THE COTTAGE GARDENER A AD COUNTRY GENTLEMAN, August 21, 1360. 
315 
They do not consume above £1 worth of gas coke per annum 
each. I have a similar stove in my lobby, warming the staircase 
and passages. 
As on the former occasion, I send you a few of the Grapes to 
prove that they may be well grown in a house so heated; and 
my careful gardener kept on the narrow shelves in the green¬ 
house about 1200 plants during the late severe winter, and oidy 
lost six. [The Grapes are very fine.] 
Six years ago, wishing to build an additional greenhouse with 
a span-roof, I turned my attention to heating by hot water. The 
power it possesses is remarkable, and one boiler will heat so 
great an area, and there is so much advantage in having a single 
fire to attend to, that for any extent of heating it is certainly the 
best system. 
I may here remark that I think I have adopted a much better 
plan than the usual one—of placing the return-pipe underneath 
the flow-pipe by continuing it round the house, of course in¬ 
serting the air-pipe at the highest point. This equalises the 
temperature. In a small stove adjoining I find that by adopt¬ 
ing the double junction, which I found in Mr. Jones’ advertise¬ 
ment in your journal, and keeping two pipes on the same level, 
I gained much more heat than if the water had been returned 
in the usual way. 
Many questions are asked respecting heating small greenhouses 
by gas. Two years ago I was struck with the simplicity of Por¬ 
ter’s National Gas Apparatus, manufactured at Lincoln in my 
own neighbourhood, I put it up, and find it works well. My 
house and stables are perfectly lighted at a small cost. If he 
does not advertise in your journal I tell him he should do so ; 
and as his apparatus lias for three years got the prize from the 
Highland Society of Scotland, where gas is much more used and 
understood than it is in England, I think I must be safe in 
recommending it. 
Having got gas, I next look how to apply it to horticulture. 
The stove made by Ivukla, Pentonville Road, I think deserves 
your inspection. In the combustion of gas mixed with atmo¬ 
spheric heat it produces moisture, and thereby, I should think, 
counteracts the noxious air, which we know in ordinary gas¬ 
burning is so detrimental to plants. I made a hurried call there 
on my way to the Great Northern Railway. The cost is trifling, 
and he said he was placing them in greenhouses, so you may be 
able to trace the result, which I cannot do.—A. L. M. 
THE SCIENCE OF GARDENING. 
(.Continued from page 301.) 
THE FRUIT AND SEED. 
When the blossom begins to fade, “the joy of the plant ” is 
departing, but other beauties and parts more important to the 
animal world are advancing to succeed the decaying inflorescence. 
The fruit and the seed are then entering on the season of maturity; 
will soon offer to the palate some of our most delicious luxuries, 
nor will beauty of colour be altogether wanting. “ The ripened 
tints of autumn are equally pleasing with the bloom of spring, 
and the colours of the Peach and Apricot, the Plum and Cherry, 
are in nothing inferior to the blossom which preceded them.” 
The petals, stamens, pistils, and frequently the calyx, having 
performed their destined functions, fall and leave the ovary, or 
embryo seed-vessel, remaining attached to the parent plant. The 
embryo increases in growth and becomes the fruit, which title is not 
restricted merely to such as are edible, but includes every matured 
ovary with its contents, and which matured ovary, in botanical 
language, is known as the pericarp. This takes various distinct 
forms, and as all are subjects of interest to the gardener, each 
may have advantageously a separate notice. 
1. The capsule is dry, woody, or membranous, containing one 
or more cells—as in the Poppy, Clematis, Ash, and Pteony. 
2. The siliqua, or pod, is long, dry, and has two valves sepa¬ 
rated by a linear receptacle, along the edges of which are ranged 
the seeds alternately. Instances are in the Stock, Wallflower, 
and Cabbage. 
3. The legume has two dry, long valves united by a seam at 
their edges, having no dividing receptacle as in the pod, but with 
the seed attached to one edge—as in the Pea, Beau, Laburnum, 
and other leguminous plants. 
4. The drupe, or stone, with fruit usually soft and fleshy, not 
separating into valves, but enclosing a woody nut to which it is 
attached—as in the Peach, Plum, Olive, and Cherry; but some¬ 
times the fruit is more dry—as in the Almond and Cocoa Nut. 
5. The pome, or apple, is usually fleshy like some drupes, but 
enclosing a capsule with several seeds, instead of a nut—as in the 
common Apple and Pear. 
G. The berry is pulpy, and has its seed embedded in its sub¬ 
stance as in the Asparagus, Currant, Gooseberry, Strawberry, 
Raspberry, Potato, Orange, Melon, Cucumber, and Medlar. 
7. The strobile, or cone, is scaly, tough, and woody, formed of 
the catkin or calyx which has become indurated. It is the seed- 
vessel of the Pine tribe, the Plane tree, and Comptonia. 
Though thus varying in form, they have all one common office 
—the protection and maturing of the seed they contain. To 
effect this they require a due supply of sap as well as of the 
peculiar juice of the parent plant; for they make no further 
advance if the entire wood be cut through below them, so that 
they are only attached to the parent by a strip of bark; neither 
will they advance, though fully supplied with sap, if the peculiar 
juices are cut off from them by removing the leaves that are 
above them on the branch. The loss of such leaves, as previously 
stated, may be supplied by inarching to the denuded branch one 
still retaining its foliage. We have also shown that the applica¬ 
tion of a ligature to a Peach or Apple, shows by the enlargement 
on one side of the ligature that the sap really circulates through 
them. 
Yet each fruit has a peculiar elaboration of its own to perform; 
for though the fluids afforded by the branches and leaves be 
nearly similar, yet each fruit differs from another in fragrance 
and flavour : six different varieties of the Peach and of the Apple, 
budded upon the same branch, still retain their particular tunes 
of ripening, and their distinctive colours and flavours. Now the 
processes going on at different periods of a fruit’s growth are 
very opposite in their character. During their green and growing 
state they are usually converting gummy matter into an acid; 
but during the ripening they as commonly are converting an acid 
into sugar. 
To convert gum or mucilage into tartaric acid, as in the early 
growth of the Grape, oxygen in excess should be absorbed; for 
their relative components stand thus :— 
Gum. 
Tartaric acid. 
Carbon.. 
. 43-23 
. 24-05 
Oxygen 
. 50-84 
. 69-32 
Hydrogen . 
. 6-93 
. 6-63 
100-00 
100 00 
They might, therefore, be expected to absorb more oxygen 
than tiie leaves; and this is actually the case, for though a Vine 
branch will continue to vegetate in a glass globe hermetically 
sealed, yet the Grapes upon it will not increase in size unless 
oxygen gas be from time to time admitted. The same pheno¬ 
menon occurs during the ripening of the Grapes; oxygen has to 
be absorbed during the conversion of the tartaric acid into sugar, 
but a larger volume of carbonic acid has to be evolved, and this 
is coincident with the result of well-established experiments, 
uniformly testifying that carbonic acid is given out abundantly 
by ripening fruit. “ Six equivalents of tartaric acid,” says Liebig, 
“ by absorbing six equivalents of oxygen from the air, form Grape 
sugar, separating at the time twelve equivalents of carbonic acid.” 
This, however, is not the only decomposition taking place 
whereby sugar is formed in ripe fruit; but there is sufficient 
reason to believe that its mucilage and starchy constituentsara 
converted into saccharine matter by the combined agency of 
warmth and the acids. It is thus that Apples are rendered so 
much sweeter by baking, and M. De Candolle states that the 
pulp of Apple dissolved in water with a vegetable acid is con¬ 
verted into sugar; that gummy matter obtained from starch 
and mixed with tartaric acid, aided by warmth, effects a similar 
transmutation ; and M. Kirchoff proved long since that starch, 
digested at a gentle heat with diluted sulphuric acid, becomes 
sweet. 
Dr. Kane observes that, “ If we examine the composition, of a 
voung Apple, we find it nearly tasteless, and to consist of a loose 
ligneous tissue, in which is embedded a quantity of ordinary 
starch; as its growth proceeds, the starch appears to diminish 
in relative amount, the fruit become sour, from the presence of 
! tartaric acid ; after some time the acidity bcomes of a much less 
disagreeable kind, and the tartaric acid is found to be replaced 
by malic acid ; whilst the tissue is found to be infiltrated with 
pectin or pectic acid; finally, in the next and concluding stago 
