January 21, 1899. 
THE GARDENING WORLD 
338 
HIPPOPHAE RHAMNOIDES. 
The fine decorative properties of the Sea Buckthorn 
have from time lo time been descanted upon by 
various writers, and yet the plant is not planted to 
the extent that its merits would entitle it. After it 
has reached a fair age it fruits heavily and regu¬ 
larly each year, and the rich orange yellow berries 
afford one of the richest of winter effects. The 
silvery foliage too is both uncommon and handsome. 
The shrub is quite hardy, and is thus fully able to 
take care of itself, but when we get hard frost 
early in the winter it takes a great deal of the colour 
out of the berries. As we have had no frost to speak 
of this winter the berries have preserved their colour 
wonderfully, and are almost as bright as they were 
in autumn. Visitors to Kew should remark a fine 
clump of the Sea Buckthorn at the south-western 
corner of the ornamental water in front of the Palm- 
house, for the plants are exceptionally well fruited. 
- I— — 
METHODS OF PREPARING RUBBER. 
(Concluded from p. 317.J 
The most general method of preparation in Mexico 
is to add an extract of the leaves and stem of the 
Moon-flower (Ipomoea bona-nox), and allow the 
mixture to stand over-night. The floating clot which 
forms is then pressed to remove some of the water. 
As in all these cases of preparation by "wet” 
methods the rubber contains large quantities of 
water, it loses from 12 to 30 per cent, on drying. 
Another method is in use in Nicaragua. The latex 
is mixed with about three parts of water, and allowed 
to stand over-night, when the rubber comes to the 
surface in particles, which do not unite to form a 
solid mass. The water is then drained off from 
below, and the rubber particles are mixed with a 
fresh supply of water, and the process is again 
repeated. The particles are then brought into a solid 
mass by pressure. The latest account of this method 
is apparently given by Hart, in an article on the 
“ Coagulation of Rubber,” who appears to have re¬ 
discovered it. I quote it in full as I may be mistaken. 
•' After the addition of water, the mixture is well 
shaken ; the globules of rubber (having a lighter 
specific gravity than the albnmenoids and proteids 
[sic] contained in the latex) will float quickly to the 
surface. It is found, moreover, that on the addition 
of further volumes of water and the removal of 
albumenoid liquors from below the floating rubber, 
the globules rise much more quickly to the surface.” 
The following criticism of this " creaming ” process 
is given in " Le Caoutchouc et la Gutta Percha ” :— 
“ Ce mode de preparation est bien rudimentaire et 
ne peut fournir qu’un produit de qualite inferieure, 
qui perd souvent plus de 50 per cent., surtout 
lorsqu’il fraichement prepare.” 
Recently there has been some talk of extracting 
rubber from leaves and twigs by means of solvents, 
as has been done in the case of gutta-percha. A 
description of this latter process may therefore be of 
interest. It originated in the smallness of the yield 
of the Isonandra gutta tree, a tree from 25 to 30 
years old, only giving 13 lbs. of gutta percha when 
felled. The explanation of this fact is to be found in 
the work of De Bary, who showed that the latici- 
ferous system of the tree consisted of short, closed 
sacs. This being the case, a great many would remain 
unopened, and thus a considerable per-centage of the 
gutta-percha would remain in the bark. As the 
demand for gutta-percha has been large, and the 
supply has been obtained by felling the trees, they 
have become almost extinct. 
Serullas proposes to utilise the leaves and twigs of 
the shoots from the old butts to extract the gum 
from. They are dried, treated with caustic potash to 
destroy colouring matters, and treated with a solvent 
for gutta-percha. The solvent is then distilled off 
and may be used again and again. 
Rather more than 1 lb. of gutta-percha is said to 
be yielded by 30 lbs. of chopped up fresh leaves and 
twigs. 
For several reasons I do not think this process 
could profitably be applied to the preparation of 
rubber. The most important of these are (1) on 
gathering the leaves and twigs there would be an 
immense loss of latex, and (2) stripping trees cf 
their foliage (the part which builds up their food 
supply) invariably kills them. 
The direction in which research work should tend, 
I venture to think, is to prepare rubber free from the 
other constituents of latex, so that among other 
things, freight and customs charges on these im¬ 
purities may be avoided. 
Now it has been shown conclusively that the 
chemical constitution of latex varies with its source, 
so that it is improbable that any one reagent can be 
found capable of coagulating any given latex. Thus 
from the fact that acetic acid coagulates the latex of 
certain Hevea species, it cannot be argued that it 
will coagulate the latex of Kicksia species. 
Then expert opinions, as we have seen, show that 
the preparation of rubber by these chemical means is 
not satisfactory, for the product is far from pure. 
I have recently succeeded, however, in preparing 
pure rubber by a physical process, and so demon¬ 
strated that chemical methods are not necessary. 
This is effected by centrifugalising the latex in a 
special form of separating machine, when the rubber 
particles, which have a smaller specific gravity than 
the medium in which they are suspended, are thrown 
out of the bowl in an almost dry state. They may 
then be converted into a solid mass by slight pressure, 
or by draining oft the small quantity of water which 
remains with a porous tile. So prepared, the rubber 
forms a translucent mass, free from its usual smell 
and from all danger of decomposition. 
The merits and demerits of this mode of prepara¬ 
tion must rest entirely with me, but I cannot be 
responsible for any statements made in Trinidad, 
where a copy of my experimental machine was 
recently exhibited without my consent or knowledge. 
— R. H. Biffen, in the Journal of the Society of Arts. 
Questions add AnstueRs 
*,* Will our friends who send us newspapers be so good 
as to mark the paragraphs or articles they tvish us to see. 
We shall be greatly obliged by their so doing. 
[ Correspondents, please note that we cannot undertake to 
name florists' flowers such as Carnations, Pelargoniums, 
Chrysanthemums, Roses, nor such as are mere garden 
varieties, differing only in the colour of the flower. 
Florists' flowers, as a rule, can only be named by those who 
grow collections of them.] 
Leaves of Yellow Marguerite. — Omega : The leaves 
you sent were very badly affected with the grubs of the 
Chrysanthemum leaf miner, Phytomyza nigricornis. 
The grubs tunnel their way through the soft interior 
tissue of the leaves, feeding upon the same and 
causing the tunnels to become white at first and 
brown afterwards. The best way will be to pick off 
all the worst leaves and burn them. Then examine 
the under surface of the less injured ones and you 
will be able as a rule to locate the whereabouts of 
the grub, which you should squeeze between the 
finger and thumb and so destroy it. The flies breed 
at all seasons of the year provided the weather is 
mild as at present, but they are the most active ir. 
summer. Besides pursuing the above policy of 
destroying the grubs, you should syringe your plants 
with tobacco water at intervals of ten days or so to 
keep the female flies from laying their eggs in the 
leaves. By pursuing these methods you should be 
able to keep the pest in check. 
Transplanting Common Primroses. — Omega : 
October or even September in some seasons would 
have been the best time to lift and transfer Primroses 
to a frame for early flowering, because they would 
have had plenty of time to develop fresh roots before 
spring. As it is you should accomplish the work at 
once, lifting the plants with g^od balls of soil. Use 
a compost of loam and plenty of leaf mould, and 
press the soil firmly about the roots. There should 
be no difficulty about the matter ; but if the Prim¬ 
roses had been transplanted in autumn, they would 
have made stronger growth and flowered better in 
the spring. 
Elementary Text Book of Botany.— J. D. : The 
book is published by Messrs. Swan, Sonnenschein 
and Co., White Hart Street, Warwick Lane, London, 
E.C. It runs to 600 pages, making an octavo volume 
about in. thick and contains a vast amount of 
information by Sydney Vines, M.A., one of the best 
authors on the subject in this country. 
Treatment of Clerodendron halfourianum.— 
Reader, J.B.: The temperature of the house you 
mention is quite high enough for the present. Keep 
the plant rather dry at the roots till spring, when 
the young shoots should be pruned pretty hard back. 
You do not say whether your plants are large or 
small, or in a pot or planted out. All those particu¬ 
lars would be advantageous by enabling us to give 
more definite instructions. A plant that is as large 
as you want it to be, requires more pruning than a 
young one that you wish to extend. When the young 
shoots begin to push again, after the plant has been 
pruned, you should repot the plant, if necessary, into 
a larger size pot, using a compost of fibrous loam, 
with a quantity of peat or leaf mould, some well 
rotted cow dung, and sufficient sand to keep the 
whole porous and open. After pruning the plant it 
should be placed in a higher temperature, and as 
the shoots begin to grow give more and more water, 
as it requires the same. Stove treatment is what it 
requires, both as to heat and moisture when growing. 
Second Crop Pea to follow William Hurst — 
Omega : There are several that might well be sown 
to follow William Hurst. Chelsea Gem and The 
Daisy are 2 ft high, and do well on most soils. 
Sutton’s Dwarf Defiance grows 3 ft., and Exonian 
3 i ft- It is very often advisable to sow several kinds 
to prove which does best on your soil, and in your 
district, where the climatic conditions differ slightly 
from those which prevail about London and in the 
eastern counties generally. All of the above are 
good Peas, and have generally given great satisfac¬ 
tion ; but Peas are Ilka other subjects, they vary 
somewhat in different localities. You might try two 
of them this year, and the other two next season if 
those you try do not come up to expectation. 
Treatment of Lapageria alba — Reader J. B.: 
\ou do not say whether 55° is the day or night tem¬ 
perature of your house ; but if it is the night tem¬ 
perature it is far too high. About 40° to 45 0 would 
be nearer the mark, the lower figure for preference, 
as the plant is nearly hardy and does not like much 
heat. If you are growing it in a pot you should put 
it in a cooler house. A greenhouse temperature is 
what it wants. Some people grow it wholly in peat, 
but you may use half loam and the rest peat and 
leaf-mould, with a quantity of sand to keep the whole 
porous and open. Train the shoots as they grow, 
and never allow them to get twisted one with the 
other, nor very much crowded. In summer the 
house should be kept cool and ventilated; and if a 
light shading is given during hot weather, so much 
the better. If you have it in a pot re-potting may 
be done now or a little later, if the operation is 
necessary at all. 
How to Grow Physalis Franchetti.— Bath : In 
the neighbourhood of London, and in various counties 
further afield Physalis Franchetti is simply planted 
in beds or borders of good soil in fully exposed 
positions, and left to nature. There seems no 
difficulty whatever in getting the big ” bells ” or 
inflated calyx to colour up beautifully. The climate 
of your district should be quite as warm as that of 
London, both in summer and winter. There is no 
necessity for growing it in pots. Select a bed or 
border of good friable soil in a fully exposed position, 
not under the shade of trees or walls ; trench the 
soil to a depth of 18 in. or thereby, and mix the soil 
with some farm-yard manure. This will insure good 
growth, and we fail to see why the bells should not 
colour up in due time. We consider that free ex¬ 
posure to sun and air, in a fairly rich, and naturally 
well drained soil is all that is necessary to insure 
success. We say rich soil, because the growth would 
be finer and the bells bigger than if the plants were 
starved. Perhaps your plants were too young or not 
properly established to give the desired results. 
Fruits to Name.— W. B. G :—Both Apples are 
highly coloured specimens of Dumelow's Seedling. 
Names of Plants. —W. B. G.: Polygala Chamae- 
buxus -.—George Cole : Cypripedium spicerianum.— 
B. T. 1, Berberis Darwinii; 2, Sparmannia afri- 
cana ; 3, Liboniafloribunda; 4, Reinwardtia trigyna; 
5, Acacia lophantha,— J. B.: 1, Lachenalia pendula ; 
2, Freesia refracta alba ; 3, Primula floribunda ; 4, 
Cyrtanthus Mackenii.— R. H. W. : 1, Cyclamen 
Coum ; 2, Cassinia fulvida ; 3, Raphiolepis japonica ; 
4, Euonymus radicans variegata.—S. H. : 1, Pteris 
longifolia; 2, Pteris quadriaurita argyraea; 3, 
Asplenium marinum elongatum; 4, Asplenium ob- 
tusatum lucidum. 
Communications Received.— B. Lockwood.— 
Sutton & Sons.—Black Watch.—C. F. D.—C. B. G. 
—A. V.—R. H. S.—K. & S —R. B.—W. M.—J. B. 
R. M.—T. A.-C. A—R. M — Joe.—Cabbage.— 
Geo. L. C.—A. R. 
TRADE CATALOGUES RECEIVED. 
Wm. Baylor Hartland, Cork, Ireland. — Hart- 
land’s Garden Seeds. 
Robert Sydenham, Tenby Street, Birmingham. 
—Unique List of the Best Vegetable and Flower 
Seeds. 
Thyne & Paton, 18, Union Street, Dundee.— 
Reliable Seeds, Jubilee Edition. 
W. Wells & Co., Ltd., Earlswood Nurseries, 
Earlswood, Redhill, Surrey. Special List or Sup¬ 
plement to Descriptive Catalogue of Chrysanth¬ 
emums for 1898-99 also Wells' Chrysanthemum 
Calendar. 
Henry Eckford, Wem, Shropshire.—Catalogue 
of Giant Sweet Peas, Culinary Peas, Vegetable 
Seeds, Flower Seeds, &c. 
Harlan P. Kelsey, i,to6, Tremont Building, 
Boston, Massachussets, USA.—Kelsey’s Hardy 
American Plants and Carolina Mountain Flowers. 
