650 



THE STANDARD DICTIONARY OF FACTS 



OTHER FARM PRODUCTS 

 (From the United States Census Reports.) 



1 Includes all milk products, the value 

 before ginning. 3 Includes value of cider, 



of which was $472,369,255. 2 Not including products sold with fiber 

 etc. 6 Amount sold as cane only. 



Air-pump, an instrument for removing the 

 air from a vessel. The essential part is a hollow 

 brass or glass cylinder, in which an air-tight 

 piston is made to move up and down by a rod. 

 From the bottom of the cylinder, a connecting 

 tube leads to the space which is to be exhausted, 

 which is usually formed by placing a bell-glass, 

 called the receiver, with edges ground smooth, 

 and smeared with lard, on a flat, smooth plate or 

 table. When the piston is at the bottom of the 

 barrel, and is then drawn up, it lifts out the air 

 from the barrel, and a portion of the air under 

 the receiver, by its own expansive force, passes 

 through the connecting tube, and occupies the 

 space below the piston, which would otherwise 

 be a vacuum. The air in the receiver and barrel 

 is thus rarefied. The piston is now forced down, 

 and the effect of this is to close a valve placed 

 at the mouth of the connecting tube, and opening 

 inwards into the barrel. The air in the barrel 

 is thus cut off from returning into the receiver, 

 and, as it becomes condensed, forces up a valve 

 in the piston, which opens outwards, and thus 

 escapes into the atmosphere. When the piston 

 reaches the bottom, and begins to ascend again, 

 this valve closes ; and the same process is repeat- 

 ed as at the first ascent. Each stroke thus 

 diminishes the quantity of air in the receiver; 

 but from the nature of the process, it is evident 

 that the exhaustion can never be complete. 

 Even theoretically, there must always be a por- 

 tion left, though that portion may be rendered 



less than any assignable quantity; and practi- 

 cally the process is limited by the elastic force of 

 the remaining air being no longer sufficient to 

 open the valves. The degree of rarefaction is 

 indicated by a gauge on the principle of the 

 barometer. The air-pump was invented by 

 Otto Guericke, 1654. 



Alcohol, the purely spirituous or intoxi- 

 cating part of all liquids that have undergone 

 vinous fermentation, extracted by distillation 

 a limpid colorless liquid, of an agreeable smell 

 and a strong, pungent taste. When brandy, 

 whisky, and other spirituous liquors, themselves 

 distilled from cruder materials, are again dis- 

 tilled, highly volatile alcohol is the first product 

 to pass off. The alcohol thus obtained contains 

 much extraneous matter, including a proportion 

 of water, from the first as high as 20 or 25 per 

 cent., and increasing greatly as the process con- 

 tinues. Charcoal and carbonate of soda put in 

 the brandy or other liquor, partly retain the 

 fusel-oil and acetic acid it contains. The prod- 

 uct thus obtained by distillation is called recti- 

 fied spirits or spirits of wine, .and contains from 

 55 to 85 per cent, of alcohol, the rest being 

 water. By distilling rectified spirits over car- 

 bonate of potassium, powdered quicklime, or 

 chloride of calcium, the greater part of the water 

 is retained, and nearly pure alcohol passes over. 

 It is only, however, by very prolonged digestion 

 with desiccating agents and subsequent distilla- 

 tion that the last traces of water can be removed. 



