May, 1921] 
MCNAIR TRANSMISSION OF RHUS POISON 
249 
{d) Dermatitis occurs only on the area of skin to which the poisonous sap 
has been applied; a general irritation as by volatile irritants is not produced. 
{e) It does not diffuse rapidly in the skin, as is shown microscopically in 
sections of diseased skin. 
(/) The period of latency is too long. 
2. Portions of the plant which do not cause dermatitis are: the pollen, 
the trichomes, the epidermis, the cork cells, and the xylem. 
3. The poison is confined exclusively to the resinous sap. 
4. Leaves decrease in malignancy in drying from the loss of fluidity of 
the sap and from the oxidation of the poison. 
5. Poisoning without contact with the plant may occur from the smoke 
of the burning plant or by contact with substances that have the poisonous 
sap on them, such as clothing, shoes, cordwood, tools, the hair of animals, etc. 
6. Dermatitis caused by other plants is sometimes attributed to Rhus. 
There is difficulty in distinguishing eczema from Rhus dermatitis. 
LITERATURE CITED 
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Chem. 2: 547. 1906-1907. 
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3. Barnes, E. The poison ivy. Med. Rec. 30: 157-158. 1886. 
4. Bennett, J. J. Plantae javanicae rariores descriptae iconibusque illustratae. Ft. i, 
p. 60. London, 1838. 
5. Bibb, L. B. Experimental Rhus poisoning. Texas Med. Jour. 30: 162-163. I9I4~ 
1915- 
6. Bogue, E. E. Garden and Forest. 1894. 
7. Burrill, T. J. Some vegetable poisons. Amer. Monthly Micr. Jour. 3: 192-196. 1882. 
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10. Cantrell, J. A. Unusual mode of transmission in a case of dermatitis venenata^ 
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12. Du Fresnoy, de V. Des caracteres, du traitement et de la cure des dartres et de la 
paralysie, etc., par I'usage du Rhus radicans, Vol. i. Paris, an VIL 
13. Fontana, F, Trattato de veleno della vipera de velem American i: 148; 3: 114-117. 
Naples, .1787. Eng. transl. by Joseph Skinner. 2nd ed. 2: 181-184. London, 1795. 
14. Frost, J. Remarks on the erysipelatous inflammation produced by the juice of Rhus 
Toxicodendron. London Med. Physical Jour. 55: 116. 1826. 
15. Frost, L. C. The bacterial etiology of poison oak dermatitis (Rhus poisoning). Med. 
Rec. 90: 1121-1123. 1916. 
16. Hadden, A. Poison ivy or Rhus Toxicodendron. Med. Review of Reviews 12: 764. 
1906. 
17. Hubbard, S. Rhus poisoning. Med. Brief 32: 884. 1904. 
18. Hunt, J. H. Rhus poisoning. Brooklyn Med. Jour. 11: 392-406. 1897. 
19. Hurlbut, E. T. M. Antidote to poison oak. Calif. Homeopath 7: 235-239. 1869. 
20. Ingenhousz, J. Experiments upon vegetables, discovering their great power of puri- 
fying common air in the sunshine, and of injuring it in the shade and at night. 
London, 1779. 
21. Inui, T. Ueber den Gummiharz-Gang des Lackbaumes und seiner verwandten Arten 
(Abstr.). Bot. Centralbl. 83: 352. 1900. 
