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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
Mr. E. W. Berger: A little test that I made in 1922 may serve as a 
near-answer to Mr. Dietz’s question. I had trouble with Root-Knot 
Nematode severe!} 7 infesting a few rows of Swiss chard in my garden. 
I transplanted several small plants into two flower-pots, being particular 
to select plants equally infested, and used infested soil from the same 
spot in the garden. 
The soil in one pot was regularly drenched (perhaps, on an average, 
once per week) with a one-tenth per cent solution of glacial acetic acid 
in water (later 2-tenths per cent was used), while the soil in the other 
pot was always drenched only with an equal amount of plain water. 
Both were treated alike as to fertilization. 
It was soon apparent that the plants receiving the weak acid were 
doing much better. When, after several months (February to June, 
1922), the plants receiving only water died, examination showed that 
the treated plants had developed an abundance of apparently healthy 
rootlets, which was not the case with the plants that had received 
only water. The treatment had evidently checked the development 
of the nematodes in the soil, allowing the development of healthy or 
nearly healthy rootlets, whereas the roots of the untreated plants were 
unusually full of nematode-knots. 
Mr. W. E. Hinds: For a number of years we have used 
sodium cyanide solution alone, particularly in treatment of green house 
soils, with fairly satisfactory results so far as the control of nematodes 
is concerned, ' and with beneficial results so far as the growth of 
vegetation is concerned. This treatment is practicable with lettuce, 
squash, and crops like that of a truck nature. Its use would seem to 
be justified entirely from the fertilizer standpoint alone. Planting just 
as soon as the soil is dried out enough to plant any seed has seemed 
to be safe. A solution of 1 oz. sodium cyanide in 8 gallons of water 
is applied at the rate of 1 gallon per square foot of area. 
President A. G. Ruggles: The next paper will be read by Mr. 
K. C. Sullivan. 
THE USE OF CALCIUM CYANIDE FOR THE CONTROL OF 
FLEAS AND OTHER INSECTS 
By K. C. Sullivan, Columbia , Mo. 
Abstract 
Calcium cyanide was successfully used for the control of the Dog fleas Wtenoce- 
phalus canis Curtis) and the Human flea (Pluex irritans L) in both open and closed 
buildings. Calcium cyanide used at the rate of four ounces per 100. sq. ft., will 
