40 EEPORf OF NATIOiSTAL MUSEUM, 1899. 



basaltic columns, collected for the MuseuDi by Mr. F. W. Crosby, has 

 lately been added to this series. Manuscript for upward of 2,500 

 labels has been prepared and is ready for the printer. The actual 

 work of arranging these collections, it should be stated, has fallen 

 upon Mr. W. H. Newhall, with such assistance as could be given by 

 Museum laborers. 



I might add that in all the work of this department steps are being 

 taken toward a reduction of the number of specimens exhibited and an 

 improyement in the quality. The reduction in number in certain of 

 the collections is necessitated by lack of space, but it is believed that 

 on the whole a careful selection of the specimens exhibited will cause 

 the collections to have more educational value than will an increase in 

 number. 



The collections in the Division of Mineralogy, as stated in my last 

 report, have been as well arranged as possible with the present exhibi- 

 tion cases. New cases are needed along the west wall. As the collec- 

 tions in this division are now well systematized, I submit Mr. Tassin's 

 report upon them in full. 



The exhibition series is arranged under the following heads: System- 

 atic series; comparative series; gem collection; meteorite collection. 



The systematic series is divided into two general classes — native ele- 

 ments and compounds of the elements. The compounds of the 

 elements are further divided and grouped under certain heads accord- 

 ing to their more negative constituents, as follows: 



Compounds of the halogens, fluorides, chlorides, bromides, and 

 iodides. Compounds of sulphur, selenium, tellurium, arsenic, and 

 antimony, including sulphides, selenides and tellurides, arsenides, 

 antimonides, sulpharsenides, and sulphantimonides; also sulphosalts. 

 Oxygen compounds, including oxides and the oxygen salts, borates, 

 aluminates, chromites, ferrites, manganites, plumbates, arsenites and 

 antimonites, selenites and tellurites, carbonates, silicates, titanates, 

 columbates and tantalates, nitrates, vanadates, phosphates, arsenates 

 and antomonates, sulphates, selenates and tellurates, chromates, molyb- 

 dates and tungstates, iodates, and uranates. Compounds of organic 

 origin, including salts of organic acids and carbon compounds. 



Each of these classes is further separated into groups according to 

 their chemical relationships. Each group is preceded by a general 

 group label stating the class to which it belongs, the group name, a 

 list of the minerals composing that group, together with their chemical 

 formulge, system of crystallization, and a short description of the 

 occurrence, association, and characteristic foi"m of each member of the 

 group. Following the group label, arranged in order from left to 

 right, are the several members of the group selected to illustrate, as 

 completely as the conditions will permit, their occurrences, associations, 

 color, habit, etc. 



