THE EUPHORBIA GROUP 



2157 



the eyelids, face, and neck, but it may also occur on the hands and 

 feet. Left to itself, the eruption remains well marked for some four 

 to five days, and then gradually subsides, serum discharges from 

 the vesicles, and after some desquamation the affected area returns 

 to normal after some ten to twenty days. 



Treatment.— Wash the affected parts thoroughly with soap and 

 water, and then clean with a lotion of alcohol and ether, and finally 

 apply the ordinary lead and opium lotion or a solution of acetate 

 of aluminium. In mild cases calamine lotion is very efficacious. 



Prophylaxis. — Remove the poisonous ivy. This can only be 

 performed by digging up the roots. 



The Lacquer Poison. — Rhus vernicifera De Candolle is the 

 lacquer or varnish-tree of Japan. Lacquer poisoning has, however, 

 been described on p. 191, and need not be repeated here. 



The Parsnips. — In the same group with the poisonous ivies 

 come the parsnips, of which Pastinaca sativa Thomas, the common 

 parsnip, and Heracleum lanatum Mich [H. giganteum Fischer) , 

 the cow parsnip, cause symptoms analogous to those described above. 

 The treatment is similar. 



II. THE EUPHORBIA GROUP. 



jThe Euphorbia group is placed in the non-volatile division, 

 because, although it is definitely known that the milky juice if it 

 touches the skin caus,es dermatitis, it is not so evident that any 

 volatile principle contained therein can act at a distance, though 

 it is possible that it does so. The subject requires further investi- 

 gation. 



In this group the poisonous principle is contained in a thick milky 

 juice, the latex, which is contained in special lactiferous cells. 



Hippomane mancinella Linnaeus (Euphorbiacese) , which is the 

 celebrated manchineel-tree of the Grenadine Islands, is also found 

 in Colombia, South America, where it is called ' Pedro Fernandes ' 

 or ' mansanillo.' It causes very severe pruriginous and painful 

 urticaria in people who rest under its shade. According to Martinez 

 Santa-Maria, this eruption usually disappears in about twenty-four 

 hours, but occasionally it may last for two or three days, or even 

 longer. 



The Euphorbias.-^ All euphorbias possess more or less irritating 

 juices, which, if rubbed into the skin, cause inflammation. The 

 thick milky latex is acid, and contains a dense oil, which is very 

 irritating. As an example of this group may be mentioned E. 

 pilulifera Linnaeus or E. resinijer Bergmann. The former is common 

 in many parts of the tropics, and the latter occurs in North Africa. 



Hura crepitans Linnaeus, of Central America and the West Indies, 

 and H. hrasiliensis, of Brazil, possess a milky juice, said by Piffard 

 to cause severe swelling of the face, while the latter was employed in 

 Brazil as a treatment for leprosy. . 



