364 BOARD OF AGRICULTURE. 



interesting group of alimentary principles. Starch is the 

 chief constituent of many of our most valuable foods, such 

 as the seeds of the cereal grasses, tubers, roots, stems and 

 fruits. 



In the process of digestion starch is converted by the 

 ptyalin (the diastase of the saliva) and trypsin (the diastase 

 of the pancreatic secretion) into dextrine and grape sugar, 

 which, absorbed into the blood, is arrested in the liver, 

 where it is changed into animal starch — glycogen — and 

 further transformed into fat, either in the liver or by the 

 cells of the tissues ; just how we do not certainly know. 



The sweet taste of liver is due to the glycogen and sugar. 

 Starch is not digested in the stomach, and is not found in 

 the blood. 



Sugar is a luxury and a necessity much used and highly 

 prized by all civilized races. Its consumption is enormous. 

 Fifty pounds per head in the United States, with 60,000,000 

 of people, amounts to 1 ,500,000 tons. Sugar was first made 

 in Bengal, and its use was widely established in eastern 

 countries as early as 766 ; but it was not until 1700 or 1750 

 that it came into general use. The sweet of ancient nations 

 was honey gathered by the busy bee from flowers. Sugar is 

 derived chiefly from vegetable sources, — from the sap and 

 juices of the cane, grape, beet, maple, and several other trees 

 and plants. 



A sweet substance derived from coal tar has lately l)een 

 discovered by Dr. Fahlburg, a German chemist residing in 

 this country, called saccharine. It is the king of sweets, 

 beins: 250 times sweeter than our best susrars. It is not a 

 carbo-hydrate, is not decomposed in the body, and is not 

 therefore a food. Its uses and value are yet to be determined. 



Susrar is found in various combinations in brain, inlands 

 and nmscles. It does not pass through any process of 

 digestion, but is split up — metabolized — by chemical ac- 

 tion into new compounds. A part is converted into grape 

 sugar, is reconverted into animal starch or glycogen, and 

 finally into fat, t!ie uses of which have been considered. 



The carbo-hydrates, therefore, are to the physical system 

 the same as coal to the locomotive, — by oxidation, genera- 

 tors of heat and force. 



