of soda from culinary salt, it is first
converted into sulphate of soda. In this first
part of the process, the action of sulphuric
acid produces fuming concentrated muriatic
acid, to the extent of one and a half times,
or twice the amount of the sulphuric acid
employed. At first, the profit upon the soda
was so great, that no one took the trouble to
collect the muriatic acid,—indeed, it had no
commercial value. A profitable application
of it was, however, soon discovered: it is a
compound of chlorine; and this substance
may be obtained from it purer and more
cheaply than from any other source. The
bleaching power of chlorine has long been
known; but it was only employed upon a large
scale after it was obtained from this residuary
muriatic acid; and it was found that in
combination with lime it could be transported
to distances without inconvenience. Thenceforth
it was used for bleaching cotton; and,
but for this new bleaching process, it would
scarcely have been possible for the cotton
manufacture of Great Britain to have attained
its present enormous extent,—it could not
have competed in price with that of France
and Germany," That is on account of the
high price of land in England, and the large
quantity that would have been required for
bleaching-ground.

"In the old process of bleaching, every
piece had to be exposed to the air and light
during several weeks in the summer, and
kept continually moist by manual labour.
For this purpose, meadow land, eligibly
situated, was essential. Now, a single
establishment near Glasgow, of only moderate
extent, bleaches fourteen hundred pieces of
cotton daily." Fancy the acreage of land
that would be requisite to produce in the old
way a decidedly inferior result.

Then, again, the cheap muriatic acid got in
this manner is applied to the extraction from
old bones of their glue. Furthermore, the
extended applications of sulphuric acid have
led to its economic use in the processes of
refining. A one twelve-hundredth or one
two-thousandth part of gold formerly not
worth extracting, and left wasted in the
silver, is extracted now, and pays the refiner
for his work. He returns to his employer,
without charge, the silver and the copper
separated from each other, paying himself
with the modicum of gold—one to one-and-a-
half per cent, of the value of the silver, which
sulphuric acid has enabled him without
difficulty to extract.

We must interrupt here our catalogue of
consequences which have followed from the
process pointed out by M. Le Blanc; we
break it off abruptly for want of space, and
not for want of matter. The space already
occupied we certainly do not regret; for it is
worth while now and then to consider in
detail what we all acknowledge in the gross.
The services of scientific men are very
important; we are all ready to say that; but
we are not all ready to see how absolute and
solid are the gains which we derive from
silent meditation in a student's chamber.
The sense of service, the consciousness of
working for the world, is too often the only
reward of a man whose thoughts shall put
money by thousands or millions into the
pockets of his country.

We have taken this illustration out of
Liebig's Letters upon Chemistry. It would
have been as easy to point out the practical
work done for the human race, the material
and moral prosperity advanced, and still to be
advanced, by any other science; by Geology,
for example, or Astronomy.

Out of the same book from which we have
already quoted, we take now a note upon a
geologic subject, bearing upon the interests of
agriculture; illustrating the quiet earnestness
of the real workers for the world, and touching
on a future possibility. "When Dr.
Daubeny had convinced himself, by a series of
his own experiments, of the use and the
importance of phosphate of lime for vegetation,
his attention turned to the extensive formation
of phosphate of lime, which, according to
respectable authors on mineralogy, occurs in
some parts of the Spanish provinces of
Estremadura. He made a pilgrimage along with
Captain Widdrington to that country, to
satisfy himself 'whether the situations of the
mineral in question were adapted for supplying
the fields of England with phosphate of
lime, in case other sources of it should be
dried up.' To this journey we owe an
authentic report of the occurrence of this
most valuable mineral, which forms in
Estremadura, near Logrosan, seven miles from
Truxillo, a bed or vein from seven to sixteen
feet wide, and several miles in length. This
is one of the treasures of which Spain has so
many, sufficient perhaps, at no distant period,
to pay a part of the National Debt of that
country. It is deeply to be regretted that the
railways, projected seven years ago, which,
crossing each other at Madrid as a centre,
were to unite Portugal with France, and
Madrid with both seas, have not been executed.
These railways would render Spain
the richest country in Europe." Spain, the
richest country in Europe! We smile,
incredulous; but why does Spain now lag
behind in her civilisation? She was great
when her ships traded in all seas; great
because she was commercial; not commercial
because she was great; and she was great in
spite of superstition only at a time when few
minds were emancipated from the thrall of
priestcraft. Free to think, and free to
trade, Spain may become some of these
days; she may have railways in abundance,
then, and circulate rich blood through all
her arteries.

At all times the true doers of the world's
work have demanded freedom for the intellect.
How grandly Galileo speaks to those who
persecuted him and truth, for what they