44 2 Baker. — On the Effect of Formaldehyde on Living Plants. 
Experiments with Carbon Disidphide in Light. 
Experiment I. February-March, 1911. Plants used: Cress. 
Length of capillary in diffusion bulb, 10 cm. 
Temperature ranged from io° to 18 0 . 
Atmosphere. Orig. dry weight. Final dry weight. 
Air + CS 2 • 
Air — C0 2 
Air + C0 2 
C0 9 
0*1982 grm. 
0*1972 „ 
0*1977 » 
o* 1 145 grm. 
Final / orig. weight. 
57*8% 
56 * 0 % 
59*7 % 
o*ix8o „ 
Notes. — As the weather was dull and cold throughout, none of the 
plants were very vigorous. 
Experiment II. March- April, 19 11. Plants used: Cress. 
Length of capillary in diffusion bulb, 4 cm. 
Temperature ranged from 9-5° to 18 0 . 
Orig. dry weight. Final dry weight. Final /orig. weight 
62*6 % 
69-2 % 
Atmosphere. 
Air + CS 2 - C0 2 
Air - C0 2 
Air + C0 2 
0*2005 grm. 
0*2015 „ 
0*2000 ,, 
0*1255 grm. 
0*1385 „ 
0-1575 
78*8% 
Notes. — Plants under this concentration of carbon disulphide showed 
signs of poisoning. The chief symptoms were an entire absence of helio- 
tropism and geotropism, and a curled appearance. Besides this, there was 
often a reversal of the usual sequence in the emergence of root and shoot 
from the seed, and in many cases the cotyledons were bright orange in 
colour. 
Experiment III. April-May, 1911. Plants used : White Mustard 
(. Brassica alba , Boiss.). 
Length of capillary in diffusion bulb, 10 cm. 
Temperature ranged from n° to 27 0 . 
Atmosphere. Orig. dry weight. Final dry weight. Final / orig. weight. 
6 i *5 % 
63-2 % 
85*4% 
Air — C0 2 
Air + CO, 
0*399° g rm - 
o-3995 ,» 
0*399° » 
0*2455 grm. 
0*2525 „ 
0*3400 » 
Notes. — Both cultures without C 0 2 were beginning to shrivel, when 
the experiment was stopped ; the other was vigorous and showing second 
leaves. 
Conclusions. — As in the experiments with acetylene, there is no 
assimilation with carbon disulphide. The slight apparent increase in the 
first experiment was due, no doubt, to some irregularity in the lighting. 
It was also performed at an unfavourable time of year. Again, in this case 
the vapour has the effect of increasing respiration, though not to the same 
extent as acetylene, a fact which has been observed before by other 
methods. 1 
1 Cf. H. E. and E. F. Armstrong : Proc. Roy. Soc., 1910, Ixxxii, B, p. 588. 
