152 Wisconsin Academy of Sciences, Arts, and Letters. 
turned to the title Liquor Arsenicalis 41 and has maintained it 
throughout its revisions; the title of the London Pharmacopoeia of 
1851, viz. Liquor Potassae Arsenitis being used as a synonym. 
If the official title is to be justified because we really know little 
about the exact chemistry of the solution, this excuse or line of 
reasoning will not hold when we study the English practice as to 
the designation of the principal ingredient of the solution. In the 
1809 London Pharmacopoeia it was Arsenici Oxidum Sublimatum, 
hence in accordance with the dualistie nomenclature. Yet in 1824 
it was changed back to Arsenicum album sublimatum. In 1851 it 
became Acidum Arseniosum, again in accordance with the dualistie 
nomenclature. But whereas the designation of 1809, viz. Arsenici 
oxtidum, is indicative of a base, that of 1851, Acidum Arseniosum, 
is plainly indicative of an acid. It is possibly because of this that 
the phrase (Acidum metallicum sublimation praeparatum) is added 
in parenthesis. Whereas the element is still pronounced metallic 
in character, its oxide is now, not a base, but an acid. 
A peculiar incongruity in spelling is found in the words arseni- 
ous and arsenite. The ending ous is that of the acid with lower 
oxygen content, and becomes ite for the salts thereof. The ending 
ic is that of acids of higher oxygen content and becomes ate for its 
salts. Hence arsenic should yield: 
A. ) arsenous acid, and its salts should be arsenites; also 
B. ) arsenic acid, and its salts should be arsenates. 
However the former acid is commonly spelled arsenious acid 
(P. L. 1851; B. P. 1864, 1885, 1898, 1914.). Hence the salt should 
be arseniite, but almost invariably it is spelled without the second 
i i j, > > 42 
The English pharmacopoeias are not the only offenders in this 
direction. Koscoe and Schorlemmer, in their “Treatise on Chem¬ 
istry”, vol. II, p. 1246 (1911) still use arsenious acid and arsenites. 
Our own Pharmacopoeias, after having clung to arsenious acid 
(Latin, Acidum Arseniosum) from 1820 to 1880 inclusive, in 1890 
changed its spelling to Arsenous acid (Latin, Acidum Arsenosum), 
only to be changed in the subsequent editions to Arsenic Trioxide 
(Latin, Arseni Trioxidum ). 
41 “This appelation is certainly very objectionable, as it conveys an erroneous 
idea of the preparation, even admitting that the term arsenic may be used to 
designate the white oxide: it should have been Liquor Arsenialis Potassae or 
Liquor alcalinus Oxidi Arsenici”, A. T. Thomson, The London Dispensatory, 
4th edition, 1826. 
42 The single exception observed thus far is found in the Norwegian Pharma¬ 
copoeia of 1913: Liquor Arseniitis Kalici. 
