60 SCIENTIFIC AGRICULTURE. 



MUTUAL RELATIONS OF LIGNINE, STARCH, GUM AND SUGAR. 



It is a remarkable fact, that these four substances, though 

 possessing properties so entirely different, are composed of the 

 same elements in the same proportions. This fact, so evident 

 to the analytical chemist, is still little more comprehensible to 

 him, after his most profound investigations, than to the most 

 unlearned. And, although we can readily separate the ele- 

 ments of these bodies, we cannot combine the same elements 

 so as to form any one of them. The formulae below show 

 their constitution. 



Woody fibre is composed of C. 12, H. 10, 0. 10. 



Starch " " C. 12, H. 10, 0. 10. 



Gum " ' " C. 12, H. 10, 0. 10. 



Cane sugar " C. 12, H. 10, 0. 10. 

 These four substances are capable of being transformed ono 

 into another, as woody fibre into starch, starch into sugar, gum 

 into sugar, &c., as will be hereafter described. 



GLUTEN. 



Gluten exists in the flour of wheat, rye, barley and oats, 

 from which it may be obtained by washing the paste or dough 

 for a long time in water. It is a soft, tenacious, elastic, grayish 

 substance, with very little taste or odor. It is nearly insoluble 

 in water, but easily dissolved by alcohol, acids and alkalies : 

 when moist gluten is dried at 212; it becomes a semi-trans- 

 parent, yellowish, brittle mass, resembling glue. Wheat con- 

 tains more gluten than any of the other grains: it contains, 

 according to its quality, from 8 to 35 per cent. Gluten is 

 highly nutricious: it is composed of carbon, hydrogen, oxygen 

 and nitrogen. 



ALBUMEN. 



Albumen is a gelantinous, colorless substance, without taste 

 or smell, dissolved by acids and alkalies, but insoluble in 



