682 
Journal of Agricultural Research 
Vol. XI, No. 13 
per cent pure. Since practically no free alkali was found to be present, 
no doubt hygroscopic moisture made up the 5.58 per cent. Therefore 
the amount of carbon in the 3 tons of lime used per acre was 680 pounds, 
which number appears in the fourth column of the table. The figures 
in the next column were obtained directly from Table I. In the column 
headed “Inorganic carbon at end” are given the values obtained from 
the analysis of the soil for inorganic carbon by the Maclntire (5) method. 
These soils were analyzed while still moist, immediately after removal 
from the apparatus. No doubt the reason for finding inorganic carbon 
in the unlimed soil was that some carbon dioxid was retained in the soil 
moisture. No carbonates were found in the original air-dried soil. As is 
observed, only the averages of the duplicates are given. The greatest 
Fig. 3—Graphs of the quantity of carbon evolved as carbon dioxid in soils treated with green clover alone 
and in combination with manure and lime. 
variation of the averages for the inorganic carbon in the unlimed soils 
* was 2.5 pounds, while the greatest variation of the corresponding values 
for the limed soils was 5 pounds. This is thought to be a satisfactorily 
low experimental error. The weight of “Organic carbon lost” in the 
case of the unlimed soils were obtained simply by adding the total carbon 
lost to the inorganic found at the end of the experiment. For the limed 
soils, the following method was followed: The amount of inorganic 
carbon at the end of the experiment was subtracted from the amount 
added at the beginning. This, which is, of course, the number of pounds 
of inorganic carbon lost, was subtracted from the number of pounds of 
total carbon lost. This gives the desired figures listed in column 7. 
The next column is self-explanatory. In order to obtain the values 
found in column 9, it was assumed that in every case where organic 
matter was added to the soil the amount of carbon lost from the original 
