[143] Frankforter, G. B. A Chemical Study of Astragalus Caryocarpus. Amer. Journ. Pharm., vol. 72, p. 320. 1900. [144] Maisch, J. M. Poisonous Species of Astragalus. Amer. Journ. Pharm., vol. 51, p. 240. 1879.--Fleurot. Chimiques et Pharmaceutiques sur la Racines d'Astragale sans Tiges. Journ. de Chim. Med., vol. 10, p. 656. 1834. [145] Porcher, F. P. Resources of the Southern Fields and Forests, p. 204. 1869. [146] Smith, J. G. Fodder and Forage Plants. U. S. Dept. Agric., Div. Agrost., Bul. 2 (rev. ed.), p. 12. 1900. [147] Holmes, E. M. Notes on Chinese Drugs. Pharm. Journ. and Trans., vol. 21, 3 s., p. 1149. 1891. [148] Hough, W. Environmental Interrelations in Arizona. Amer. Anthropologist, vol. 11, pp. 143, 147. 1898. [149] Barrows, D. P. Ethno-Botany of the Coahuilla Indians of Southern California, p. 67. 1900. [150] Matthews, W. Navajo Names for Plants. Amer. Nat., vol. 20, p. 772. 1886. [151] Givens, A. J. Loco or Crazy Weed. Med. Century, vol. 1. p. 21. 1893.--Compare Hurd, H. M. Amer. Journ. Insanity, vol. 42, p. 178. 1885-86. [152] Rosenthal, D. A. Synopsis Plantarum Diaphoricarum, Erlangen, 1861, p. 1004. Greshoff, M. Beschrijving d. Giftige en Bedwelmeude Planten bij de Vischvangst in Gebrulk, p. 51. 1900. [153] Pott, E. Handb. d. tierisch. Ernährung, vol. 2, p. 113. 1907. =LABORATORY EXPERIMENTS--PHYSIOLOGICAL.= The first point in our investigations was to determine whether the plant exerted any poisonous action and to find some animal which responded regularly to it; then to ascertain if the lack of results of previous investigators was not due to insufficient doses, and later to see if by feeding smaller amounts at repeated intervals symptoms comparable to those described as occurring on the range could not be produced. The animal finally selected was the rabbit. =EXPERIMENTS ON RABBITS.= =ACUTE CASES.= _Experiment No. 1._--On September 8, 1905, an aqueous extract of 333 grams of fresh _Astragalus mollissimus_, made in Hugo, Colo., and shipped preserved in chloroform,[154] killed a rabbit weighing 1,616 grams in one hour and thirty-five minutes, while an extract corresponding to 167 grams merely caused drowsiness and loss of appetite in a rabbit weighing 765 grams. _Experiment No. 2._--On November 29, 1905, a rabbit weighing 1,162.3 grams was fed with a concentrated aqueous extract of 500 grams of fresh _Astragalus mollissimus_, which had been shipped from Hugo, Colo., preserved in chloroform in sealed vessels. This animal died in one hour and ten minutes. The symptoms consisted in dullness, rapid respiration, and signs of pain. At autopsy the stomach and upper part of the small intestines showed hemorrhagic ecchymoses, with dilation of the dural vessels of the brain and cord, with a clot over a portion of the spinal cord.