128 
THE COTTAGE GARDENER. 
[November 28. 
fruit of reddish yellow colour, and produced in abun -1 
dance, making the tree look very rich late in the 
autumn; and if not devoured by birds, which are fond 
of it, it dries on the tree, and hangs in black clusters all 
the winter. It is a native of North America, and grows, 
I on good soil, to a large tree from 20 to 30 feet high. 
C. macrantha (The Long or Lai'ge-spined Thorn.)— 
Very long stiff spines, and large plain leaves, with 
shining red fruit, produced in large clusters and early, 
are the chief characteristics of this one; besides, it always 
looks healthy, and does not come to a large size for 
many years, therefore, it is one of the best of the large- 
leaved sorts for small gardens. A native of North Ame¬ 
rica, with very succulent fruit for a thorn. 
G. Oliveriana (Oliver’s Thorn).—A very distinct variety 
of the common hawthorn, with small hoary leaves 
deeply cut, with small hlack fruit, very numerously pro¬ 
duced, and are very ornamental in the autumn. Well 
worth having. 
G. heterophylla (Various-leaved Thorn).—This is a 
fine, large, beautiful species, with numerous small red 
fruit in the autumn, and loaded with dense clusters of 
sweet-scented white flowers early in the season. Sup¬ 
posed to be a hybrid between the common thorn and 
the Azarole. 
C. punctata (Dotted-fruited Thorn).—A very desirable 
kind from North-west America, where the native Indians 
make wedges of it to split other wood with. There are 
three other forms of it, which were got from seeds in 
this country, one of which has yellow fruit, and another 
with purplish large fruit, and an upright way of grow¬ 
ing, which they call fastigiate ; all four have a fine 
appearance in the autumn. 
G. glandulosa (The Glandular Thorn).—Native of 
North America—from Canada to the Rocky Mountains, 
with large red fruit; very spiny, and a dense bushy way 
of growth. Of all the American thorns, it is the best to 
form hedges with. 
C. crus-galli (The Cock-spur Thorn).—Every one 
knows the Cock-spur thorn, or ought to know it; the 
spines are long, and curved backwards a little like a 
cock-spur, hence the name. It is a liealthy-looking tree, 
owing to the smooth dark-green shining leaves, which 
are not cut up into lobes like many of them, but only a 
little notched on the edges. In good land and warm 
situations, it holds the leaves on till very late in the 
winter; the fruit, which is of a dark red colour, hangs 
also very late. It is one of the American thorns, and 
one of their very best. 
G. Douglasii (Douglas’s Thorn).—Poor Douglas! the 
gardeners never look on your namesake without regret- 
ing your unfortunate end. The little Primwort, which 
also commemorates your name, and which you found in 
bloom on the Rocky Mountains, with a wreath of snow 
for a mantle, we shall never forget. I wish I had no¬ 
ticed this fine and very distinct thorn sooner, as I can 
never write about my brave countryman without de¬ 
pressing the spirits. The fruit is small, purplish , and 
ripe in August. The leaves are the thickest or most 
leathery of all the thorns. It is one of the latest to 
come into leaf, and they fall off early—fit emblems of 
its discoverer’s short appearance on this stage. 
D. Beaton. 
GREENHOUSE AND WINDOW 
GARDENING. 
Ventilation and Collateral Matters. —Various 
inquiries having been made, I shall in a random manner 
throw a few ideas together upon the subject. Ventila¬ 
tion is the act of getting rid of noxious vapours, expel¬ 
ling impure air, and supplying then place with those 
which are pure. According to the knowledge or skill of 
the operator, this act will be followed by buoyant health 
and luxuriance, or attended with danger and ruin. The 
air long looked upon by our forefathers as a simple 
element of nature, is now recognised as a compound 
body, consisting chiefly of nitrogen and oxygen,—79 
parts of the former and 21 parts of the latter, with vary¬ 
ing proportions of carbonic acid gas and water in a 
state of vapour—the former from one-iive-lnmdredth to 
one-thousandth part, and the latter, on a rough calcu¬ 
lation, about one part in a hundred, but varying in 
proportion, according to the temperature and the dry 
or moist situations over which the air is placed. 
Invisible, elastic, inodorous, and tasteless, air is the 
great vehicle for the transmission of light and sound, 
the wafting of odours, and the diffusing of contagious 
malaria. ' The chief changes experienced are owing to 
heat, moisture, motion, and light. Though invisible, the 
air possesses the usual projierties of matter, such as 
compressibility, weight, &c., and is, like other material 
objects, influenced by chemical action. It may well be 
considered the great laboratory in which are conducted 
the various processes of organic existence, be that exist¬ 
ence animal or vegetable. The state of the air, there¬ 
fore—its changes, its heat, its elasticity, its dryness, its 
comparative freedom from, or its being loaded with other 
substances, either in a gaseous, aeriform, or a vapourised 
state, its brisk breezy action, or its stillness and re¬ 
pose—must ever exercise a favourable or unfavourable 
influence upon the phenomena of life. In a greater or 
lesser degree, these matters must be considered, before 
intelligent people, like our inquiring friends, can resort 
to the processes of ventilation in such a manner as to 
feel the satisfaction in their own minds that they are 
doing wdiat is right. In this, though sometimes attended 
with disappointments, consists the superior pleasure in 
conducting operations upon an understood well-defined 
principle, over that enjoyed in working merely by rou¬ 
tine, and conducting experiments in the dark and at 
hap-hazard. In the one case, our chart may deceive us 
and we may mistake its teaching; in the other, we are 
groping our way without chart or compass at all. One 
striking feature of The Cottage Gardener is, not 
merely to expatiate upon the modes as to the hows, but 
to give the reasons as to the whys. 
Of all other classes none are more indebted to the dif¬ 
fusion of cheap knowledge and benevolence of feeling 
combined than the young gardeners of the present day. 
Even when the ventilation of their plants and forcing- 
houses was deemed of such import, that hi changeable 
weather, in order needlessly to keep them at a given 
degree, they were under the necessity of jumping about 
like lamplighters, abridging or enlarging the quantity of 
air, just as the sun was covered by, or had emerged from, 
a cloud. There was so little, nay so much of no attention 
at all to the securing a pure air in the miserable hovels 
in which they were often lodged, that the wonder is, not 
that gardeners as they became old were the victims of 
decrepitude and rheumatism, hut that alter passing 
through such ordeals they should ever be old at all—-a 
consummation which when it did take place, after 
being situated in such circumstances, was generally 
owing to the pure ah and invigorating exercises of the 
day neutralising, to a certain extent, the baneful influ¬ 
ences of the dark, murky, confined receptacles in which 
they alike lived and slept. Owing, as we have seen, to the 
diffusion of cheap knowledge, combined with the spread 
of beneficence,—owing to the practical recognition of the 
principle, that a man cannot live for himself, but that Iris 
happiness must be identified with the happiness of 
others,—the highest and noblest of our aristocracy think 
it nought beneath them to investigate the means of 
health in the abodes of their humblest dependants; and 
thus the miserable lean-to bothies in gardens are giving 
place to airy and roomy structures, and means are afforded 
