52 



disease under which a plant is suffering, it is too usual 

 for him to confine his attention to the part immediately 

 affected. It is looked upon as a strictly local derange- 

 ment, and the remedies are as erroneously topical. 



To consider that because a bud, a branch, or a root 

 is diseased, that the cause of the disorder is to be 

 sought for there, is as sensible as to, suppose that 

 every local pain endured by the human frame arises 

 from a disorganization of that part. On the contrary, 

 we know that the diseases of animals arise almost 

 universally from the stomach ; and, as Addison re- 

 marked, " that physic is generally the substitute for 

 temperance or exercise. 53 The functions of the sto- 

 mach, by whatever cause deranged, render digestion 

 imperfect, and the secretion defective ; the bile is 

 superabundant or deficient in quantity, and head-ache 

 is the result ; the liver is diseased, and it causes a 

 pain the most acute between the shoulders ; the blood 

 is ill elaborated, and eruptions are thrown out on the 

 surface of the body. With plants it is the same. It 

 may be laid down as an axiom, without exception, that 

 all vegetable diseases, unpreceded by external injury, 

 arise from the ill-prepared state of the sap— a state 

 brought about conjointly or separately by the impro- 

 per food imbibed, and the deranged digestive power 

 of the leaves and other organs. That this is so will 

 not appear strange, when we reflect, that from the 

 sap all parts of the plant are formed, and are conti- 



