64 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, May 3, 1859. 
had, indeed, already been accomplished, although analysis had 
proved that the amount of tannin which these galls contain is 
much less than that contained in the ink-galls of commerce. 
Mr. Westwood exhibited some of the portable cases formed by 
the larva; of the little Moth Coleophora gryphipennella, and which 
infest Roses both in greenhouses and in the open air at this 
season. 
Mr. White read the description of one of the new species of 
Beetles received from New Guinea from Mr. Wallace, to which 
he applied the name of Demochroa carinata. It belongs to the 
splendid family Buprestid®, of which we have scarcely any repre¬ 
sentatives in this country—the most brilliant being inhabitants of 
the tropics. 
THE SCIENCE OF GARDENING. 
C Continued from page 54.) 
To plants in pots, good drainage is not less essential than to 
those in our borders. 
To secure this, not only should at least two inches of broken 
potsherds and rubbly charcoal be placed beneath the soil put into 
pots, but the soil itself should be allowed to retain its pebbles, 
instead of having them sifted out, as was the ancient practice. 
The soil must vary according to the nature of the plant; but 
whatever be its quality, instead of being sifted fine, as gardeners 
formerly directed, let all the small pebbles remain, and pieces of 
charcoal, none smaller than nuts, be mixed so as to pervade the 
earth at distances of about two inches. Let the whole rest upon 
a drainage composed entirely of charcoal, the pieces not less than 
small walnuts. This treatment, suggested by nature, but first re¬ 
commended by Mr. Barnes, of Bicton Gardens, secures acceptable 
food to the roots, and prevents the occurrence to them of that fatal 
evil—stagnant water. Let the plants once a year be taken out of 
their pots, their heads reduced in size, and a portion of the 
exterior roots removed. Let them be returned into the same 
pots, with similar attention to the soil and drainage; for it is an 
inconvenience mostly growing out of error, to give them larger 
pots annually. Mr. Knight grew even a Nectarine tree for more 
than nine years in the same pot. This restriction to small-sized 
pots cannot be always effected; and when shifting is necessary, 
it is advisable to remove, as much as possible, the old soil, of 
course without injuring the roots. This i3 generally best effected 
by soaking the ball of earth in water : and thus it may be washed 
almost entirely away, and the roots be left coated with a mud 
that is beneficial to them, and preserves them from drying, until 
the fresh soil is well settled about them. The number of roots 
within a given space of soil is much larger than when the plants 
grow in the open soil; for, being restrained by the side of the pot, 
they fork into numerous fibres, spread over its surface and even 
turn inwards again in search of food, they being gifted with the 
power of forming an extra number of radicles whenever deficiency 
of food renders such compensatory power necessary. The gardener 
endeavours to render it needless, by supplying the plants with 
liquid manure. But this richness of pasture can only be per¬ 
mitted to a certain extent; for if a plant is so well supplied with 
food as not to render a certain consumption of its proper juices 
in forming roots requisite, so much more of those juices is stored 
in the stem and branches, rendering the plant over-luxuriant, 
and, consequently, unproductive of flowers and fruit. 
Mr. Barnes observes that the common earth-worm is too 
generally regarded as an enemy ; whereas, by its perforations of 
the earth, it facilitates the admission of air to the roots of plants : 
and we have found that thrusting a knitting needle down through 
the soil of potted plants, as well as stirring its surface, is highly 
beneficial. 
Hunt’s pots, supported by small feet, are well calculated to 
facilitate drainage ; and, by permitting the passage of air beneath 
the pots, they also admit it more readily to the roots. 
Drainage, however, is not the only desideratum to potted plants, 
for they have many other difficulties to contend against, from 
which those in the open soil are preserved. The soil, at a few 
inches below its surface, is always, during winter, some degrees 
warmer than the exterior air ; but, owing to the evaporation from 
the sides of garden-pots, this is rarely the case with the soil in 
them. To preserve this salutary warmth to the roots, a double 
pot has been suggested, but placing the plant-pot within a larger 
pot, and stuffing moss in the interval between them, is a cheaper 
and readier safeguard. 
The importance of following the dictates of nature in keeping 
the roots of plants, natives of the torrid and temperate zones, as 
warm or warmer than the branches, was too much neglected by 
the gardener in his forcing department. In the vinery, for ex¬ 
ample, the stem and roots are even now too often absurdly exposed 
to the rigour of winter; whilst the buds are expanding within 
the glass shelter in a temperature of 60°. A Yine so treated 
is like the felled Elm, which, allowed to retain its bark, though 
rootless, puts forth its leaves in the spring; expands its buds, and 
advances through the first stages of growth, merely from the sap 
stored within its stem and branches. This is no mere suggestion 
of fancy; for repeated experiments have shown that hot-house 
Vines, with their roots thus kept torpid by exposure to cold, 
were with buds unfolded; whilst other Vines, treated in all 
respects similarly, but with their roots kept genially warm, were 
actually in bloom. 
But a worse mischief arising from this absence of reciprocal 
action between the roots and branches is the causing of disease. 
Thus the shanking and spot in Grapes, occur apparently from the 
roots not supplying the sap so fast as the expanding fruit requires 
it. The application of more warmth and genial moisture to the 
soil usually arrests the progress of these diseases. They are 
really like mortification in the animal frame. If the necessary 
supply of blood is not given to any part of the human body, as 
by cutting in two a main artery, that part becomes cold, shrinks, 
ulcerates, and mortifies. 
Although an excess of water applied to the roots of plants is 
injurious to them, yet all of them are benefited by a due supply' 
of that liquid, and the supply has to be regulated by the amount 
of their daily transpiration. The gardener knows that this differs 
in every species, and during different seasons. For instance, in 
a dry hot day, a Sunflower, three feet and a half high, transpired 
1 lb. 4 ozs., being seventeen times more than the human body ; 
during a hot, dry night, it transpired 3 ozs.; during a dewy night 
there was no transpiration; and during a rainy night the plant 
absorbed 3 ozs. 
Therefore, the gardener finds it best to apply water during dry 
weather, early in the morning, just before the chief demand occurs, 
which is from six A.M. till two in the afternoon, or in the evening 
whilst hot weather continues, for the dews then supply the chief 
natural moisture at night; and during moist weather he refrains 
from the application entirely. Then, again, the gardener keeps 
his Agaves and other fleshy-leaved plants in a dry stove, for they 
transpire but sparingly in proportion to their mass, and require 
watering but seldom, and then abundantly ; for they take up, as 
in their native siliceous soils, a large supply, and retain it per¬ 
tinaciously in defiance of the long-protracted droughts to which 
they are exposed. 
In the same species we have always found varieties transpire 
abundantly, and require a larger supply of water in proportion 
to the extent of their transpiring surface. Thus the broad-leaved 
Fuchsias and Pelargoniums transpire from two to threo times as 
much as those varieties which have smaller and less abundant 
foliage.—J. 
(To be continued.) 
ALOES AS AN INSECT SLAYER. 
I see you are alluding to Aloes for destroying insects ; and I 
can assure you that I have not used anything else for the purpose 
during more than a year past, and I have a friend who has done 
the same. We soak a pound of Barbadoes Aloes in two quarts of 
hot water, then add cold to make it up to six gallons. With this 
liquor you may dip or syringe as you like. Small plants I dip in 
the tub ; and the large ones I syringe, leaving them for a day or 
two, then washing them afterwards with clean water. It is ex¬ 
cellent for fruit trees till the fruit sets, and then the Aloes are apt 
to make the fruit taste. I have not used any tobacco for any 
plant since I tried this. 
I do not know how you will account for it, but I sent you the 
result of my trial in the month of October last, being the time I 
dipped all my Pelargoniums in a large tub of it previous to 
housing them. As I fancied I had made a mistake in the quan¬ 
tity, I wrote again the next day, so there were two letters in one 
week, and I felt very much surprised they were not noticed in 
your work. I have written others to you, and received answers 
to them, and thank you for the same; but I do think it very 
strange those letters were not acknowledged. 
My friend is Mr. Tilley, of the Barking road ; if you ask him 
he will tell you how useful it is to him. He says it does not cost 
one-third for Aloes that it did for tobacco. We pay Is. 6d. 
