- 463 - 
HERRICK, G. XI. (2005) 
1920. INSECTS 01 ECONOMIC IMPORTANCE . 172 pp. New York. 
Tobacco dus-t is often used against plant lice, animal lice, and 
ticks. Black Leaf 40 is also briefly discussed "by referring to the 
literature (pp. 19-29). 
Under fumigating substances, tobacco papers are briefly described. 
Paper soaked in tobacco extract is sold for fumigation purposes in green- 
houses. These papers will burn when lighted and are much raore convenient 
to use in houses than tobacco stems (p. 28). 
HOLMES, G. K. (2006) 
1920. THREE CENTURIES OE TOBACCO. U. S. Dept. Agr. Yearbook for 1919, 
pp. 151-175. 
This is a popular account of the production, geographic distribu- 
tion, exports and imports, and various other phases of tobacco. 
After enumerating the various uses of tobacco, the author says 
that it was long ago learned that a decoction of stems or leaves would 
rid plants of insects and domestic animals of external parasites, if 
the animals were dipped in it, and that the smoke would expel insects 
from plants (p. 165) . 
ANONYMOUS (2007) 
1921. HERSTELLUNG VON TABAKBRUHE AUS TABAKSTAUB. Landw* -bakteriol. 
and Pflanzenschutzstation, Vienna. [Abstract in Rev. Appl. Ent . 
(A) 10: 384. 1922.] 
To prepare a spray containing about 1 percent of tobacco extract, 
2 lb. of tobacco dust is soaked, with repeated stirring, in 5 imperial 
gal. water and then allowed to settle. The liquid is then filtered through 
linen end is ready for immediate use. The addition of 1 part lysol to 
20,000 of the liquid acts as a preservative, "fretting power is enhanced 
by adding soft soap or lysol prior to spraying. 
ALLEN, tf, J. (2008) 
1921. COMBINED SPRAYS. Agr. Gaz. New South TTales, 32(8): 559. [Abstract 
in Rev. Appl. Ent. (A) 9: 564. 1921.] 
In making combined sprays it is essential that the quantities are 
correct. To make a spray of 100 gal. of lead arsenate and nicotine solu- 
tion at the rate of 1 lb. of arsenate to 25 gal. of water and concen- 
trated nicotine solution 1 pt. to 100 gal. of water, the best way is to 
mix the 4 lb . of lead arsenate in 95 gal. of water to which the pint of 
nicotine concentrate mixed with 4 gal. 7 pt..of water should be added. 
