ft WALL'S MANUAL 



made from the juice of corn-stalks, from starch, from 

 linen, and from woody fibre. 



In the plant, during its growth, these elements are 

 constantly changing. At one time they assume the 

 form in which they cannot be dissolved in water, and 

 remain fixed in their places. 



At another time, the chemical influences on which 

 growth depends, change them to a soluble form, and 

 they are carried by circulation of the sap, to other 

 parts of the plant, where they may again be 

 deposited in other insoluble forms. 



As an illustration, the turnip devotes the first 

 season of its growth to storing up, in its root, a large 

 amount of starch and pcctic acid; in the second 

 Reason (when set out for seed), these substances 

 become soluble, arc taken up by the circulation, and 

 again deposited in the form of woody fibre, starch, 

 etc., in the stems, leaves, and seed-vessels, above the 

 ground. If a turnip root be placed, in the spring, in 

 moist cotton-lint, from which it can obtain no food, 

 it will simply, by the transformation of its own 

 substance, form stems, leaves, flowers, and seed. 



Those products of vegetation which contain 

 nitrogen, are of the greatest importance to the farmer, 

 being the ones from which animal muscle is made. 



They consist, as will be recollected, of carbon, 

 hydrogen, oxygen, and nitrogen, or of all of the 

 atmospheric elements of plants. They are all of, much 

 the same character, though each kind of plant has 

 its peculiar form of this substance, which is known 

 under the general name of protein. 



The protein of wheat is called gluten that of 

 Indian corn is zein that of beans and peas is 



