804 e 
THE GARDENERS CHRONICLE. 
[Nov. 18, 
apt to damp off and perish; and if too dry, their growth 
is checked, and they get exceedingly liable to the attacks 
of red spider and other insects. Where high temperatures 
are maintained, either by hot-water pipes or common flues, 
the latter condition is much more liable to occur than the 
former; and if no other means are used than the ordinary 
watering of the plants to supply the air with moisture, it 
is almost certain to become too dry. The reason of this 
depends on a property of air, of extensive appliance in the 
economy of nature, by which its capability of dissolving 
water increases in a much higher ratio than its tempe- 
rature. Thus, if we take a certain portion of air at the 
temperature of 50°, and heat it a fifth part more, thus 
raising it to 60°, and if we saturate it with moisture in 
both instances, it will be found to contain much more 
than a fifth part additional water at 600 than it did at 50°; 
or, if we take two equal portions of air at 50° and 60°, both 
holding as much water in solution as they possibly can, 
and mix them, an instantaneous deposition of moisture 
occurs, for the resulting mean temperature of 55° renders 
the air unfit to hold the whole in solution. If it were not 
for this simple property of air, we could neither have fogs 
nor rains. One d to the o 
houses will be able by his feelings to tell whether the 
house he enters be moist or dry, particularly if he gets a 
glance at the thermometer. “A moist air always feels 
warmer than a dry air at the same temperature, because in 
the latter case a freer exhalation of vapour takes place from 
the surface of the body, keeping down its temperature. But 
the feelings are not always to be relied on either in horti- 
culture or other operations ; Mason’s hygrometer should, 
therefore, be provided. This is neither more nor less thana 
couple of thermometers, the bulb of one of them being 
covered with a bit of rag kept always moist. The dry 
ulb thermometer measures the temperature of the atmo- 
sphere of the house, and the wet bulb one the intensity 
of evaporation, or its capability of dissolving moisture— 
hence its dryness. When plants are in active growth the 
wet thermometer should not be above two or three de- 
grees below its neighbour, and may be often equal with it; 
but when they are at rest the difference may and ought to 
The wet bulb instrument not only indicates 
the dryness of the atmosphere, but also gives the gardener 
another important hint; it tell8 him the temperature of 
the soil in his pots, at least, if these are duly supplied 
with water. The same cause, evaporation, which sinks 
the mercury in his moistened glass, is at work with his 
pots, cooling them down in like degree ; so that, instead of 
the fostering influence of bottom-heat, he-has its stinting 
antithesis of bottom-cold. A dry atmosphere is thus 
not only hurtful directly, by its aridity, but indirectly, by 
its frigorifie influence on the roots of plants, unless the 
pots are exposed to the direct radiation of heat from the 
flues, which may thus counterbalance the deficit. 
The means of keeping up a moist atmosphere are various, 
‘Where steam is employed as the heating medium,. the 
necessary quantity permitted to escape will readily effect 
this object; where warm water is the material, a portion 
ofits surface exposed, proportioned to the heat and size of 
the house, will be effective. And where only close pipes, 
tanks, or flues exist, a number of earthenware trays, or 
basins, filled with water and placed on them, will yield 
the requisite supply ; or, as formerly hinted, a few inches 
of sand, ledged in and kept moist over the flue, will answer 
the same end.—J/, L., Newburgh. 
(To be continued.) 
ROSES IN POTS, No. III.— FORCING. 
Ross required for forcing, in as far as regards soil, 
time of removal, and potting, may be treated in the same 
manner as those intended to be grown in pots in the open 
air. They should be pruned early in November, and it is 
well if they can be allowed to make their growth, and 
bloom out of doors, the first season after removal. That 
plants taken from out of the ground and potted early in 
autumn will bear forcing and bloom tolerably well the 
succeeding spring, we know from experience ; but from 
direct observation, it is evident that, having been a year 
in pots, they become better established, produce a greater 
quantity of flowers, and form more compact plants. The 
first week in January is a very good time for conveying 
the plants into the forcing-house, commencing with a 
gentle heat, say 40° to 50°, Very soon the buds will 
become excited, when the temperature may be gradually 
raised to about 50° at night, and 60° 
day, and the plants lightly syringed morning and evening, 
Great care is required in the admission of air. 
should be admitted, 
mild weather. I have found the plants more liable to 
suffer from the admission of cold air, even on sunny days, 
Whilst they do not 
appear to suffer from the latter high temperature, the too 
Pt the plants 
reqvire to be kept tolerably moist, and the water should 
Se some time before required for 
nd syringing, that it may become 
The description of plants I 
prefer, are for the ™ost part those worked on 
them steadily, they may be drawn out from the base, thus 
effectually removing them as they appear, without dis- 
turbing the roots. 
The grub which attacks Roses so generally out of doors, 
frequently finds its way into the forcing-house, and should 
be carefully’ sought after and removed by hand. The 
green-fly, though more under our command here, is not 
less troublesome; as soon as any are seen, the house 
should be fumigated with tobacco to destroy them, and 
this continually repeated through the season as they re- 
appear. The red spider and mildew will sometimes infest 
the plants, for which sulphur is the generally acknow- 
ledged remedy. Dusting it on the leaves after syringing 
is an easy methcd of applying it. From the red spider, 
however, in a house with a moist atmosphere, there is not 
much to fear ; and it is perhaps as well to remove plants 
inclined to mildew—which some varieties are more than 
others—as soon as the first spots are seen. 
About the middle of March the flower-buds will show 
colour; syringing should then cease, and a liberal supply 
of water be given. Should worms work into the pots, 
they may be occasionally watered with lime-water 5 andif 
large flowers be sought after in preference to number, the 
small backward flower-buds should be removed. A few 
plants may now be carried to a colder house, which will 
give the remaining ones more room, and by selecting them 
of different degrees of forwardness, a continual supply of 
flowers may be obtained; and further, the temperature 
being diminished, the flower-buds will have more time to 
expand, and produce larger flowers approaching nearer to 
their natural colour. It is the custom with some, as soon 
as the buds show colour, gradually to lower the tem- 
perature of the house; by this method a greater display 
may be obtained at one time,' but the Succession of flowers 
is lost, and the whole retarded. When the flowers begin 
to expand, it will be found necessary to form a light 
shading to screen them from the mid-day sun ; and at this 
season a thin canvass will be found sufficient, But to see 
Roses in perfection in the forcing-house, we should visit 
them at the same time as we would Roses in the open air 
—with the rising sun, just as the buds are unfolding, and 
while they are wet with the dews of morn, Thus have 
we arrived at the season when the flowers appear, which 
by their beauty and fragrance redouble the pleasure we 
have enjoyed during their progress. Among forcing Roses 
of the classes Hybrid, Perpetual, and Tea-scented, I knoy 
not which may claim the precedence. The former beauti- 
ful class has the claim of novelty, and has recently im- 
proved and increased at such a rapid rate as to threaten 
the exclusion of many of the Damask Perpetuals, The 
flowers are for the most part large and double, but there 
is a similarity in appearance, the flowers being chiefly 
purple or crimson, They possess the fragrance of the 
Damask Perpetuals, and are free growers, with fine foliage, 
Tea-scented Roses are of opposite colours, being chiefly 
white, yellow, and rose, They may be considered as 4 
selection from the Chinese on account of their delicious 
fragrance, and whether for forcing or out-door pot plants, 
form very handsome Roses. Many of the Bourbons are 
also admirable forcing Roses, of erect growth, forming 
pretty compact heads when worked: the flowers are finely 
shaped, colours clear, and foliage broad and handsome. 
The Chinese Roses are very abundant bloomers, and there 
is something striking and handsome in their habit of 
flowering peculiar to themselves ; among them are also 
some of the most brilliant crimson Roses. The Damask 
Perpetuals are very sweet, and are probably best worked 
on the Dog-rose when grown in pots. They appear to 
derive an additional vigour from this ‘ exalter of the Rose 
tribe,”’ and being compact growers, form very neat objects, 
Some of the hybrids of Chinese also force well, In addi- 
tion to the varieties recommended in the Gardeners’ 
Chronicle, p. 541, the following are excellent forcing 
Roses :— 
Blush to Pink :—N. Custalie, T, Bardon, Mossy de 
Meaux, T. grandiflora, H. C. Blairii, No. 2, Ch. Anthe- 
ros, Ch. miranda, H. P, Marquisa Boccella, T. Origi- 
nale, T. Clara, Ch. Virginal. 
Sulphur and Bronze Yellow :—Ch. Miellez, T. Prin- 
cesse, Helene du Luxembourg, T, Pauline, Plantier, T. 
Aurore, T. Mansais. 
Rose :—T. Hardy, B. Madame Desprez, B. De Neuilly, 
B. Psyche, B. Henri Plantier, B. Augustine Margat, H. 
C. Charles Louis, H. C. Daphne, H. P. Lane, Perp. 
Madame Feburier, Red Moss, T. Bon Silene. 
Crimson :—Perp. Triomphe de Montmorency, Prov. 
Due d’Angouléme, Lawrenciana rubra, Ch, Nemesis, B, 
Josephine Garnier, Ch. Cramoisie superieure. 
Purplish Crimson and Purple :—B. Due d’Aumale, 
Ch. Triomphante, Ch. Comble de Gloire, B. Crimson 
Globe, H. C. Plantier, H. P. Julie Dupont, Perp. Louis 
Philippe, Perp. Warratah, H. P. Prince Albert. 
The colours of forced Roses are not quite equal to 
what they are when produced in the open air, and in this 
respect I believe there is a greater difference in the light- 
coloured than the dark varieties. Many of the sorts 
above enumerated, though of first merit as forcing Roses, | 
do not at all times expand their flowers when grown out 
of doors; of which we may instance, Ch. Virginal, H. P. 
Prince Albert, and T. Princesse, Helene du Luxembourg. 
The colours which may appear wanting in the above list 
will be found given in the preceding one. 
As soon as the plants are out of bloom the surface of 
the soil should be removed to the depth of half an inch, 
or an inch, if practicable, without injuring the roots, and 
the space supplied with well-pulverised manure. The 
plants which bloom but once in the season may be gradu- 
ally hardened off when the house will admit more plants, 
which should be kept in reserve for that purpose. But 
with regard to what are usually termed Autumnal Roses, 
these may be treated so as to produce a good supply of 
flowers a second time by the middle of May. The weak 
shoots should be entirely cut out, and the stronger ones 
shortened back to within two, or at most, three eyes, 
taking care, however, not to deprive the plants of more 
leaves than is absolutely necessary in the operation. If, 
as is sometimes the case, the shoots in autumn-proning 
were left long, and the eyes at the top have only shot 
forth, these may be cut quite off, when the buds near the 
base will be excited, and fine flowers be produced there- 
from. As the season advances, less fire heat will be 
necessary, Towards April, a fire lighted of an evening 
and kept in for a few hours will (unless the weather be 
unusually cold) be found to impart sufficient warmth ; and 
after the buds show colour, even this will not be requisite. 
The plants having bloomed a second time, air may be 
gradually admitted for a few days, when they may be 
taken out and plunged in the open air, there to remain 
till required for forcing the following year. 
Roses will force well for years in Succession ; but every 
autumn they should be turned out of the pots, a good 
portion of the old soil shook away and fresh supplied. 
Some few will probably require larger pots, of which we 
must judge by the condition of the plant and roots.—W. 
Paul, Nurseries, Cheshunt, Herts. 
The following, which is employed in 
one of Stephenson’s 
iron tanks, is employed successfully by Mr. Beck, of Isle- 
worth. A single tank, DEF G, is applied to a small 
greenhouse, divided into two compartments by the parti- 
tion, B C, which nearly corresponds with the separation 
of the houses. When the left-hand house is to be heated, 
the slides B C are inserted in the cross partition, and the 
slide A is removed; a current is then established from E 
to A and from A to D ; but if both divisions are to be 
heated, the slide A is inserted, while those at B and Care 
removed, when the current passes from E to G, from G 
to F, and from F to D; and thus both compartments will 
become heated. The wooden slides, which are apt to warp, 
are prevented from doing so by a piece of iron hooping 
being driven into the bottom edge. 
LISIANTHUS RUSSELIANUS, 
Tax above plant was introduced to this country about 
8 years ago, and is allowed by all who have seen it well 
cultivated to be one of the most beautiful plants of modern 
introduction—yet, strange to say, it is rarely to be met 
with well grown, even at the Metropolitan Horticultural 
exhibitions. This, some attribute to its being a plant that 
is very difficult to cultivate ; but not having found itsuch, 
I beg to offer a few remarks on its culture. The seed 
should be sown in March, in seed-pans filled with soil 
composed of three parts of light loam, two parts of well- 
decomposed leaf-mould, and one part of silver sand, taking 
care that the drainage of the pans is perfect ; the seed 
should be covered very slightly, the pans placed in a 
Cucumber-frame, (or any other,) ata temperature of about 
75°. The frame should be shaded to intercept the 
direct rays of the sun, and the shading should not be 
removed until the young plants have expanded their third 
or fourth leaf ; by this time they will have struck deep 
root into the soil, and will be able to stand the fall rays of 
the sun. By the middle or end of June the 
will be fit to pot off; they may be potted in 60-sized pots, 
in the same kind of soil as that recommended for the seed, 
returned to the frame and shaded again for a week or ten 
days, and at the end of that time they will be able to 
stand full exposure to light. They may remain in the 
frame till the end of September—care being taken to admit 
more air and give less artificial heat as the season 
advances. After a time they will become hardened, and 
may be removed to a warm dry shelf in the greenhouse, 
where they may remain until the first week of February. 
While in the greenhouse they should have as much water 
as will keep them from flagging, but no more—no plant is 
more susceptible of injury from wet at this season of the 
year than this is, About the first week of February they 
may be removed into a Vinery where forcing has com- 
menced, or into the Pine-stove or Cucumber-frame, and 
with increased heat receive an increase of water. When they 
have been growing in heat for a week, if you turn one 
of the plants out ofits pot, the roots which were produced 
in autumn (that have remained comparatively dormant all 
winter) will be found breaking out into an abundance of 
young lateral fibres ; if this is the case the plants may be 
shifted, either on the progressive or ‘ one-shift’’ system. 
I have grown them successfully both ways: if the latter sys~ 
tem be adopted, a 16-sized,‘or, at the largest, a 12-sized pot 
