437 
the Effect of Formaldehyde on Living Plants. 
bubbler were reversed, so that the paraform tube came next to the culture. 
In the Experiments 3 and 4, therefore, the full percentage of formaldehyde 
yielded by paraform at room temperature (about 0-0875 % ; see p. 419) was 
present in the air which passed over the formaldehyde culture. 
In all these experiments (except the ‘ check ’ without formaldehyde of 
Experiment 4, which suffered from excessive water-supply) growth was 
healthy and the plants vigorous and well developed. No toxic symptoms, 
except the sparse production of root-hairs, were shown by any of the 
formaldehyde cultures. 
Each experiment lasted from ten to fourteen days, and the plants 
varied in height from 3-10 cm., according to the prevailing temperature 
conditions. 
The Balance used was by Oertling, London, sensitive to o-oooi grin* 
and taking a 250 grm. load. 
Quantitative Results on the Effect of CHfD in Darkness. 
Orig. wt. ..... 
Orig. dry wt 
Final dry wt 
Loss in dry wt. . . . 
Expt . 1. 
Expt . 2. 
Expt . 3. 
Expt . 4. 
+ ch 2 o . 
- cb 2 o . 
+ CH % 0 . 
- CH ^ O . 
+ ch 2 o . 
- CH ,0 
+ CH , 0 . 
- ch 2 o . 
grms . 
0-4006 
0-3470 
0*3333 
0-0137 
grms . 
0-4003 
0-3467 
0-3296 
0-0171 
grms . 
0-3998 
0-3690 
0-3577 
0-0113 
grms . 
0-4000 
0-3692 
0-3378 
0-0314 
grms . 
0-4036 
0-3734 
0'3456 
0-0278 
grms . 
0 -4040 
0-3738 
0-3357 
0-0381 
grms . 
0-4090 
0-3940 
0-3784 
0-0156 
grms . 
0-3996 
0-3857 
o -3796 
0-0061 
Gain on hydrolysis . 
Total loss in resp. dry 
0-0223 
0-0360 
0-0223 
0-0394 
0-0223 
0-0336 
0-0223 
0*0537 
0-0225 
0-0503 
0-0225 
0-0606 
0-0227 
0-0383 
0-0223 
0-0284 
Dist. water given . . 
Nut. soln. given . . . 
Total water given . . 
4-4993 
2 *3957 
6-8950 
3-7722 
2-3994 
6-1716 
4-5016 
3 -I 317 
7-6333 
5 -i 5 2 5 
3-1672 
8-3197 
6-4749 
3*8469 
10-3218 
6- 0366 
7- 7656 
13-8022 
6-1381 
5*3754 
1 i- 5 i 35 
5-5325 
5-7964 
11-3289 
Water on seeds . . . 
Water in CaCl 2 . . . 
Water in * house ’ . . 
Total water caught. 
1-9101 
o- 45 i 7 
5-2175 
7*5793 
1-7110 
0-6334 
4-0922 
6-4366 
1-9563 
0-6988 
. 5 -o 8 45 
7-7396 
2-7190 
0-6376 
4 ' 94 i 7 
8-2983 
5*4852 
0-3217 
4-6569 
10-4638 
8-3693 
0-2857 
5 'H 36 
13-7686 
8-5885 
o- 45 i 3 
2-3814 
11-4212 
8-3411 
0-2676 
2-5856 
Ti -1943 
Loss in wet wt. . . . 
0-0214 
0*0336 
0-0923 
0-1346 
H 2 0 evolved .... 
C 0 2 evolved .... 
0-0495 
0-0561 
0-0511 
0-0323 
0-0718 
0-0655 
0-0270 
0-0805 
0-0576 
0-0365 
Theoretical Values . 
C 0 2 calc, from dry wt. 
C 0 2 calc, from wet wt. 
0-0528 
0-0576 
0-0493 
0-0787 
0-0788 
0-0739 
0-0889 
0-1232 
0-0559 
0-0404 
Conclusions . — The quantitative results show that in presence of formal- 
dehyde vapour the carbon dioxide evolved during respiration is exactly the 
same in amount as in normal respiration. Hence formaldehyde is not con- 
verted by the plant into carbon dioxide, nor can it be utilized for the 
synthesis of food materials in the dark, for any gain in weight on either of 
H h 2 
