104 NEW AMERICAN ORCHARMST. 



potash. But the tar does not at all times afford a perfect se- 

 curity ; for when vast numbers arise at once from the earth, 

 a bridge over the tar is speedily formed of the carcasses of 

 those which first attempt the ascent, and over these an in- 

 numerable host may safely pass, and the labor of tarring, 

 previously bestowed, is lost for that season. 



The tarring process is a tedious one, requiring constant 

 attention during a long period; the omission of a single 

 night favorable to the ascent of the grubs, may prove fatal 

 to the trees for that season, and the labor previously be- 

 stowed is lost. 



Various other modes have therefore beei> proposed, with 

 the design of preventing their ascent ; but however in- 

 genious or effectual they may have proved, they have not 

 to my knowledge yet been introduced to general practice. 



The strip of list or girdle to surround the tree, and cov- 

 ered with the mercurial ointment, as recommended by Dr. 

 Spofford, of Bradford, Mass., as an effectual remedy, wag 

 tried by Gen. Dearborn in the course of his experiments, 

 and with him has totally failed ; it offered no obstruction 

 whatever to the ascent of insects. [See New England 

 Farmer, Vol. vin. Nos. 23 and 48.] 



What the particular causes of the failure in this instance 

 were, provided it has in other instances proved effectual, 

 we cannot conjecture, unless we suppose that the insects 

 passed over while the mercurial preparation was yet in a 

 new and fresh state, and before it had time to imbibe that 

 portion of oxygen from the atmosphere which Dr. Spofford 

 lias asserted renders its poison more active arid effectual. 



The Hon, John Lowell has stated in Vol. in. No. 4 of 

 the Mass. Agr. Repository, that he caused the ground 

 around sixty apple trees to be dug to the depth of four 

 inches, and to the distance of two or three feet from the 

 roots ; it having been ascertained by Professor Peck, that 

 the insect seldom descended into the ground at a greater 

 distance than three or four feet from the trunk. The 

 ground being laid smooth, three casks of effete or air- 

 blacked lime were spread over the surface thus prepared, 

 to the depth of about an inch. These trees were tarred 

 as well as the others; and, although grubs or worms ap- 

 peared on most that were not limed, not a single grub was 

 to be perceived on the trees limed. 



Mr. Lowell has spoken of the result of the experiment 



