No. ti. DEPARTMENT UF AGRICULTURE. 359 



the iiatui-e aud use of what are comnionly called "fei'tilizeis'' alone. 

 Aud this is only one of several helps that are forcefully illustrated 

 at every one of the more than three hundred institutes held in the 

 State annually. Five weeks ago 1 visited a locality in which one of 

 those institutes was held last winter, and was told that the informa- 

 tion then obtained had saved them eighty dollars ($80) on a single 

 car-load. The narrator himself had profited eight dollars ($8) by 

 listening understandingly to one lecture. 



Of the fourteen elements that combine to make a plant, ten are 

 abundant everywhere. And we need concern ourselves with only 

 one, two, three or possibly four. Each of these has a peculiar func- 

 tion, and cannot be substituted. 



The perfect plant lias roots, stalk and seed, and each member re- 

 quires food for its development. If all are abundant and available, 

 the plant is vigorous and healthy, but if any one is absent, or avail- 

 able only in insufficient quantity, failure is the result. Our crops 

 differ as to their requirements. A crop of wheat, for instance, re- 

 quires precisely the same food that makes a paying yield of jpota- 

 toes or of fruit, but the proportions of nitrogen, phosphoric acid 

 and of potash differ widely, so that profitable culture demands a 

 knowledge of the constituents of each. It may be helpful to some 

 who may read this paper long after you and I have forgotten it, to 

 know that in a general way, nitrogen makes leaf and twig growth, 

 phosphoric acid is indispensable in grains and seeds, while potash 

 predominates in roots and fruits. 



An acre of good corn will require twice as many pounds of nitro- 

 gen as will a full crop of potatoes, because of the great stalk devel- 

 opment, but the potatoes will require double the quantity of potash. 

 The nitrogen of our commercial fertilizers is derived from manv 

 sources, but principally from the nitrate of soda, a crude product 

 found in the rainless districts of Western South America. Also 

 from blood and tankage from the slaughter-houses and from bones. 

 The phosphoric acid is the most abundant in the fossil remains of 

 animals and fish found in South Carolina, Florida, Tennessee, Cuba 

 and elsewhere. Bones are also rich in this element. The potash 

 comes almost entirely from very deep mines in Germany. Plants 

 c vn take their food only in a liquid form, and any material used 

 to build up the structure of a plant is held in solution. The water 

 absorbed by plants is not pure, containing probably two to four 

 pounds of soluble matter from which plants derive their entire 

 su])])ly of solid material, in each ton. If a plant is burned we find 

 in the ashes all the elements derived from the soil, except the nitro 

 gcu. These solids will scarcely amount to more than two or three 

 per cent, of the original weight of what was supposed to be dry 

 matter. The great remainder is air and water which passes oft" 



