July 4th, 1885. 
695 
THE GARDENING- WORLD. 
Chrysobactron Hookeri. —A most interesting and 
showy perennial, having long linear leaves and dense 
spikes of yellow flowers about 1 ft. or 18 ins. high; 
it prefers a cool, somewhat shady spot, and grows 
well in light sandy and peaty soils ; flowers in July. 
Coreopsis lanceolata.— This is not only the best 
of this family, but certainly one of the best of all 
hardy plants. It grows 2 ft. 6 ins. high, and its 
flowers, which are bright golden yellow, are 3 ins. 
across, and produced in the greatest profusion during 
the summer months. It is indispensable among 
really choice free-flowering perennials. It is a plant, 
too, which needs no special culture, but will thrive in 
most garden soils. It is easily increased by division, 
and also by seeds and cuttings ; the latter, however, 
must be taken before the plant begins to flower. 
Corydalis nobilis.— “ The Noble Fumitory” is a 
most handsome plant, delighting in partial shade. 
It grows to the height of 1 ft. when established, 
produces rich golden-yellow flowers early in spring, 
and is a plant which, though generally supposed to be 
a lover of peat, I have grown equally well in rich 
loam, which must be well drained ; it prefers 
abundant moisture in the growing season. 
Cruclanella stylosa coccinea.— A neat plant of 
trailing habit, having large globular heads of crimson 
flowers, the general appearance of which remind one 
of the Pimeleas among hard-wooded plants. For a 
large rockery, for edgings, for sloping banks, or the 
like, it is very useful. It is of free growth, and 
easily rooted from cuttings.— J. 
—— 
INSECTICIDES. 
Petroleum, in its various forms, has long been 
recognized as one of the most effective insecticides in 
our possession, all oily substances being particularly 
deadly to insects. Unfortunately, they are also 
injurious to plants, and one of the problems the 
solution of which I have had in mind for many years 
has been their use in such dilution as to kill the 
insect without injury to the plant. Refined kerosene 
has been used to a limited degree by forcible attenua¬ 
tion in water and spray, while some plants withstand 
doses of the pure oil. But the safe and general use 
of kerosene for the purpose under consideration dates 
from the year 1880. Of the various substances used 
in attempts to emulsify and mix kerosene with water 
none are more satisfactory than soap and milk, both 
being everywhere accessible and cheap. Milk was 
first suggested in 1880 by Dr. W. S. Barnard, while 
carrying on experiments for me against the Cotton- 
worm, and subsequent experiment, especially by 
another of my assistants, Mr. H. G. Hubbard, has 
given us the simplest and most satisfactory method of 
making the emulsion quickly and permanently. An 
emulsion resembling butter can be produced in a few 
minutes by churning with a force-pump two parts of 
kerosene and one part of sour milk in a pail. The 
liquids should be at about blood-heat. This emulsion 
may be diluted with twelve or more parts of water 
to one part of emulsion, thoroughly mixed, and may 
be applied with the force-pump, a spray nozzle, or 
with a strong garden syringe. The strength of the 
dilution must vary according to the nature of the 
insect to be dealt with, as well as to the nature of the 
plant; but finely sprayed in twelve parts of the water 
to one of the emulsion it will kill most insects without 
injury to the plant. An equally good emulsion may 
be made as follows :— 
Kerosene, 2 gals.; common soap, lb. ; water, 
1 gal. Heat the mixture of soap and water, and add 
it boiling hot to the kerosene. Churn the mixture by 
means of a force pump and spray nozzle for five or 
ten minutes. The emulsion, if perfect, forms a cream, 
which thickens on cooling, and adheres without oili¬ 
ness to the surface of glass. Dilute with cold water 
before using, to the extent to which experience will 
indicate is best. 
The simplest discoveries are often the most valuable, 
and this discovery of so simple and available a means 
of diluting, ad libitum, oil with water is important 
and far-reaching in its practical application. 
Pyrethrum. 
Pyrethrum roseum, a plant native to the Asiatic 
countries south of the Caucasus Mountains, and 
Pyrethrum cinerarirefolium, a native of Dalmatia, 
have long been known to possess insecticide pro¬ 
perties, especially in the powder from the dried and 
pulverized flowers. The powder, sold under various 
names by druggists, was chiefly used against house¬ 
hold pests, however ; and though Mr. C. Willemet, as 
early as 1857, in France, and Mr. William Saunders, 
m 1879, in Canada, tried it in powder form on some 
that are injurious to plants, its importance as a field 
insecticide did not appear till 1880, when, in pro¬ 
secuting the work of the United States Entomological 
Commission, we discovered that it could be used in 
liquid solution. Both species proved to be hardy 
throughout the greater portion of our country, and 
Mr. G. N. Milco, of Stockton, Cal., has for some years 
cultivated cinerariajfolium quite extensively at great 
profit, the product being sold under the name of 
“ Buhach. ’ The insecticide property dwells in a 
volatile oil. It acts only by contact, and its action 
on many larvcs is marvellous, the smallest quantity 
in time paralysing, and ultimately killing. Its in¬ 
fluence in the open air is evanescent, in which respect 
it is far inferior to the arsenical products ; but being 
perfectly harmless to plants, it can frequently be used 
on vegetables where the more poisonous substances 
would be dangerous. 
Pyrethrum is supposed to have no effect on the 
higher animals, but that is a mistake, as my own 
recent experience is that the fumes in a closed room 
have a toxic influence, intensifying sleep and inducing 
stupor ; while the experience of Professor A. Graham 
Bell with the powder copiously rubbed on a dog 
showed that the animal was made sick and was 
affected in the locomotive organs very much as insects 
are. The wonderful influence of this powder on 
insects has led me to believe that it might prove useful 
as a disinfectant against fevers and various contagious 
diseases by destroying the microzoa and other micro¬ 
organisms, or germs, which are believed to produce 
such diseases. It should be tried for that purpose. 
It is remarkable that these two plants of all the many 
known species of the genus should alone possess the 
insecticide property. 
Bisulphide of Carbon. 
Of all insecticides to be used against root-feeding 
or hypogean insects, naphthaline, sulpho-earbonate 
of potassium, and bisulphide of carbon are the chief. 
Dr. Ernst Fischer, in a recent work, has shown that 
naphthaline in crystal maybe satisfactorily used under¬ 
ground, destroying by slow evaporation. But bisul¬ 
phide of carbon still holds the first place in France 
against Phylloxera vastatrix. It is conveyed beneath 
the ground at the rate of one-half to one kilogram per 
^ ine by special injectors, or by more complicated 
machinery, drawn by horses. I believe that petroleum 
emulsions will sujiersede it as an underground insec¬ 
ticide, and prove to be the best we have, cheapness, 
safety, and efficiency considered. After the discovery 
of a satisfactory insecticide, however, various impor¬ 
tant problems must be solved, and particularly how to 
apply it to greatest advantage, having safety to man 
and stock, harmlessness to plant, and economy in 
mind. The solution of these points, and others that 
the peculiar habits of the insect to be controlled 
involve, brings us to the question of mechanical con¬ 
trivances and appliances ; for while much ingenuity 
has been exhibited in devising mechanical means of 
directly destroying noxious insects without insecti¬ 
cides, it is chiefly in the proper application of these 
last that the greatest mechanical advances have been 
made, both in this country and in Europe. 
It will already have been gathered, from what has 
preceded, that the chief insecticides are applicable 
in liquid form, and as liquids have an advantage over 
powders in field use, instruments for atomising and 
distributing liquids constitute the most important part 
of insecticide machinery. The desiderata in a spray- 
nozzle are, ready regulation of the volume to be 
thrown ; greatest atomising power, with least tendency 
to clog ; facility of cleansing ; cheapness, simplicity, 
and adjustability to any angle. 
What has been described and illustrated in my late 
official reports as the eddy or cyclone nozzle, consists 
of a small circular chamber with two flat sides, one of 
them screwed on so as to be readily removed. Its 
principal feature consists in the inlet through which 
the liquid is forced being bored tangentially through 
its wall, so as to cause a rapid whirling or centri¬ 
fugal motion of the liquid which issues in a funnel- 
shaped spray through a central outlet in the adjustable 
cap.— Prof. Riley, in American Entomologist. 
ALSTRCEMERIAS. 
It is only rarely one sees a thoroughly effective 
group of Alstroemerias, and yet they represent an 
exceedingly beautiful and profuse genus of tuberous- 
rooted plants of easy growth, and though once grown 
in hot-houses because it was thought they required 
this treatment, they have now come to be regarded as 
perfectly hardy in many districts if planted at a suit¬ 
able depth. All the species and varieties have one 
uniform mode of upright growth, and they do best in 
a free rich soil, the subsoil of which should be well 
drained. Under a south wall, for instance, they flourish 
admirably, blooming from May until August. 
There is a remarkable growth of Alstroemerias at 
Gunnersbury Park, Ealing. They were planted on 
both sides of the south entrance to the large square 
vinery in the rear of the gardener’s house, and in all 
probability having been well treated in the first 
instance they have done admirably, and have so 
increased themselves by extending their roots under 
ground, and also by seeding, that they now form two 
large groups. Unfortunately, they frequently fall a 
sacrifice to late spring frosts; but this season they have 
been spared any disfigurement in this way, and they 
are just now flowering finely and brilliantly. A good 
mulching with dung is given the plants every autumn, 
and this serves as some protection in spring, while it 
nourishes them during the summer. 
The roots of Alstrcemerias are largely grown in 
Holland and other places, and imported to this country 
in August and September with other bulbs. They can 
be had in separate varieties, or in mixture, and with 
but few exceptions they are not expensive. The roots 
should be planted from 6 ins. to 9 ins. deep ; deep 
planting is essential to their well-being, while it places 
the bulbs out of the reach of harm from ordinary 
frost, which if it reached the roots in the soil would 
do them great injury. Thus we see the advantage 
derived from the mulching given to the plants by Mr. 
Roberts. Once planted they are of no further trouble 
beyond keeping the soil free from weeds, and giving 
protection in winter. It is not uncommon for these 
to produce seeds, and shedding them upon the ground, 
increase in this way as well as by root-extension 
beneath. They grow from 2 ft. to 3 ft. in height. 
There is one remarkable fact about the Alstrce 
merias, that they retain their beauty as cut-flowers in 
water longer than most plants, rivalling that longest 
preserved, perhaps, of all cut-flowers, the Gladiolus, 
which will continue to expand its buds while in 
water. 
Botanists have observed in the Alstroemeria a 
strong tendency to variation ; and such a race of 
varieties have been obtained from two or three pro¬ 
lific species, that it is now difficult, indeed, to draw a 
distinction between species and varieties. Originally, 
there came from Chili a small group of species, such 
as Aurantiaca, orange, streaked with red; Chilensis 
or Hcemanthos, blood-red, very fine ; and Versicolor, 
variously coloured. A few good and distinct varieties 
that are obtainable are as follows :—Pelegrina, large 
heads of purple flowers, beautifully striped ; Pelegrina 
alba, pure white; Peruviana, a very distinct plant, 
and admirably adapted for any moderately dry 
border ; it grows about 24 ft. in height, and bears 
heads of flower varying from deep crimson to light 
rose, spotted and splashed with distinct shades; 
Psittacina, crimson, splashed with green and orange ; 
Pulchella, white, striped with red ; and Tricolor, beau¬ 
tifully marked with white, cream, and yellow. Mr. T. 
S. Ware grows a large collection in his nursery at 
Tottenham, where they can now be seen in flower ; 
and it may be added, that so popular are the Alstroe¬ 
merias becoming for cut purposes, that large quan¬ 
tities are grown for supplying Covent Garden Market 
with cut-flowers. 
The peculiar formation of the roots of Alstrcemerias 
do not fit them for pot-culture; the long-bundled 
or fasciated roots are too much confined in pots, and 
require larger space for free development. Where the 
soil is unsuitable, a fitting compost can be obtained 
by mixing loam, peat, and sand together, using the 
largest bulk of the former. The border in which they 
are planted should be drained, and thus it is that a 
natural slope suits the plants. They do well also on 
a gravel subsoil, and it matters not how open and 
sunny the spot may be. I know of no common name 
for the Alstrcemeria. It may have one, but I am 
unacquainted with it.— R. D. 
