There are differences of opinion as to its value in lupus: Mr. Hunt, for instance, and Mr. Milton esteeming it highly, and recommending its continuous administration for months or years; but others, and, indeed, the majority of observers, recording no definite result from it. I have never been able to satisfy myself that it controlled the disease, although the local caustic effect is, as already mentioned, highly valuable.

Ichthyosis is congenital, and, though it may be relieved, is scarcely curable; the evidence as to the value of arsenic in its treatment is but slight.