236 Cause of imperfect Ripening cf Forced Grapes. 



Note hi) Mr. Main. — We are all well aware of the effect 

 of irrigation on meadow land ; the liquid covering which ex- 

 cludes the chilling air, and not the light, stimulates vegetation 

 surprising!}', it being only a denser medium, in which, per- 

 haps, the principal food of plants exists, and where no other 

 quality necessary for them is wanting. When motion, also, 

 can be given, it is an additional advantage ; and now, since 

 the discovery of forming fountain wells, by which small, never- 

 failing streams of water can be procured and carried in any 

 direction, we really think it within the bounds of practicability 

 (since reading the above communication) to force asparagus, 

 and perhaps several other plants, by means of water only. It 

 has also struck us that Mr. Foster's experience accounts most 

 satisfactorily for the superiority of the Gravesend, Deptford, 

 and Battersea crops of asparagus, the alluvial banks of the 

 Thames being so near an approach to the circumstances 

 mentioned by our correspondent. 



Art. XXI. Observations on the Cause of the imperfect Ripen- 

 ing of Forced Grapes, By W. M. 



Sir, 

 ' I AM surprised so little has been written on the shrivelling 

 of grapes in forcing-houses ; and it being a matter of some 

 interest to gardeners to provide against this evil, I am in- 

 duced to trouble you with a short notice, by way of calling 

 attention to the subject, in order to excite some abler pen to 

 explain the cause, and direct a cure for this defect in our 

 management. 



I shall shortly state my own opinion why this invariably 

 happens in forcing-houses, and not in the open air. In the 

 former case, the trees are unnaturally affected in respect of the 

 temperature in which their roots and branches are placed ; in 

 the latter, both are excited equally, and in a more natural 

 degree. In the house, the progress of the branches, with their 

 burden of leaves and fruit, precedes the exertion of the roots ; 

 and at the very time when the greatest demand is made on 

 the latter, they are unable to render the necessary supply : 

 hence the imperfect swelling of the bunches. But as this does 

 not always happen, and is, therefore, only a local misfortune, 

 I am"strongly of opinion that this can only be attributed to 

 injudicious planting, namely, in placing the roots too deep in 

 a clayey or retentive subsoil, and where no sufficient attempts 

 at draining have been made. Whoever is acquainted with the 



