OPENING AND SHUTTING OF FLOWERS. 119 



sel'la, is in the same order with the corn-cockle. 

 The leaves, which are like those of the trefoil, 

 close up on the approach of rain ; and open again 

 when it is dry. They are very acid, like those of 

 the common Sorrel, Ru'mex aceto'sa ; and a salt 

 is prepared from them, which is sold in the shops 

 under the name of essential salt of lemon. 



By the opening and shutting of several flowers 

 as well as leaves, we are enabled to judge of the 

 state of the atmosphere. If the Son'chus Siber'icaj 

 Siberian Sow-thistle, shuts at night, the following 

 day will probably be fine; but if it remains open, 

 it will be cloudy and rainy. When the African 

 Marigold, Tage'tes erec'ta, continues shut, long 

 after its usual time of opening in the morning, 

 rain is nearly approaching ; and the Convolvulus 

 arven'sis, small Bindweed, and Anagal'lis arven'sis, 

 scarlet Pimpernel, even after they have opened, 

 shut themselves up again on the approach of rain. 

 From this circumstance, the Pimpernel has 

 been called the poor man's weather-glass. 



EDWARD. 



Are there any trees in the tenth class ? 



MOTHER. 



I do not know of many, and none of them 

 except the Ar'butus are native: but I will tell you 

 what I recollect of a few foreign ones, 

 i 4 



