340 QUALITIES 



there are often very contradictory, or opposite 

 properties in them. Thus, the Jatropha manihot, 

 which has been mentioned as forming the bread 

 of the natives of central America, not only belongs 

 to an exceedingly, poisonous family (Euphorbiacete), 

 but is, when raw, a deadly poison. The various 

 spurges, and other members of the family which 

 are found in England, are all acrid; and their 

 milky juice, which blisters very delicate skin, is 

 used to remove warts and other callosities. Some 

 plants of that family yield valuable, or at all events 

 powerful medicines, such as castor and croton 

 oils; but some of them act too powerfully for 

 being used even in the smallest quantity. The 

 perennial mercury, or " dog's cabbage," said to be 

 so called from dogs preferring it to any other 

 plant, when they physic themselves with green 

 vegetables, and which grows in the woods of some 

 parts of Britain, the male plants usually in one 

 patch and the females in another, is eatable, though 

 still aperient when well-boiled, but poisonous raw, 

 or even roasted or fried. That property is so 

 general that, when experiments are made as to 

 whether new vegetables may or may not be used 

 as food, the safest plan is to boil them, and throw 

 away the water in which they are boiled. 



One of the most curious orders of plants in that 

 respect is the fig tribe, or as they are sometimes 

 called, from comprehending the different species 

 of bread-fruit, the bread-fruit tribe. Of fruits well 

 known in England, the fig and the mulberry belong 

 to that family ; and though the fruit of these be 

 eatable, the juice of both, that of the fig especially, 

 is a poison. This family are very numerous in 

 the warm countries, and some of them are highly 



