5«2 
Journal of Agricultural Research v 0 i. xxi, no. s 
OTHER MATERIALS INVOLVED IN THE REMOVAL OF MERCURIC CHEORID 
DIRT 
For the purpose of determining tlie extent to which other materials 
associated with the treatment are responsible for taking up the mercuric 
chlorid from the solution, tests were made with dirt, sacks, a hamper, 
concrete, and a barrel. Three types of dirt were used. Sample i was 
composed of the sweepings from a sweet-potato storage house and 
consisted chiefly of soil and fine roots which had collected where crates 
had been moved about or potatoes picked over. This was run in dupli¬ 
cate. Sample 2 was obtained from a field on which rye had been grown 
during the previous autumn and spring at the United States Depart¬ 
ment of Agriculture Experimental Farm at Arlington, Va., and had 
just been plowed under a short time before the sample was taken. The 
soil was a dark loam and contained roots of rye and weeds. Sample 3 
was a red clay subsoil almost or entirely devoid of humus, taken several 
feet below the surface. One pound of each sample was treated in 2 
gallons of mercuric-chlorid solution, and the results are given in Table V. 
Table V .—Percentage of mercuric chlorid removed from solution by treating 1 pound of 
dirt in 2 gallons of solution 
Length of 
treatment. 
Percentage of HgCla present in solution. 
Percentage of HgCh removed from solutions. 
Soil sample i. 
Soil 
sample 2. 
Soil 
sample 3. 
Soil sample 1. 
Soil 
sample 2. 
Soil 
sample 3. 
Control®. 
91. I 
75-8 
75 - 5 
75-5 
75*8 
63. 6 
100. 0 
82. 4 
82. 0 
82. 0 
IOI. 9 
IOO. 5 
97.6 
94. O 
93-0 
92. 2 
5 minutes.... 
10 minutes... 
30 minutes... 
60 minutes... 
24 hours. 
I 5 - 3 
15. 6 
15.6 
I 5 - 3 
2 7 - 5 
17. 6 
18. 0 
18. 0 
1.4 
4-3 
I. 0 
1.8 
68. 2 
31-8 
° Solution unused. 
The results presented in Table V show a considerable difference in the 
amount of mercuric chlorid removed by the three types of soil. The 
two sets of soil sample 1 removed 15.3 and 17.6 per cent, respectively, 
during the first 5 minutes, after which there was little or 110 change up 
to and including 60 minutes. At the end of 24 hours there was a decided 
decrease in the strength of the solution. There was some variation in the 
changes produced by this dirt in the two trials, but in general the results 
are similar. However, a decided difference is apparent in the results of 
the experiment with soil sample 2. After 5 minutes only 1.4 per cent of 
the mercuric chlorid was removed, as compared with 15.3 per cent and 
17.6 per cent with soil sample 1. Another increase to 4.3 per cent took 
place in the next 5 minutes, while in these cases the amount of mercuric 
chlorid seemed to remain constant for some time after the first 5 minutes. 
