The Ground Water. 
47 
and magnesic sulfates in the ratio of two to one; they together constitute 80 
per cent, of the mass. Calcic sulfate is subordinate in quantity with sodic 
chlorid and carbonate still more so, 
26. The salts dissolved in the ground water, the 1 total solids, consist 
much more largely of calcic sulfate than of sodic sulfate, and contain about the 
same amount of magnesic sulfate as the incrustation from this plot. The ratio 
of calcic sulfate to the magnesic and sodic sulfates in the total solids is approx¬ 
imately 2 : 134 - 1 - 
27. The salts extracted from the first two inches of the soil by continued 
treatment with water consisted of the same salts, they made up nearly 80 per 
cent of the total, but the ratio was approximately 4:2:1. 
28. The aqueous<extract of the second two inches of soil contained very 
little magnesic sulfate, no sodic sulfate, and almost 51 per cent, of calcic sulfate. 
This extract showed a large amount of soluble silicic acid, corresponding to 14.5 
per cent, of sodic silicate calculated on the dried residue. 
29. The upper portions of the ground water are richer in total solids 
than the successively deeper portions and the salts in solution differ, especially 
in their relative quantities. 
30. There seemed to be an abundant formation of nitric acid in the 
upper portions of the soil, even in portions of the plot where the alkali salts 
were abundant. 
31. Nitric acid occurred so generally in the ground waters and its vari¬ 
ations were so dependent upon other conditions that we cannot judge of the 
effect of the alkalies present nor of that of the mechanical conditions. 
32. There was no relation between the amount of total solids and that 
of the nitric acid present. 
33. There was no relation between the different wells in regard to the 
quantity of nitric acid present or its variations. 
34. Irrigating the ground increased the nitric acid in the well waters, so 
did even light rainfalls, probably due to increase of capillary exchange of the 
nitrates between the upper portions of the soil and the ground water. 
35. The ground water from this plot is richer in nitrates than that from 
neighboring land which is in better condition. 
36. The nitrites in the ground water are relatively high and are in¬ 
creased by irrigation. This is probably due to the biological conditions of the 
soil and the deportment of solutions of nitrites toward the soil, especially in re¬ 
gard to the readiness with which they will pass through it. 
37. The free ammonia and ammonia salts were not especially abundant 
in the ground water, either before or after irrigation, though more abundant 
after than before. 
38. The ground water was slightly richer in free ammonia than the drain 
water from this plot. 
3'h The albumenoidal ammonia in the ground water was not excessively 
high, but it was materially increased by irrigation. The albumenoidal ammonia 
did not appear to pass freely into the drain water. 
40. The amount of nitrates removed by off-flow water is probably quite 
limited as their quantity in the off-flow diminished rapidly. 
