60 ESSEX SOCIETY. 



than two months, when they yielded to a cold storm and 

 disappeared rapidly. They staid too long, however, for the 

 crop. It was estimated in June that there would be five hun- 

 dred bushels upon the half acre — there cannot now be one 

 hundred bushels. 



But this may not occur again in ten years. Besides, some 

 very simple remedy may be yet discovered. When the govern- 

 ment of Sweden called the attention of Linnaeus to the fact, 

 that all the ship timber in the dock was worm-eaten, he discov- 

 ered the cause to be a little fly, and so simple a thing as laying 

 the timber under water for the few days, during which the fly 

 laid its eggs, prevented the difiiculty entirely. Some other 

 Linneas may find, that though he cannot lay a turnip lot under 

 water, there may be a kind of water which can be sprinkled 

 upon the turnip, destructive to the louse, and yet safe for the 

 plant. I would recommend an experiment, beginning Avith 

 soap-suds, adding dissolved potash gradually, going from medi- 

 um strength to one that would color the leaf. Animal life 

 would feel it before vegetable. Something short of the death 

 of the plant would kill the louse, there can be no doubt. Much 

 observation would be necessary to determine what strength of 

 alkali would be required, but, as the turnip aphides is so per- 

 ceptible to the eye, any one can ascertain when it is sufficient 

 to overcome the insect. It will be a triumph worth achieving 

 to overcome this pest, so contemptible for its size, yet so 

 mighty for its numbers. Like the army-worm, nothing vege- 

 table can stand before it. 



With respect to using potash upon the turnip, though as be- 

 fore stated, a strength that would spare the leaf, might destroy 

 the insects : yet, even if the leaf were killed and cut off" with 

 the scissors, it would be a smaller evil than to allow the rav- 

 ages to go on, because, though the leaf should be killed with 

 the alkali, a new one would grow long before the louse would 

 otherwise leave it. The insect began to disappear, in the case 

 referred to, before the middle of October, and new leaves, in 

 many cases, began to grow ; but it is obvious that the leaf 

 would have grown long before that time, had it been cut off" 

 by the first of August. 



