No. 141.] 201 



dition, having no chemical deficiencies, it will produce the high- 

 est order of plants (grains, &c.,) and will be incongenial to many- 

 weeds ^ while if it has deficiencies it is not only liable to be occu- 

 pied by plants of a lower order, such as many weeds, but the cul- 

 tivated crops, struggling for growth under such unfavorable aus- 

 pices, have less energy and power to subdue the intruders. Hence 

 we conclude that our means of security against weeds is to put 

 the soil in the highest state of fertility, and fit it for the cultivated 

 plants, instead of weeds. It does not appear necessary that there 

 should be a certain kind of seed in the soil before a certain kind 

 of plant, peculiar to that seed, can be produced. If we place 

 the soil in the proper condition for any order of plants, w^e may 

 expect their growth, apparently without seed. Soils deficient in 

 some of the inorganic elements of vegetation produce pine trees. 

 This forest may stand for two hundred or three hundred years, 

 during which time some of the elements which are deficient in the 

 upper soil are collected by their roots, which extend to great 

 depths in the soil, and are f^eposited in the wood and bark. If 

 the forest be now burned, or if it decay, these matters become 

 mingled with the surface soil, and so alter its character that it 

 spontaneously produces the oak, or an analogous plant, and a 

 forest of thi^ growth succeeds the evergreen. No one would sup- 

 pose that acorns had existed in tlie soil for the two hundred or 

 three hundred years during which the pine trees were growing, 

 still less that they had been produced by the j)ines. If we follow 

 the changes still further, it is very likely we should find, that if 

 the oak trees be cut down and removed, they would be followed 

 by evergreens — not because they had produced the seeds of ever- 

 greens, but because, in their removal, they had carried away so 

 much inorganic matter from the soil as to leave it better fitted for 

 their production than of the oak. The scientific discussion of the 

 theory of native production may be left to older and wiser heads. 

 It is stifficient for tlie present occasion to know that such facts 

 exist, and may undoubtedly be applied to the production of 

 weeds as well as of trees. If the importance of removing and 

 avoidiiiEC weeds be proportionate to the annoyance which they 

 occasion, these subjects demand attention. 



