186 Field Columbian Museum — Reports, Vol. II. 



resenting graphically the composition of the minerals affording that 

 metal. Thus in order to illustrate each mineral affording copper, for 

 example, there is shown in an adjacent tube a quantity of copper, 

 sulphur, silica, water, or other ingredient going to make up the mineral 

 in the exact proportion in which each enters into its composition. 

 The demonstration of composition to the eye is thus made more vivid 

 than it could be if expressed in figures alone, and the exhibition in 

 series enables the relative richness of the different minerals in any 

 metal to be determined at a glance. In Hall 70, a large number of 

 the coal specimens have been treated to prevent disintegration, 

 and the series of graphite ores has been rearranged and enlarged. 

 Several important improvements have been made in the Depart- 

 ment Laboratory to afford better facilities for chemical work, chief 

 among which has been an entire rebuilding of the hood. The old 

 wooden frame was taken down and sashes fitted with large 

 lights of glass put in its place. The interior of the hood was lined 

 throughout with white porcelain tile, thus affording a clean and 

 smooth surface. A large air bath was constructed within the hood, 

 and the interior piped for water, gas and compressed air. The stock 

 of chemicals and apparatus has been considerably increased, the addi- 

 tions to apparatus including a lever air-pump, pycnometer, calorime- 

 ters, and dichroscope. The work of cataloguing and numbering the 

 specimens in the field during the previous year absorbed the attention 

 of the staff in the Department of Anthropology, leaving little time 

 for new installation and rearrangement. But a single hall has been 

 installed during the year, namely, that illustrating the ethnology of 

 the Islands of the Pacific. As is customary, during the autumn of 

 each year, all the cases in the department have been examined and 

 overhauled. Interchangeable black and gold numbers were placed 

 upon each case containing permanently installed specimens, and a 

 black and gold label now adorns most of the cases in the department. 

 These additions enable visitors to readily refer to the official guide 

 for more extended information regarding the contents. 



Among the permanent improvements made in the building, the 

 following may be noted : The construction of a new laboratory for the 

 osteologist in the east end of the building, and a room for the photo- 

 gravure operator in the east gallery. Several of the offices were en- 

 tirely overhauled and provided with fresh coats of paint and kalsomine. 



Printing. — It will be noticed that an unusually large number of 

 labels have been printed during the year. The office is well equipped 

 and it is clearlv evident that this verv useful section of the Museum 



