433 
the Effect of Formaldehyde on Living Plants. 
Quantitative Results on Respiration in Darkness. 
1 
Expt. T. 
Expt . 2. 
Expt . 3. 
Orig. wt 
Orig. dry wt. ... 
Final dry wt 
Change in dry wt. . . 
grin. 
0*4020 
0*3870 
0*3670 
— 0*0200 
grm. 
0*4020 
0*3870 
0*3426 
— 0*0444 
grm. 
0*4000 
0*3850 
0*3865 
+ 0.0015 
Gain on hydrolysis . . 
Total loss in resp. dry 
0*0224 
0*0424 
0*0224 
0*0668 
0*0223 
0*0208 
Dist. water given . . 
Nut. soln. given . . . 
Total water given . . 
4*7225 
0*5985 
5 " 3 2I ° 
3*3590 
7-3965 
1 O’ 7555 
3-2235 
5-0335 
8*2570 
Water on seeds . . . 
Water in CaCl a . • • 
Water in ‘ house ’ . . 
Total water caught 
1*5810 
0*6735 
3*0510 
5-3055 
6*6020 
0*4925 
3-3260 
10*4205 
! 5 * I 3 2 o 
T ‘3955 
1*7185 
8*2460 
Loss in wet wt. . 
0*0155 
0 - 335 ° 
0*0110 
H a O evolved in resp. . 
CO a evolved in resp. . 
0*0269 
1 0*0590 
0*0885 
0*0098 
0*0285 
Theoretical Values. 
CO a calc, from dry wt. 
CO a calc, from wet wt. 
0*0620 
0*0568 
! 0*0981 
0*0303 
0*0403 
The last two sections show the values for carbon dioxide, calculated 
from the found loss in dry weight and wet weight of the plants respectively, 
on the assumption of the quantitative formula for respiration representing 
the complete oxidation of a glucose : — 
c 6 H 12 0 6 + 60 2 = 6 C 0 2 + 6 H 2 0 
Parts by weight 30 32 44 18 
(The proportions obtaining when a polysaccharide, such as saccharose 
or starch, is oxidized are sufficiently close to these to be within the limits of 
experimental error.) It will be seen that, except in the ‘ wet 5 values of 
Experiment 2, which (as explained above, p. 432) are probably low because 
the plants grew out of their ‘ house ’, these calculated values approximate 
very closely to the found weights of C 0 2 . This shows that in mustard seeds, 
under the experimental conditions, respiration is, in the main, represented 
by a reaction in which carbohydrate is converted quantitatively into carbon 
dioxide and water. 
There is, therefore, a somewhat surprising agreement with the results 
of Day (previously cited, p. 426) for germinating barley. This is particularly 
remarkable when it is remembered that mustard is an oily and barley a 
starchy seed. Besides this, Day’s experiments were only concerned with 
the very first stages of germination, before the plumule had appeared ; 
while in the present experiments it has been found that by far the greater 
