It would be out of place here to enter into the details of soap-making, because perfumers do not manufacture that substance, but are merely “remelters,” to use a trade term.  The dyer purchases his dye-stuffs from the drysalters already fabricated, and these are merely modified under his hands to the various purposes he requires; so with the perfumer, he purchases the various soaps in their raw state from the soap-makers, these he mixes by remelting, scents and colors according to the article to be produced.

The primary soaps are divided into hard and soft soaps:  the hard soaps contain soda as the base; those which are soft are prepared with potash.  These are again divisible into varieties, according to the fatty matter employed in their manufacture, also according to the proportion of alkali.  The most important of these to the perfumer is what is termed curd soap, as it forms the basis of all the highly-scented soaps.

CURD SOAP is a nearly neutral soap, of pure soda and fine tallow.

OIL SOAP, as made in England, is an uncolored combination of olive oil and soda, hard, close grain, and contains but little water in combination.

CASTILE SOAP, as imported from Spain, is a similar combination, but is colored by protosulphate of iron.  The solution of the salt being added to the soap after it is manufactured, from the presence of alkali, decomposition of the salt takes place, and protoxide of iron is diffused through the soap of its well-known black color, giving the familiar marbled appearance to it.  When the soap is cut up into bars, and exposed to the air, the protoxide passes by absorption of oxygen into peroxide; hence, a section of a bar of Castile soap shows the outer edge red-marbled, while the interior is black-marbled.  Some Castile soap is not artificially colored, but a similar appearance is produced by the use of a barilla or soda containing sulphuret of the alkaline base, and at other times from the presence of an iron salt.

MARINE SOAP is a cocoanut-oil soap, of soda containing a great excess of alkali, and much water combination.

YELLOW SOAP is a soda soap, of tallow, resin, of lard, &c. &c.

PALM SOAP is a soda soap of palm oil, retaining the peculiar odor and color of the oil unchanged.  The odoriferous principle of palm oil resembling that from orris-root, can be dissolved out of it by tincturation with alcohol; like ottos generally, it remains intact in the presence of an alkali, hence, soap made of palm oil retains the odor of the oil.

The public require a soap that will not shrink and change shape after they purchase it.  It must make a profuse lather during the act of washing.  It must not leave the skin rough after using it.  It must be either quite inodorous or have a pleasant aroma.  None of the above soaps possess all these qualities in union, and, therefore, to produce such an article is the object of the perfumer in his remelting process.