42 
Bulletin 65. 
ALKALINITY OF THIS SOIL. 
§ 83. Several attempts were made to estimate the alkalinity of 
the soil, but without satisfactory results. It was simply determined 
that they all reacted with cochineal and a properly prepared litmus 
solution, showing an alkaline reaction. This reaction was more de¬ 
cided when the moistened soil was placed on litmus paper and al¬ 
lowed to remain there for a few minutes. While the samples were 
all alkaline, none of them were strongly enough so to permit of its 
determination by a one hundredth normal acid solution. I was not 
at all satisfied as to the cause of the alkaline reaction, for the sam¬ 
ples of soil which had been washed free from the sulfates still 
showed the reaction when placed on litmus paper. 
4 ' 
FREE AMMONIA IN THE SOIL. 
§ 84. Though aware of the unsatisfactory results obtained in 
endeavors to make this determination, I thought that the peculiar 
character of our soil and the very frequent occurrence of similar 
soils in Colorado, would justify me in making the attempt. 
§ 85. The samples were taken in their fresh condition, mag- 
nesic oxid added, and after standing a short time, an hour or so, 
were subjected to distillation. Ammonia-free-water was used 
throughout this experiment. The disillate at first was rich in am¬ 
monia, and while it became poorer and poorer, it continued to give 
a decided reaction with Nessler’s reagent for ten days, when the ex¬ 
periment was stopped. It the case of sample No. 3, the whole of the 
ammonia was given off in four days. Three samples, Nos. 1 and 3 
from plots which had not received any manure, and No. 2 from a 
manured plot, were subjected to distillation. The results obtained 
were: 
No. 1. Ammonia in dry soil-0.00962 per cent. 
No. 2. Ammonia in dry soil_0.00765 per cent. 
No. 3. Ammonia in dry soil_0.00367 per cent. 
The persistency with which the ammonia continued to come 
over, showed that it was probably being formed during the distilla¬ 
tion and was not originally present as free ammonia, or as ready 
formed ammonia salts. In order to obtain as much evidence as 
possible regarding the occurrence of free ammonia in this soil, a 
fresh portion of sample No. 1, was taken and subjected to distilla¬ 
tion with the addition of ammonia-free-w r ater alone. The distilla¬ 
tion was, as in the previous cases, permitted to proceed very slowly 
until two and a half litres of distillate were collected. There were 
still traces of ammonia coming over. The ammonia obtained 
equalled 0.00211 per cent, of the dry soil. The comparatively 
abundant evolution of ammonia in the early stages of the distilla¬ 
tion with magnesic oxid, and the decided quantity yielded upon 
