When once its valuable detersive powers were
discovered—doubtless by accident—its employment
spread rapidly. Numerous soap
manufactories sprang up in Italy, notably in the little
seaport town of Savona, near Genoa, whence the
French name of soap, "savon." The manufacture
spread in Spain and France. Marseilles
became famous for its marbled soaps. Our
word "soap" may come from the Latin "sapo,"
which is mentioned by Pliny as an invention of
the Gauls.

As woollen garments preceded linen, so the
fuller's art (for cleansing, scouring, and pressing
cloths and stuffs) is older than the washerwomans,
being due, it appears, to one Nicias,
the son of Hermias. His grand discovery would
be the employment of an earth, since named
after the persons who use it. The Roman
fullers, who washed dirty togas, were persons
of no little importance. Their trade, and the
manner of carrying it on, were regulated by
laws, such as the Lex Metella de fullonibus.
At one time, fuller's earth (found of a very
superior quality in Staffordshire, Bedfordshire,
and other English counties) was considered so
indispensable for the dressing of cloth, that, to
prevent foreigners from rivalling English fabrics,
it was made a contraband commodity, and its
exportation made equally criminal with the
heinous and wicked export of wool. How
completely public opinion has changed! No weather-
cock could make a more perfect gyration from
north to south, from east to west. What is it
criminal to export now? Convicts and contraband
of war, perhaps; but certainly not harmless
earth and wool.

Soap, in general terms, is an artificial
compound of oily substance and alkali. The alkalis
used, have been kelp (the ashes of seaweeds) or
other vegetable ash, and more recently pure
soda and pure potash obtained by improved
methods, and lime. For fats recourse has been
had to olive-oil, whale-oil, tallow, and of late
years to cocoa-nut and other vegetable oils.
Soaps are manufactured of three distinct kinds;
soft soap, for dyers, washerwomen, and fullers;
hard soap, for ordinary household purposes;
cake or ball soap for the toilette-table. The
great merit of soap consists in its being a
portable means of cleanliness; the less water
it contains, the more concentrated and portable
it is, the greater its merit. Hard soap
is more convenient than soft; still it is possible
to make hard soaps which contain a large
proportion of water. The marbled soaps have the
reputation of containing the least. Thrifty
housewives cut up their blocks of hard soap
into cakes, and expose them to a current of air,
to get rid of the water and cause them to
dissolve less rapidly.

The degree of ease with which soap is applied,
depends in some measure on the quality of the
water. Soft and hard water are figurative
expressions, to denote water which is not impregnated
with earths and minerals, as rain water
when it falls, and that which is, as springs
which have traversed various strata. Hard
water is often heavily charged with sulphate and
other combinations of lime. Soft water washes
well, because it unites freely with soap and
dissolves it. Hard water, on the contrary,
decomposes it, and forms new compounds which have
not the same detersive properties. The soda of
the soap combining with the sulphuric acid of
the sulphate, and the oil of the soap with the
lime of the sulphate, form curdy flakes which
float in the water and are useless for cleaning
purposes. The water remaining is, however,
softened. In like manner, wood ashes make
hard water soft. Their carbonic acid, combining
with the sulphate of lime, converts it into chalk,
which is precipitated as a sediment, and may be
so got rid of.

Soap, then, serves in general to communicate
to water the power of dissolving, by emulsion,
grease soaked into or adhering to stuffs. But,
besides this, when linen stained with grease is
boiled for a sufficient time in soap-water, the
salts contained in the latter are decomposed;
neutral oleates are formed; and the excess of
alkali set at liberty serves to soapify the grease
adhering to the linen. Soap then acts exactly
as an alkali. The ancients scarcely knew any
alkali besides ammonia, which, after obtaining
it from an offensive putrifying liquid, they
employed to take the grease out of their
clothes. It was the trade in this article which
the Emperor Vespasian taxed so profitably;
and which he justified by showing the gold it
brought in, and asking whether the money had
any unpleasant smell.

At the present day, ammonia is replaced by
soda and potash; which are now obtained pure
by chemical means, but which, formerly, could
only be procured by burning vegetables. Ashes,
in fact, contain carbonates of soda and potash;
on which account they largely serve for making
lie to wash with, especially in rural districts
where wood is the principal fuel. But the
quantity of those salts contained in ashes is
very variable; moreover, there are mingled with
them many foreign substances more or less
soluble; so that the use of ashes has the
inconvenience of making the wash of variable
composition, and sometimes of charging it with
matters actually injurious to the linen. Their
great economy prevents their being given up;
but it is preferable to substitute for them the
crystallised sub-carbonate of soda, which may
be had at a moderate price, and which has
the further merits of being constant in its
composition and of not being open to adulteration.
Caustic potash and soda do not present
the same advantages.

In France, and in Paris especially, great use
is made of "eau de javelle" and chloride of
lime. The former is a hypochloride of soda,
and the latter really a hypochloride of lime.
These two substances do not act, like alkalis or
alkaline salts, by soapifying grease spots; their
action on soiled linen is merely that of
discolorants. The alkali which enters into their
composition (the soda or the lime), being but
feebly united to the hypochloric acid, easily