164 Wisconsin Academy of Sciences, Arts, and Letters. 
1840 on that the “fine powder” is again directed to be used in 
1880. 
6. ) Potassium Bica/rbonate or Carbonate as an Ingredient. 
Fowler calls it Sal alkalinum fixum vegetabilis or “salt of fixed 
vegetable alkali” to differentiate it from the fixed mineral alkali 
or sodium carbonate and the volatile alkali or ammonium carbon¬ 
ate. The designation of the U. S. P. 1820 is in accordance with 
the antiphlogistic nomenclature. The alkali used to facilitate the 
solution of the “arsenious acid” varies. According to the U. S. P. 
1820 and the New York edition of 1830 it is Potassae subcaxbonas 
or “Subcarbonate of potass.”, which according to the 1820 edition 
is the “Impure subcarbonate of potass.” or “Pearl ash”. The 
Philadelphia edition of 1830 designates that “Purest Carbonate of 
Potassa” or Potassae Carbonas Purissimup be used, which is to be 
prepared from potassium bitartrate by ignition and lixiviation. (p. 
172, not that in the Materia Medica list p. 20.) The editions of 
1840, 1850 and 1860 direct that a “pure” carbonate be used. Ac¬ 
cording to the 1840 edition this is prepared from the bitartrate, 
according to the 1850 and 1860 editions, by heating the bicarbonate. 
From 1870 the bicarbonate is directed to be used in the formula. 
Upon heating, as directed, the pure bicarbonate is changed to the 
pure carbonate. 
7. ) Ratio of Ingredients. Not only the ratio, but the exact quan¬ 
tities, viz. 64 grains of both the acid and alkaline ingredients, are 
the same in all editions of the U. S. P. up to 1870 inclusive, as they 
are in the original formula of Fowler. This would seem quite 
rational but for two considerations, viz.: 
1. The purity of the potassium carbonate originally employed, 
no doubt, varied greatly. (For details of this see No. 6.) 
2. In the 1870 edition, bicarbonate of potassium was substituted 
for carbonate, but the amounts (64 grains of each) remained the 
same. 
Hence the ratio of acid (anhydride) to alkali (carbonate or bi¬ 
carbonate) fluctuated greatly in the several revisions from 1820 to 
1870 inclusive. Although the U. S. P. 1880 is a relatively modern 
treatise, as compared with its immediate precursors, the ratio was 
not changed in 1880, but the change was made in 1890, so that 
since that date the alkalinity of Fowler’s Solution was once more 
what it may be supposed to have been originally, provided, how¬ 
ever, that the “alkaline vegetable salt” of Fowler’s formula was 
