46 
Bulletin 72. 
varied both in quantity and in the ratio of the different salts present. Their 
amount and character depended upon the conditions obtaining in the immediate 
vicinity of the well. 
13. The total solids rose and fell with the water plane, passing into the 
water as it rose, and remaining in the soil when it fell. This is the same as say¬ 
ing that the total solids in solution depend upon the relative masses of the water 
and soil and vary with the character of the soil, including the salts retained in it. 
The preceding is a general statement and does not consider the irregular increase 
or decrease-of the total solids in the same well at different times. These are un¬ 
questionably dependent in a large measure upon the unlike conditions of chemi¬ 
cal equilibrium obtaining in the solution at different times. 
14. The increase in the amount of total solids in a well water is not 
always the greatest in those wells which show the greatest rise in the water plane, 
nor in those which usually show the greatest quantities of total solids. The 
increase in the total solids due to the rise of the water plane seems to be partly 
dependent upon the rate of diffusion through the soil. 
15. The height of the water in the different wells was essentially the 
height of the water table in the soil. 
16. The total solids in the well waters were less than in the water in the 
soil. This difference was not due to a mixture of water entering the wells from 
different sources, but was seemingly due to the modification of the laws of dif¬ 
fusion and solubility by the soil itself. 
17. The total solids in the ground water were lower in 1899 than in 1897 
as indicated by samples of ground water taken 10 days after irrigation. 
18. The chlorin, or its corresponding salt, sodic chlorid, was at no time 
very abundant in the ground water and bore no definite relation to the total 
solids, as the sodic chlorid ranged from 5 to a little more than 14 per cent, of 
their total weight. The increase or decrease of sodic chlorid, common salt, was 
not proportional to the increase or decrease of the total solids and did not serve 
as an index of either the amount of total solids present or of their variation, ex¬ 
cept within very wide limits. 
19. The chlorin may not alw T ays be present in the form of sodic chlorid, 
which is tacitly assumed in the preceding statement. Analytical results indi¬ 
cate that it may sometimes be present as magnesic chlorid, and the irregular de¬ 
portment of chlorin in the waters may be due to such causes, i. e., differences in 
the manner of its combination. 
20. The chlorin present in the ground waters and its variations in quan¬ 
tity throw but little or no light upon the movement of the alkali salts within this 
soil. 
21. The term total solids is equivalent to the salts constituting the free 
solution in the soil. The term represents a different mixture of salts than is 
found in the incrustations forming on the surface of the soil, or obtained by 
evaporating an aqueous extract of the soil to dryness. 
22. The total solids in the ground water varied greatly in the different 
wells, and also from time to time, in regard to their quantity, but only to a lim¬ 
ited extent in their chemical composition. The difference in the latter respect 
was almost exclusively confined to the relative quantities of the respective salts. 
23. The method of combining the analytical results has been adopted 
as convenient and probable, but not as infallible. 
24. In combining up the analyses there is frequently a slight excess of 
sodic oxid, this is often within the limits of analytical errors, at others it is 
rather high. We have observed that this excess is usually higher when the loss 
on ignition is high and are inclined to attribute it to the presence of organic 
acids. 
25. The alkali incrustations from this plot consist essentially of sodic 
