Oct. 1899. Annual Report of the Director. 367 



age section and a larger and more complete, work-room, to which 

 three tables have been added for the accommodation of specialists 

 and monographists who desire to use the collections for research. 

 The growth of the collections has been so large and the charac- 

 ter so excellent that this section of the department now takes 

 high rank as the largest herbarium in the Central United States, 

 while the methods of installation and recording of specimens 

 establishes its usefulness. The labor of arranging the large amount 

 of departmental material for exchange has progressed favora- 

 bly. Over 5,000 plants have been mounted, poisoned, find installed 

 in the cases, and over 2,000 identified, classified, and prepared for 

 publication. Hall 70, devoted to coals and hydrocarbons, has been 

 entirely rearranged and the collections newly installed. Many of 

 the specimens, especially the larger ones, had not before been cased 

 and were suffering from dust and disintegration. Wall cases, 8 

 feet high and from 17 to 29 inches deep, have accordingly been pro- 

 vided, and these, with four floor cases, furnish casing for all the 

 specimens. In order to guard against danger from spontaneous 

 combustion, the case containing the larger specimens has been 

 lined at the base with asbestos millboard ^/^-inch thick, and the 

 adjoining walls have been covered with two thicknesses of asbestos 

 paper. The interiors of all the cases have also been painted with 

 asbestos paint. Many of the«pecimens in the form of blocks, 6x6x 10 

 inches in size, have been treated by soaking twenty-four hours in thin 

 shellac in order to prevent disintegration. For exhibiting lump coal 

 or coal in broken fragments, a form of metallic tray was devised which 

 serves admirably for purposes of exhibition. The form (illustrated 

 elsewhere) is that of a deep tray with two sides divergent, cut down in 

 front to a narrow strip the contents giving support to the label. 

 The tray is made of tinned iron, bound at the edges with wire 

 and enameled a drab color outside and white inside. It is be- 

 lieved it will be found admirably adapted for exhibiting other loose 

 substances, such as clays and earthy minerals, in upright cases. To 

 the specimens formerly exhibited in the hall have been added a 

 number of new series recently received by gift or collection or 

 brought from storage, so that the collections now fully illustrate 

 the varieties, origin and uses of coals and mineral hydrocarbons. 

 The collections in Hall 78, devoted to non-metallic minerals of 

 use in the arts, have been entirely rearranged in order to make room 

 for new material and rectify the classification. Four new cases 

 have been added, and the interiors of all the cases have been 

 painted black. Among the new material added are two collections 



