172 Wisconsin Academy of Sciences, Arts, and Letters. 
The presence of the potassium bicarbonate crystals would seem to 
indicate that a reaction had taken place between the arsenic tri¬ 
oxide and the potassium carbonate, and that the liberated carbon 
dioxide combined r i f h some of the carbonate to form the bi¬ 
carbonate. 
V.) One hundred and twelve grams of potassium hydroxide, the 
equivalent of 200 grams of potassium bicarbonate, were dissolved 
in 100 mils of water and to the boiling solution 100 grams of 
arsenic trioxide were added. Then the mixture was immersed in a 
bath of boiling water until a clear solution resulted. After stand¬ 
ing several days a solid mass 94 separated out. This was assayed 
with the following results:— 
Weight 105.0, gm. 36.0 p. c. KOH 43 p. c. As a 0 3 
The mother liquor was allowed to stand at room temperature in 
an open dish and several portions of a similar mass were collected 
at various intervals. These were assayed with the following 
results:— 
Second mass 36.5 p. c, KOH 43.0 p. c. As 2 0 3 . 
Third mass 19.6 p. e. KOH 21.67 p. c. As 2 0 3 
Fourth mass 19.07 p. c. KOH 19.9 p. c. As 2 0 3 
VI.) Fowler’s solution is alkaline to litmus 95 due to the hy¬ 
drolysis of the potassium arsenite. 96 In order to ascertain the 
alkalinity of the finished product three solutions were prepared of 
different composition. The first was prepared by dissolving 10 
grams of arsenic trioxide and 20 grams of potassium bicarbonate 
in sufficient water to make 1000 grams; the second, 10 grams of 
potassium bicarbonate in 1000 grams of solution and the third by 
substituting an equivalent amount of potassium hydroxide for the 
bicarbonate of the first solution. These solutions were assayed for 
As 2 0 3 and KHC0 3 with the following results:— 
94 The mass could not be removed from the beaker without breaking the dish 
so it was dissolved in water. Upon adding the water to this mass a lowering 
of temperature was noticed while solution was taking place, differing decidedly 
from the action of potassium hydroxide. 
05 United States Pharmacopoeia. 
99 Kommentar zum Deutschen Arzneibuch , 5. Ausgabe 1910. 
