SHADING. 
109 
object to the use of coloured glass, which it has been lately- 
attempted to reintroduce: a much easier and cheaper mode 
applicable to existing erections, without incurring the necessity 
of alterations of any kind, and which we fancy to possess a great 
advantage, inasmuch as it will not interfere with the ripening 
process, may be provided in the blind; the union of the two 
rays most conducive to the development of vegetation, the yellow 
and the blue, will it is known form a green, varying in density 
according to the preponderance of one or the other, and as it is 
necessary to admit as much light as possible to prevent etiolation, 
we would advise in the combination of the colours to allow the 
yellow to predominate, thus forming a pale green ; of this colour 
we would have the shades dyed, and thus the agency of the 
growing principles would be secured, while the occasional removal 
of the blind in the active season would check any undue develop¬ 
ment ; and when maturity is desired, to take away the shade and 
admit the natural sun-light appears all that is necessary to bring 
the red or ripening ray in contact with the recent parts, which 
are then in a state to receive its influence with benefit. The 
effect of a common blind is beneficial in so far as it breaks the 
force of the heat ray, but then it reduces each of the others in 
the same proportion, and thus its advantages are but of a negative 
character; the space beneath such a shade is at the best but 
darkened, an effect by no means desirable among growing plants, 
and we have been practically cognizant of instances of scorching 
under blinds of a pure white colour. 
The superiority of one possessing the advantages we have 
described must be evident, and the agreeable softened light it 
emits, in which the tints of flowers are heightened in a surprising 
manner, must be seen to be duly appreciated; blinds of the 
kind, to be all that can be desired, must be thin and rather loose 
in texture, strong, and the dye must be lasting, or a shabby 
appearance will annoy before the end of the season. 
