368 Field Columbian Museum — Reports, Vol. i. 



prepared by Assistant Curator Nichols, illustrating the Le Blanc 

 and ammonia processes for the manufacture of soda and the differ- 

 ent products obtained. The graphic method of installation which 

 has been described in a previous report and which has proved most 

 satisfactory in the representation of metallurgical processes, has 

 here been employed as well. Where liquids are exhibited, the 

 cases being flat, a rectangular glass tray, 6x5x1^ inches in size, with 

 a glass cover, has been employed. Specially corrosive or poisonous 

 liquids and gases are exhibited in sealed glass tubes about i 

 inch in diameter and 9 inches in length. The collection of min- 

 eral paints in Hall 77, which stood in a central case obstructing 

 the passageway, has been removed, with additions, to another part of 

 the hall. A collection of art tiles has also been placed upon the 

 walls of this hall. In Hall 71, devoted to petroleum and its prod- 

 ucts, the cases have been repainted inside and out, the specimens 

 cleaned and newly installed. The heavy iron label frames and 

 exposed jars, which were liable to cause or to suffer injury, have 

 been removed, and all the material in the hall is now cased. Six 

 large ore specimens in Hall 72 have been provided with individual 

 cases. The valuable series of iron and steel fractures shown in 

 Hall 76, which were beginning to rust, has been carefully cleaned. 

 The cases containing the fractures have been relined and repainted 

 inside and the sashes fitted with jambs of rubber. With the case 

 thus made air-tight, by the use of lime or other drying ingredient 

 it is expected to keep the case interiors dry and thus prevent any 

 further rusting of the fractures. Some other minor changes have 

 been made in the casing in this hall. The interiors of most of the 

 wall cases and part of the floor cases in Hall 79 have been painted 

 white, and a large wall case added to contain the heavy specimens 

 formerly piled along the south wall. About one-third of the cases 

 containing the systematic mineral collection. Hall 63. have been 

 relined, the specimens cleaned and reinstalled. A stack of trays for 

 storage purposes has been placed along the east wall of Hall 75. An 

 aspirator, filter-pump and air-bath have been added to the equipment 

 of the laboratory. The work-room of vertebrate palaeontology has 

 been provided with stacks of storage-trays, work-tables and other fit- 

 tings. New pasteboard trays have been supplied throughout to the 

 palaeontological collection in Halls 35, 36 and 59. The old trays, 

 being of inferior quality, had become much faded and soiled. The 

 new style of tray, adopted after some experimenting, was a shallow 

 tray covered with black glazed paper, except where the specimen was 



