he vast number of less known proposed additions to toilet soaps,
mention may be made in passing of:--

_Fluorides._--These have been somewhat popular during recent years for
the disinfection of breweries, etc., and also used to some extent as
food preservatives. Of course only neutral fluorides are available for
use in soap, acid fluorides and soap being obviously incompatible. In
the authors' experience, however, sodium fluoride appears to have little
value as a germicide when added to soap, such soaps being found to
rapidly become rancid and change colour.

_Albumen._--The use of albumen--egg, milk, and vegetable--in soap has
been persistently advocated in this country during the past few years.
The claims attributed to albumen are, that it neutralises free alkali,
causes the soap to yield a more copious lather, and helps to bind it
more closely, and a further inducement held out is that it allows more
water to be left in the soap without affecting its firmness. Experiments
made by the authors did not appear to justify any enthusiasm on the
subject, and the use of albumen for soap-making in this country appears
to be very slight, however popular it may be on the Continent. Numerous
other substances have been proposed for addition to soaps, including
yeast, tar from peat (sphagnol), Swedish wood tar, permanganate of
potash, perborates and percarbonates of soda and ammonia, chlorine
compounds, but none of these has at present come much into favour, and
some had only ephemeral existence. Of the many drugs that it has been
suggested to admix in soap for use in allaying an irritable condition of
the skin, the majority are obviously better applied in the form of
ointments, and we need not consider them further.

_Ether Soap._--Another form of medicated soap made by a few firms is a
liquid ether soap containing mercuric iodide, and intended for surgeons'
use. This, as a rule, consists of a soap made from olive oil and potash,
dissolved in alcohol and mixed with ether, the mercuric iodide being
dissolved in a few drops of water containing an equal weight of
potassium iodide, and this solution added to the alcohol-ether soap.

_Floating Soaps._--Attempts have been made to produce tablets of soap
that will float upon the surface of water, by inserting cork, or floats,
or a metallic plate in such a manner that there is an air space between
the metal and the soap. The more usual method is to incorporate into
hot soap sufficien