The Potatoe Plague. 105 



from the same causes in previous years. There is no question 

 that the vital energies of a plant, if excited beyond a given 

 point, are injured in their organization, and rendered unfit 

 for the purposes of reproduction. I speak now of those 

 plants which are reproduced by cuttings, layers, and tuberous 

 appendages growing from them. Florists who, by the nature 

 of their business, are obliged to watch the nature of all plants 

 propagated by these means, understand the operation of this 

 principle, and the individuals they propagate from are gen- 

 erally selected with greatest care. The rules which apply 

 to other root crops, will not and cannot apply to potatoes, 

 because other root crops are reproduced by seed, and cannot 

 be produced by cuttings, sets, or tubers. The potatoe set is 

 part of the plant ; it is forced from its parent stem to perform 

 the unnatural office of perpetuating its kind. Now, this fact 

 borne in mind, it will be seen that the causes which I have 

 named as producing disease, are the most obvious, as well as 

 the most natural ones, and it is the simplicity of the thing 

 alone which has prevented the deeply learned and scientific 

 from making the discovery before. They have undoubtedly 

 made observations on these causes and understand fully the 

 operation of them, but as they were simple and evident, have 

 passed them by as of no immediate consequence. 



The same thing may be remarked with regard to progress 

 in morals, religion, and any of the sciences. Professors in 

 these branches of knowledge, have not distinguished them- 

 selves, by any wonderful additions to their subject ; they only 

 adopt, apply, and illustrate known truths. New discoveries 

 they make not ; they are things unknown ; they search for 

 them, indeed, but look for profound and mysterious laws, 

 forgetting that all the truths in the arcana of nature, are so 

 simple that a child can understand them. This rule of 

 thought and action has prevented progress from the earliest 

 ages to the present time, and a modern professor will be as 



