112 EEPORT OF KATIOKAL MUSEUM, 1925 



worthy being a series showing the ingredients used in compounding 

 and coloring dental rubbers and the applications of dental and base 

 plate rubber when vulcanized; an exhibit of coal-tar dystuffs, and 

 a large number of jars of foodstuffs canned according to the cold- 

 pack method. 



The installations made in the Wood Court during the present 

 fiscal year included: Photographs and charts descriptive of the 

 hardwood distillation industry; specimens showing the process and 

 products of resinous wood distillation; a series of specimens illus- 

 trating the manufacture of lead pencils, and another showing steps 

 in the making of a stock for the United States military rifle, model 

 1903 ; an exhibit showing the use of English willow in the production 

 of an artificial limb ; timbers of southern yellow pine and Douglas fir 

 flanking either side of the entrance; and a complete reinstallation 

 of the board specimens of mahogany and other commercial woods, 

 which have been shown on the south wall. 



In the Division of Medicine, 54 new or rearranged installations 

 were made. The more important of these were: The Gorgas 

 medals; specimens illustrating the history of electric medical prac- 

 ice; mementos of Dr. John King; the method of making medicinal 

 preparations of digitalis uniform in therapeutic activity ; the right 

 and wrong way to deal with cancer; old pharmaceutical balances 

 and weights; enlarged transparent representations of pathogenic 

 parasites; a model depicting the value of public health activities; 

 enlarged glass models of water microorganisms; health progress ex- 

 hibit; health posters; and oral and social hygiene exhibits. Several 

 exhibits — some installed during the year just closed and others 

 arranged in previous years — were constructed in such a way that it 

 was necessary to illuminate them, and they were appropriately 

 lighted this year. 



In the Division of Graphic Arts the permanent^exhibit of mezzo- 

 tint was entirely rearranged with two important technical series 

 added which give a clear idea of both the early and the later 

 methods, the first by the use of roulettes and the later by the use 

 of the rocker. The series include plates in various stages, progress 

 prints clearly illustrating the processes, and the various tools used. 

 Other series help in the understanding of varying methods, such 

 as the mixed method, in which the design is etched into the plate 

 before rocking. The historical mezzotint series, which consists of 

 only about 20 prints, contains examples of the work of some of the 

 men who have contributed to the development of the art, but neegls 

 a few of the rare historical prints to make it more comprehensive, 

 such as prints by von Siegen, Prince Rupert (both now represented 

 by reproductions) , and some of the other prominent workers in this 

 field. 



