February, ’23] 
PARROTT & GLASGOW: TOBACCO DUST 
91 
or tobacco dust in lime sulphur and glue sulphur sprays. Considerable trouble was 
encountered with certain types of spraying machines from clogging of the nozzles 
and strainers. Pumps with poppet valves and rather coarse strainers gave less 
trouble. Fine tobacco dust undiluted or with 10 percent of lime hydrate showed 
marked toxicity. The insecticidal properties of tobacco dust, on an average were 
not uniformly as high as that of dust mixtures containing nicotine sulphate. The 
concentrated tobacco solutions are apparently more economical than powdered 
tobacco. 
Tobacco dust has long been employed to combat certain injurious 
insects, but very little data, apparently, are available dealing with its 
insecticidal properties and range of usefulness for the protection of garden, 
field or orchard crops. In the literature disseminated by agricultural 
institutions, various commercial extracts in concentrated form such as 
nicotine sulfate or nicotine solution are commonly recommended. Usu¬ 
ally little, if any, mention is made of powdered tobacco. 
During the course of our studies relative to susceptibility of sucking 
insects to dusting preparations, provision was made for a number of 
tests to determine the killing properties of tobacco dust incorporated in 
dusting and spraying mixtures. The present paper deals with some of 
the more important facts gained from these experiments. 
The Nicotine Content and Physical Properties of Tobacco Dust 
In the Virginia Station Bulletin 208, Ellett and Grisson state “that 
the nicotine content of tobacco varies greatly, depending upon many 
factors. The fertility of the soil and the kind of soil both have influence. 
In curing, the temperature is often allowed to run too high and nicotine 
is lost by volatilization. To ascertain the amount of nicotine, chemical 
analysis is required.” fl'he nicotine content of Virginia tobacco is as 
follows: stems, 0.48 to 0.60 percent; sweepings, 0.73 to 0.88 percent; 
N. L. Orinoco, 5.35 to 5.62 percent; olive, 3.63 percent; light, 2.9 per¬ 
cent; smoker, 2.30 percent; wrapper, 3.05 percent; cutter, 3.46 percent; 
dark, 2.83 percent; medium smoker, 3.76 percent; and common smoker 
2.47 percent. “Stems had less nicotine content than leaves and dark 
varieties of tobacco, as Narrow-leaf Orinoco and Burley, had' higher 
ratios of nicotine than bright or flue-cured types.” 
There is, apparently, no standard for tobacco dust either with respect 
to nicotine content or physical condition. In comparison with the fore¬ 
going figures, it is interesting to note that analysis of various lots of 
tobacco dust purchased in the State of New York showed considerable 
variation in nicotine, as follows: Sample 1, 0.88 percent nicotine; Sample 
2, 0.58 percent; Sample 3, 0.50 percent; Sample 4, 0.95 percent; Sample 
5, 0.98 percent; and Sample 6, 1.00 percent. 
