168 Wisconsin Academy of Sciences, Arts, and Letters. 
Table III. 
10 Gm. As 2 0 3 
to 
20 Gm. KHC 0 3 
Volume (mils) 
25 
50 100 
Time (minutes) 
4 
6.5 5 
The slight increase in time is, no doubt, due principally to the 
removal of the arsenic trioxide from the solution by the escaping 
carbon dioxide. 
D.) In a fourth series of tests ten grams of arsenic trioxide and 
11.2 grams of potassium hydroxide, the equivalent of 20 grams of 
potassium acid carbonate, the latter dissolved in 25 mils, 50 mils 
and 100 mils respectively, of boiling water, were mixed, and the 
time required for solution noted as above. In each case the time 
was not more than one minute. Apparently the arsenic trioxide 
dissolved as fast as it came in contact with the solvent quite ir¬ 
respectively of the degree of concentration of the alkaline solvent. 
10.) Solution of Arsenic Trioxide. For the chemistry of the 
solution see Hydration of Arsenic trioxide. 
The formula for potassium arsenite given in the U. S. P. IX is 
KAs 0 2 , potassium metarsenite. Whether it is assumed that the 
salt exists as the metarsenite in the official solution is not made 
clear. Apparently writers differ as to the composition of the 
arsenite in the solution. L. Bullock 80 speaks of the “chemically 
indefinite liquor arsenicalis, ” M. H. Buignet 81 suggests that only 
part of the arsenous acid is combined with the alkali, the remainder 
being in simple solution. H. K. Bamber 82 concludes that a reac¬ 
tion takes place between potassium carbonate and arsenous acid in 
preparing the solution, basing his conclusions on the fact that 
carbon dioxide was given off during the process. This drew forth 
a number of comments by Redwood, Garrod, Attfield and others as 
to its correctness, the main criticism being that the concentrations 
of Bamber’s experiments were not comparable to the pharma¬ 
copoeia! conditions. A. F. Haselden 83 refers to the controversy 
relating to the correctness of the title “arsenite of potash” or 
80 Pharm. Jour., 10, p. 357 (1850.) 
81 Jour, de Pharm. et de Chim., 59, p. 439 (1856.) 
82 Pharm. Jour., 17, p. 481 (1858.) 
83 Pharm. Jour., 16, p. 541 (1857.) 
