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by the destruction of his hoped for harvests, as he 

 does to detect the disorder of, and the panacea for, 

 some miserable pig ? Diligence, perseverance, and 

 judgment, then, have never for any length of time 

 been directed to € diseases of plants ; they are yet 

 without their jEsculapius. The subject is one of dif- 

 ficulty, but it is commensurately important; difficulty 

 is very far distinct from impossibility ; and the im- 

 portance of the research is a stimulus to exertion. 

 Human knowledge is acquired by observation and 

 experience ; that is, by conversing v^ith the things 

 about us, by noticing them attentively, and subsequent 

 reflection. Every cultivator is capable of doing this ; 

 and if, when he found his crops diseased, he would 

 reflect and record from what soil he attained his seed, 

 how and in what weather it was committed to the 

 ground ; its subsequent culture ; the crops that pre- 

 ceded ; the treatment of the soil ; the seasons, whether 

 wet or dry, or severe, through which it has vegetated ; 

 with any miscellaneous observations that his own com- 

 mon sense might dictate, vegetable medicine would 

 soon advance more in one year towards that state of 

 reasoned knowledge that deserves the name of science, 

 than it has done during the last century. As obser- 

 vations multiply, the adjutant sciences. Chemistry and 

 Botany, will contribute and apply their improved 

 stores of information ; and if few specifics for the 

 diseases of plants are discovered, we are quite sure the 



