July is, 1921 
Reduction Strength of Mercuric-Chlorid Solution 583 
Soil sample 3 behaved in much the same manner as sample 2, removing 
1 per cent during the first 5 minutes and 1.8 per cent at the end of 10 
minutes. It seems probable that the variation in the amount of vegetable 
matter present in the soils was largely responsible for the differences in 
the amount of mercuric chlorid removed, although other factors may have 
been involved. Soil adhering to the potatoes or that present in the 
containers is therefore responsible for the removal of a considerable part 
of the mercury. In view of these facts the extent to which a solution 
should be used depends somewhat upon the amount of soil and roots 
adhering to the potatoes. 
SACKS 
The amount of mercuric chlorid removed by two sacks treated in 2 
gallons of solution was next determined. One was a 2-bushel cotton 
grain sack of the ordinary type, and the other a gunny sack of about 
equal capacity which had contained a commercial stock feed. The grain 
sack was washed and dried before being treated. The gunny sack was 
turned inside out and shaken thoroughly to free it as nearly as possible 
of adhering materials. 
An examination of Table VI shows that a grain sack and a gunny sack 
remove a considerable amount of mercuric chlorid even during a 5-minute 
treatment and an increasingly larger amount as time goes on. If the 
rate at which a sack will remove the mercuric chlorid is proportional to 
the amount of solution in which it is treated, then the amount of mercuric 
chlorid removed by the bag from about 32 gallons would be something 
like 1 per cent for each treatment. Since the sacks continued to remove 
the mercury for at least 24 hours, they alone would be responsible for 
the removal of enough of the disinfectant to interfere seriously with the 
effectiveness of the subsequent treatments. It would therefore seem 
unsafe to use sacks as containers in the treatment of sweet potatoes. 
Table VI .—Percentage of 'mercuric chlorid removed from solution by treating sacks in 
2 gallons of solution. 
Length of treatment. 
Percentage of HgCl 2 
present in solution. 
Percentage of HgCl? re¬ 
moved from solution. 
Grain 
sack. 
Gunny 
sack. 
Grain 
sack. 
Gunny 
sack. 
Control a . 
04. 6 
101 c 
5 minutes. 
84.5 
QI. 2 
IO. I 
10.3 
10 minutes. 
77-9 
87-3 
16.7 
14.2 
30 minutes. 
72.7 
82.5 
21.9 
19.O 
60 minutes. 
70.4 
78.6 
24.2 
22.9 
4 hours. 
65.4 
Of\ 0 
5 hours. 
6 c c 
f ' * 
24 hours. 
54-8 
' 0 
IO.O 
39-8 
30.° 
91-5 
a Solution unused. 
