112 THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, November 22, 1859. 
Dutrocliet gave the names of— endosmose denoting the inward 
progress, and exosmose the outward progress of the fluid. He 
supposed them to be due to the action of two opposite currents 
of electricity, and he likens the phenomena observed during the 
circulation of the sap in plants to the appearances presented 
during the above experiment. 
This hypothesis cannot be satisfactory; for such endosmose has 
no power sufEcient to sustain thirty-two inches and a half of 
mercury, as is done by sap propelled by the Yine, and it entirely 
fails to explain the discriminatory power possessed by the 
spongioles, as well as the fact that the sap will be ascending on 
the heated side of a tree, whilst it will be quite unmoved on the 
side which is cold. 
Thus propelled, the sap is distributed along each branch to every 
leaf, and to every fruit of the plant, gradually acquiring during 
its passage a greater specific gravity, not only by exhalation, but 
by dissolving the peculiar secretions of the plant formed during 
its previous year’s growth, and deposited in the alburnum from 
the sap during its downward course in the inner bark from the 
leaves. It is in the leaves that the chief elaboration of the sap 
takes place, and those peculiar juices are formed characteristic of 
the plant, and which are found deposited there, or in the bark, 
or still further altered in the fruit and seed. 
The ascending sap of the Yine, Elm, Beech, and some few 
others has been analysed, but the results are so similar that we 
need only particularise two. Dr. Prout, M. Robiquet, M. Deyeux, 
and others, agree in stating that the sap of the Vine ( Vitis 
vinifera ) has a specific gravity not greater than that of pure 
water, a fact explained by its containing much carbonic acid gas. 
Its taste is sweetish. When 2300 grains of it were evaporated 
to dryness, only one grain of solid matter remained, about half 
of wliich was saline, composed of tartrate of lime and bitartrate 
of potash, and the remainder was a gummy vegetable substance. 
Boussinghault has analysed the sap of the Plantain {Musa 
Paradisica), finding in it tannin, gallic acid, acetic acid, com¬ 
mon salt, and salts of lime, potash, and alumina.— {Journ. de 
Pharmacia , xxii., 385.) 
After being elaborated in the leaves the ascending sap is en¬ 
tirely changed in its qualities and constituents, and the descend¬ 
ing sap is found to be either milky, gummy, resinous, astringent, 
sugary, acid or saline. 
Milky descending saps. —We will only particularise that of the 
Lettuce ( Lactuca sativa). This contains albumen, caoutchouc 
(Inclian-rubber), wax, chloride of calcium, phosphate of lime, 
potash, gum, nitrate of ammonia, acetic, with another acid, and 
a bitter principle called lactucarium. In this lactucarium the 
peculiar flavour and properties of the Lettuce reside. It has 
been employed in medicine as a substitute for opium, possessing 
its soothing without its iuconvenient properties. 
Gummy descending saps are familiar to us in the Cherry, 
Plum, and Peach; but, in truth, all descending saps are gummy, 
for cambium, the substance deposited in all those parts of vege¬ 
tables where growth is occurring, is chiefly gummy or mucilaginous 
matter. 
The resinous descending saps are familiar to us in the Coniferse ; 
and the sugary in the Carrot, Parsnip, and Beet. 
The saline and acid descending juices are still more varied and 
peculiar. Thus that of Wolf’s Bane ( Aconitum lycoctonum ) 
contains citrates of lime and potash; Delphinium elatum , Ra¬ 
nunculus aconitifolius, Thalictrum flavum , Clematis recta, and 
C. viticella, all contain similar combinations of citric acid; 
Clary ( Salvia sclarea ) contains benzoate of potash ; Rue {Ruta 
graveolens ) contains malates of potash and lime; Agrimony 
(Pupatormm cannabinum) contains phosphoric and another acid; 
Spinach {Spinacea oleracea ) contains oxalates of lime and 
potash, and malate and phosphate of potash; the common 
Indian Cress, or Nasturtium {Tropceolum majus ) contains phos¬ 
phoric, nitric, and malic acids united to lime and potash; Vir¬ 
ginian Poke {Phytolacca decandra) contains oxalate of potash ; 
and the Sorrels and Oxalises all contain an excess of oxalic 
acid.—J. 
{To be continued .) 
RESTING ORCHIDS. 
When should the season commence for resting the following 
Orchids— Cattleya crispa, C. bicolor, C. labiata (blooms cut 
November 10), C.Mossice, C. Skinneri, Dendrobium chrysanthum? 
I possess Williams’s “ Orchid-grower’s Manual 5 ” but his answer 
is, “when they have made their growth.” Now, unhappily, my 
Cattleyas, especially crispa, are always growing, and seldom 
blooming. Labiata blooms well in the same house; but I at¬ 
tribute this to being three weeks or a month in the window of 
the drawing-room whilst in bloom,—A Subscriber of several 
Years. 
[Cattleya labiata blooms in the autumn, consequently it should 
have its season of rest through the winter, and be started into 
growth about the middle of March, and perfect its pseudo-bulbs 
by the end of July. Cattleya crispa, bicolor, Mossiae, and 
Skinneri flower about May and June. Flowering so early there 
is time to make a good growth by the end of October, and then 
they also ought to rest through the winter up to the end of 
April. If such plants are constantly growing, there is some 
great mistake in their culture. The season of rest must be 
enforced, or no flowers will be produced. The way to obtain 
this rest is to lower the temperature of the house in which they 
grow to 45° by night and 55° by day, and also to lessen the 
quantity of moisture both in the air and at the root. When 
growing the heat should not exceed 65° to 70° in summer. The 
same treatment will suit Dendrobium chrysanthum, D. densi- 
jlorum, D. oculatum, D. pulcliellum, D. speciosum , and all Loelias, 
the New Holland species ; also all the species from Guatemala. 
If “ A Subscriber” has only one house, he should place all his 
Cattleyas and the hardier Dendrobes, &c., at the coolest end near 
the glass. The Indian species of Orchids—such as Aerides, tender 
Dendrobes, Saccolabiums, Phnlcenopses, and Vandas—must have 
a higher temperature, even when at rest. The proper tempera¬ 
ture for these genera is 60° to 65° in winter, and 70° to 85° in 
summer.] 
USE OF THE VEGETABLE MARROW, GOURD, 
AND POMPION. 
In the absence of Apples, ripe Vegetable Marrows, Gourds, or 
Pompions offer a substitute more agreeable to the palate and 
constitution than many persons will imagine who have not tried 
them; and it is remarkable that in the present year (1859), 
when Apples are scarcer throughout the breadth of the land 
than has been known for many years past, that the whole 
family of Pompions, from the Mammoth Gourd to the small, 
delicate Custard Marrow, should the same season be distin¬ 
guished for their greater abundance aud more perfect maturity. 
Indeed, the circumstance appears traceable to an all-wise inter¬ 
position of Divine Providence, to alleviate the disheartening loss 
of the Apple crop. The cause of this and similar failures of 
some other productions the last few years it is not our province 
to determine; but probably it has been the want of some hygro- 
metrical character in the atmosphere. 
Marrow, Gourd, or Pompion tarts, pies, and puddings con¬ 
sequently may be now reckoned amongst the leading pastry of 
the present day. To' preserve the fruit, it should be slung in 
some airy and dry apartment, and it will keep till next summer 
if it has not been frozen. For tarts and pies this fruit should 
be first stewed with only a small quantity of sugar, and a few 
other simple ingredients, as candied Orange or Lemon peel, and 
a little nutmeg; but for puddings the stewing is not necessary. If 
it be well boiled, or baked thus, with the addition of about two 
ounces of Currants in each pie or pudding, it is acknowledged to 
be sufficient to make it pleasingly desirable for working people 
and their children (some of them say a small quantity of vinegar 
t.o give acidity to the fruit is good; but this we will not re¬ 
commend). In fact, these substitutes will not disgrace a noble¬ 
man’s table, nor give their cooks discredit if they use them in¬ 
stead, or with Apples in their mince pies at Christmas time. The 
Marrows and Gourds are, however, preferable to the old-fashioned 
Pumpkins, the flesh being yellow, much richer, and firmer. 
Of the Mammoth Gourds, very many fine specimens have 
been grown and exhibited this season in various parts of the 
kingdom, some exceeding 100 fi>3. each in weight; but there are 
two distinct kinds now common; the parents of the largest, we 
believe, were of the Portuguese origin, and have been exhibited in 
the windows of the most distinguished nurserymen in the metro¬ 
polis, weighing upwards of 150 lbs. each.* We ourselves had a 
single plant this year, growing at the corner of one of our fields, 
running over hedges and ditches, without the aid of any manure 
or other stimulant, except water and a little extra cultivation by 
the fork, which produced in the short space of twelve weeks from 
its being planted, ending October 20th, when frost put an end to 
* Edward May, Esq., Colebrook Street, Winchester, informs us that one 
Gourd grown there this summer weighed 220 lbs.!— Eds. 
