INTRODUCTION. ix 



The study of natural philosophy makes us acquainted with 

 the laws of light and heat; of attraction and gravitation; of the 

 nature of water, air and electricity and of various principles 

 that are indispensable to the thorough knowledge of the natural 

 phenomena pertaining to agriculture. 



In geology we read a history of the formation of the earth's 

 crust, with its rock formations; its fossils; i. e. shells, corals, 

 leaves, and other remains of plant and animal life, that once 

 existed on the globe. 



Through chemistry we learn the composition of materials 

 in soils, plants and animals and of the transformations which they 

 undergo. And biology makes us acquainted with the principles 

 of life as demonstrated in heredity, training, environment, evolu- 

 tion and progress. 



Thus in the intelligent study of soils, in its relations to the 

 elements of agriculture, the scientist must know something about 

 the sciences: astronomy, geology, chemistry, physics, botany, 

 zoology and biology. 



It may properly be said that agriculture affords us one of 

 the broadest fields for the development of the intellectual powers, 

 for the study of agriculture is concerned chiefly in the three 

 great divisions of nature the mineral, the vegetable and the 

 animal kingdoms. 



How to Get Agricultural Information. 



The United States is expending approximately forty mil- 

 lions of dollars annually for agricultural education. Wherever 

 agriculture has been added to the course of study in the public 

 schools it has therefore become necessary for teachers to become 

 acquainted with the work that is being done by the following 

 institutions : 



1. The United States Department of Agriculture, Washington, D. C. 



2. The State 'Experiment Stations. 



3. The State College of Agriculture. 



4. The State Board of Agriculture. 



5. The State Department of Public Instruction. 



It should be the aim of these different departments to co- 

 operate in the promotion of agricultural instruction. 



