VEGETABLE LIFE. 301 



stance, the cambium, or " changeable matter." 

 That begins to be formed as soon as ever the little 

 plant puts out a leaf, but the nature of the sub- 

 stance which is formed depends not a little upon 

 external circumstances; and the quality of the 

 timber which the tree is to produce is, in all pro- 

 bability, determined by the circumstances under 

 which the young plant performs its very first action. 



We know from observation, that no plant will 

 live without air, or be healthy if the air is not 

 pure and good; and we know, from the same 

 source, that if the plant is shut up from the light, 

 it is colourless, and contains little or no charcoal. 

 If, therefore, the young plant be in air that is 

 tainted, or too deep in the ground, its action must 

 be vitiated, and it must, as one may say, " start 

 with bad timber." Now, if a taint is given at 

 the commencement, that is a constitutional taint, 

 and must remain with and vitiate the tree, how 

 long soever it may live, or what size soever it 

 may attain. 



Complaints are every day made of the badness 

 of the oak timber now, as compared with what it 

 was formerly ; and these complaints are well 

 founded. What with dry rots in confined air, 

 and rots in water, and slow decomposition in the 

 atmosphere, modern oak, which is, generally 

 speaking, planted oak, is absolutely less durable 

 than even some of the inferior species of pine, 

 and far inferior to the native pine of the 

 mountains. A piece of heart of oak, chosen 

 by the king's builder for royal purposes, had 

 been seasoned and prepared in the most care- 

 ful manner ; and after that, it had been kept dry 

 in the centre of a trussed beam for more than 

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