H0W CROPS FEED. 



A TREATISE ON THE 



ATMOSPHERE AND THE SOIL 



AS BELATED TO THE 



NUTRITION OF AGRICULTURAL PLANTS. 



With nittstratlons, 



BY 



SAMUEL W. JOHNSON, M.A., 



Pbofbssor op Analttical and Agbicultubal Chemistkt in the Shep- 



FIBLD SCIENTIPIC SCHOOL OP YALB COLLEGE ; CUEMIST TO THE COS- 



NECTICUT State Aqricultubal Society ; Member op 

 THE National Academy of Sciences, 



The work entitled " How Crops Grow " has been received with very great 

 bvor, not only in America, but in Europe, The Author, therefore, puts forth 

 this volume — the companion and complement to the former — with the hope 

 that it also will be welcomed by those who appreciate the scientific aspects 

 of Agriculture, and are pereuaded that a true Theory is the surest guide to a 

 snccessful Practice. lu this, as in the preceding volume, the Author's method 

 has been to bring forth all accessible &cts, to present their evidence on the 

 topics under discussion, and dispassionately to record their verdict. If this 

 procedure be sometimes tedions, it is always safe, and there is no other mode 

 of treating a subject which can satisfy the earnest inquirer. It is, then, to all 

 Students of Agriculture, whether on the Farm or in the School, that this vol- 

 ume is specially commended. 



CONTENTS. 

 DIVISION I. 



The Atmosphere as Belated to Tegetatlon. 



CHAPTER I.— Atmospheric Air as Food op Plants. 



CHAPTER n. — The Atmosphere as Physically Related to Vegetatiok. 



DIVISION II. 



The Suil as Related to Vegetable Prodnction. 



CHAPTER I.— Introductory. 



CHAPTER n.— Origin and Formation of Soils. 



CHAPTER ni,— Kinds op Soils, theik Definition and Classification. 



CHAPTER IV.— Physical Characters of the Soil, 



CHAPTER V,— The Son, as a Source of Food to Crops: Ingredients 



WHOSE Elements are op Atmospheric Origin. 

 CHAPTER VI.— The Soil as a Source op Food to Crops Ingredients 



WHOSE Elements are Derived prom Rocks. 



Price, post-paid, $2. 



ORANGE JUDD COMPANY, 



751 Broadway, New-York. 



