HARMFUL EFFECTS OF ALDEHYDES IN" SOILS. 13 
portions of ether, the ether extract combined and shaken with a con- 
centrated aqueous solution of sodium bisulphite, which will remove 
aldehydes from the ether solution if present, by forming a water- 
soluble combination with the sodium bisulphite. The bisulphite solu- 
tion was separated from the ether, strongly acidified with sulphuric 
acid, and air was blown through to remove the sulphur dioxide liber- 
ated. This acidified solution, in which the aldehyde is now liberated 
from its combination with the bisulphite, was then shaken with several 
portions of fresh ether, the ether extracts combined, and the ether 
removed by evaporation. There remained a small quantity of mate- 
rial, often resinous or oily in appearance. 
This material was further purified by again taking up in water, 
extracting with ether, and the ether solution, after filtering, allowed 
to evaporate. Sometimes this operation was repeated. The purified 
residue contains the aldehyde material, if present. 
This aldehyde material was treated with a small quantity of water. 
The aqueous solution is frequently colored, and on evaporation a 
yellow oil is often noticeable, as would be the case if salicylic aldehyde 
were present. The odor of the latter is also sometimes observed, 
although in other cases other odors are perceptible, suggesting other 
aldehydes. 
The fuchsine reagent was added to a portion of the solution, and 
to another portion a small amount of ferric chloride was added. 
Salicylic aldehyde, as mentioned, gives a violet color with ferric 
chloride and a pink color with the fuchsine reagent. Where both 
these reactions were observed the soil was considered as containing 
aldehyde. While the nature of the material is not thereby definitely 
shown to be salicylic aldehyde, yet the manner of isolation with ether 
and extraction therefrom with sodium bisulphite, together with the 
reaction shown with the fuchsine reagent, show the material to be 
an aldehyde, and the physical character of fluidity and the reaction 
with ferric chloride make it quite probable that in most of these cases 
salicylic aldehyde was under consideration. The amount obtained 
did not permit of further identification than is here given, especially 
as the main object was to determine the physiological property of the 
extracted material. 
The main portion of the material remaining after making the above 
tests was dissolved or mixed with 250 c. c. of pure distilled water and 
the resulting liquid used as a culture for wheat seedlings in order to 
test the physiological effect of the extracted material from the soil. 
This was done with every soil examined, whether the above tests 
were negative or positive. 
In order to study the presence of aldehydes in soils a number of 
samples were tested. Included in this test were a number of soils 
sent to this bureau from time to time by gardeners and greenhouse 
