The Fixation of Nitrogen. 65 
way when there is no excess of water, as we have demonstrated by 
experiments. 
In regard to the water question in this case the facts are not 
clear. I have given the depth of the water plane as seven feet 
and stated that the annual variation above this is probably not more 
than ten or twelve inches. These statements are based upon the 
heighth of the water in the cellar of the house standing at the lower 
edge of the low portion of this land and also upon the results ob¬ 
tained by digging a hole nine feet deep and extending it by means 
of a post-hole auger to sixteen feet when the water rose to within 
seven feet of the surface. These figures were given to me by the 
manager of the property and are entirely reliable. The water at 
sixteen feet is evidently under some hydrostatic pressure but not 
enough to force it nearer to the surface than seven feet. The 
cellar referred to is a large one, 25x50 feet, and I think gives the 
true heighth of the water plane. These statements are not made 
to indicate that the surface of the land is not wet, for it is, but to 
indicate that the wet condition of the surface is not due to a high 
water plane but to surface waters. This water near the surface is 
probably none other than irrigation water, it is certainly not due to 
the run-off from heavy rainfalls, and is not due to leakage from an 
irrigating ditch to the north of the orchard. A salready stated holes 
or wells dug north of the orchard but south of the ditch did not 
show much water and a trench from fou rto six feet deep, dug the 
whole length of the orchard developed no water. The only water 
that could collect on this ground would be that used in irrigating 
about twenty acres of land. The orchard must no wbe fifteen years 
set and so the concentration of salts by washing and evaporation 
must have been going on this long at least. During this time, 
however, some may have been carried away by run-off waters. 
Laboratory No. 996 is a sample of white, effloresced alkali 
and contained no nitrates. No. 1027 is a sample of surface soil 
and alkali taken two months later than No. 996 from another, but 
a very bad portion of the land, in my judgment, the worst. No. 
1029 is a sample of alkali and soil taken from an adjoining orchard 
indicated as Case No. 23 which is wholly neglected by its owner 
and no further mention will be made of it. No. 1028 is the water- 
soluble portion of a soil sample taken October 28, 1910, one and 
one-half inches deep. There was no white alkali at this place and 
the soil was in fine condition, but the trees were dying, the water- 
soluble in this sample was 3.11 percent but the nitrates present 
were equal to 0.676 percent of the sample. No. 1046 is another 
sample of soil taken Feb. 1, 1911, about four inches deep. This 
sample was taken west of the bad ground by taking smaller samples, 
uniting them and cutting down the mass to a convenient size. The 
water-soluble equalled 1.25 percent of the soil and the nitrates 
