The Sun.
London, England, 1842-05-19 00:00:00

HORTICULTURAL SOCIETY.

On Friday last, the third lecture oz Chemistry ap-
plied to cultivation, was given by Mr. Edward Solly,
jun., at the Society's Rooms, in Regent-street, which
was well attended. We observed amongst the audi-
ence Sir John Sebright and family, Sir P. Egerton
and Lady, Lady Caroline Poulett, the Earls of 11-
&ester and Sandwich, Lord Prudhoe, Sir Charles
Lemon, Sir 0. Moseley, Sir J. South, Hon. Mr. Ver-
non Harcourt, &c. &c.

We extract the following from the Gardeners
Chronicle on the subject :-- •
" Mr. Solly's third lecture was delivered to-day.
He commenced by an account of the nature and pro-
perties of nitrogen, showing that it exists in the air,
of which it constitutes about four-fifths; and that,
being possessed of properties in all respects the re-
verse of oxygen, and distinguished by the absence of
any marked characters, it appeared that its principal
office is to dilute the oxygen of the air, and diminish
the too powerful effects which it would produce in an
undiluted state. In the air, however, oxygen and ni-
trogen are only mixed : when combined they form
nitric acid ; and, on the other hand, when nitrogen
and hydrogen are combined, they form ammonia :
thus affording two excellent illustrations of the cu-
rious results of chemical combination, and the very
great difference existing between compounds and
their elements. Having thus described the four great
elements of Plants, or those compounds of oxygen,
hydrogen, nitrogen, carbon, in different proportions,
which, as woody fibre, gum, sugar, starch, gluten,
&c., constitute vegetable matter ; the properties, na-
ture, and different forms of these substances was
described, and the curious metamorphoses which they
undergo, and the transformations which they suffer,
when acted on by acids and alkalies, was explained.
Mr. Solly concluded by saying that, having gone
through th►e introductory part of the subject, he should
next take up the groat question of the food of plants,
which would occupy the next lecture."

LONDON ELECTRICAL SOCIETY.
TuEsruy, mAy 17.—At this Meeting were read-Ist.
Extracts of notes from Mr. Weeks, wherein it was stated
that, when lie commenced the experiments, which have
shown the development of insects, he made other and
similar arrangements, through which he did not allow
the voltaic current to pass, and in these cases no insects
are to be found. Mr. W alker, the Secretary, then read
a long and carefully written paper "On Lightning Con-
ductors." He took for his subject, or rather, he based
his subject upon, the damage done to the steeple of
Brixton Church, by the thunder-storm of Sunday,
April 24 ; and was induced to survey the steeple, front
having just previonsly heard Dr. Faraday's lecture on
the subject. The glaring error of placing discontinuous
conductors 'at such elevation -as church-steeples pre-
sent was but too clearly evinced in this case. An insu-
lated cross overmounting the steeple, and an iron pipe,
also insulated, gave the flash the opportunity of passing
through twenty, And then ten feet of air. The conse-
quent explosions were attended with serious damage.
The ," lateral discharge" was much dwelt upon by the
author. It is a subject of great difficulty among even
men of science. The mass of mankind do not under-
stand it at all, and think when they have erected
a capacious conductor, they' have done all that is
needed. The erroneousness of this position was made
manifest, first, by referring to the experiments of the,
Royal Institution ; and then by explaining what oc-
curred at Brixton, where the fluid left one conductor for
another, for no other reason than that it obtained by
this means a wider path. And it was shown that this
property of electricity, desiring a wider path as well as a
direct one, renders a badly Awed lightning rod an enemy,
and not a friend. To prevent the " lateral discharge"
wherever the probability occurs, it was recommended to
convert it into a certainty ;. that is, whenever it seemed
possible that electricity might pass from conductor to
conductor, it should be compelled to pass, not indeed
through the air, to develope light and heat. but through
a good metallic connexion, by which it could pass safely.
'This communication was drawn up with a considerable
degree of care, and was illustrated by drawings of the
church, &c. We must refer our readers to the next
number of the Proceedings of the Society for the paper
in full, and meanwhile ould recommend architects to
consult electricians on this important matter. We almost
omitted to mention that Mr. Walker alluded to the
immense value of trees as conductors, and recommended
their being planted wherever it was, possible. Sonic
notices on "Electrotype Manipulation" and Mr. Week's
journal were then read.

We learn from Arras that the Paris diligence on
that road was overturned on the nth inst., but for-
tunately without doing serious injury to any one.
Among the passengers was a lady who was in one of the
waggons of the Versailles railroad most in danger, but
who made her escape by forcing her.way out.