AND FARMING PRODUCE. 323 



while the spring planted ones of the same kind 

 had scarcely a leaf which escaped, or one in six 

 sound tubers. 



It appears then, that the diseases are as much 

 owing to a want of natural maturation of the 

 tubers and haulms, as to any other cause 

 discovered at present. They may be diseases 

 of cultivation, brought on like diseases of 

 civilization and domestication, by an excess of 

 stimulants, and a preponderance of decomposible 

 substances, not fully matured, nor thrown out of 

 the plants, by natural processes, when under un- 

 favourable conditions. If so, they must, when 

 fully understood, be met with such artificial 

 checks, as may render them comparatively harm- 

 less. And in future, we probably must sub- 

 mit to diseases which we have brought out for 

 special purposes, and curb them by checks that 

 they do us little harm ; as we submit to smut, 

 ergot, &c. in our grain crops; and small pox, &c. 

 among ourselves ; and be thankful, that when 

 we work with too much steam, we can either 

 open the safety valve for its escape, or apply 

 the governor to regulate, as we wish, all its 

 movements. 



