218 MEDICINAL AND POISONOUS PLANTS 



is to rub thoroughly the affected part every few hours with 

 a concentrated sohition of sugar of lead in alcohol of 50-75% 

 strength. As alkalis convert the oil into a harmless soap, 



Fig. 210. — Poison-ivy (Rhus Toxicodendron, Sumac Family, Anacardiacece) . 

 a, spray showing air-roots and leaves, i; b, fruit, 4. (Chesnut.) — 

 Climbing or trailing shrub becoming 6-15 m. long, sometimes erect 

 and bushj': loaves .smooth or downy; flowers green; fruit smooth, waxy, 

 grayish. Native home. North America. 



relief is also found by the application of a strong solution of 

 cooking soda, as soon as possible after the poisoning. 



A fixed oil similar to cardol has been found to be tlie cause 

 of poisoning by two of our native orchids known as lady- 



