48 ELEMENTS OF AGRICULTURE 



widely distributed both in the vegetable and minera! 

 kingdoms; all plants contain sulphur, and it occurs in 

 large deposits in some parts of the earth. When eggs 

 decay the sulphur in the protein unites with hydrogen 

 and forms a gas called hydrogen sulphide, which has a 

 very disagreeable odor. It is the formation of this gas 

 that makes decaying eggs so disagreeable. 



45. Non-Nitrogenous Compounds. — In all plants 

 there are a number of organic compounds that contain 

 no nitrogen; such compounds are largely carbohy- 

 drates. They are made up of carbon, hydrogen, and 

 oxygen. The word carbohydrate means carbon com- 

 bined with hydrogen and oxygen in the proportion to 

 form water. The Greek word for water is liydor, so we 

 speak of a substance combined" with water as a 

 hydrate.. Here we have carbonhydrate or carbohy- 

 drate. Starch, sugar, gum, and woody matter (cellu- 

 lose) are all substances containing no nitrogen, and 

 are made up of C, H, and 0. They are consequently 

 carbohydrates. These four compounds make up a large 

 part of all plants, and are found in varying quantities 

 in different plants and different parts of the same plant. 

 Sugar is found in the stem of sugar cane and sorghum, 

 in the roots of sweet potatoes and beets, in the fruit of 

 many plants, and small quantities are found in the seed? 

 of most plants. Starch is found in the leaves of trees 

 and the stems of young plants, in the roots of many 

 plants, notably the sweet potato, and in the tubers of 

 the Irish potato. The grains of many seeds contain 

 quantities of starch; corn and wheat contain about 70 

 per cent starch. Woody matter makes up the stem and 



