vili CONTENTS. 
CHAPTER XI. 
THE BLOOD OF TREES. 
Experiments in Connection with the Circulation of Sap in Trees.— 
Variety of Sap-exuding Trees.—Non Sap-yielding Species.—The 
Influence of Climate on Flow of Sap.—Composition of Sap, to What 
Due. — Distinctive Characteristics of Sap-yielding Trees Demon- 
strated.—Effect of the Temperature of Soil and Atmosphere on Sap- 
flow.—Principal Ingredients of Sap.—Daily Meteorological Obser- 
vations and What they Prove.—Explanations on the Alternations of 
Sap-flow.—The Observations of Biot and Nevins, and What they 
Determine.—The Opinion of Mr. Hubbard Confirmed by Experi- 
ments.—The Absorbent Power of Roots.—Development of Leaf 
and Flower, How Influenced, and Origin of their Vitality..Page 47 
° CHAPTER XII. 
SHELTER-BELTS. 
Vegetable Need of Protection Illustrated. — Observed Fallacies and 
Reasonable Contradictions.—Laws of Heat Radiation Demonstrated. 
—Nightly Atmospheric Heating.—Condition and Elevation of Air 
Favorable to Vegetable Life.— Atmospheric Vapor, How Supplied. 
—The Benefits of Transpiration of Forests. — Observations in 
Europe, and What they Prove.—A Conclusion Established.—Ad- 
duced Facts.—Motion of the Atmosphere.—Liquid and Aerial Mo- 
tion Contrasted. — Aerial Motion Illustrated. — Protective Systems 
and their Controlling Influences.—Experienced Facts versus Theo- 
ry.—A Study for the Orchardist and Farmer.—Experienced Testi- 
mony on the Influence of Shelter-Belts................0...008 54 
CHAPTER XIII. 
KINDS OF TREES TO PLANT. 
The White, Blue, Black, Green, Red, and European Ashes.—Their 
Growth, Usefulness, and Manner of Culture. —Climate and Soil 
best Suited to their Growth.— Distinguishing Traits and Proper- 
ties of Varieties.—The Mountain Ash.—Its Deportment, Uses, and 
Manner of Propagating.—Its Enemies.—The American Flowering 
Ash Described .c.ssyeengecgees 42 2hcawae dad ak coves Sdeededeen 63 
CHAPTER XIV. 
THE WALNUT. 
Its Culture, Usefulness, and Productiveness.—Value of the Walnut as 
a Crop.—Seed per Acre.—Its Nativity.—Traces of its Antiquity 
and Introduction into Europe.—Recognized Roman Varieties and 
their Names. —Its Modern Cultivation and Increased Varieties. 
—The Black Walnut.— Where Found, Attainable Size, and At- 
tendant Features. —The Butternut.— Climate best Suited to its 
