296 Remarks on Tilc-Draiiiing. 



It will be seen that Mr. Linwood's coinmiinication fiirnisl)es a 

 reply to my query, in p. 287., relative to the place of abode of 

 the larvae of the perfect individuals which attack the vines and 

 other wall trees. It will, also, be seen, that J. B. W.'s note is 

 partially at variance with the observations of Mr. Linwood ; viz., 

 that the insect seldom does much damage to the vines after the 

 first or second year. In case of the attacks of the Otiorhynchi 

 upon the vines or peaches, it would, I should think, be service- 

 able not only to water the roots known or suspected to be in- 

 fested with the larvae, with tobacco water or infusion of quassia, 

 or some such bitter fluid, but also occasionally to lay bare the 

 roots to a short distance, and examine if the insect is present. 

 This can, of course, be done with much greater facility with 

 vines than with succulent plants ; although I see no great diffi- 

 culty even with the latter. 



The other insects sent by Mr. Linwood were specimens of one 

 of the species of Elateridae ; the larvae of which are very injurious 

 to cultivators, and are known under the name of wire worms. 

 These will form the subject of an early article in my series. 



I am, &c., 

 Jime 12. 1837. J. O. Westwood. 



Art. III. Remarks on Tile-Draining, and on certain Benefits tvhich 

 might result yrom the Use of Draining Tiles in sjipplying Air to 

 the Subsoil. By Robert Arthur, Gardener at Wall Tower Gar- 

 dens, North Berwick. 



Draining by means of tiles may justly be reckoned one of 

 the greatest improvements in modern agriculture; nor are all 

 the purposes to which tile-draining may be applied, as yet fully 

 ascertained. 



Without going into detail as to the amelioration of the soil, 

 &c., by tile drains, I would merely suggest that it has occurred 

 to me, that the tunnels formed by drain-tiles might be employed 

 for at least one purpose besides drying the soil, I mean the intro- 

 duction of large quantities of atmospheric air into the earth, 

 which might be a means of saving manure and increasing the 

 fertility of the soil. Should the idea now thrown out be deemed 

 worthy of consideration, 1 think I could point out a method by 

 which the confined air could be withdrawn from these tunnels, 

 and large quantities of atmospheric air forced in, which would 

 find its way towards the surface. One objection to tile-draining 

 is the great outlay of capital it occasions : this there is every 

 reason to hope is in a fair way of being greatly reduced. The 

 Marquess of Tweeddale has succeeded in constructing a machine 

 which, from the facility and expedition with wiiich it forms the 

 most beautiful and substantial bricks and tiles, cannot fail to re- 



