544 JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. [ December 14,1882, 
being furnished with five spreading spurs, giving the flowers a 
totally different appearance. The species itself is an attractive 
plant, but this variety is superior to it, as the flowers are produced 
so abundantly that they form a dense spike 6 to 9 inches or more 
in length, and of an extremely pleasing yellow colour. As a garden 
plant it is much appreciated both on account of its peculiarity 
and its beauty, and as it is readily increased by its roots a stock 
can soon be obtained. Occasionally fine specimens may be seen 
at exhibitions where classes are provided for hardy plants, and 
they form some of the most effective for such collections. 
Though not very common, this Linaria has been long known 
both to cultivators and botanists, and in the sixth fasciculus of 
Curtis’s “ Flora Londinensis ” are given some interesting par¬ 
ticulars concerning the history cf the plant, as follows :—“ The 
earliest account that we find of the Peloria is in the first volume 
of the ‘Amoenitates Academicae’ of Linnaeus, published in 1749. 
It there forms a distinct thesis or dissertation written by Daniel 
Rudberg, who enters minutely into the history of the plant, 
describes it fully, and illustrates it by an engraving. The plant 
appears to have been first discovered in the year 1742 growing in 
a province of Sweden about seven miles from Upsal by a botanical 
student named Zioberg, w T ho gathered a specimen of it, and placed 
it in his herbarium as a plant he had not met before.” Professor 
Celsius observed this specimen, and called the attention of Lin- 
n;eus to it, who secured plants for the Botanic Gardens at Upsal. 
Linnaeus, it is said, at first considered it a new genus, but further 
examination proved that it was only a variety of Linaria vulgaris, 
or Antirrhinum Linaria as it was then termed. Plants of the 
variety Peloria have been found wild in several parts of Great 
Britain, but it is very rare. 
DEW IN HOTHOUSES. 
I Am much obliged to Mr. Taylor for his offer to answer queries 
on this subject privately ; but I am not at present seeking infor¬ 
mation in that way, and I feel sure you will not think I am 
occupying your pages frivolously in returning shortly to a subject 
on which Mr. Taylor has said “ his whole theory and practice of 
giving air is entirely based,” and which he says he is quite alive 
to the importance of. I think the subject is both interesting and 
important; and the question is not one of answering elementary 
questions, but whether the theory laid down by Mr. Taylor to 
your readers is the correct one. If I misunderstood Mr. Taylor 
on the subject of the dew-point, and he means what I mean and 
explained on that point, then it seems he does not differ from 
“W. Y.,” who, he said, was right on the subject of dew outdoors 
but w T rong on dew in hothouses. Mr. Taylor makes it appear 
that the cause of the production of dew uuder a rising tempera- 
t are is distinct from that which takes place from a falling tem¬ 
perature, which is not the case. In both cases the cause is a 
lowered temperature coming in contact with a warmer one and 
producing condensation. To assert anything else is contrary to 
the text books and only tends to confuse the reader. Neither do I 
think Mr. Taylor is at all correct in teaching that “ a dew deposit 
in any way is one of the things we have to guard against” with 
a few exceptions in the case “ of decorative plants that have not 
very soft foliage,” &c. This idea of Mr. Taylor is to me quite 
new as well as directly opposed to the teachings of Lindley and 
others, who have pointed out that the absence of dew in hothouses 
wa,s not an advantage but one cf the distinct drawbacks of arti¬ 
ficially heated glass houses. Speaking of dewing in hothouses, 
Lindley advocates it by every practical means, observing that “ in 
this as in all things else the operations of Nature should be imi¬ 
tated with all the. exactness possible.” Dewon Vines, Peaches, 
or plants at night is one of the most satisfactory signs I know of, 
especially when the plants are growing, but it is never seen 
hardly except after hot days when pipe heat has been dispensed 
with during the night, when dew is always condensed or deposited 
on the leaves.— Casual. 
The subject of dew on plants in houses has been lately dis¬ 
cussed ; but the question of the deposit of dew on the leaves of 
plants in glass structures, and more particularly on Grapes, rests 
on one simple fact. All cultivators of the Vine under glass must 
have observed that when air is not admitted sufficiently early dew 
will be deposited on the berries, and more especially when the 
temperature inside is not obtained artificially ; and if air is not 
then admitted very carefully scalding of the foliage and rust on 
the berries will be the result. If the temperature is artificially 
raised internally the foliage, fruit, and every object in the house 
is of the same temperature, and moisture will not then be con¬ 
densed, Mr. Taylor evidently understands the question of dew- 
iormation, and his practice is to raise the inside temperature early 
in the morning, admitting air also early, so that no dew shall be 
deposited. This appears to be the whole of the argument, and, 
so far as my knowledge goes, is all that Mr. Taylor professes. 
My opinion is that much of the scalding of- which we frequently 
hear complaints and see examples is due to too low a night tem¬ 
perature being maintained, and that the fires are not pushed on 
rapidly enough early in the morning, the sun then acting on the 
Vines with increased power however early the ventilators are 
opened.— John Gadd. 
ROSES FROM CUTTINGS. 
I have tried three methods of Eose-growing, and now give the 
results of my experiments. 
1. On the 29th of July, 1881, I inserted in a bottomless box 
cuttings from Gloire de Dijon, Coupe d’Hebd, Duke of Edin¬ 
burgh, Princess Louise Victoria, Marie Baumann, Madame Moreau, 
Miss Ingram, and Xavier Olibo. I covered the box with a sheet 
of glass and made it air-tight. I kept it closed for fully a month, 
and then opened it in fine weather and supplied water as was 
necessary. I kept on the glass during last winter. The cuttings 
of Miss Ingram and Xavier Olibo all failed ; of the others 40 per 
cent, have succeeded, and these are now well-rooted plants. 
2. On the 1st of November, 1881, I planted out in the open air 
a number of cuttings from twelve varieties of Eoses. I protected 
them with litter during the winter, and watered them in spring 
when necessary. From these I have very few plants, and only of 
three kinds—Gloire de Dijon, La France, and Duke of Edinburgh. 
Only 11 per cent, of those slips succeeded. 
3. On the 30th of November, 1881, I inserted under a hand¬ 
glass cuttings from Camille Bernardin, Sir Garnet Wolseley, 
Thomas Mills, Duchess of Edinburgh, Gloire de Dijon, and of 
these 90 per cent, have succeeded. 
But, notwithstanding my many failures, I am happy to say that 
from these slips I have at this time (1st November) a goodly num¬ 
ber of excellent well-rooted plants, and I have tried all the three 
modes this season again. 
I may add that the soil is rich loam, and that I mix a good 
quantity of river sand with it.— Amateur, Strathbogie. 
CULTURE OF HORSERADISH. 
The present being a good time to prepare for next year's 
supply of Horseradish, I offer a few remarks which, if followed, 
cannot fail to bring some first-rate roots, young and tender, the 
produce of one year’s care ; and instead of having to dig perhaps 
a rod of ground to find one stick that is presentable, the first 
may be taken with the certainty of its being good. Prepare a 
portion of ground large enough to grow one year’s supply by 
trenching, or, what is better, double-digging, and apply a dressing 
of decayed manure as the work proceeds, and let it remain rough 
on the surface exposed to frost till March, which will be the 
month for planting. It is often said that any corner will grow 
Horseradish, but experience teaches that open ground will grow 
it best, and when well managed a few rows of Horseradish look 
well in any garden, whereas on the old corner principle it is 
generally overrun with weeds, and will, if the old saying be true, 
give trouble for seven years. 
To prepare the sets take the long side shoots, any size up to the 
size of the little finger, and from 8 inches to 1 foot in length, 
then with an old blunt knife carefully scrape off the little side 
roots to within an inch or two of the bottom, rub them with an 
old piece of cloth, tie the roots in bunches of two dozen more 
or less, and bury them in soil or ashes in the bunches level with 
what will be the crowns, then when planting time comes examine 
them and break away any growths they may have made except 
two or three at the crown. If properly done there will be no 
roots but those on the portion left for that purpose at the bottom. 
By this method we not only get it straight but rootless as well, 
consequently it can be easily scraped for use, and being of one 
year’s growth is young and tender. The sticks will vary from 
1 to 2 inches in diameter, according to cultivation. 
In March mark out the number of rows required from 15 to 
18 inches asunder, and dibble the roots in 15 inches apart in the 
rows, or, better still, with the spade dig out a trench the required 
depth and place them at the side by the line, filling the trench 
firmly, just covering the crowns. Keep them free from weeds, 
and lift the roots any time after the leaves have died ; prepare 
sufficient side shoots for the next year, and lay the remainder in 
to be used as required. 
I may add that an article on the culture of Horseradish ap¬ 
peared in the Journal of Horticulture four or five years ago. 
Since that time I have grown mine on the principle there recom- 
