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is, that the inorganic constituents of plant-food 

 require very large quantities of water for their 

 solution. Mr. Lawes calculated that two thousand 

 grains of water have to pass through the vegetable 

 system before one grain of solid matter can be 

 deposited within the cells of the plant. 



From the root, the liquid, ^containing the inorga- 

 nic elements obtained from the soil, travels up the 

 stem, and is distributed among the different parts 

 of the plant, to assist vitality and impart nourish- 

 ment to the leaves, buds, flowers, and fruits. On 

 examining a stalk of Indian corn or sugarcane cut 

 for the purpose, there can be seen, even with the 

 naked eye, a number of very minute cells, enclosed 

 by a thin cuticle, called epidermis, which contains 

 (this is the case in all grasses, canes, cereals, &c.) 

 a large percentage of silicious earth, which seemss 

 necessary to protect it from injury, and to impart 

 to the stalk the strength required to bear the weight 

 of the ear. This fact explains why silica in an 

 assimilable state is indispensable to the growth of 

 cereals. The minute cells which this epidermis 

 encloses are the conveyors of the sap, as the fluid 

 which rises from the root is termed ; they are also 

 the storers and assimilators of the vegetable food. 

 The sap travels, through all those minute sexagonal 

 cells, to the leaves, where it is exposed, in numerous 

 little tubes and cells, to the chemical influence of 

 heat, light, and atmospheric air, whereby the crude 



