170 Wisconsin Academy of Sciences, Arts, and Letters. 
potassium acid carbonate and arsenic trioxide, using N/l acid and 
N/10 iodine respectively. The following results were obtained:— 
Wt. 
Crystals 7.6 gm. 67. p. c. KHC0 3 4.5 p. c. As 2 0 3 
Liquid 24.0 gm. 39.4 p. c. K 2 C 0 3 35.5 p. C. As 2 Q 3 
II.) The experiment was repeated using 200 grams of potassium 
acid carbonate dissolved in 250 mils of water, and boiled for about 
thirty minutes. While boiling, this solution was added to 100 
grams of arsenic trioxide contained in a flask and the whole im¬ 
mersed in a bath of boiling water until a clear solution resulted. 
The solution was allowed to stand over night when the crystals 
were collected and assayed as before. A duplicate experiment was 
made. The following results were obtained:— 
Crystals 
Liquid 
Total 
Crystals 
Liquid 
Total 
81. gm. 96. p. c. KHC0 3 1.7 p. c. As 2 0 3 
359. gm. 
j 3.6 p. c. KHC 0 3 
l 22.1 p. c. K 2 C0 3 
20. p. c. As 2 0 3 
440. gm. 
100. gm. 96.09 p. c. KHC0 3 2.13 p. c. As 2 0 3 
oofi j 2.0 p. c. KHC0 3 26.6 p. c. As 8 0 8 
330. gm. | 23a £ c KjCOj* 
430. gm. 
III.) The results obtained so far lead to a desire for more in¬ 
formation and the experiment was repeated on a still larger scale. 
In this case four times the original quantities were used. Instead 
of allowing the solution to stand over night it was cooled and the 
crystals formed at definite temperatures were removed and exam¬ 
ined. The first crop of crystals was collected at 30° C., the second 
crop at 20° C. Then the solution was placed out doors and al¬ 
lowed to stand over night. The next morning the liquid in the 
flask registered —10° C. A separation between the crystals and 
the liquid was effected as quickly as possible. At room temperature 
the separated crystals were apparently decomposing hence were 
placed in a funnel and allowed to stand twenty-four hours. By 
that time the crystals had lost approximately one-half of their bulk 
with the formation of a liquid. Each lot of crystals, likewise the 
