162 Qtieries and Answers. 



inhei'ent power there is in soils in converting foreign substances into their 

 own nature. It is a subject of some importance ; and a paper upon it by one 

 of your philosophical correspondents would, I think, prove useful to many of 

 the readers of your Magazine. Has the subject been treated upon by M. 

 de Candolle, or any other person of deep research ? If so, an extract might 

 suffice. I have long been convinced, from experience, that this is not merely 

 an imaginary theory, and, accordingly, gave my advice some time since as to 

 the mode a friend of mine might take, in making a peach border, to prevent it ; 

 and it is singular that, almost immediately afterwards, there was a paragraph in 

 one of the daily prints in confirmation of my opinion on the subject. In 

 treating upon it, I should propose the question as to which of the natural soils 

 has the greatest inherent power of conversion ; viz. whether that of the cal- 

 careous, argillaceous, siliceous, &c., and to what extent either of them has this 

 property ; to be stated, as far as experience has gone, by way of proof. A few 

 hints, also, would be useful upon the kinds of manure, as well as of other 

 ingredients, which might prove the most useful to counteract, as far as may be, 

 the effect of this inherent power in the different kinds of soil that the horti- 

 culturist has to compete with. — T. Riitger. Portland Place, 1833. 



Destruction of the Thiips. — Could any of your numerous readers supply me 

 with anything approaching to a safe and effectual remedy for that destructive 

 jumping insect the thrips ? I have been terribly annoyed with whole shoals 

 of them this last summer ; and, as yet, I have found out no remedy. Tobacco 

 smoke will destroy the green fly, and plenty of syringing, or a moist atmosphere, 

 will chase away the red spider ; but neither of these methods have much influ- 

 ence upon the hardier constitution of the thrips. I once gave some plants such 

 a fumigation with tobacco, mixed with a little sulphur, that in the morning 

 there was not one of them possessed of a green leaf; and yet, luxuriating in 

 the general wreck, the thrips with which they were infested appeared gay and 

 sprightly as ever. What I have found best for their ravages, was syringing the 

 plants with soap-water, and keeping them growing in an atmosphere saturated 

 with moisture, and of a high temperature. I hope this will meet the eye of some 

 experimentalist. — R. Fish. Hyde Park Corner, November 7. 1833. 



Destruction of Insects. — Weston, writing about the middle of the last cen- 

 tury, says, " If any insects attack the trees, immediately apply quicksilver, 

 by the method directed in the Museum Rusticum, of boring a hole with a 

 smooth awl, in two or three of the branches, but sloping so as not to touch 

 the pith, and about an inch deep ; fill it almost full with quicksilver, and then 

 stop it with a bit of wax. I have tried it on thirty cherry trees ; and the 

 insects disappeared in three days. It were proper, also, to apply the fumi- 

 gating bellows with tobacco." (Weston's Tracts on Agriculture and Gardening, 

 p. 28.) Have any of your readers proved the effect of mercury in this way ? 

 This ought to be done, as the statement has lately been running the round of 

 the newspapers as a new thing. — John Brown. Kent, February, 1833. 



A Machine for discharging Bidlets has been invented by Mr. Toplis, of the 

 Museum of National Manufactures, Leicester Square, London. It can be re- 

 moved into any situation where horses or men can go, and can be made at 

 will to pour out, for any desired time, a continued stream of bullets, which can 

 be directed with the same facility as a stream of water from a fire-engine. If 

 so, might not such a machine be so modified as to distribute soil over the sur- 

 face of a bog, powdered manure over a field, or water or liquid manure over 

 sown crops or grass lands ? — J.D. S. Birmingham, November, 1834. 



Serpentine Garden Walls. (Vol. XI. p. 334.) — " The wall that surrounds the 

 garden is of stone, lined inside with brick : it is wavy, or serpentine ; but Mr. 

 Bane says it is not so good as a straight wall, as it causes currents of air." 

 Perhaps the relater of this singular fact, or he who observed it, will favour us 

 with some explanation of this remark. Having hitherto held that irregular or 

 uneven surfaces impeded, diverted, or considerably lessened the force of air 

 when impelled by natural causes, I was surprised to hear, not only that this 

 law did not apply to serpentine walls, but that they acted in a contrary manner. 



