174 



GROWTH OF PLANTS 



the plants except the tomato and willow, and scrubbing it through NaOH 

 solution reduced the toxicity markedly for all. 



The investigators showed that there was a close agreement between the 

 amount of cyanides in the volume of gas that was needed to cause a given 



Figure 64. Comparison of injuries on tomato due to residues of illuminating gas left 

 in the soil and those caused by flowing gas and residues. A, Seedlings placed in soil 

 previously gassed. B, Roots of seedhngs in soil subjected to flowing gas. Left to right 

 in (A) and (B): control, one cubic foot, two cubic feet. 



