JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
404 
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t May 19, 1881. 
are as a rule produced chiefly under this negative condition, and 
hence it is that such a covering facilitates and accelerates root- 
formation and the germination of seeds, See. ; whilst as soon as 
the green appears it is absolutely necessary to give air, or in other 
words to restore the confined atmosphere from its negative to its 
normal positive condition, otherwise the growths become sickly. 
Let these facts be applied to glass coverings on a larger scale, 
and the result will be identically the same. On referring to the 
figures 1, 2, and 3, page 355 of the previous volume, illustrating 
the chemical effects upon the metal as being greatest at A, fig. 1, 
where the positive and negative elements meet, we have an ana¬ 
logous proceeding with that occupying the opposite surfaces of 
the glass—the one positive and the other negative—and hence 
the nearer to the glass the greater the electrical attraction, and 
consequently the drawn effects occurring from distance. But this 
is only one side of the question. By exposure near to the glass 
the sides and undergrowth of a plant as well as the top are brought 
under the electrical influence, and thus become induced to form 
a sturdy and bushy growth instead of the weaklings similar to 
the too thickly placed seedlings of a seed pan or the too thickly 
planting of trees in a wood or plantation. Thus theoretically, the 
lower the glass be extended downwards, and the more open and 
exposed the situation, the better ought it to succeed. Here, too, 
we have an explanation of the effect of placing a sheet of glass 
close over freshly sown seeds either in the open or in pots. The 
first advantage is, that it keeps up a damp negative atmosphere, 
and next that it brings the electrical influence close down upon 
the surface of the soil. In the former case I find that laying a 
sash-frame down upon the fresh-raked earth, and sowing the seeds 
within the several compartments made by the impression of the 
frame, is very much the most successful way of effecting their 
germination. 
These facts lead us to the consideration of a most important 
subject which few practical men seem to be agreed upon—namely, 
the best means of shading and the extent to which it can be most 
satisfactorily resorted to. It must, however, be understood at the 
outset that there are two opposite conditions involved in the 
result of shading, one the weakening of the intensity of the light, 
the other the lessening of its quantity, but in both cases it is an 
essential and indispensable point that the chemical and some 
other properties of the light be not destroyed or deteriorated. A 
case in point will give a good illustration of the reality of such 
an occurrence. On one side of a conservatory, in consequence of 
its being overlooked from the adjoining premises, the glass was 
kept painted with whiting ; but this was rather troublesome from 
its oft-required renewal, and hence it was suggested that by 
mixing the whiting with drying oil this might be obviated. It 
was at once put into practice, and with such a promising appear¬ 
ance that it was had recourse to in several other instances. Putty 
thinned with raw linseed oil and a little dryer gave the surface 
much the look of rough sheet glass, and seemed to obstruct but 
little light, yet the ultimate result was anything but what would 
have been expected. 
Along the entire side so treated extended a shelf filled with 
large old scarlet Pelargoniums which had occupied the same posi¬ 
tion for a number of years and had always done well previously, 
but this spring the greater part of them proved to be dead or 
dying, and this was at first attributed to the frost; but when a 
small frame as well as two pots covered by bellglasses similarly 
dulled, the former filled with small plants of Ferns, the others 
with bulbils, were found to have shared the same fate, it became 
an irresistible conclusion that it was caused by some deleterious 
action of the light. But the most remarkable fact remains to be 
stated. In a small greenhouse devoted chiefly to Boses, but 
having an 18-inch shelf in front, the first three rows of panes 
over this had the inside of the glass dulled in the same way ; 
and although the seedlings, Sec., for the rest of the summer did 
not do satisfactorily, nothing was thought of it until the succeeding 
spring on the Boses beginning to break into leaf, when the truth 
became most incontestably apparent. Two strong shoots of the 
Cheshunt Hybrid had been carried up to the top of the house; 
and the singular part is, that on the stem more than 2 feet long 
under the dulled glass there was not a single side shoot, whilst at 
the commencement of the clear part of the roof the branches began, 
and now form a dense mass up to the top, every joint having its 
shoot and bud ; but since the glass has been cleaned a few weakly 
shoots without buds have made their appearance. A few panes of 
glass immediately over a Triomphe de Bennes previously smeared 
with common whiting and left so through being inaccessible for 
the oil has acted without similar results, and is a fair contrast 
in the effects, whilst it proves that the quality of the light is of 
infinitely more importance than its quantity or its intensity. Now 
it is an essential condition that some portion of the glass, how¬ 
ever small, should be left clear and clean, forming interstices 
between the shading material. This is Nature’s principle of 
shading ; for all plants and shrubs growing under trees receive 
their portion of sunshine through the spaces arising between the 
leaves and branches, and it is sunshine rather than diffused day¬ 
light against which shading is required. Practically, I have 
found a trellis of laths most effective, and far more satisfactory 
than any kind of textile fabric. It is considered that a horizontal 
slit admits more light through it than a vertical one, and certainly 
my experience leads me to believe it; but when only a moderate 
degree of obstruction is desired, a diagonal or lozenge-shaped 
opening gives apparently the best results, otherwise a kind of 
Venetian blind formed of laths or rods may be made so as to roll 
up when not required. For a temporary rough shading outside 
a roof or frame a small quantity of clay, made into a cream with 
water and sprinkled with a brush or put on with a syringe, is 
much better than whiting, as the first shower effectually washes 
it all away, which it does not with the latter ; and clean glass I 
hold to be a desirable point,— W. K. Bridgman. 
jfs 
» WORK/°fi THE WEEK,- v 
1% 
1) 
FRUIT HOUSES. 
Vines .—Late Vines started in February or early March are com¬ 
mencing flowering, and to insure a good set maintain a minimum 
temperature of 70°, and shake the rods several times a day to distri¬ 
bute the pollen. The best plan,however, is to take pollen from those 
Vines that afford it abundantly, such as Hamburghs, and apply it 
with a camel’s-hair brush to the stigmas of all shy-setting kinds, 
such as Muscats. A somewhat lessened supply of atmospheric mois¬ 
ture will, if accompanied with a circulation of warm air, aid the set¬ 
ting. Besort as little as possible to stopping or removing laterals 
whilst the Vines are in bloom ; but as soon as the fruit is set pinch 
frequently, as it is inadvisable to allow the laterals to extend 
greatly and afterwards be obliged to remove them in large quanti¬ 
ties. During bright weather very little fire heat will be necessary 
if the houses are closed early, as with sun heat and plenty of 
atmospheric moisture the temperature may rise to 90° or 95°, 
which will do more to advance the crop than three times as long 
firing in dull weather. These remarks only apply to Vines in 
full growth, as those that have fruit nearly or quite ripe will 
be better kept cooler. Ventilate early in the morning. Afford 
copious supplies of tepid water or liquid manure to inside borders 
where the Grapes are swelling; and for borders where the soil is light 
and porous water may be necessary, as the rainfall of late has been 
considerably under the average. If any is supplied it must be at a 
temperature of 85° to 90°. Where Grapes are ripening maintain a 
constant circulation of warm rather dry air, but do not entirely with¬ 
hold moisture, or it is likely the foliage will suffer and be attacked 
by red spider. There is no better remedy for this pest than painting 
the hot-water pipes thinly with flowers of sulphur mixed with skim 
milk. Attend to stopping and tying the Vines in succession houses, 
allowing no more foliage than can have full exposure to light and 
air. Vines struck from eyes early in the year and grown in pots 
or turves may now be planted out, giving a good watering at 95° to 
100°, mulching the surface with a couple of inches of short manure, 
maintaining a humid atmosphere, and affording shade during bright 
sun until the Vines are established. 
Melons .—Directly the fruit is cut in the earliest house and the 
plants are required to give a second crop, cut back the old stems to 
promising growths at the base. Bemove some of the surface soil and 
supply fresh lumpy loam, watering with weak liquid manure at 90°. 
Maintain a rather close and moist atmosphere, and if the plants are 
in good health they will soon produce another crop of fruit. If the 
old plants are very much enfeebled by carrying the first crop, or if they 
have been infested with red spider, an entire removal of the old 
compost must be made, and the house thoroughly cleansed. Beyond 
covering the rubble over hot-water pipes with turves, only hillocks 
