372 
THE FLORAL WORLD AND GARDEN GUIDE, 
glass is alternately introduced and withdrawn, is very surprising. Looked at 
through the same glass, the meadows in May appear of a warm purple. With a 
solution of permanganate of potash, which, while it quenches the centre of the 
spectrum, permits its ends to pass more freely than the Tiolet glass, striking effects 
are also obtained. Both in foliage and in flowers, we have striking differences of 
absorption. The Copper Beech and the Green Beech, for example, take in difiereut 
rays. But the very growth of the tree is due to some of the rays thus taken in. 
Are the chemical rays, then, the same in the Copper and the Green Beech ? In 
two such flowers as the Primrose and the Violet, where the absorptions, to judge by 
the colours, are almost complementary, are the chemically active rays the same ? 
The general relation of colour to chemical action is worthy of the application of the 
method by which Dr. Draper proved so conclusively the chemical potency of the 
yellow rays. — Tyndall’s Lectures on Light. 
TO CORRESPONDENTS. 
Gerajciums, Greenhouse, Etc, — Ter Mare, per Terram. — In reference to the 
first question, w'e would advise you to prune them back rather severely, taking care 
of course to prune them into a symetrical form. They should be allowed to remain 
out of doors until the end of the month, and then bo removed to a frame or green- 
house, where they can be placed near the glass. Keep them rather dry at the roots 
during the winter, and in the spring shift them iuto larger pots and use a compost 
consisting of turfy loam, leaf mould, and silver sand, the loam being employed at the 
rate of three-parts to one-part of the leaf-mould. Sufficient sand will be required 
to give the compost a gritty feel, but usually a sixth-part of the entire bulk will 
suffice for this. The Azaleas and Cameilias should be kept in the greenhouse, and 
receive sufficient water to maintain the soil in a moderately moist state. The 
small shoots which are pushing up from the base of the azalea should be removed, 
as most likely the plants are grafted upon stocks raised from seed. A very good 
liquid manure for plants in pots may be obtained by mixing two ounces of guano, 
and a handful of soot, with three gallons of water. The drainings from the stable, 
when diluted with about four parts of water, is also very useful for the assistance of 
plants in pots. The assistance of liquid manure is of more importance for the en- 
couragement of the plants previous to their coming into flower, than at any other 
period. The Floeal Wokld has been in existence fourteen years, and a consider- 
able number of the back numbers and volumes may be obtained from the publishers. 
Celine Forestier and Marechal Neil will be the two best roses for the greenhouse. 
Strong plants may be purchased for half-a-crown each, or less. 
Virginian Creeper. — Ampelopsis. — The plants have not sufficient root-room 
in boxes eighteen inches long, eight inches wide, and two inches deep. They should 
be planted cut in the border or in boxes containing about a square yard of soil ; 
the boxes should at all events be much larger than those at present in use, if 
vigorous growth is desired. 
Old SubscriOer. — We trust you will be long spared to grow older and older and 
wiser and wiser, and that j-ou may some day become convinced that brevity is the 
soul of wit. In the meantime, while your wisdom teeth are growing, please send 
ready-made replies with any queries you may honour us with. 
Grapes. — Young Gardener.~-The Black Hamburgh is the best of the varieties 
mentioned for ground vineries. With good management excellent crops mav be 
obtained. The other plant mentioned does not require any special system of culture, 
hut it does not usually flower freely until it has become well established. It is 
essential that, the plant should not be shaded by climbers trained to the roof. 
Pansies Dving. — An Anxious Amateur.- — The roots of the pansies have been 
eaten by the wire-worm. This pest may be trapped by inserting carrots in the 
border between the plants. They will require to be drawn out and examined occa- 
sionally for the purpose of destroying the wire-worms which will have attacked 
them. 
Gladioli. — A.J)., Tarbolton. — There is no known remedy for the disease. Good 
cultivation is the best means of preventing its doing much harm. There is no 
