August 21. 
COUNTRY GENTLEMAN’S COMPANION. 
S07 
“ bolt ? ” Then sow it in rich soil, prick it out in richer 
still, and let it remain in the “pricked” out bed until 
it is half grown. Chose a dry period for planting it 
out finally ; trim the roots according to long established 
usage, and leave the foliage totally untrimmed; after¬ 
wards, be not solicitous about water-pots, and if the 
plants are not given to bolting, I am certainly no cou- 
juror. 
This is, indeed, the history of most of our cases of 
vegetables going to seed, or “running” prematurely; 
aud I may point to Cauliflowers, to summer Lettuces, to 
Spinach, and, indeed, other things, as acting similarly 
with the Celery. 
The Mildew.—How seldom do we find our common 
Turnips mildew, as compared with the Swede ; and why ? 
The common Turnips are, in the main, annuals; the 
Swede a biennial. If the common kinds attain a con¬ 
dition which might predispose to mildew, the probability 
is that they will bolt or run before they will mildew ; at 
least, such is my impression. If I were called on to 
prepare a soil which would naturally predispose a Swede 
to bolting, I would select a soil poor in regard of 
organic manner, manure it heavily, and plough it not 
more than five inches in depth. Under such conditions, 
the plants would grow more rapidly the first six weeks 
than those on deeper ploughed and less manured land; 
but like the hare and the tortoise, in the fable, the pro¬ 
bability is, that the deep-ploughed land would overtake 
the rich and shallow-ploughed, and the first run of dry 
weather in August would put them to the test. After 
forming a gross and rapid plant, that growth would be 
as suddenly checked, and mildew would occur. 
The same with the garden Peas; to induce mildew, 
let a plot of land which has been hard cropped be 
highly manured and dug shallow, say six inches; let 
the Peas be sown very thickly, and I shall be surprised 
if they do not become heavily mildewed. 
I need hardly observe here, that the converse of these 
proceedings should lead to other results; indeed, all 
first-rate practice points to the fact. On some other 
occasion I will endeavour to return to this subject. 
R. Ebrington. 
Metallic base of Clay—Aluminium. — The last 
novelty at the Polytechnic Institution is the last dis¬ 
covery in the mineral kingdom, viz., a bar of the metal 
Aluminium. This valuable and interesting specimen of 
the metal has been received by Mr. Pepper, as a present 
from the Emperor of the French, in whose private 
laboratory in Paris it had been obtained by the skilful 
manipulation of M. H. Saint Claire Deville. The metal 
Aluminium was first discovered by Sir Humphrey Davy 
in 1808, but the labours of scientific men since that 
period produced only small grains of the metal, too in¬ 
significant to afford correct information of the value 
and properties of the metal. Subsequently CErsted en¬ 
deavoured to exhibit the metal in a detached form, by 
the employment of chloride of Aluminium; and about 
thirty years since Wohler, more successfully availing 
himself of the plan pursued by CErsted, succeeded in 
obtaining a few grains of the metal. At the Museum 
of Economic Geology, in Jermyn-street, Dr. Percy 
laboured strenuously in endeavouring to obtain the 
metal in appreciable quantities from cryolite, a mineral 
which exists in considerable quantities in Greenland; 
but the practical results fell considerably short of the 
theoretical amount. It has been reserved for M. St. 
Claire Deville to obtain Aluminium in such a quantity ; 
as to be enabled to give to the world some of the 
qualities and peculiarities of this extraordinary metal. 
The specific gravity of Aluminium is about the same 
as that which has been ascribed to it in the usual tables 
I given in chemical works, viz., 2.50, or about 2-1- times',- 
heavier than water. Its colour is between that of silver 
and zinc. Aluminium is malleable and ductile almost : 
without limit; may be beaten into the thinnest possible 
plate, or drawn out into the most attenuated of wire. 
When passed through the fingers, it exhales a slight 
odour, somewhat similar to that of iron. It conducts 
I electricity in the most perfect manner, and is expected 
to prove a much better conductor of that fluid than any 
metal at present known. It melts at a temperature 
somewhat higher than that of zinc, to which metal, in 
this respect, it approaches closerthan silver. Aluminium 
exists in a metallic state in almost every description of 
clay earths; and rubies, sapphires, and topazes, are but 
crystallised compounds of the metal. Mr. Pepper, in 
the course of his very entertaining lecture, exhibited a 
collection of these precious stones, which had been 
kindly lent to him by Messrs. Hunt and Roskell, of the 
value of upwards of .£5,000, and which, shown under 
the intense light of the oxyhydrogen microscope, 
glittered with most extraordinary brilliancy. The first 
use to which the metal has been applied has been the 
striking of some medals similar to the five-franc pieces 
of France, and also some delicately formed watch-wheels, 
which have been presented by the Emperor to her 
Majesty and Prince Albert, and the principal crowned 
heads of Europe. 
In order (says the Post ) to become impressed with 
the train of sensations we desire to create in reference 
to this metal Aluminium, let the reader, with the object 
of localising his ideas, go to the nearest wall aud pull 
out a brick; he will, except he happen to be chemically 
educated, require some amount of faith to be brought 
to believe that somewhat about one-tliird of that brick, 
by weight, consists of a beautiful metal—a metal that 
seems to be endowed with every property rendering it 
adapted for many of the elegancies and most of-the 
utilities of life—a metal resplendently white as the most 
beautiful silver, and superior to silver in being unalter¬ 
able by the sulphurous vapours which pervade the air 
of the streets of our cities and the chambers of our 
homes—a metal which can be fused with scarcely greater 
difficulty than zinc; which can be beaten into plates, 
drawn into wire, made into vessels plain and ornamental; 
which has all the sonorous qualities of the most expen¬ 
sive bronzes; and which, being not quite three times 
heavier than water, is admirably adapted for the manu¬ 
facture of defensive armour—to such an extent, indeed, 
that we hear it is in contemplation to apply it to this 
very purpose in the instance of the Imperial cent gardes. 
In giving this popular account of the new metal we 
have but inadequately conveyed a notion of the merits 
of M. St. Claire Deville, the talented philosopher to 
whom the discovery is due. Not only in the direct dis¬ 
covery of Aluminium, but in various collaterial matters 
associated with that discovery does he stand prominently 
forth as worthy of the century in which he lives, and 
the enlightened potentate under whose fostering aid he 
he has achieved his wonderful result. Before M. St. 
Claire Deville could produce the metal Aluminium, it 
was necessary that he should be able to produce, in 
large quantities, and at a moderate cost, another curious 
metal, concerning which the public is but little ac¬ 
quainted—the metal Sodium. M. St. Claire Deville 
produces Sodium from carbonate of soda with about the 
same facility that zinc is obtained from its ores. Inde¬ 
pendently of the philosophic interest attached to the 
manufacture of Aluminium, it is scarcely possible to 
overrate the practical advantages to be derived from that 
metal when it shall become an article of commerce. 
Already a company, we hear, is speculating on the 
possibility of employing it as a coating for mirror 
glasses; and a maker of delicate scale-beams threatens 
to discard brass and palladium altogether in favour of 
