Toperty of the Bureau of Entomolog 
: U. S. Department of Agriculture, 
PABCEZOE CONTENTS 
CHAP TER 
EcoynomMic USE oF HyprocyANic AcID GAs : 
Early history—First use as an insecticide— 
Experiments in California—Dry gas process 
—Inauguration of night fumigation—First use 
in Eastern orchards. 
CHAPTER II 
How THE GAs Is MADE : - : . 
Chemical iS svedients—- Combiarien of chem- 
icals — Action of chemicals—Vessel used for 
generation—Character of residue formed. 
CHAP TER SLU 
PHYSIOLOGICAL EFFECTS ON PLANTS . s : 
Experiments by Woods and Derset® seracu: 
cal tests upon orchard trees and nursery stock 
—Effects on seeds and low-growing plants. 
CHAP ERD, 
EFFECTS ON ANIMAL LIFE 5 0 : - 
Fortunate accident—Chickens pick up cyanide 
shaken from a bag—Cat destroyed in green- 
house while asleep—Experiences with various 
animals. 
CHAPTER V 
APPARATUS FOR USE IN ORCHARDS . 5 ‘ F 
Early types for fumigators—Construction of 
sheet tents—Oiling and painting tents—Vege- 
table decoction for treating tents. 
CHAPTER VI 
BELL AND Hoop TENTS ; ; : ; 
General description— Method of handling— 
The hoop tent popular in California—Construc- 
tion and manipulation. 
PAGE 
1-8 
12-24 
25-26 
27-34 
35-47 
