An _Astragalus mollissimus_ (Kit Carson County, Colo., December, 1906), which was also reported by the Bureau of Chemistry as containing no barium, was extracted with water, and a dose corresponding to an extract of 200 grams of the dried plant was fed in one dose without any serious result. The same amount of the dried plant was also similarly digested with pepsin and pancreatin and fed in two doses, but without the production of any symptoms, the rabbit gaining 60 grams in four days. Of the _Aragallus lamberti_ (Hugo, Colo., June, 1907), with an ash content of 12.44 per cent, 250 grams were ashed and the ash treated with acetic acid and, after evaporating off the acetic acid, was extracted with water and the ash digested with pepsin and pancreatin. The aqueous extract and the digestion products of the ash were then fed after concentration, but without any serious effects to the animal, indicating that in this plant the barium is in a form insoluble in water and in the ashing is further changed so that it can not now be made soluble by digestion--an opposite result to the experiment in which the barium was first rendered soluble by digestion and the digestion products ashed, suggesting a possibility that plants might be found in which the barium is not extracted by digestion, at present a hypothesis. Of dried _Astragalus decumbens_ (Ephraim, Utah, 1907), which was reported by the Bureau of Chemistry to contain no barium, 200 grams also failed to produce symptoms in rabbits by our test. A solution containing 50 milligrams of barium acetate (crystallized) was mixed with an aqueous extract of 200 grams of the dried _Aragallus lamberti_ which had proved inactive pharmacologically, but a precipitate formed (BaSO_{4}?) and the extract still remained inactive, suggesting that the question of toxicity depended not only upon the presence of barium, but also whether other agents, such as sulphates, etc., might not be present in sufficient amount to render the barium insoluble; that is, pharmacologically inactive. This _Aragallus lamberti_ yielded an ash content of 37.3 per cent, and the SO_{3} group was estimated at 0.27 per cent of the ash, while a corresponding lot which was obtained two years later from the same area yielded an ash content of 12.44 per cent and a SO_{3} content of 0.24 per cent of the ash. It may be urged that the full lethal dose of the barium was not always found in the plant, yet it must be remembered that the toxic action was the resultant of the action of the total constituents and that if the barium was removed the extract was practically harmless.