Langenhan—The Arsenical Solutions. 
167 
mersed into a bath of boiling water. The mixture was constantly 
agitated and the time required to obtain a clear solution was re¬ 
corded. Three separate determinations were made for each dilu¬ 
tion. The results are recorded in the following table: 
Table I. 
1 Gm. As 2 0 3 
to 
2 Gm. KHC 0 3 
Volume (mils) 
25 
50 
100 
Time (minutes) 
1 , 2,2 
2,3,3 
2,3,3 
A glance at the table reveals the fact that the differences for the 
several dilutions are no greater than those obtained from the same 
dilution, hence fall within the limits of experimental error. 
B.) In the next series an attempt was made to secure more 
satisfactory results by increasing the amounts of the chemical 
agents acting upon each other. Ten grams of arsenic trioxide and 
the equivalent 20 grams of potassium bicarbonate (as carbonate) 
with varying amounts of water were used. In this series one ex¬ 
periment only was performed with each volume of water. The 
results are herewith tabulated. 
Table II. 
10 Gm. As 2 0 3 
to 20 Gm. KHC 0 3 
Volume (mils) 25 
50 
100 200 300 400 
1000 
Time (minutes) 3 
4 
3 5 3 4 
3.5 
Again the results 
tend 
to disprove the assumption that, 
with 
proper conditions, the rate of solution is hastened to any appre¬ 
ciable extent by greater concentration. 
C.) A third series was made in an attempt to note the effect of 
the effervescence (mentioned in the preliminary experiments), 
when larger quantities of reagents were used. Ten grams of ar¬ 
senic trioxide and 20 grams of potassium bicarbonate were mixed 
with 25 mils, 50 mils and 100 mils of boiling water, and the time 
of solution determined as before. The results are again tabulated. 
