One hundred and eight thin-slices of rocks and meteorites 

 have been prepared. 



IV. — Investigation. 



Crystallographic and optical investigations have been made 

 of celsian, paracelsian and natrolite from a new occurrence in 

 North Wales, and of zeolites (including phacolite, gmelinite, 

 analcite and natrolite) from the basalts near Belfast. 



Crystals of an unknown mineral from the Binnental have 

 been measured, and their morphological characters determined. 



A large and curiously developed crystal of anatase from the 

 Binnental has also been examined. 



Crystals of zircon and tourmaline from Ceylon, phenacite 

 and prehnite from Cornwall, apophyllite from Durham, and 

 artificial crystals of gypsum have been measured. 



Specimens of the following minerals have also been 

 examined : atacamite, calcite, caracolite, cassiterite, chrysoberyl, 

 epidote, idocrase, labradorite, marcasite, paratacamite, pectolite, 

 spessartite, spinel, wollastonite, and zircon. 



The materials of certain worked stones in the Collection at 

 Bloomsbury have been determined and named. 



A spherulitic dolerite from Natal, presenting remarkable 

 structural features, has been microscopically examined, and a 

 description of the rock has been prepared for publication. 



Collections of rocks from Kerguelen Land, Dutch New 

 Guinea, the Channel Islands, Stonehenge and other localities 

 have been examined. 



Stone implements from Malta have been examined, and the 

 materials of which they consist determined. 



A chemical investigation has been made of a meteoric 

 stone which fell on 28 June, 1911, at El Nakhla el Baharia, 

 Egypt. 



In the chemical laboratory, quantitative analyses have been 

 made of sepiolite from Weardale, bismutite from South Africa^ 

 tilasite and fermorite from India, cordierite from Finland^ 

 staurolite from Switzerland, and the meteoric stone from Egypt ; 

 and many doubtful minerals have been qualitatively analysed. 



