ESSEX SOCIETY. 73 



Mangel wiirtzel I consider of great practical importance to 

 the farmer, but as the crop is not so certain, and as it leaves 

 the land in much worse condition for future crops, while ca- 

 rets leave the land in excellent condition, I give the latter the 

 preference. 



The ruta baga is a very valuable crop, not only for stock, 

 but for the market as a vegetable. Its importance consists par- 

 tially in the quickness of its growth, as it may be sowed after 

 other early crops are taken off, or in. case of the failure of 

 other crops ; the seed may be sowed as late as the 25th of July, 

 with good success, but this crop has the same objection as the 

 mangel wurtzel, in regard to its injury to succeeding crops. 



The flat turnip is very easily raised, attended with little 

 expense, and is of comparatively little value for stock, although 

 I think it better to raise them than no roots at all. 



With me, the cultivation of the parsnip has been attended 

 with considerable uncertainty and expense, proving unprofita- 

 ble either for the market or stock, although a delicious vegetable 

 for the table. 



The onion crop I have found to be about as profitable and 

 safe for the farmer to invest in, as any. Notwithstanding the 

 blights, and attacks of lice and cut- worms to which it is liable, 

 we generally have a crop that repays for the labor bestowed 

 upon it. 



Marblehead, Nov. 13, 1850. 



Joseph Snelling, Jr.'s Letter. 



I do not attribute the cause of the potato disorder to an in- 

 sect or animalcule burrowing in the plant. If it can be demon- 

 strated by optical glasses, that insects inhabit the vines, or ani- 

 malcules the rotten potatoes, they exist there, not as a cause, 

 but as an effect of the disorder. The cause of the disorder, I 

 attribute to the want of a certain principle or element in the 

 soil, which is indispensable to the health of the potato plant, 

 and which has, in many parts of Massachusetts, as well as in 

 Ireland, become exhausted. I believe that this element exists 

 in natural deposits, in many places throughout the state, not 

 far below the surface — perhaps no deeper than the subsoil. 

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