No. 144.] 513 



operations, which, in a changeable climate, is a great advantage, 

 as the cultivator seldom misses the time to sow, and manures al- 

 ways produce the desired effect. 



The admission of air to the soil through the drains below, is a 

 great advantage; flower pots would be much improved if there 

 were five holes in the bottoms of them, instead of one. The 

 object of draining is not entirely to deprive the soil of moisture, 

 but to equalise the quantity, so that the highest degree of fertility 

 may be produced; In orcharding, if the annual increase in the 

 growth of trees on undrained land, is four per cent., the increase 

 on drained land will be eight per cent ; and on drained and irri- 

 gated land, sixteen per cent. Fruit trees, which had always proved 

 barren, have been thrown into full bearing by thorough drainage ; 

 and wood lands, growing oak trees, supposed to be two hundred 

 years old, have been much benefited by draining; gardens that 

 produced spare crops, have been made fit for the introduction of 

 a succession of crops during the same season, enabling the culti- 

 vator to apply liquid manures and irrigation successfully. The 

 wetter your land is, the greater, of course, will be the evapora- 

 tion; and consequently, the greater its excess of coldness. This 

 may be illustrated by the method used to cool wine in summer, 

 by wrapping a piece of wet flannel around the decanter, and 

 placing it in the sun; as the moisture evaporates from the flannel, 

 the temperature of the wine falls almost to the freezing point ; 

 you may wrap a vessel of w^ater in flannel, wet with brine, and 

 place it before a hot fire, it will soon produce ice. Wet land is 

 warmer in the shade than in the sun. Soil does not act chemi- 

 cally in the process of the germination of seeds; its only action 

 is to afibrd the means of supplying moisture, air, and warmth 

 continuously after germination. I have examined several soils 

 under a strong microscope, and found them to consist wholly of 

 particles of various shapes and sizes, consequently, they never can 

 come so close together but that there will exist passages between 

 them, making the soil more or less porous. I found, even, impal- 

 pable powdered soil, when placed under the microscope, presented 

 the same wondertnl variety of shape. In all soils there are two 

 classes of pores : first, those which exist between the particles of 

 [Assembly, No. 144.] G 2 



