[171] Acqua, C. Sull'acc.u.mulo di Sostanze Radioattive nei Vegetali. Atti della Reale Accad. dei Lincei, 5 s, vol. 16, sem. 2, p. 357. 1907.

[172] Compare Meltzer, S. J. Toxicity of Magnesium Nitrate When Given by Mouth. Science, vol. 26, p. 473. 1907.

[173] Burga.s.si, G. Modificaz. del Ricambio per Azione dello Stronzio. Archiv. di Farmacol., vol. 6, p. 551. 1907.

[174] Noyes, A. A., and Bray, W. C. System of Qualitative a.n.a.lysis for the Common Elements. Journ. Amer. Chem. Soc., vol. 29, pp. 168, 172, and 191. 1907.

NOTE.--Barium sulphate is nontoxic on account of its insolubility. Orfila fed 16-24 grams to dogs without causing any disturbance. Bary, A. Beitr. z. Baryumwirkung. Dorpat, 1888, p. 25.

[175] Sprengel, C. Von den Substanzen der Ackerbrume und des Untergrundes, Journ. f. Techn. u. OEkon. Chem., vol. 3, p.

313. 1828.

[176] Eckard, G. E. Baryt, ein Bestandtheil der Asche des Buchenholzes. Annal. der Chem. u. Pharm., n. s., vol. 23, p.

294. 1856.

[177] Forchhammer, J. G. Ueber den Einfluss des Kochsalzes auf die Bildung der Mineralien. Annal. d. Physik u. Chemie, vol. 5, p. 91. 1905.--Lutterkorth, H. Kohlensaurer Baryt, ein Bestandtheil des Sandsteines in der Gegend von Gottingen.

Annal. d. Chem. u. Pharm., n. s., vol. 23, p. 296. 1856.

[178] Dworzak, H. Baryt unter den Aschenbestandtheilen des.

aegyptischen Weizen. Landw. Versuchs.-Stat., vol. 17, p. 398.

1874.

[179] Knop, W. a.n.a.lysen von Nilabsatz. Landw.

Versuchs.-Stat., vol. 17, p. 65. 1874.--Compare also Demoussy, E., Absorption par les Plantes de Quelques Sels Solubles, These, Paris, 1899.--Knop, W., Einige neue Resultate der Untersuchung uber die Ernahrung der Pflanze, Ber. u. Verhandl. d. konigl. sachs. Gesells. d. Wissens. zu Leipzig, Math. Phys. Cl., vol. 29, p. 113, 1877.--Suzuki, U., Can Strontium and Barium Replace Calcium in Phaenogams? Bul.

Coll. Agric. Tokio Imp. Univ., vol. 4, p. 69, 1900-1902.

[180] Hornberger, R. Ueber d. Vorkommen d. Baryums in d.

Pflanze und im Boden. Landw. Versuchs.-Stat., vol. 51, p.

473. 1899.

[181] Roscoe, H. E., and Schorlemmer, C. Treatise on Chemistry, vol. 2, p. 455. 1897.

[182] Hillebrand, W. F. a.n.a.lysis of Silicate and Carbonate Rocks. Dept. Interior, U. S. Geol. Survey, Bul. 305, p. 18.

1907.

[183] This report came from the Plant a.n.a.lysis Laboratory of the Bureau of Chemistry, a different one from that which later controlled the writer's tests quant.i.tatively and qualitatively. In other words, the conclusions of the writer as to the presence of barium were controlled by three separate individuals.

[184] Kobert, R. Kann ein in einem Pflanzenpulver gefundener abnorm hoher Barytgehalt erklart werden durch direkte Aufnahme von Baryumsalze durch die lebende Pflanze aus dem Boden? Chem. Zeit., vol. 10, p. 491. 1899.

NOTE.--The writer has also found barium in entirely different botanical families from the loco-weed, and it is hoped a report can shortly be made of some of these.

NOTE.--The first sample of ash a.n.a.lyzed by the Bureau of Chemistry had 0.21 per cent Fe_{2}O_{3}, 0.92 per cent Al_{2}O_{3}, 0.98 per cent CaO, 0.37 per cent MgO, 5.50 per cent SiO_{2}. The second lot was only examined for certain const.i.tuents, and gave K_{2}O, 2.25 per cent; CaO, 1.20 per cent; MgO, 0.41 per cent; P_{2}O_{5}, 0.52 per cent; and SO_{3}, 0.24 per cent.

=TOTAL ASH DETERMINATIONS OF LOCO PLANTS.=

The reports of the ash a.n.a.lyses of the loco plants show marked variations in the total amount of the ash. Thus, from _Aragallus lamberti_ Dyrenforth obtained 4.32 per cent and O'Brine 13.52 per cent of ash. The Bureau of Chemistry a.n.a.lyzed two different samples of this dried plant and reported in one case 11.15 per cent and in the second 11.64 per cent of ash. O'Brine[185] obtained 13.52 per cent of ash from the same species. The writer's a.n.a.lysis[186] gave in one sample of _Aragallus lamberti_, collected at Hugo, Colo., in 1907, 18.8 per cent of ash; a second lot (1907), 12.44 per cent; a third (1906), 11 per cent, and a fourth (May, 1905) gave 37.3 per cent of ash.[187] One lot from Woodland Park, Colo. (October, 1906), gave 6.4 per cent. One lot from Hugo, Colo. (October, 1907), yielded 9.6 per cent.

In the case of _Astragalus mollissimus_, Wentz obtained 6.76 per cent, Sayre 12.01 per cent, Kennedy 20 per cent, O'Brine 12.15 per cent, while the sample a.n.a.lyzed by the Bureau of Chemistry gave 18.4 per cent of ash. One sample from Kit Carson County, Colo. (December, 1906), which proved inactive physiologically, gave an ash content of 6.9 per cent. A sample of _Astragalus missouriensis_ collected at Hugo, Colo., June, 1907, yielded an ash content of 21.8 per cent, and an _Astragalus missouriensis_ collected at Pierre, S. Dak., September, 1907, yielded 27 per cent. An _Astragalus nitidus_ from Custer, S. Dak. (July, 1907), gave 5.2 per cent ash, while an _Astragalus nitidus_ collected at Woodland Park, Colo., in October, 1906, yielded 7.8 per cent, and another specimen of _Astragalus nitidus_ also collected at Woodland Park, Colo., in October, 1907, gave 12.2 per cent. An _Astragalus drummondii_ from Custer, S. Dak. (July, 1907), gave 5.9 per cent.

_Astragalus pectinatus_ (Hugo, June, 1907) yielded 6.1 per cent. A fresh (undried) specimen of _Astragalus mollissimus_ (unknown origin, November, 1907) yielded 3.8 per cent of ash. One sample of _Astragalus dec.u.mbens_ (Ephraim, Utah, August, 1907) gave 21.8 per cent of ash.

These determinations must necessarily be only approximate, as the plants were collected by different persons who exercised different degrees of care in freeing them from adherent soil, and possibly in drying the plants, so that the main value of these figures is their aid in determining the amount of barium present.

FOOTNOTES:

[185] The detailed a.n.a.lysis of O'Brine can be found on page 32 of this report.

[186] All ash and barium determinations were made from the dried plants save when otherwise specified.

[187] Evidently these plants must have been imperfectly freed from soil.

=BARIUM DETERMINATIONS IN THE ASH OF LOCO PLANTS.=

Attention has been called to the fact that in ashing plants containing barium a part at least of this barium is converted into the insoluble sulphate and a part into the carbonate, so that the characteristic pharmacological action of the ash will depend not upon the total barium present, but upon the form in which it occurs--little action if much BaSO_{4}, and more complete if more BaCO_{3} results. A further difficulty in the recognition of barium in plants is due to the fact that certain inorganic salts interfere with the precipitation by H_{2}SO_{4}.

A specimen of _Aragallus lamberti_ (Hugo, summer of 1907) with 12.44 per cent of ash was examined for its barium content by Hillebrand's method.[188] The method was as follows:

Two grams of the ash were first fused with sodium carbonate and the fused ma.s.s washed with water containing sodium carbonate. The residue was washed into a beaker and treated with a few drops of sulphuric acid.

The residue now remaining was filtered and after ignition was treated with hydrofluoric and sulphuric acids. After evaporating off these acids, the residue was treated with sulphuric acid water, filtered, and then fused with sodium carbonate. After extracting with sodium carbonate water, the residue was dissolved in just enough hydrochloric acid and precipitated with sulphuric acid. The precipitate was dissolved in concentrated sulphuric acid and reprecipitated by water and weighed as BaSO_{4}.[189] So far as the writer can ascertain, there have been no control experiments made for this method to determine the experimental error.

Of the above ash, 1.998 grams gave 5.2 milligrams of BaSO_{4}, which would correspond to 75.75 milligrams of barium acetate crystals-- Ba(C_{2}H_{3}O_{2})_{2}+H_{2}O--in 200 grams of the dried plant. The residue by the Hillebrand method after weighing was tested with the spectroscope and gave a bright spectrum for barium. The same ash was a.n.a.lyzed by the Bureau of Chemistry, using a shorter method, and they reported 2.7 milligrams of barium sulphate in 1.1217 grams of ash. A second sample collected earlier in the summer, with an ash content of 18.6 per cent, was shown to yield barium corresponding to 3.4 milligrams of BaSO_{4} in 2.5 grams of the ash.[190]

One lot of _Aragallus lamberti_ collected at Hugo, Colo., in May, 1905, and which gave an ash content of 37.3 per cent, was found to yield 3 milligrams of BaSO_{4} from 1.998 grams of ash, or 173.88 milligrams of Ba(C_{2}H_{3}O_{2})_{2}+H_{2}O in 200 grams of the dried plant, but this ash also contained 0.27 per cent of SO_{3}. The Bureau of Chemistry reported the barium to correspond to 2.9 milligrams of BaSO_{4} in 2.45 grams of the ash.

The _Astragalus missouriensis_ (Hugo, June, 1907), with an ash content of 21.8 per cent, gave 3 milligrams of BaSO_{4} in 2.01 grams of ash, or 76.58 milligrams of Ba(C_{2}H_{3}O_{2})_{2}+H_{2}O in 200 grams of the dried plant. The residue after weighing was tested spectroscopically and gave a bright barium spectrum.

The _Astragalus drummondii_ from Custer, S. Dak. (1906), _Astragalus mollissimus_ from Kit Carson County, Colo. (December, 1906), and _Astragalus nitidus_ from Woodland Park, Colo. (October, 1907), were reported by the Bureau of Chemistry to contain no barium.

The ash of the _Astragalus pectinatus_ (Hugo, June, 1907) was reported by the Bureau of Chemistry to show no barium on spectroscopic examination.

Two grams of active loco plant ash yielded from 5 to 6 milligrams of BaSO_{4}, but it can be easily seen that in multiplying this amount to correspond to 200 grams of the dried plant errors would be likely to arise, so that the whole amount of barium would not necessarily be accounted for.

FOOTNOTES:

[188] Hillebrand, W. F. a.n.a.lysis of Silicate and Carbonate Rocks. U. S. Geol. Surv. Bul. 305, p. 116. 1907. See also Folin, O., On the Reduction of Barium Sulphate in Ordinary Gravimetric Determinations, in Journ. Biol. Chem., vol. 3, p.

81. 1907.