62 



Ordinary Dog-fennel (Anthemis Cotula L.) was found to affect seven 

 out of twenty persons as the result of free handling. Seven others were 

 poisoned following rubbing and six were unaffected. The statement that 

 the "juice is sufficiently acrid to poison sensitive skins" seems borne out 

 by the results. 



Arctium Lappa L., or Burdock, is a skin irritant through mechanical 

 action, the dry burs producing the most serious inflammations, although 

 the leaves, because of their roughness, are also irritant. The resultant 

 inflammations after handling were so evidently traumatic that no experi- 

 ments were made. 



It is claimed that the ordinary cultivated Nasturtium (Tropoeolum 

 majus L.) "in exceptional cases produces dermatitis." Repeated experi- 

 ments with all parts of the plant upon twenty-two subjects failed to give 

 any verification to this statement. After extended inquiry I have failed 

 to find any person who knew of any case of poisoning due to this plant. 



The Oleander (Nerium Oleander L.), so largely cultivated, is probably 

 under certain conditions poisonous. "An acrid principle in the leaves 

 affects some people as Rhus." Loudon contents himself with saying "it is 

 poisonous." Figuier calls it a "formidable poison." Van Hasselt says 

 it causes "an internal burning and itching when rubbed in the skin." 

 Five persons were experimented upon in the manner indicated by Van 

 Hasselt and all suffered a greater or less irritation accompanied by burn- 

 ing and itching. It is probable that the thick-walled epidermal cells pre- 

 vent poisoning in the ordinarj- handling of the plant. The most painful 

 case of skin poison I experienced was from the oleander. It was, how- 

 ever, of short duration and in none of the cases indicated the persistence 

 or tendency to recurrence of Rhus. 



Of the cvdtivated Primroses, one. I'rimula obconica Hance, is occa- 

 sional irritant. The cause, however, is plaiulj^ enough traumatic. No 

 experiments were undertaken, although I know of one case in Avhich the 

 handling of this species is invarial)Iy followed by an annoying skin irri- 

 tation. 



The results of these experiments may be summarized as follows: 



1. The great majority of the plants included in the preceding list are 

 harmless under ordinary handling. 



2. Some of these may act as skin irritants as the result of prolonged 

 application or unusually rough handling. Careful washing after handling 

 anj' of the forms will reduce the danger to a minimum. 



