482 



THE FARMERS' REGISTER. 



spersed wilh isoetes lacustris, and other plants 

 common in this and all the other neighboring 

 lakes; alter remaining some time ahove the 

 water its verdure is much improved. For a lew 

 inches in depih it is composed of a clayey or 

 earthy matter, apparently deposited by the water, 

 in which the growing plants have fixed their 

 roots ; the rest is a congeries of decayed vegeta- 

 ble matter, forming a stratum ol loose peat earth, 

 about six leet in thickness, which rises from a 

 bed of very fine soft clay. A considerable quan- 

 tity of air is contained m the body of the island, 

 and may be dislodged by probing the earth with 

 a pole. This air was Ibund by Dr. Dalton to 

 consist of equal parts of carbureted hydrogen 

 and azotic gases, with a little carbonic acid." 



JMr. Olley farther adds — 



"That one material circumstance has, how- 

 ever, generally escaped observation — ndmely, 

 that the air to which the rising of this island hns 

 been attributed is not collected in a body under- 

 neath it, but interspersed through the whole mass. 

 And the most probable conclusion seems to be, 

 that air or gas is generated in ihe body of the 

 island by decomposition ol the vegetable matter 

 of which it is lormed ; and this gas being pro- 

 duced most copiously, as well as being more rare- 

 fied in hot weather, the earth at length becomes 

 so much extended therewith as to render the 

 mass of less weight than an equal bulk of water. 

 The water then insinuating itself between the 

 substratum of clay and the peat earth Ibrming 

 the island, liears it to the surlace, where it conti- 

 nues for a time, till partly by escape of the gas, part- 

 ly by its absorption, and partly by its condensation 

 consequent on a decrease ol heat, the volume is 

 reduced, and the earth gradually sinks to its 

 Ibrmer level, where it remains till a sufficient ac- 

 cumulation of gas again renders it buoyant. But 

 as the vegetable matter of which the island is 

 principally composed appears to have been amass- 

 ed at a remote period, when the lake was of less 

 depth than at present, receiving very little addi- 

 tion Irom the decay of plants recently grown 

 upon the spot, it is reasonable to suppose that 

 the process of furnishing the gas cannot from the 

 same materials be continued ad wfinitum ; but 

 there must be a time when it shall have arrived 

 at its maximum, alter which the eruptions will 

 become less extensive or less frequent." 



OIV A METHOD OF DESTROYING THE CANKER 

 WORM GRUB. 



By John Porter, esq., Newburyport, Mass. 



From the Magazine of Horticultare. 



Hapving seen, in your valuable magazine lor 

 this month, an article describing the best method 

 for the destruction of the canker worm, I am in- 

 duced to stale the result of an experiment made 

 by myself. The trees on which I tried the expe- 

 riment had been exposed lor five or six years to 

 the ravages of the grubs, without taking any 

 steps to prevent them ; and therefore it is liiir to 

 inler that the ground contained a bountiful supply 

 for their fiiture operations. 



Around each tree I placed a square box, about 

 twelve or fourteen inches high, made of rough 



boards, leaving a space of four or six inches be- 

 tween the box and the tree. A ledge of about 

 two inches in width was nailed entirely round the 

 top of the box, and the box was inserted two or 

 three inches into the ground, for the purpose of 

 keeping it steady. On the outside of a box, and 

 under part ol the ledge, I tarred frequently, and 

 the grubs were thus prevented Irom ascending 

 from the outside. I filled the inside of the box 

 about two-thirds full of cotton waste (which can 

 be obtained at any cotton manufactory for a cent 

 per pound, or less,) well pounded down, and this 

 effectually prevented them Irom ascending from 

 the inside. Hi however, a few grubs should suc- 

 ceed in gelling over the tar from the outside, they 

 have to descend the inside of the box until they 

 reach the cotton waste, and crawl over that until 

 they reach the tree. This they cannot do, as they 

 immediately become entangled by the cotton, and 

 cannot proceed. I have tried this two years in 

 succession, and I have not had a worm on trees, 

 which, lor several years previous, had been en- 

 tirely denuded liy Ihis enemy of the apple tree. 



The expense is very trifling, as any common 

 boards will answer, and any person who can use 

 a fore-plane, a saw, and a hammer, can easily 

 prepare the boxes. 



No possible injury can result to the tree, for the 

 tar does not touch it ; and as soon as the season 

 is over for the grubs to ascend, I remove the 

 waste, and sf»read it to dry lor another season, 

 and in this way it will answer for use several 

 years. 



I li^el entirely satisfied that the foregoing plan 

 will effectually put an end to the ravages of the 

 detestable grub-worm, and I hope that all those 

 who have trees worth preserving, will try the ex- 

 periment. 



THE OHIO EVER-BEARING RASPBERRY. 



By A. H. Ernst, Nurseryman, Cincinnati, Ohio. 



From the Magazine of Horticulture. 



Last spring I had occasion to send a few things 

 to some Iriends in your vicinity. I availed my- 

 self of the occasion to present you with one do- 

 zen of the Ohio ever-bearing raspberry plants, 

 which I hope you have received.* I feel some 

 desire to aid in spreading this fruit over the coun- 

 try ; less, however, to the north than to the west 

 or south, because your region is more congenial 

 with the growl h of the raspberry, and abounds in 

 fine high flavored Iruif, of superior quality, which 

 continues to Iruit abundantly during the latter 

 part of the summer, so that, to a great extent, the 

 deficiency does not exist with you, which would 

 make this raspberry particularly valuable to your 

 section of country. 



The Ohio ever- bearing raspberry, as you are 

 ^aware, is a native of Ohio. It was, 1 think, first 

 'found and brought into notice by a community of 

 Shakers, residing some thirty miles north-east of 

 this city, from whence, from the best evidence I 

 can procure, it has been very slowly spread into 

 this city and vicinity. To my mind it is valuable 



* We did, in excellent order, and Mr. Ernst will 

 receive our thanks for his attention.— JEci. Mag. 



