CK. Vni.] THE DISEASES OF PLANTS. *245 



weather it was committed to the ground : the subse- 

 quent culture of the crop : the crops which preceded 

 it; the thermometrical and hygrometrical registries 

 of the seasons through which it has grown; the 

 treatment of the soil ; its drainage ; with the ma 

 nures employed ; the wateiings ; the piiming ; and 

 any other miscellaneous observations his owa com- 

 mon sense may dictate. If this were done, vegetable 

 medicine would soon advance more in one year 

 towai'ds that state of reasoned knowledge, which 

 alone desen^es the name of science, than it has done 

 during the last century. 



As observations multiply, the adjutant sciences, 

 chemistr}^ and physiology, will contribute and apply 

 their improved stores of information, and if but few 

 specifics for the diseases of plants resulted, yet I am 

 quite satisfied that the causes of diseases would be 

 more accurately ascertained : and every one is aware 

 that to know the cause of an evil is the most im- 

 portant step towards the prevention of its occur- 

 rence. 



It is a very important preliminaiy to the study 

 of the diseases of plants, that the nature of these be 

 understood — for our ignorance of, or inattention to, 

 the nature of these organized creatures, is one of the 

 causes from whence arises the little progress made 

 in this branch of natural philosophy. 



Its students ought fully to understand that this 



