(SO 



The cured leaves are sold either in the entire condition or 

 powdered, and afford the chief beverage of Paraguay and 

 many parts of the Argentine Republic and southern Brazil. 

 They contain much less caffeine than ordinary tea, and 

 have a very different flavor, but are used for the same pur- 

 pose and produce the same effect. Paraguay-tea is ex- 

 tremely cheap as compared with ordinary tea, and brief 

 use makes people equally well satisfied with it. In the 

 block of cases devoted to beverages may be found choco- 

 late, which is derived from the seed of the chocolate tree 

 (Theobroma). The collection shows the chocolate fruits, 

 the principal commercial varieties of the seeds, unroasted 

 and roasted, nibs of different degrees of fineness, germs, 

 cocoa-liquor, cocoa-butter, cocoa-cake, and the same ground 

 into "breakfast "-cocoa, with several varieties of confect- 

 tioners' chocolate, as put up for the market. 



Miscellaneous Specimens. Case 50. — In this case may 

 be seen the substances used in the manufacture of insect- 

 powders and related substances, and soap. Soaps are 

 made from fats or fixed oils, acted upon while hot by a 

 caustic alkali, or "lye," ordinarily by boiling the two to- 

 gether. The fat consists of one or more acids, variously 

 combined with glycerin. The alkali takes away the 

 acids, uniting with them to form soap, the glycerin being 

 set free. Either animal or vegetable fats can be em- 

 ployed, the characters of the soaps differing more or less 

 with the particular fat used. The character of the alkali, 

 such as soda or potash, also modifies the quality of the 

 soap. The soap may contain free alkali, free fat, free 

 glycerin, or water, in variable proportions, all of which 

 will modify its quality. Official soap (that used in medi- 

 cine) should not float on water and should contain not 

 more than 36 per cent, of water. 



Fixed Oils and Volatile Oils. Cases 51 to 56. — The 

 volatile oils form a large series, and in their manufacture 

 various parts of the plants are used; for example, roots are 

 used to make the oils of lovage-root, elecampane, and 



