274 ORGANIC AGRICULTURAL CHEMISTRY 



(a) For weight of phloroglucid " a " under 0.03 gram. 



Furfural = (a + 0.0052) X 0.5170 

 Pentoses = (a + 0.0052) X 1.0170 

 Pentosans = (a + 0.0052) X 0.8949 



(b) For weight of phloroglucid " a " over 0.300 gram. 



Furfural = (a + 0.0052) X 0.5180 

 Pentoses = (a -4- 0.0052) X 1.0026 

 Pentosans = (a + 0.0052) X 0.8824 



For weight of phloroglucid " a " from 0.03 to 0.300 grams use 

 Krober's table ^ or the following formulas : ^ 



Furfural = (a + 0.0052) X 0.5185 

 Pentoses = (a +0.0052) X 1.0075 

 Pentosans = (a + 0.0052) X 0.8866 



Sugars 



Both monosaccharoses and disaccharoses are found very 

 widely distributed in the vegetable kingdom. They are all 

 soluble compounds and are, therefore, found in the plant juices, 

 especially in fruits. 



Sucrose. — Of the three common disaccharose sugars, viz. 

 sucrose or cane sugar, maltose or malt sugar and lactose or milk 

 sugar, the first two are present in plants, while the last is found 

 only in animals. 



The most abundant disaccharose in plants is common cane 

 sugar, or sucrose. Its most important sources are the juice of 

 the sugar cane and of the sugar beet. From these two agri- 

 cultural crops almost all of the sugar used as human food is 

 obtained. This has all been fully discussed in the chapter on 

 the chemistry of the carbohydrates (Chapter VII). Numerous 

 other plants contain cane sugar in considerable quantity, but, 

 with the exception of the sorghum cane and the sap of the hard 

 or sugar maple, none of them serve as commercial sources of 

 sugar. 



^ J. Landw. 48, 379, igoo. See p. 226 of the above bulletin. 



2 These factors were calculated from Krober's tables by C. A. Browne. 



