38 . PREPAEATION OF THE SOIL. 



ing upon a bank, exposed on one side entirely unpro- 

 tected, to a severe winter, without injury. The 

 requisite condition, or heat being maintained by their 

 connection with the larger body of roots, which were 

 protected in the soil — just as we daily expose a part 

 of the person to tlie cold with impunity, while the 

 naked body would not endure a temperature many 

 degrees higher, without perishing. 



There is an equal danger in exposure to the opposite 

 extreme of temperature, though not so rapid in its 

 consequences. A cold bleak wind is far more effective 

 in drying up the sap than a moderately warm tem- 

 perature, exerted for the same length of time. The 

 effects of both extremes of heat and cold are the same. 

 The sap is inspissated to such a degree, that the 

 empty cells close up, and become incapable of again 

 exerting the mysterious endosmose action by which 

 their functions are employed. Could the lungs of a 

 drowned person be once more inflated, the blood would 

 commence its flow ; or could the blood be induced to 

 move by friction, the empty air-cells of the lungs 

 would All, and the vital functions of life once more 

 commence. Could we fill the collapsed sap-vessels of 

 the dried tree, we should gain one point in its recovery, 

 and in the approjpriate place the means for this will 

 be discussed. 



SOILS FOR PEAKS. 



It is somewhat mortifying to the promologist, after 

 twenty years of careful study of the laws which 

 govern the growth and fruiting of trees, to feel con- 



