2 BULLETIN 108, U. S. DEPARTMENT OF AGRICULTURE. 
aqueous solution of sodium bisulphite. The bisulphite solution 
was separated from the ether, strongly acidified with sulphuric acid, 
and air blown through to remove sulphur dioxide. This solution 
was then shaken with several portions of fresh ether, the ether 
extracts combined, and the ether removed by evaporation over a 
small volume of water. The solution remaining was filtered from 
a small quantity of resinous insoluble material and as thus obtained 
was a slightly colored solution having an aromatic odor and the 
properties of a solution of salicylic aldehyde. On slow evaporation 
of the water there was left a yellow oil, soluble hi water with some 
difficulty, but very soluble in alcohol or ether. The water solution 
developed a pink color hi fuchsine aldehyde reagent almost immedi- 
ately and gave an intense violet color with ferric chloride. When 
treated with phenylhydrazine, a precipitate was formed which on 
recrystallization from alcohol was in the form of yellow leaflets that 
melted at 143°, the characteristic form and melting point of the 
phenylhydrazone of salicylic aldehyde. The separation of this 
compound from ether solution by an aqueous solution of sodium 
bisulphite and the color produced with fuchsine reagent fix it as an 
aldehyde. The general properties of the compound and the forma- 
tion of the hydrazone melting at 143° are sufficient to identify it as 
salicylic aldehyde. 
As the large sample of soil collected was used up in the above 
isolation and identification of some of its organic constituents, a 
second shipment of the soil was secured and sufficient salicylic alde- 
hyde obtained to make some tests of its action on plants. 
The effect of the soil aldehyde was tested on wheat by growing 
the plants in water cultures. An experiment was made with the 
aldehyde dissolved in pure distilled water. The wheat was grown 
in water in culture jars holding 250 c. c. One jar contained pure 
distilled water, and the second contained the water in which was 
dissolved the aldehyde separated from the soil. The plants grew 
for two weeks. The aldehyde was quite harmful, reducing growth 
about 37 per cent. Another experiment was made, using a good 
nutrient solution with and without the substance. The aldehyde 
from the soil was extremely harmful, even in the good nutrient 
solution; the green weight of the plants was reduced 40 per cent. 
These experiments with the salicylic aldehyde extracted from the 
soil on growth are shown in Plate I, figure 1. The plants show the 
harmful effect of the substance on growth. It will be seen that 
both tops and roots in nutrient solution and in distilled water are 
badly affected by the presence of the salicylic aldehyde. 
Having thus demonstrated the harmful action of this substance 
when isolated from a soil, there remains a further study of the action 
of this compound on various plants and in various culture solutions, 
