1913] KNIGHT & CROCKER—TOXICITY OF SMOKE 351 
NH,;, nicotine, tar, and solids, while of course the latter removes 
CO, and HS. There results a mixture of colorless gases which is 
stored over water. This method of storage is adequate, since 
the most toxic constituent of the smoke is very slightly soluble in 
water, as shown by the slight fall in toxicity when thus stored, also 
by evidence given later in the paper. 
To obtain the cigarette smoke used in the following experiments, 
7 Murad cigarettes, weighing 1.3 gm. each, were two-thirds con- 
sumed, with a yield of 10 liters of gas. Each liter of smoke, there- 
fore, results from the smoking of 0.6 gm. of cigarette; 20 liters of 
cigar smoke were produced by 15 gm. of cigars; each liter of smoke 
required 0.75 gm. of cigar. The paper smoke was derived from a 
cigarette of bond paper not giving lignin tests; 4 liters of smoke were 
produced from 1.4 gm. of paper; each liter was derived from 0.35 
gm. of paper. So far as we know, the tobacco and paper smoke 
thus washed will contain, in common, nitrogen of the air drawn 
through in smoking, more or less unused oxygen, certain dry dis- 
tillation gases of the carbon compounds involved (methane, ethy- 
lene, acetylene, and carbon monoxide), and perhaps higher homo- 
logues of methane, ethylene, and acetylene. The tobacco smoke 
will contain in addition traces of pyridine and perhaps other com- 
pounds. In this experiment the epicotyls in each culture at the 
beginning of the exposure varied from 2 to 3 cm. in height. The 
seedlings were subjected to the smoke for three days in total dark- 
hess at 20° to 24° C. The following data give the various concentra- 
tions and varieties of smoke used, along with the condition of the 
epicotyls at the close of the experiment. 
1. Check culture in so-liter chamber; epicotyls 6-12 cm. tall, vertical and 
very slim. 
2.2 25 cc. of cigar smoke (output of 0.0188 gm. of cigar) in 50-liter chamber; 
epicotyls 4-7 cm. tall; greatest declination 30°; no swelling; greater diameter 
than check. 
3. 50 cc. cigar smoke (output of 0.0375 gm. of cigar) in 50-liter chamber; 
epicotyls 3. 5-4. 5 cm. long; swollen; declined portion 1.5-2.5 long, with a 
declination of 75°-90°. 
2In all the work the smoke was measured under existing atmospheric pressure. 
No corrections for barometric pressure and temperature were deemed necessary, for a 
doubling of the concentration was required to give noticeable differences in response, 
hence the errors of this method were far beyond detection by the seedling. 
