61 



The oonuiioii Mullein (Verbaseuni Tliapsns L.) is irritatiiiiL;- to the skin 

 because of its wooly hairs, the leaves being often applied to the throat for 

 the rubefacient eil'ect. Its action is so evidently mechanical that no ex- 

 periments were tried. 



The flo-\vers of the Catalpa (Catalpa Catalpa (L.) Karst.) are said to be 

 irritant to many persons, causing "reddening of the skin." In experiments 

 tried and often repeated upon twenty subjects, no such resvUts were ob- 

 tained, although in some cases the flowers were rubbed upon the cheeks 

 vigorously, the jtiice being allowed to remain for several hours. I have 

 also been unable to find any definite record confirming the statement. 



Indian Tobacco (Lobelia infhita 1>.), "when applied to the skin is cap- 

 able of producing irritation." Experiments upon fifteen persons failed to 

 confirm this alleged fact. 



The Cockleburs (Xanthium) are irritant on account of dust and hairs 

 with wliich they are covered and not because of a toxic principle. No 

 experiments were made with this form. 



Of the Goldenrods (Solidago) the statement is made that the "whole 

 family is to be regarded Avith suspicion bj^ persons with sensitive skin. 

 Solidago odora Ait. possesses a volatile oil that is an irritant and rube- 

 facient." T~\venty-two persons were subjected to tests Avith various 

 species of goldenrod, but no results were obtained to indicate the presence 

 of a toxic element in our native species. Solidago odora was used with 

 five subjects without resulting inflammation. It is extremely doubtful 

 whether any skin irritation is produced by species of this genus save 

 through mechanical causes. 



The common Fleabane (Leptilon Canadense (L.) Brit.) it is said "con- 

 tains a volatile oil possessing irritating (lualities to those handling." 

 Eleven persons were used in experiments upon this form. Two had skin 

 irritations following the free handling of this plant. Five others were 

 poisoned by the "rubbing" process. Four were unaffected under either 

 procedure. In this case also, the maximum point of the toxic principle 

 seemed to be the flowering season. 



Common Beggar Ticks or Spanish Needles (Bidens frondosa L.), it is 

 alleged, "causes itching on handling." Out of fifteen persons this was 

 found to be true in three cases, one of them being peculiarly susceptible to 

 skin irritation, as mentioned in a preceding paragraph. P'our others were 

 affected by the "rubbing" process. The remaining eight reported no 

 change in skin sensations. 



