Part 9 (1/2)

Cold made soaps are usually pressed without milling, although it is readily feasible to mill a cold made soap provided it is not a filled soap such as has just been described.

PERFUMING AND COLORING TOILET SOAPS.

Equally important as the soap itself or even to a greater extent is the perfume of a toilet soap. A prominent manufacturer recently made the statement, which is often the truth, that it makes no difference to the public what kind of soap you give them, as long as you put plenty of odor into it. The perfuming of soaps is an art in itself and a subject to be treated by one versed in this particular branch. We can only take into account the importance of the perfume as related to toilet soap not only, but the necessity of adding a certain proportion of the cheaper products of odoriferous nature to laundry soap to cover and disguise the odor of even this type of soap.

The price of a cake of toilet soap to a great extent depends upon the perfume, and the manufacturer should aim to give the best possible perfume for a certain price. He should not allow his personal likes or dislikes to enter into the judgment of whether an odor is good or not, but submit it to a number of persons to obtain the concensus of opinion.

In giving or selling a piece of soap to the consumer, it is second nature for him to smell it, and in the great majority of cases his opinion is formed not from any quality the soap itself may have during use, but from the odor. This only emphasizes the fact that the perfume must be pleasing, not to one person, but to the majority, and many brands owe their popularity to nothing more than the enticing perfume.

Perfuming of soap is closely allied to the soap making industry, but as stated a branch in itself. It is, therefore, not our purpose to give numerous formulae of how to perfume a soap, but rather to advise to go for information to some one who thoroughly understands the characteristics of the numerous essential oils and synthetics and give positive information for the particular odor desired. Under no circ.u.mstances is it advisable to purchase a perfume already compounded, but since all perfumes are a blend of several or many essential oils and synthetics, it is a more positive a.s.surance of obtaining what is desired, by purchasing the straight oils and blending or mixing them as one desires.

The perfume is added to a milled soap just before the milling process in the proper proportion per hundred pounds of soap. In cold made or unmilled soaps it is added in the crutcher while the soap is still hot.

By this method, of course, a proportion of the perfume is lost due to its being more or less volatile.

COLORING SOAP.

While much toilet soap is white or natural in color, many soaps are also artificially colored. The soap colors used for this purpose are mostly aniline dyestuffs. The price of these dyestuffs is no criterion as to their quality, as the price is usually regulated by the addition of some inert, water soluble substance like common salt or sugar.

The main properties that a dyestuff suitable for producing a colored soap should have are fastness to light and to alkali. They should further be of such a type that the color does not come off and stain a wash cloth or the hands when the soap is used and should be soluble in water. Under no circ.u.mstances is it advisable to add these in such a quant.i.ty that the lather produced in the soap is colored. It is customary to first dissolve the dye in hot water as a standardized solution. This can then be measured out in a graduate and added to the soap the same time as the perfume is put in. About one part of color to fifty parts of water is the proper proportion to obtain a perfect solution, though this is by no means fixed. In making up a solution thus it is an improvement to add to the same about one-half of one per cent.

of an alkali either as the hydroxide or carbonate. Then, if there is any possibility of change of color due to alkalinity of the soap, it will exhibit itself before the color is added.

A particularly difficult shade to obtain is a purple, as there is up to the present time no purplish aniline color known which is fast to light.

Very good results in soap may be obtained by mixing a fast blue, as ultramarine or cobalt blue, with a red as rhodamine or eosine.

Inasmuch as the colors for soap have been carefully tested by most of the dyestuff manufacturers, and their information, usually reliable, is open to any one desiring to know about a color for soap, it is better to depend upon their experience with colors after having satisfied one's self that a color is what it is represented for a particular shade, than to experiment with the numerous colors one's self.

MEDICINAL SOAPS.

Soap is often used for the conveyance of various medicants, antiseptics or other material presumably beneficial for treatment of skin diseases.

While soap is an ideal medium for the carrying of such materials, it is an unfortunate condition that when incorporated with the soap, all but a very few of the numerous substances thus employed lose their medicinal properties and effectiveness for curing skin disorders, as well as any antiseptic value the substance may have. Soap is of such a nature chemically that many of the substances used for skin troubles are either entirely decomposed or altered to such an extent so as to impair their therapeutic value. Thus many of the claims made for various medicated soaps fall flat, and really have no more antiseptic or therapeutic merit than ordinary soap which in itself has certain germicidal and cleaning value.

In medicating a soap the material used for this purpose is usually added at the mill. A tallow and cocoanut oil base is best adapted for a soap of this type. The public have been educated more or less to the use of colored soap to accentuate its medicinal value, and green is undoubtedly the most popular shade. This inference, however, is by no means true for all soaps of this character. Possibly the best method of arranging these soaps is briefly to outline some medicinal soaps.

SULPHUR SOAPS.

The best known sulphur soaps contain anywhere from one to 20 per cent.

of flowers of sulphur. Other soaps contain either organic or inorganic sulphur compounds.

TAR SOAP.

The tar used in the manufacturing of tar soap is obtained by the destructive distillation of wood, the pine tar being the most extensively employed. While the different wood tars contain numerous aromatic compounds, such as phenols, phenyl oxides, terpenes and organic acids, these are present in such a slight proportion so as to render their effectiveness practically useless. It has, therefore, been tried to use these various compounds contained in the tar themselves to make tar soap really effective, yet tar is so cheap a substance that it is usually the substance used for medicating a tar soap. About 10 per cent.

of tar is usually added to the soap with 2 ounces of lamp black per hundred pounds of soap.

SOAPS CONTAINING PHENOLS.