G6 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. [ January 25, 1883. 
materially interfering with the utility of the structure. 
Some of the best Grapes I have seen this season, and 
which were bought in this district, were grown in a glass 
corridor originally constructed for the purpose of afford¬ 
ing a covered way between a private house and an 
office. A friend of mine grows Cucumbers in an engine 
room, and we also hear of similar places being utilised 
for plant culture. Glass is of necessity freely employed 
in the construction of railway signal boxes, and most 
of us have seen many of these gay with healthy pot 
plants. 
One other example of the advantages of a glass roof 
and I have done. Several years ago I walked a con¬ 
siderable distance to see the crops of fruit hanging on 
a number of trees grown under a timber shed owned 
by a builder at Beeston near Nottingham. If I remem¬ 
ber rightly ihe glass roof was supported at the back by 
a low garden wall, and in the front, which was highest 
and open, with pillars at wide intervals. Here was 
stored a great quantity of timber, while the roof was 
covered with Apricot, Peach, Nectarine, and Plum 
trees. The fruit of the former had been picked, but 
the others were beautifully fruited. Pitmaston Orange 
Nectarine and Coe’s Golden Drop Plum were particu¬ 
larly fine. The trees were standard-trained, and I 
believe were planted and trained under the surveillance 
of the late Mr. Pearson of the Chilwell Nurseries.— 
W. Iggulden. 
CURRENT TOPICS. 
INSECTICIDES—CARBOLIC ACID AND METHYLATED SPIRITS— 
WATERING, VENTILATING. 
There is nothing, I quite agree with W. Litchfield of 
Coventry, like soft water and the syringe as an insecticide. If 
plants are kept in good health by proper care and attention in 
watering and syringing there is not the same need for insecti ¬ 
cides, and a little soft soap in the water used at a tempera tire 
of 120° to 130° will do no plants harm, and is a pretty sure 
remedy against red spider, thrips, and green fly. I am, how¬ 
ever, very much surprised that so many persons still recommend 
tha most dangerous insecticide under its different names of 
paraffin, petroleum, kerosene oil, &c. It is quite insoluble in 
water. No doubt with soft soap, soda, and constantly working 
the syringe into the mixture it may for a time he separated 
into smaller particles, but it is almost always left behind on 
the leaves in its original form of paraffin, and nothing is more 
destructive to tender foliage than it is. The smell, too, which 
is left behind when a house has been freely syringed with it, 
is enough to drive anyone out of it for many days, and, after 
all, it will not kill mealy bug. 1 have found carbolic acid 
much safer to use ; merely the common commercial carbolic 
acid. 
One of the simplest ways is to get half a dozen dr more clear 
quart winebo'.tles and place in half of them about an ounce of 
carbolic acid each, then fill up with soft wa er. When the 
acid, which is heavier than the water, has settled pour off the 
liquid, which will be nearly clear, in o one of the empty 
bottles, and continue the process till all the acid is dissolved. 
The result is a saturated solution, as pure soft water is capable 
of dissolving, according 1o the strength of the carbolic acid, a 
certain per-centage. This solution may be corked for use, and 
about one part to ten be added in the water used for syringing. 
It is especially useful for scale and the white aphis, and one 
advantage is that it does not leave the same unpleasant smell 
behind, nor does it injure paint as soft soap and paraffin does. 
It is better no, to use it too strong with tender young foliage, 
but plants that have stiffer foliage, such as Camellias and 
Cyclamens, can bear it stronger. 
I have also found methylated spirit a very useful application 
to destroy mealy bug, used with a feather or camel’s-hair brush 
in places where it is difficult to remove with a sponge. Take, 
for instance, the flower of the Poinsettias in the centre of the 
brae is, and those of the Stephanotis when first showing buds. 
May I ask those who have tried fir-tree oil whether there is 
any practical difference between it and pure turpentine, which 
I have of en used in very weak solution, especially for black 
aphides on Peach trees in a small unheated Peach house, 
syringing afterwards with pure water ? 
While speaking of the free use of soft water, I can quite 
corroborate the remarks of one of your correspondents on the 
subject of watering plants, especially, I may say, in winter 
and early spring. I find it most difficult to make persons 
who are not thoroughly experienced in watering understand 
when to water and how to water. So many men water all the 
plants in a house, when they are told to water, indiscriminately, 
whether they are in large pots or small, or whether they are 
dry or not, or whether exposed to the action of hot-water pipes 
or standing in the cooler parts of the house. I remember once 
in a friend’s garden being asked by the gardener what to do 
to prevent Calceolarias damping off. He took me to see them, 
and I saw the bedding Calceolaria amplexicaulis and C. aurea 
floribunda in small pots on shelves in a vinery facing the 
south, catching every ray of sun there might be, and flagging 
by want of water. He was rather surprised when I told 
him the only chance was to take them down from the shelf 
and plunge each in a bucket of water, and then to stand them 
in the coolest place he could find ; and he was still more sur¬ 
prised when I told him that none of my bedding Calceolarias 
were ever inside a house, but were always struck in the open 
ground with a frame over them, and merely protected by litter 
in severe weather. Some persons, again, only keep the surface 
of the soil damp, giving a slight sprinkling with a rose on the 
surface, whereas the roots may be as dry as ever. Others, 
again, when the pots are thoroughly dry and the soil cracked 
away from the sides, hear the water go through, and think that 
the plant must be properly watered. Nothing in my experience 
injures plants more in winter when fire heat has to be kept up 
than allowing them to be too dry at the roots, especially wffien 
on open staging over hot-water pipes, for when once the leaves 
of a plant flag by want of water the younger and tender 
rootlets are sure to suffer. 
The question of ventilation, too, which has much to do with 
watering, has cropped up in your last issue. For my part I am 
sure that in winter very little ventilation is ever required, as 
hot-water pipes secure a constant circulation of air. I have 
openings in the brickwork under the stages with moveable 
shutters worked by means of a cord, and air is supplied under 
the plants so as to come in contact with the hot-water pipes 
before it is admitted to the house. What we have to avoid is 
cold draughts, which are not necessary for securing a proper 
change of air.—C. P. P. 
TASTES IN FLORICULTURE. 
In his note on “ Horticulture in 1882 " “ D., Deal," speak¬ 
ing of the “ craze for single Dahlias” (page 5G) says, “ The 
craze has, I think, been evidently encouraged by the granting 
of seven certificates for single Dahlias in one day by the Floral 
Committee.” Will you allow me to remind him and your 
readers that on this occasion the two largest growers exhibited, 
and that a great part of the tables on both sides of the Council 
room were covered with endless new varieties of colour, 
making a display which will not soon be forgotten ? The 
Floral Committee selected seven out of the hundreds for first- 
class certificates—that is, they marked seven single Dahlias as 
being in their opinion far in advance in colour and form, and 
as being very desirable plants, but did not in any way con¬ 
sider the comparative merits of single and double Dahlias. I 
think, judging from the opinions expressed by people about 
here, considered of taste, on single Dahlias grown in a neigh¬ 
bour’s garden, the craze is likely to be an enduring one. There 
is no doubt that there are situations in some gardens suitable 
for single Dahlias where the most beautiful of the doubles 
would be out of place, unless, perhaps, some of the beautiful 
little Pompons which Mr. Turner has brought to such perfec¬ 
tion. It seems to me best to enjoy one’s own hobbies, and let 
others enjoy theirs. The bountiful mother Horticulture has 
