XIV PKEFACE TO THE 



better than any attempt to improve their condition by the 

 exertion of their reasoning faculties. For such persons, books 

 are not written. 



I hope that what has now been said will not lead any one 

 to suppose that this sketch is offered to the reader as a 

 complete theory of Horticulture in all its varied branches; 

 such a work would be alike tedious to the author and the 

 reader, and, I fear, as unprofitable ; for, if a gardener, when once 

 made acquainted with the general principles of science, has not 

 the skill to apply them to each particular case, it is to be feared 

 that no disquisition, however elaborate, would enable him to do 

 so. So far has it been from my intention to enter into subor- 

 dinate details, that I have carefully avoided them, from a fear 

 of complicating the subject, and making that obscure which in 

 itself is sufficiently clear. All that a physiologist has really to 

 do with Horticulture is, to explain the general nature of the 

 vital actions of a plant, and the manner in which these are 

 commonly applied to the arts of cultivation; if he quits this 

 ground, he extends his limits so much that there is no longer a 

 horizon in view. No one, indeed, could advantageously inves- 

 tigate the minor points of cultivation in all their branches, 

 unless he were both a good physiologist and a practical gardener 

 of the greatest experience, a combination of qualifications which 

 no man has ever yet possessed, and to which I, most assuredly, 

 have not the shadow of pretension. 



In conclusion, let me, in impressing upon the minds of gar- 

 deners the importance of attending to first principles, also caution 

 them against attempting to apply them, except in a limited 

 manner, and by way of safe experiment, until they fully under- 

 stand them. The difference between failure and success, in 

 practice, usually depends upon slight circumstances, very easily 



