100 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1939 
decomposition products are insoluble* and with that modification the 
procedure was then shown to he applicable to the analysis of samples 
of insecticida] phenothiazine itself. 
All the published color reactions for derris resin or for the rotenone 
or other constituents contained in it were given comparative trials so 
that their possibilities and Limitations might be Learned. The dig 
ery that racemic deguelin forms with carbon tetrachloride a complex 
that is of low solubility Led to the development of a new method for 
the determinat ion of deguelin in roots and re-ins. and gives for the first 
time a convenient means of studying this, the second most important 
constituent of derris and cuhe. 
Methods suitable for the determination of mercury, fluorine, arsenic, 
zinc, and copper in impregnated wood were published; the question of 
estimating the suitability of a particular bog iron ore, or bmonite, as 
a corrective for arsenical damage to soil by determining the amount of 
iron oxide readily available for reaction with certain test solutions was 
investigated; a new apparatus was developed for the better testing of 
geraniol preparatory to its purchase as a means of baiting the Jap- 
anese beetle; and the importance of viscosity as a diagnostic property 
in studying decomposed baits was demonstrated. Improvements were 
made in the Rast and Segnor methods for detennining molecular 
weights. Finally, a new apparatus was developed for the phys 
analysis of insecticides, comprising a very simple set-up for determin- 
ing the average particle size of powdered materials. It is entirely self- 
contained and portable, occupies only about 1 square foot of space, and 
even contains an alignment chart which makes the calculations almost 
automatic. By its use a determination can be made in less than half 
an hour. 
TRANSIT INSPECTION 
Inspectors stationed at parcel post, express, and freight terminal 
points in 10 cities inspected 1,163,897 shipments for compliance with 
regulations of Federal domestic plant quarantine. Over 030.0O) 
freight waybills were examined to determine certification statu< of 
shipments consigned thereunder. There were 3,719 violations inter- 
cepted, of which approximately 30 percent were of such nature that 
they were inspected, certified, and released by transit inspectors. 
One hundred and forty-eight apparent violations of intrastate quar- 
antines relating to pests on account of which Federal quarantines 
have been established were reported to State plant-pest-control offi- 
cials. One of the important phases of transit inspection is reporting 
to State officials shipments of nursery stock which have been con- 
signed in apparent violation of State certification requirements. 
Over 560 of this type of shipments were so referred. During No- 
vember and December tin 1 transit inspection force in New York and 
Boston was materially increased by the assignment of inspectors from 
another Bureau project so that thorough inspection could he made 
of the Christmas-season movement of decorative-plant material from 
the gypsy moth regulated area. This inspection resulted in the 
interception of approximately 300 shipments i^\' material consigned 
in apparent violation of the gypsy moth and brown tail modi quaran- 
tine. 
