LETTER OF TRANSMITTAL 
Honolulu, Hawaii, August 1,1914. 
Sir: I have the honor to submit herewith and recommend for 
pubHcation as Bulletin No. 38 of the Hawaii Agricultural Experiment 
Station, a paper dealing with the Effect of Fertilizers on the Physical 
Properties of Hawaiian Soils, by William McGeorge, assistant chemist 
of this station. The peculiar constitution of Hawaiian soils makes a 
study of the physical properties of these soils one of unusual impor- 
tance. In this paper there are described systematic experiments 
made to determine the effect of various fertihzers upon capillarity, 
percolation, flocculation, cohesion, apparent specific gravity, vapor 
pressure, and hygroscopic moisture. Before it is possible to reach 
a thorough understanding of Hawaiian soils it has been found neces- 
sary to study them from all standpoints. The paper is a contribu- 
tion to the knowledge of the physical properties of soils and particu- 
larly of the effect of fertilizers in other ways than as plant food. 
Respectfully, 
E. V. Wilcox, 
Special Agent in Charge. 
Dr. A. C. True, 
Director Office of Experiment Stations, 
Z7. S. Department of Agriculture, WasMngton, D. C. 
PubHcation recommended. 
A. C. True, Director, 
PubHcation authorized. 
D. F. Houston, 
Secretary of Agriculture, 
(3) 
