Arseni Trioxidum, Arsenous Acid, White Arsenic. The U. S. P. Liq. acidi arsenosi is a 1% solution of white arsenic. The well-known Fowler's solution is of the same strength. These preparations are all of similar therapy, and are antiperiodic, antiseptic, and alterative. In doses of 1-30 to 1-15 grain arsenous acid is valuable in neuralgia of the fifth and intercostal nerves, periodic neuralgia, chorea, paralysis agitans, chronic arthritis, malarial cachexia, enlarged lymphatics, obesity due to defective assimilation, diabetes of hepatic origin, albuminuria, eczema, lichen, psoriasis, and other skin lesions.

In general, it may be said that moderate doses of arsenic are indicated when there is defective nutrition with deposits of low or imperfect albuminoid material. Its antiperiodic influence is marked, but it should not be employed in doses of any size where there is irritability of the nerve centers of an acute character. In small doses arsenic is regarded as a vital stimulant, and is used in states of debility, exhaustion, and restlessness, and where burning pain and prostrating diarrhea exist. Small doses are applicable in the degenerative changes of aged persons, bronchitis with burning expector ation, irritative dyspepsia, cirrhosis of the liver, reflex vomiting, some cases of chronic diarrhea, and in skin rashes occasioned by indigestion (1-1000 to 1-100 gr.).