192 ACCOUNTS, ETC., OF THE BRITISH MUSEUM. 



originally purchased from Henry Heuland, an index of the 

 names of purchasers at the Heuland sales of 1829-]846 has 

 been prepared, and marginal notes in a copy of the sale 

 catalogues which belonged to Heuland have been incorporated 

 in the Museum copy. 



A slip-catalogue of the cr3^stal-sections has been prepared, 

 and the catalogue of the gem-stones has been brought up to 

 date. 



Six hundred and eighty-three labels for the Collection of 

 Meteorites have been prepared for press, and the printed labels 

 have been placed with the specimens exhibited in the four cases 

 in the Pavilion. 



A topographical index of the meteorites in the Collection 

 has been prepared. 



The preparation of a slip-catalogue of the topographical 

 rock collections has been continued. 



Two hundred thin-slices of rocks have been microscopically 

 examined and labelled. 



Two thousand and eighty-five thin-slices of rocks have been 

 cleaned, and the registration-numbers have been written on 

 them with a diamond. 



The preparation of a copy of the register of the specimens 

 in the Collection has been continued. 



III. — Preparation. 



Two hundred and ninety- two thin- slices of rocks and 

 meteorites have been prepared. In connection with this work 

 new and improved apparatus for slitting rocks, and for grinding 

 and polishing rock-sections have been made from designs 

 prepared in the Department, and have been installed in the 

 Lapidary's room. 



IV. — Investigation. 



A crystallographic and optical investigation has been 

 made of a pyroxene from the Azores, and that of zeolites and 

 associated minerals from the basalts near Belfast has been 

 continued. 



A crystallographic and chemical investigation has been made 

 of a supposed new sulpharsenite of lead from Binn, Switzerland. 



Specimens of the following minerals have also been examined : 

 auatase, atacamite, beryl, calcite, corundum, dufrenoysite, garnet, 

 halloysite, mica, platinum, quartz, seligmannite, and vanadinite. 



A collection of copper-ores^ including specimens of bayldonite 

 and the new mineral, tsumebite, from Tsumeb, German South- 

 West Africa, has been examined. 



Collections of rocks from the Azores, British East Africa, 

 the Antarctic, Mongolia, Madagascar, Costa Rica, and lona have 

 been examined. 



