66 ORANGE CULTURE IN FLORIDA. 



It is better not to cut at all unless the wound is to 

 be covered at once. Shellac dissolved in alcohol, 

 or a coating of whitewash, or a soft paste made of 

 lime and fresh cow-dung, are good applications. 

 When a plant is frosted, the direct rays of the sun 

 will suddenly thaw and so contract the bark as to 

 enlarge the avenues to the atmosphere and make 

 the cold more fatal in effect. Hence, shading a 

 frozen plant, or thoroughly drenching with water, is 

 often a preventive of injury. I have seen orange 

 trees saved by setting a pine bough or other shelter 

 on the south and east, and when the thaw occurs 

 in the afternoon, on the west side of the tree. 



It has before been mentioned that the sowing of 

 oats thickly upon the ground in the fall will check 

 the circulation of sap during winter by taking up 

 the soluble manures. Nature has two methods of 

 fortifying perennials against the effects of severe 

 frost. One method is to deplete the tree of sap 

 during winter. Deciduous trees are so rendered 

 hardy. Their wood during winter contains so lit- 

 tle sap that the expansion by frost is not sufficient 

 to rupture the cells. Another method is to so com- 

 mingle oil with the water of the sap as to counteract 

 this law of expansion universal to frozen water. 

 While frozen water expands, frozen oil or hydro- 

 carbonates contract. The clockmaker has faintly 

 imitated nature in this. By combining different 

 metals in the rod which suspends the pendulum he 

 has made the law of expansion furnish him with a 



