158 Wisconsin Academy of Sciences, Arts, and Letters. 
LIQUOR POTASSI ARSENITIS U. S. P. 1890 
Solution of Potassium Arsenite 
[Fowler’s Solution.] 1 
Arsenous Acid, 4 in fine powder, 5 ten grammes 7 . 10 Gm. 
Potassium Bicarbonate, 6 twenty grammes T . 20 Gm. 
Compound Tincture of Lavender, 11 thirty cubic centimeters - 30 Cc. 
Distilled Water, 8 a sufficient quantity. 
To make one thousand cubic centimeters 12 ..- . 1000 Cc. 
Boil the Arsenous Acid and Potassium 1 Bicarbonate with one 
hundred (100) cubic centimeters 9 of Distilled Water, until solu¬ 
tion has been effected. 10 Then add enough Distilled Water to make 
the solution, when cold, measure nine hundred and seventy (970) 
cubic pentimeters, and, lastly, add the Compound Tincture of Lav¬ 
ender. Filter through paper. 
If 24.7 Cc. of the Solution be boiled for a few minutes with 2 Gm. of 
sodium bicarbonate, and the liquor, when cold, diluted with water to 100 
Cc., and mixed with a little starch T.S., it should require from 49.4 to 50 
Cc. of decinormal iodine V.S. to produce the blue tint of iodide of starch 
(corresponding to 1 Gm. of arsenous acid in 100 Cc. of the Solution). 15 
LIQUOR POTASSII ARSENITIS U. S. P. 1900 
Solution of Potassium Arsenite 1 
An aqueous solution, which should contain Potassium Arsenite 
corresponding in amount to 1 percent, of arsenic trioxide. 2 
Arsenic Trioxide, 4 in fine powder, 5 ten grammes' 1 . 10 Gm. 
Potassium Bicarbonate, 6 twenty grammes 7 ... 20 Gm. 
Compound Tincture of Lavender, 11 thirty grammes....- . 30 Gm. 
Distilled Water, 8 a sufficient quantity, 
To make one thousand grammes 12 . 1000 Gm. 
Boil the Arsenic Trioxide and Potassium Bicarbonate, in a 
tared dish, with one hundred grammes 9 of Distilled Water, until 
solution has been effected. 10 Then add enough Distilled Water to 
make the solution weigh nine hundred and seventy grammes, and, 
lastly, add the Compound Tincture of Lavender. Filter through 
paper. 
If 24.6 Gm. of Solution of Potassium Arsenite be diluted with water to 
100 Cc., the mixture very slightly acidified with diluted hydrochloric acid, 
and then made alkaline with 2 Gm. of sodium bicarbonate, it should re¬ 
quire not less than 50 Cc. of tenth-normal iodine V.S. to produce a perma¬ 
nent yellow tint (corresponding to 1 Gm. of arsenic trioxide in 100 Gm. 
of the Solution.) 15 
Average dose. —0.2 Cc. (3 minims). 16 
