Part 18

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.

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.

Power and Cambier, Sayre, and Kennedy had previously called attention to the abundance of calcium in the plant, and the writer's investigations confirm this. Pharmacologists are averse to believing calcium given per os poisonous. The writer has, however, fed 5 grams of the acetate of calcium in solution to a rabbit weighing 652 grams. This animal died in two hours, with marked irritation of the stomach, the result being due to the so-called "salt action." Much larger amounts were fed in divided doses, but without injury. Calcium phosphate and calcium sulphate in 2-gram doses proved harmless to a rabbit weighing about 1,400 grams. Three grams of magnesium acetate were fed in solution for five successive days to a rabbit weighing 1,417 grams, but without apparent effect.

Strontium acetate c. p., in 2-gram doses, likewise caused no disturbance. No strontium in any amount recognizable by chemical tests was proved in the plant. So that by a process of exclusion the writer was forced to think of barium as the main cause of the trouble.

The writer noted that if the ashed plant was extracted with H{2}SO{4} water and this extract freed from sulphuric acid with PbCO{3} and H{2}S the solution proved inactive to rabbits and also that after this extraction the acetic acid extract of the ash failed to kill. In other words, the sulphate of our body was insoluble in water. At times in passing H{2}S into active solutions of the ashed plant freed from the acetic acid by evaporation the filtrate and likewise the precipitate were inactive. Noyes and Bray have noted that if H{2}S is passed into certain solutions in the presence of an oxydizing agent, such as ferric iron, H{2}SO{4} would be formed, which would throw any barium out of solution.

In one blood-pressure record made with a dog (vagi nerves cut), a rise in blood pressure (a characteristic physiological action of barium) was seen to follow the intravenous injection of the aqueous extract of the plant, in spite of its normal acid reaction.

Accidentally the writer found that Sprengel had reported the presence of barium in Astragalus exscapus, a closely allied plant. Barium has also been found in the vegetable world by Scheele in 1788, and later by Eckard, who found it in beech, while Forchhammer proved it in birch, and Lutterkorth found it in the soil of the same area in which Eckard worked. Dworzak noted the occurrence of traces of this element in wheat grown along the Nile, and Knop found it in the soil. Doctor Balfour, of Khartum, Egypt, informed the writer that he knew of no cases in which this barium in wheat had produced poisoning. Hornberger found barium both in the red beech grown in Germany and in the soil on which these trees grew. It has also been claimed that various marine plants may take up barium from the sea.

Hillebrand has called attention to the fact that the igneous rocks of the Rocky Mountains showed a higher percentage of barium than rock from other portions of the United States, so that under these conditions one might expect the presence of barium in plants growing in this region. A sample of Aragallus lamberti and one of Astragalus mollissimus were sent to the Bureau of Chemistry for spectroscopic examination for various elements and they reported traces of barium in each.

With these arguments the writer felt sure of the presence of barium, and the matter was discussed with Dr. E. C. Sullivan, of the United States Geological Survey, and he kindly corroborated the conclusions reached as to the presence of barium, controlling its presence by means of the spectroscope, and estimated it roughly as 0.1 per cent BaO in the ash of a sample of Aragallus lamberti (6.3 milligrams BaSO_{4} in 4 grams ash). This determination was made by Hillebrand's method.

Kobert has anticipated this result, saying that "all plants are in the position occasionally to take up barium combinations from the soil," and "the plants which thus contain barium may act injuriously to men and animals."

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FOOTNOTES:

Swain, R. E., and Harkins, W. D. Arsenic in Vegetation Exposed to Smelter Smoke. Journ. Amer. Chem. Soc., vol. 30, p. 915. 1908.--Harkins, W. D., and Swain, R. E. The Chronic Arsenical Poisoning of Herbivorous Animals. Journ. Amer. Chem. Soc., vol. 30, p. 928, 1908.

A similar extract was sent to the Bureau of Chemistry, and that Bureau also reported an absence of the elements of the H_{2}S group.

Bachem, C. Pharmakologisches über einige Edelerden. Arch. Internat. de Pharmacodyn., vol. 17, p. 363. 1907.

Sestini, F. Esper. di Vegetaz. del Frumento con Sostituz. della Glucina alla Magnesia. Staz. Sper. Agrar. Ital., vol. 20, p. 256. 1891.--Di alcuni Elementi Chimici Rari a Trovarsi nei Vegetabili. Staz. Sper. Agrar. Ital., vol. 15, p. 290. 1888.

NOTE.--The ammonium sulphid precipitate was very small if the phosphates were first removed with tin and nitric acid.

Böhm, C. R. Darstellung d. seltenen Erden, vol. 1, p. 40. 1905.

Wait, C. E. Occurrence of Titanium. Journ. Amer. Chem. Soc., vol. 18, p. 402. 1896.

NOTE.--There seem to be no records of any study of the pharmacological action of titanium.

Compare Jaksch, R. v. Ueber Mangantoxikosen und Manganophobie. Münch. Med. Woch., p. 969. 1907.

Wohlwill, F. Ueber d. Wirkung d. Metalle d. Nickelgruppe. Arch. f. Exper. Path., vol. 56, p. 409. 1907.

Laband, L. Zur Verbreitung des Zinkes im Pflanzenreiche. Zeits. f. Untersuch. d. Nahrungs u. Genussmittel, vol. 4, p. 489. 1901.

Cæsium occurs in various plants and the possibility of poisoning by this element must be considered. It is hoped that the writer may be able to undertake a more thorough pharmacological study of this element.

Acqua, C. Sull'accumulo di Sostanze Radioattive nei Vegetali. Atti della Reale Accad. dei Lincei, 5 s, vol. 16, sem. 2, p. 357. 1907.