REPORT ON THE UNITED STATES NATIONAL MUSEUM. 37 



In the division of medicine efforts were concentrated on obtaining 

 exhibition material of educational rather than scientific value. Illus- 

 trating organotherapy was a series of fresh specimens of glands and 

 glandular tissues together with finished products of the different 

 forms in which they are administered. Specimens illustrating the 

 manufacture of pepsin and the finished product in various forms in- 

 cluded a sample of pure pepsin with a standardized strength of 

 1:20,000, that is, it has the power to dissolve 20,000 times its own 

 weight of freshly coagulated and disintegrated egg albumen. Other 

 exhibits of crude vegetable drugs, synthetic medicinal chemicals, in- 

 organic chemicals, plant constituents, opium and its products, cin- 

 chona bark, aloes, and cascara sagrada were secured. 



Mineral technology. — In assembling collections representative of 

 mineral technology, comprehensive popular exhibits had been ar- 

 ranged at the beginning of the year, comprising abrasives, asbestos, 

 asphalt, cements, coal, copper, glass, gold, graphite, iron, lead, lime, 

 mica, petroleum, plaster, salt, sulphur, and tin. Under existing con- 

 ditions it was decided to confine activity to enhancement of what 

 was already established, deferring for the time being the various 

 projects for numerical expansion. Accordingly an exhibit was added 

 to the coal series showing the scope of recent American enterprise 

 in the direction of coal product manufacture. It consists of a 200- 

 pound lump of bituminous coal with derivatives in the form of dye- 

 stuffs and other chemicals to the number of 233. The series treating 

 of gold was enriched by a large panoramic model showing the occur- 

 rence and the various methods employed in winning the metal. The 

 magnificent panoramic model of the Bingham Canyon Copper Min- 

 ing operations was completed, as was also the model, in part placed 

 on display a year ago, showing the operations of lead manufacture. 



In an effort to be of service in the present emergency of war five 

 lines of investigation, which have been under consideration for sev- 

 eral years in assembling exhibits, have been developed in the course 

 of the year. These comprised fertilizer materials, sulphur, coal 

 products, power, and petroleum. To mobilize the economic forces 

 of production and to fill in their gaps is as necessary as that of 

 effecting the requisite military organization, and far more intricate. 

 The difficulty in building up deficiencies as they become apparent 

 lies in the complexity of interrelationship. Especially is this true 

 among the chemically conducted industries. First, there is the group 

 relationship of progressive segregation, notably instanced in the 

 coal-product series, wherein the isolation of any one product entails 

 the work leading to the isolation of many others. Then comes the 

 group relationship of recombination into usable form, as in the case 

 of fertilizer manufacture, where an entirely different basis of inter- 

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