MOUNTAIN LAUREL, A POISONOUS PLANT. 25 



sheep if suddenly turned into a laurel area may eat it at any time. 

 As the leaves are tasteless and of a tough, leathery consistency, it is 

 very evident why animals will not eat the plant under ordinary con- 

 ditions. 



A good illustration of actual poisoning is given by Rusby a where 

 out of a flock of 1,000 sheep which escaped into a laurel area, at least 

 27 showed symptoms of poisoning. Those affected were mainly the 

 young ones. In these cases the tracks on the snow around the bushes 

 and the presence of leaves in the stomach showed conclusively the 

 cause of the trouble. Halsted h reported poisoning in cows after 

 eating laurel wreaths which had been thrown from a cemetery into 

 their pasture. A striking case occurred in the National Zoological 

 Park, Washington, D. C., where six Angora goats were poisoned by 

 laurel thrown to them by visitors; later, a Diana monkey died with 

 typical symptoms after eating the leaves held to it by a visitor. The 

 leaves of the plant were found in the monkey's stomach. The post- 

 mortem examination in this case was negative. Since these poison- 

 ings occurred visitors have been prohibited from carrying laurel into 

 the park. 



Barton in 1802 G called attention to the fact that the honey made 

 from Kalmia angustifolia- was poisonous to man, and while no direct 

 proof d has been published that honey made from K. latifolia is 

 poisonous it is perfectly logical to suppose that it is, as Plugge found 

 that honey made from Rhododendron ponticum? a closely related 

 plant, gave the same chemical and physiological tests on frogs and 

 mice which he considers characteristic of its active principle, androme- 

 dotoxin. Rhododendron ponticum is the plant which is supposed to 

 have yielded the honey which poisoned Xenophon's f army. 



Under these circumstances the Secretary of Agriculture advised 

 against raising bees in the neighborhood of mountain laurel. An 

 unpublished report is on file at this office of investigations in which 

 extracts of mountain laurel were mixed with honey and fed to bees. 



a Rusby, H. H. The Poisonous Properties of Mountain Laurel. Drug. Cir. 

 and Chein. Gaz., vol. 46, p. 27, 1902. 



6 Halsted, B. D. Eighth Annual Report of the. New Jersey Agricultural 

 College Experiment Station for 1895, p. 355, 1896. 



c Barton, B. S. Some Account of the Poisonous and Injurious Honey of 

 North America. Amer. Phil. Soc. Trans., 1802, vol. 5, p. 59. 



d American Bee Journal, 1896, pp. 92, 146, 246, 262.— Root, A. I. A B C of Bee 

 Culture, p. 249. — Honey from Mountain Laurel.. American Bee Journal, vol. 

 35, p. 825, 1895. 



e Plugge, P. C. Giftiger Honig von Rhododendron ponticum. Arch. d. Pharm., 

 vol. 229, p. 554, 1891.— Thresh, J. C. Notes on Trebizonde Honey. Pharm. 

 Jour, and Trans., 1887-88, vol. 18, pp. 397, 404. 



f Pliny. Nat. Hist. (Translated by Bostock and Riley), vol. 4, p. 341.— Ab- 

 bott, K. E. Letter, in Proc. Zoolog. Soc. London, pt. 2, p. 50, 1834. 



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