The filtrate, after treating an active solution of the ash with hydrogen peroxid, proved active, thus showing that zirconium was not entirely responsible for the poisonous action. Yttrium, while not found in the plant, was administered as yttrium chlorid to a rabbit weighing 1,530 grams in 2-gram doses in solution. This animal gained 113.4 grams in five days. Didymium chlorid c. p., in 3-gram doses, was fed to a rabbit weighing 1,020 grams. This rabbit lost 70 grams in four days. The administration of manganese acetate[167] in 2-gram doses was followed by a gain in weight of a rabbit of 42.5 grams, while a dose of 3 grams killed a rabbit weighing 1,077 grams in two hours and thirty minutes. Wohlwill[168] has emphasized the fact that the members of the iron group owe their comparative harmlessness to not being absorbed by the gastro-intestinal tract. No zinc was found in the plant.[169] It is well recognized that potassium salts given hypodermically are decidedly toxic and that ammonium salts given per os will kill, so that the writer considered the possibility of other members of the group being responsible for the injurious action. The fact that the alkaline distillate of the plant proved inactive eliminated the ammonium salts. Cæsium chlorid c. p., 2 grams, was fed in aqueous solution to a rabbit weighing 1,077.2 grams. In six days this animal lost 255 grams in weight, when it died.[170] A second rabbit, weighing 1,020.5 grams, was fed with 2 grams of the same solution and lost 368 grams in twenty-one days. The spectroscopic test, however, failed to show cæsium in the ashed plant. Rubidium chlorid c. p., in 2-gram doses, proved inactive. The platinum chlorid precipitate from the extract of the plant proved inactive. The fact that the filtrate after precipitation of the phosphates by tin and nitric acid and H_{2}S was active excluded the phosphoric acid radical, and the filtrate after treatment with BaCO_{3} and AgO being active excluded the H_{2}SO_{4} and HCl radicals as the toxic body. Fluorine was proved to be absent. A radio-active substance was suspected, but Dr. L. J. Briggs, Physicist of Bureau of Plant Industry, reported that the dried plant showed no special amount of radio-activity.[171]