18 BULLETIN 108, U. S. DEPARTMENT OF AGEICULIUEE, 
In Table X are given the remaining soils, which gave none or only 
an insignificant amount of extractive material when subjected to 
the method for obtaining aldehyde from soils, nor did this extract 
give the reactions with the above reagents. We must conclude 
therefore that the aldehyde material, salicylic aldehyde or other 
aldehydes, are either absent or present in much smaller quantities 
in the soils of Table X than in the soils given in Table IX. 
From Table IX it will be seen that the soil aldehyde is in every 
case harmful to growth, and that all the soils behave in this respect 
like the Mount Vernon soil (Xo. 1), which has been already more 
fully described and in which salicylic aldehyde of poisonous proper- 
ties was demonstrated. 
In Plate V, figure 1, is shown the effect of this material from soil 
Xo. 2. This had been used for gardening and trucking for the last 
10 years, and had been manured each year with poultry manure 
and commercial fertilizers. The soil in the last two years produced 
poor vegetables and truck crops, and corn failed entirely. The soil 
is grayish yellow in color, is quite acid and low in organic matter. 
The separated aldehyde extract was harmful to the growth of wheat 
seedlings, causing a decrease of 33 per cent. 
In figure 2 of Plate V is shown the effect of the aldehyde extract 
from soil (Xo. 4), showing an alkaline reaction. This soil had been 
growing vegetables and truck crops for 20 years with frequent use 
of commercial fertilizers. Corn, cabbage, and cantaloupes had 
failed in certain sections of the field for the last two years, whereas 
formerly the soil grew excellent truck crops of all kinds. The soil 
and subsoil were quite alkaline to litmus paper, and both showed 
the presence of considerable aldehyde material. This aldehyde re- 
duced growth of the test plants by 26 per cent, both tops and roots 
being severely injured. 
The heavily manured greenhouse soil (Xo. 5, Table IX) is particu- 
larly interesting in that considerable aldehyde was found, whereas 
neither the raw soil (Xo. 8, Table X) nor similarly treated soil which 
had been used and then weathered for some time (Xo. 7, Table X) 
contained the harmful aldehyde material. This examination was 
made because the soil in question had been used on benches for 
floriculture and did not give good results. Soil Xo. o, Table IX. 
was a composite taken from two benches in the greenhouse where 
carnations and roses did not thrive. This contained aldehyde, 
which, when tested with wheat seedlings, gave reductions in growth 
of 35 per cent. Soil Xo. 7, Table X, had been previously used for 
greenhouse purposes and had been made in the same way by manur- 
ing heavily the raw soil, but without experiencing any difficulty. 
Since then it had been in a pile outside for several months. At the 
tune of testing no aldehyde could be found, nor was the residue 
