ON VEGETATION. 



to the atmosphere the oxygen gas, which man breathes. 

 He, on the contrary, throws off from his lungs car- 

 bonic acid gas, which is breathed in by the leaves of 

 trees, plants, &c. Here, then, is one reason why we 

 are exhilirated in a flower garden. Living flowers 

 are healthy, but dead ones are quite the reverse, 

 and should never be kept in a bed-room, as they 

 throw out noxious gasses or effluvia. 



It is to be understood by the reader, that the object 

 of this work is practical, and, therefore, I shall dwell 

 only on those parts of the philosophy of vegetation, 

 which will have a tendency to elucidate this work, 

 and throw light upon the new theory which I have ad- 

 vaaced, and which I have no doubt will be adopted 

 when better understood. I wish the reader particu- 

 larly to understand, that the author has not advanced 

 his theory from the stores of his imagination merely, 

 but from the practice of many years in the State of 

 Delaware, where he possessed every facility for ex- 

 periment. 



Tt has been asserted in this work, that the soil is 

 not exhausted by what is taken from it in the form of 

 product; but by the exposure of the surface to the 

 sun in Summer, and the frosts in Winter, The wood- 

 land is an example of this. If the old theory be cor- 

 rect, there would not be nourishment sufficient in the 

 earth to supply so many lofty oaks, placed so near 

 each other. On the contrary, we find that wood land 

 becomes gradually rich, and if covered with clover, 

 would more rapidly become so. 



