ALUMINIUM. 
651 
Tuscany, called et mountain meal” from its appearance ; and 
a similar earth is found in Lapland, which is mixed with 
ground bark of trees, and eaten by the natives in times of 
scarcity. Here, again, the microscope, in the hands of 
Ehrenberg, has demonstrated this to consist of skeletons of 
infusoriae ; and so excessively minute are their forms, that a 
cubic inch is estimated to contain forty-one thousand millions 
of them, and these weigh only 220 grains, so that each single 
skeleton weighs about the 187 millionth of a grain. Yet 
they actually constitute beds several feet in thickness, ex- 
tending over areas of many acres. How stupendously sublime 
are these illustrations of creative power ! 
In 1849 Ehrenberg w^as requested to examine some red 
spots found on potatoes, bread, &c., which were conjectured 
to be a species of fungi, but on examination he found them 
to be exceedingly minute monads, which he has termed the 
“ purple monad,” or monas prodigiosa. The body of the animal 
is but from the g-oVoth to the g ^gth P art °f a ^ ne (x^h of an 
inch,) in length, and it has a proboscis half as long as its body. 
In a cubic inch from 46 trillions, 656 billions, to 884 
trillions, 736 billions, of these minute animals may exist! 
Surely if greatness has its sublimity, so has littleness ! 
But the microscope is not alone in developing these 
wonders. Chemistry comes in for her share in the investi- 
gation of nature’s works ; and the leading inquiry at the 
present day is, how cheaply to obtain from the aluminous 
clays a metal that shall rival and supersede the use of silver. 
Nor is it at all improbable that this will soon be obtained. 
The splendid discovery of Sir H. Davy, in 1807, of 
potassium, the metallic base of the alcali potassa, followed 
in the succeeding year by that of sodium, the base of soda, 
opened up new views of the constitution of both the alkalies 
and the earths, which before this time w T ere ranked among 
the simple substances, although doubts were entertained of 
their being so. 
It was by the aid of the powerful voltaic battery of the 
Royal Institution, arranged in accordance with his own 
wishes, that Sir Humphrey succeeded in effecting the decom- 
position of these bodies. Hydrate of potassa w 7 as submitted 
by him to the influence of voltaic electricity, thus generated, 
when the metal w ? as slowly evolved along with hydrogen at 
the negative electrode. 
In the notes of a manuscript lecture, recorded by his 
brother, in his life, Sir Humphrey thus modestly expresses 
himself: “ In my first trials on potash I used strong aqueous 
solutions : dry potash is a non-conductor. I then employed 
fused potash; and in this instance inflammable matter was 
