244 Field Museum of Natural History — Reports, Vol. III. 



of fluor-spar and apatite. About these are grouped seven 

 table cases. Three of these cases contain groups of specimens 

 showing stages of the manufacture of soda from salt by the Le Blanc 

 and ammonia processes. The specimens of these collections are 

 arranged with guide lines to assist in following the process. 

 Two table cases contain a collection illustrating the uses of asbestos, 

 which was formerly displayed in a large upright case in the center of 

 the hall. Another table case contains a collection of barytes and an- 

 other a similar collection of fluor-spar. About the walls of the hall 

 eight wall cases similar in design to those employed for the mineral 

 collection have been placed. As the lighting and capacity of these 

 differ from those discarded, appropriate changes in the order of ar- 

 rangement of the collections were made. Two wall cases eighteen 

 inches deep upon the south wall contain potash compounds, includ- 

 ing a large collection of the salts mined at Stassfurt, Prussia. In 

 these cases have also been placed such other specimens as were too 

 large for the shallower cases. These larger specimens include blocks 

 of gypsum, epsom salt, rock salt, and phosphate rock. The remaining 

 wall cases are twelve inches deep. Of these the borate and nitrate 

 collection occupies half of the case and the other half is occupied by the 

 salt collection. Magnesian and similar minerals of economic value oc- 

 cupy about a quarter of a wall case and the remaining three-quarters 

 contain the sulphurs. Abrasives arranged according to their uses 

 occupy a wall case and a half, and half a wall case contains the collec- 

 tions of crude asbestos. Mica occupies half a case and the phosphates, 

 grouped according to a mineral and commercial classification, occupy 

 one wall case and nearly half of another. Among minor details of 

 installation in' this hall it may be noted that flat black trays have been 

 employed for powdered and granular exhibits in place of the buff 

 trays formerly used. An increased number of black wood specimen 

 supports have been employed and a new pattern of label holder is 

 employed for all labels in the wall cases. Hall 80 has been thoroughly 

 repainted and calcimined and Halls 70 and 72 have been dismantled 

 and calcimined in preparation for a recasing of the collections. As 

 soon as the installation of these halls and that of a single additional 

 hall, Hall 71, is completed, permanent cases will have been provided 

 for all of the collections of the Department. Comparing the distribu- 

 tion of the collections at present with that existing at the time of the 

 opening of the Museum, it appears that six halls are now devoted to 

 the paleontological collections instead of three, as at that time. 



