248 THE FARMER AT HOME. 



be estimated, only by the magnificence of its productions. There the 

 light of the sun is more vivid, its heat more permanent and intense, 

 while the soil is equally fertile, and the atmosphere equally pure. 



In southern Georgia, an island of the frozen ocean, only two plants 

 have been discovered, and but thirty have been found to grow without 

 cultivation, in the more temperate climate of Spitzberg. How con- 

 temptible are these productions, when compared with those of our 

 own climate, or the still more fertile fields of Madagascar ! But de- 

 prive Madagascar of its heat, and it becomes a second Greenland. 

 Exclude the light of the sun, and like the dark caverns of the earth, 

 it will produce only a few plants, and those of a sickly hue. Desti- 

 tute of rain, it will be like the deserts of Africa, and unsupplied with 

 air, it will exhibit no vestige of life. We must, therefore, expect, as 

 we recede from the equator, to meet with a constant succession of new 

 plants, but as we advance, we shall find them less numerous and 

 perhaps of inferior beauty and size. And as we ascend above the 

 surface of the ocean, we must be prepared for a similar, though more 

 rapid succession. This was long ago established by the observations 

 of Tournefort, and it has more recently been verified, by the researches 

 of Humboldt and Decandolle. 



LIGHTNING. That lightning is really an electrical phenome- 

 non, is now universally admitted. Philosophers had not proceeded 

 far in their experiments and inquiries on this subject, before they per- 

 ceived the obvious analogy between lightning and electricity. But 

 this hypothesis was first placed beyond a doubt by Dr. Franklin, who, 

 about the close of the year. 1 740, conceived the practicability of draw- 

 ing lightning down from the clouds. Various circumstances of resem- 

 blance between lightning and electricity were remarked by this 

 philosopher, and have been abundantly confirmed by later discoveries. 



LIGNUM VIT2E. Guaiacurn or pockwood, a genus of plants, 

 native of warm climates. The common Lignum vitsB is a native of 

 the warm climates of America. It becomes a large tree, having a 

 hard, brownish, brittle bark, and its wood firm, solid, ponderous, very 

 resinous, of blackish yel]ow color in the middle, and of a hot aromatic 

 taste. It is of considerable use in medicine and the mechanic arts, 

 being wrought into utensils, cogs, and various articles of turnery. 



LIME. This substance is obtained by exposing chalk, or other 

 kinds of limestone, or carbonates of lime, to a red heat ; an operation 

 generally conducted in kilns constructed for that purpose ; the car- 

 bonlo acid is thus expelled, and lime more or less pure, according to 

 the original quality of the limestone remains. In this state it is 

 usually called quick-lime. The purest quick-lime is obtained from 

 the calcination of white marble. Most stones that are soft enough to 

 be scratched with a knife, have a portion of lime. These are what 

 are commonly designated limestone, chalk, marble, spars, gypsum, 

 and various others. When, by ignition they are reduced to the state 



