166 
THE FLORIST AND POMOLOGIST. 
Boulevards of Paris consist of trees from ten 
to fifteen years old, and from 26 to 33 feet 
high. Each Boulevard is planted with one 
kind of tree only. Thus the Rue Royale is 
planted with Acer negundo; the Boulevards 
de la Madeleine and des Capucines with Plane 
trees; the Boulevard des. Italiens with Ailan- 
thus glandulosa; others with Elms, Horse 
Chestnuts, and Catalpas. The Plane trees 
are those which are found to succeed the best 
in the climate of Paris.— {La Belgique Horti- 
cole.) 
Watering with Tepid Water. — Every 
one who has any experience in hothouse ar¬ 
rangement knows that cold water is injurious 
to plants grown in heat; hut M. Jceger {Gar- 
tenflora ) goes further: he advocates the use 
of tepid water, particularly for winter-flower¬ 
ing plants, Camellias and Azaleas. From 
experiments which he has made, these flower 
quickly when water of 77° to 86° is used. In 
the sunless winter months a Camellia bud 
may take weeks to open, but if the plant be 
watered twice with water of the above tem¬ 
perature, or evtn a little warmer, the flower 
takes much less time to expand. For plants 
out of doors, tepid water may also be advan¬ 
tageously employed in certain cases. In proof 
of which he adduces the following fact:— 
Last summer Aroideso, and other plants culti¬ 
vated for their foliage, and requiring heat, 
grew miserably out of doors in Germany until 
August or September; but on visiting the 
garden of M. fleinemann at Erfurt, M. Jceger 
was astonished to find such plants in fine con¬ 
dition early in the season. On expressing 
his surprise he was told that the plants had 
been watered almost every day for a consider¬ 
able time wirh tepid water. It is probable, 
M. Jaeger thinks, that the tepid water, though 
acting on the roots but for a short time, places 
them in a favourable condition for absorption, 
whilst the contrary effect is produced by cold 
water. 
Grape Disease Caused by Electricity. 
— Mr. Stagman, writing in the American 
Horticulturist, states his belief that the primary 
cause of Grape rot and mildew is electricity. 
The Grape rot, he considers, is caused by the 
positive, the mildew by the negative state. 
The positive produces an excessive vegetable 
growth, while the negative retards it. Pro¬ 
perly speaking, there is but one cause, but 
two conditions : both of these may take place 
in the same season — one is very likely to 
follow the other. When both of these condi¬ 
tions are properly balanced there will be a 
healthy vital action, with neither the exces¬ 
sive growth nor the opposite. When the 
first greatly predominates it produces the rot, 
and when the latter greatly predominates it 
produces the mildew. The Grape rot, or 
rapid decay, takes place under the conditions 
most favourable to an excessive electrical 
action. For instance : damp atmosphere is a 
good conductor of electricity, and rain is 
much better; and when clouds are highly 
charged with this fluid they are in a positive 
state, compared with the earth and surround¬ 
ing objects, which contain less. The result is, 
that the superabundant fluid in the clouds 
finds its way rapidly to the earth through the 
medium of the moist air, rain, and vegeta¬ 
tion; consequently every moist leaf, twig, 
and Vine will receive an excess, which will 
produce a very rapid growth while its state 
continues. If this excessive action continues 
the sap will increase in its action also, taking 
up an increased quantity of water and crude 
material which is unnecessary to a healthy 
growth, which will enlarge the conducting 
capacity of the stock, while the evaporation 
is not increased in like proportion. If this 
state continues long enough, or comes in 
quick succession, accompanied with frequent 
lightning, it will hasten the rapid destruction 
of the fruit, and an unhealthy and immature 
vegetable growth. With regard to the Grape 
mildew, which he believes to be produced by 
a negative electrical condition, this, he says, 
takes place at a time the most unfavourable 
to the development of this fluid, or to its 
excessive action. For instance : in a very dry 
season, when the atmosphere is a poor con¬ 
ductor, and when the earth contains but little 
moisture—when this extreme state continues 
long enough, and tolerably early in the season, 
before the wood matures, the sap flows slowly, 
the vessels contract, until the plant loses its 
vital action; the mildew is then seen on the 
leaves, which soon begin to drop from the 
Vine; this fruit does not ripen, but remains 
insipid and worthless. This condition may be 
seen in a very dry season on some varieties of 
the Grape, Gooseberry, and Pea; but more 
frequently it is seen in a greenhouse grapery 
with a dry atmosphere and soil, and with 
imperfect ventilation. 
Potatoes. —Thus far this is the best year 
for Potatoes that has been known in Cornwall 
for a long time ; and it is stated that there 
has never before been anything like such a 
large importation to the London and other 
great markets at so early a period of the 
season. In one fortnight the average quan¬ 
tity daily transmitted from the western part 
of the country was from 115 to 120 tons. 
Several thousand baskets have been shipped 
from the Scilly Islands to Falmouth, and 
thence forwarded by rail. In one day 150 tons 
were sent by rail. The local markets are well 
supplied ; and Potatoes of last year’s growth, 
although in excellent condition, are by no 
means readily disposed of. This year’s crop 
is turning out remarkably well, and, as yet, 
there is all but an entire absence of disease.— 
( Times .) 
Doryanthes excelsa.—T his gigantic Ama- 
ryllid seldom flowers, and when it does it 
sends up a flower-stem of 18 to 26 feet in 
