BOTANY. 365 



juice, in order to economise their labour and time. To 

 the collected juice, a small portion of chalk is added ; 

 when, by the effervescence thus excited, the excess of 

 mucilage in the fluid, entangled with the carbonic acid 

 gas, is thrown to the surface in the form of a thick 

 scum, which is carefully removed. The liquid is then 

 strained, and allowed to stand and deposit its sediment ; 

 and when racked off, and before it is set aside for use, 

 a proportion of spirit is added to each cask. When 

 thus prepared, lime-juice will keep good at sea for an 

 indefinite time, and proves a powerful auxiliary to the 

 means employed for preserving the health of a ship's 

 company. There is no difficulty in getting the men to 

 drink it ; for when added to molasses and water (the 

 beverage called " switchel " by the Americans) it is 

 their favourite drink within the Tropics. 



The Tahitian name of this tree and its fruit is 

 taporo. 



SYNGENESIA. POLYGAMIA. ^EQUALIS. 



Adenostemna viscosa. Ethulia conyzoides. Society 

 Isles. 



Ageratum conyzoides. Sandwich and Society 

 groups. St. Helena. 



Bidens Sp. Society Isles ; native name taria opu. 

 B. arbor ea. St. Helena. 



Sonchus oleraceus. Oahu, Sandwich Isles; native 

 n&mepua eri. 



Hypochseris radicata. St. Helena. 



