CHAPTER IV

Classification of Soaps.

In considering the many different varieties of soaps, their

classification is purely an arbitrary one. No definite plan can be

outlined for any particular brand to be manufactured nor can any very

sharp distinction be drawn between the many soaps of different

properties which are designated by various names. It is really a

question to what use a soap is to be put, and at what price it may be

sold. There is, of course, a difference in the appearance, form and

color, and then there are soaps of special kinds, such as floating

soaps, transparent soaps, liquid soaps, etc., yet in the ultimate sense

they are closely allied, because they are all the same chemical

compound, varying only in their being a potash or soda soap, and in the

fatty acids which enter into combination with these alkalis. Thus we can

take a combination of tallow and cocoanut oil and make a great many

presumably different soaps by combining these substances with caustic

soda, by different methods of manufacture and by incorporating various

other ingredients, as air, to form a floating soap, alcohol to make a

transparent soap, dyestuffs to give a different color, etc., but

essentially it is the same definite compound.

The manufacturer can best judge the brand of soaps he desires to

manufacture, and much of his success depends upon the name, package,

shape, color or perfume of a cake of soap. It is the consumer whom he

must please and many of the large selling brands upon the market today

owe their success to the above mentioned details. The great majority of

consumers of soap know very little concerning soap, except the fact

that it washes or has a pleasant odor or looks pretty, and the

manufacturer of soap must study these phases of the subject even more

carefully than the making of the soap itself.

For a matter of convenience we will classify soap under three general

divisions:

I. Laundry soaps, including chip soaps, soap powders and scouring soaps.

II. Toilet soaps, including floating soap, castile soap, liquid soap,

shaving soap, etc.

III. Textile soaps.

LAUNDRY SOAP.

The most popular household soap is laundry soap. A tremendous amount of

this soap is consumed each day in this country, and it is by far

manufactured in larger quantities than any other soap. It is also a soap

which must be sold cheaper than any other soap that enters the home.

The consumers of laundry soap have been educated to use a full boiled

settled rosin soap and to make a good article at a price this method

should be carried out, as it is the one most advisable to use. The

composition of the fats entering into the soap depends upon the market

price of these, and it is not advisable to keep to one formula in the

manufacture of laundry soap, but rather to adjust the various fatty

ingredients to obtain the desired results with the cheapest material

that can be purchased. It is impossible to use a good grade of fats and

make a profit upon laundry soap at the price at which it must be

retailed. The manufacturer of this grade of soap must look to the

by-product, glycerine, for his profit and he is fortunate indeed if he

realizes the entire benefit of this and still produces a superior piece

of laundry soap.

SEMI-BOILED LAUNDRY SOAPS.

It is advantageous at times to make a laundry soap by a method other

than the full boiled settled soap procedure as previously outlined. This

is especially the condition in making a naphtha soap, in which is

incorporated naphtha, which is very volatile and some of the well known

manufacturers of this class of soap have adopted this process entirely.

A laundry soap containing rosin cannot be advantageously made by the

cold process, as the soap thus made grains during saponification and

drops a portion of the lye and filling materials. By making a

semi-boiled soap this objection is overcome. The half boiled process

differs from the cold process by uniting the fats and alkalis at a

higher temperature.

To carry out this process the following formulae have been found by

experience to give satisfactory results.

I. lbs.

Tallow 100

Rosin 60

Soda Lye, 36deg. B. 80

II.

Tallow 100

Rosin 60

Silicate of Soda 25

Soda Lye, 36deg. B. 85

III.

Tallow 100

Rosin 100

Lye, 36deg. B. 105

Silicate of Soda 25

Sal Soda Solution 20

In any of these formulas the sodium silicate (40deg. B.) may be increased

to the same proportion as the fats used. By so doing, however, twenty

pounds of 36deg. B. lye must be added for every hundred pounds of silicate

additional to that indicated or in other words, for every pound of

silicate added 20 per cent. by weight of 36deg. B. lye must be put into the

mixture. The rosin may also be replaced by a previously made rosin soap.

To make a semi-boiled soap, using any of the above formulae, first melt

the rosin with all or part of the fat, as rosin when melted alone

readily decomposes. When the mixture is at 150deg. F. run it into the

crutcher and add the lye. Turn on sufficient dry steam to keep the

temperature of the soap at about 150deg. F. in the winter or 130deg. F. in

summer. After the mass has been mixed for half an hour, by continuously

crutching the soap it will at first thicken, then grain and it may again

become thick before it becomes smooth. When the mass is perfectly smooth

and homogeneous drop into a frame and crutch in the frame by hand to

prevent streaking. After standing the required length of time the soap

is finished into cakes as usual.

SETTLED ROSIN SOAP.

Settled rosin soaps are made from tallow, grease, cottonseed oil,

bleached palm oils of the lower grades, corn oil, soya bean oil, arachis

oil, distilled garbage grease, cottonseed foots or fatty acids together

with an addition of rosin, varying from 24 per cent. to 60 per cent. of

the fatty acids which should titer from 28 to 35. A titer lower than 28

will prevent the finished kettle of soap from being capable of later

taking up the filling materials. As has already been stated under

hardened oils, these being very much higher in titer allow a greater

percentage of rosin to be added. Thus hardened fish oils and cottonseed

oil are gradually being more extensively employed in soaps of this

character.

The procedure of handling the kettle is similar to that given under full

boiled soap. The stock is steamed out into a settling tank and allowed

to settle over night, after which it is pumped into the soap kettle.

Having stocked the kettle, open steam is turned on and 10deg.-12deg. B.

lye is run in, while using a steam pressure of ninety to one hundred

pounds in order to prevent too great a quantity of condensation of the

steam, the water thus being formed weakening the lye. If a steam

pressure of fifty to sixty pounds is available, a stronger lye (20deg.

B.) should be added. Care must be taken not to allow the lye to flow in

too rapidly or the soap will not grain. The saponification is only

attained by prolonged boiling with sufficient lye of proper strength.

When saponification has taken place, the mass begins to clear and a

sample taken out with a paddle and cooled should show a slight pink with

a 1 per cent. alcoholic phenolphthalein solution.

It may be stated here that in using this indicator or any other to test

the alkalinity of soap, the soap should always be cooled and firm, as

whenever water is present, the dissociation of the soap thereby will

always react alkaline. When this state is reached the mass is ready for

graining, which is accomplished by distributing salt brine or pickle or

spreading dry salt over the surface of the soap. The kettle is then

thoroughly boiled until the mass shows a soft curd and the lye drops

clearly from a sample taken out with a trowel or paddle. The steam is

then shut off and the soap allowed to settle over night. The lyes are

then run off to the spent lye tank for glycerine recovery. In

saponifying a freshly stocked kettle it is apt to bunch. To prevent this

salt is added at various times to approximately one per cent. of the fat

used.

If, by any possibility the soap has bunched, this condition may be

remedied by the addition of more strong lye and boiling until it is

taken up. To work a kettle to its full capacity it is advisable to make

two "killing" changes. First add about 75 per cent. of the fat and grain

as directed. Run off the spent lyes and then add the remainder of the

stock and repeat the process. When the spent lye has been run to

storage, the open steam is again turned on and 18deg. B. lye gradually

allowed to run in. The rosin is now broken up and put into the kettle,

or a previously made rosin soap is pumped in.

Lye is then added until the soap has a sharp taste after about three

hours of continuous boiling, or when the soap is in the closed state.

More lye should then be run into the kettle to grain the soap well, the

grain not being too small. Then allow the soap to settle over night and

draw off the strengthening lye. The next day again boil up the kettle

and add water until the soap thins out and rises or swells high in the

kettle. A sample taken out at this stage upon a hot trowel should run

off in large flakes. The surface of the soap should be bright and shiny.

If the sample clings to the trowel, a slight addition of lye will remedy

this defect. The kettle is then allowed to rest, to drop the nigre and

to cool for some time, depending upon the size of the kettle. The proper

temperature is such that after having been pumped to the crutcher and

the filling materials having been added, a thermometer placed into the

mass should indicate 128deg.-135deg. F. after the crutcher has run from

ten to fifteen minutes. The filling material may consist of from 7-9 per

cent. of sal soda solution, 36deg.-37deg. B. warm or just enough to

close up the soap and make it rise high in the center of a screw

crutcher and make it cling close to a warm trowel. Other fillers such as

outlined below are added at this point.

An addition of from 2-3 per cent. of a special mineral oil for this

purpose will impart a finish to the soap and 3-5 per cent. starch added

prevents the soap from cracking in the frames. Other filling material as

silicate of soda, borax, talc or silex are used. After the filling

material has been thoroughly crutched through the soap it is framed,

and, after being several days in the frame to solidify and cool the soap

is ready for slabbing, pressing and wrapping.

In order to more definitely illustrate the composition of the mixture of

fats and oils entering into the formation of a laundry soap a typical

formula may be given for such a soap containing 40 per cent. rosin added

to the amount of fats used:

lbs.

Grease 7,000

Tallow 4,000

Corn Oil 7,000

Cottonseed Oil 3,000

Rosin 8,400

The following have been found to be satisfactory filling materials and

are calculated upon the basis of a 1,400-pound frame of soap.

I. lbs.

Sodium Silicate, 38deg.-40deg. B. 100

Mineral Oil 25

Sal Soda Solution, 36deg. B. 80

Borax 1

II.

Sal Soda Solution, 36deg. B. 80

Mineral Oil 25

Sodium Silicate 60

III.

Soda Ash 10

Sal Soda 55

Sodium Silicate 115

Mineral Oil 40

Brine (Saturated Solution) 10

Sodium Silicate, 38deg.-40deg. B. 100

IV.

Sodium Silicate 100

Silex or Talc 200

Soda Ash 50

V.

Sal Soda Solution, 36deg. B. 90

Sodium Silicate 50-60

Mineral Oil 25

Borax Solution, 25deg. B. (hot) 15

CHIP SOAP.

Chip soap is used extensively in laundries but is also used largely in

other branches. It may be made either as a settled soap or by the cold

made process.

To make a full boiled settled chip soap, proceed as directed under

settled laundry soap. The kettle is stocked with light grease or a

mixture of grease with corn oil or other cheap oils. For this kind of

soap the rosin is eliminated.

Chip soap may be filled as well as laundry soap. This is done in the

crutcher and the following adulterations are suitable.

lbs.

Settled Soap 700

Soda Ash 35

Sodium Silicate 215

or

Settled Soap 700

Silicate of Soda 560

Soda Ash 18

Carbonate of Potash, 26deg. B. 50

The cheapest method of drying is by running this soap through a drying

machine and this is the procedure usually carried out for making dried

chip soap.

COLD MADE CHIP SOAPS.

To make chip soaps by the cold process a sweet tallow of low percentage

of free fatty acid should be employed. The tallow is heated to 120deg. to

135deg. F. and the lye run in slowly at first and then the silicate of soda

is added. The mass is then mixed until a finger drawn through the soap

leaves a slight impression, then dropped into frames or barrels. Soaps

containing a small percentage of fat should be well covered in the frame

for twenty-four hours to retain their heat and insure proper

saponification. The following formulae are suitable:

I. lbs.

Tallow 1,200

Soda Lye, 35deg. B. 850

Sodium Silicate 750

II.

Tallow 475

Ceylon Cocoanut Oil 100

Soda Lye, 37deg. B. 325

Potash Lye, 37deg. B. 56

III.

Tallow 500

Soda Lye, 37-1/2deg. B. 297

Sodium Silicate 416

Potash Lye, 37-1/2deg. B. 37-1/2

IV.

Tallow 450

Soda Lye, 37-1/2deg. B. 255

Sodium Silicate 450

Potash Lye, 37-1/2deg. B. 50

V.

Tallow 450

Soda Lye, 35deg. B. 470

Sodium Silicate 650

VI.

Tallow 420

Sodium Silicate 600

Soda Lye, 37-12deg. B. 270

UNFILLED CHIP SOAP.

A very good grade of chip soap is made by employing no filling material

whatsoever, but unfortunately the price of this soap has been cut to

such an extent that these can not compete with a filled chip. A number

of the best soaps of this kind are made from a settled soap using a

light grease with corn oil. A soap of this nature is made as follows.

lbs.

Settled Soap 800

Sal Soda Solution, 36deg.-37deg. B. 252

Soda Ash 182

If this soap is run into frames it may be stripped and chipped in two

days.

SOAP POWDERS.

Soap powders have become so great a convenience as a general cleansing

agent that to eliminate them from the household necessities would mean

much unnecessary energy and work to the great number of consumers of

this product. They may be manufactured so cheaply and still be

efficient, that their use has almost become universal for cleansing and

scouring purposes. The uses to which soap and scouring powders are

adapted are too well known to enter into a description of their

employment. Since they offer a greater profit to the manufacturer than

ordinary household soap, many brands are extensively advertised.

Numerous combinations for soap powders might be cited and it is a simple

matter to vary the ingredients as to fat content and manufacture a

powder of this sort as low as a cent a pound. Many substances are

incorporated with soap, such as salt, soda ash, tripoli, crushed

volcanic deposits, ground feldspar, infusorial earth of various kinds,

silex, etc. In addition to these various fillers, compounds with true

cleansing and bleaching properties, in addition to soap, are added, such

as the salts of ammonium (sal ammoniac, carbonate of ammonia), sodium

perborate and the peroxides of various metals. The public, however, have

been accustomed to receive a large package of soap or scouring powder

for a small amount of money and it is a difficult matter for the

manufacturer to add more expensive substances of this nature to his

product, to increase its efficiency, without raising the price or

decreasing the size of the package.

In manufacturing soap powders, the dried soap chips might be mixed with

the filler and alkali and then pulverized. This method is not

extensively employed nevertheless. The process which is the most

economical is one whereby the ingredients are mixed in a specially

adapted mixer for heavy material until dry and then run directly to the

crusher and pulverizer, after which it is automatically packed, sealed

and boxed. Another method of procedure is to run out the mixture from

the crutcher to the frames, which are stripped before the soap cools,

and is cut up at once, for if it hardens it could not be cut with wires.

It is better, however, to run the mixture into sheets upon a specially

constructed floor and break up the mass when cool.

Formulae for soap powders which have been found to be suitable for

running dry in the mixer follow:

I

Soda ash, 58 per cent. 42 lbs.

Silica 220 "

Settled soap (usually cottonseed). 25 "

Salt 10 "

II

Soap (settled cottonseed) 40 lbs.

Soda ash, 58 per cent. 60 "

III

Settled soap 100 lbs.

Soda ash, 58 per cent. 400 "

Fillers in varying proportions may replace the soda ash in the above

formulae. It is of course understood that the soap has been previously

made and run as molten soap into the crutcher.

The following soap powders will not dry up in the crutcher upon running,

but are of the class which may be framed or run on the floor to

solidify:

I

Soap 850 lbs.

Filler 400 "

Sal soda solution, 20 degs. B 170 "

II

Soap 650 lbs.

Filler 550 "

Sal soda solution, 20 degs. B. 340 "

III

Soap 80 lbs.

Filler 550 "

Sal soda solution 170 "

IV

Soap (settled tallow) 800 lbs.

Filler 400 "

Sal soda solution 170 "

Water 100 "

V

First saponify 100 parts house grease and 100 parts ordinary grease and

make a run soap. Then use in crutcher either:

Soap 400 lbs.

Filler 575 "

Hot water 60 "

or

Soap 200 lbs.

Hot water 200 "

Filler 625 "

It would be a simple matter to write numerous additional formulae, but

the above are typical. The manufacturer must judge for himself just what

filling material to use. The filler indicated in the above formulae is

therefore left open. A few formulae for more expensive powders than

those given recently appeared among others in the "Seifensieder

Zeitung"[9]:

I

Powdered soap 90 lbs.

Sodium perborate 10 "

The perborate should be added when the powder is perfectly dry or it

loses its bleaching properties.

II

Soap powder, 20 per cent. fat.

Cocoanut oil fatty acids 25 lbs.

Olein 25 "

Bone fat 70 "

Soda lye, 30 degs. B. 90 "

Water 150 "

Ammonium carbonate 125 "

III

Soap powder, 10 per cent. fat.

Cocoanut oil fatty acids 20 lbs.

Olein 10 "

Bone fat 20 "

Soda lye, 30 degs. B. 30 "

Water 175 "

Ammonium carbonate 175 "

LIGHT OR FLUFFY POWDERS.

Light or fluffy powders containing 35-45% moisture can be made in two

ways. The first method requiring a minimum equipment is to mix the

powder and sal soda in a mixer, allow it to stand in frames for a week

to crystallize or spread it on the floor for a few hours to dry and then

grinding it.

The continuous method finishes the powder in a few minutes and with a

minimum amount of labor. By this process the various ingredients, soap,

soda ash solution, etc., are measured, run by gravity into the mixer,

mixed and the molten mass run over the crystallizer or chilling rolls

thru which either cold water or brine is pumped. From the roll the

powder is scraped off clean by a knife, passes to a screen which sends

the tailings to a grinder, falls into a storage bin from whence it is

weighed and packed by an automatic weighing machine into cartons made up

in most cases by another machine. Due to the large percentage of

moisture contained in these soap powders the carton is generally wrapped

in wax paper to aid in the prevention of the escape of moisture.

SCOURING POWDERS.

Scouring powders are very similar to soap powders and differ only in the

filler used. We have already considered these fillers under scouring

soap, from which they do not differ materially. They are usually

insoluble in water to aid in scouring. The mixer used for substances of

this kind in incorporating the soap and alkali must be of strong

construction.

SCOURING SOAP.

Scouring soaps resemble soap powders very closely in their composition,

in that they are a combination of soap and filling material. Since more

lather is required from a scouring soap than in soap powders, a cocoanut

oil soap is generally used. The usual filling material used is silex.

The greatest difficulty in the manufacture of scouring soap is the

cracking of the finished cake. This is usually due to the incorporation

of too great an amount of filler, or too high a percentage of moisture.

In manufacturing these soaps the cocoanut oil is saponified in the

crutcher with 38 degs. B. lye, or previously saponified as a run soap,

as already described under "Marine Soaps." To twenty-five parts of soap

are added a percentage of 38 degs. B. sal soda or soda ash solution,

together with a small quantity of salt brine. To this mixture in the

crutcher seventy-five parts of silex are then added, and a sufficient

amount of hot water to make the mass flow readily. Care must be

exercised to not add too great a quantity of water or the mass will

crack when it cools. The mass is then framed and cut before it sets, or

poured into molds and allowed to set. While silex is the most

extensively used filler for scouring soaps, it is feasible to

incorporate other substances of like character, although it is to be

remembered that the consumer is accustomed to a white cake, such as

silex produces. Any other material used to replace silex should also be

as fine as this product.

FLOATING SOAP.

Floating soap occupies a position midway between laundry and toilet

soap. Since it is not highly perfumed and a large piece of soap may be

purchased for small cost, as is the case with laundry soap, it is

readily adaptable to general household use. Floating soap differs from

ordinary soap in having air crutched into it which causes the soap to

float in water. This is often advantageous, especially as a bath soap,

and undoubtedly the largest selling brand of soap on the American market

today is a floating soap.

In the manufacture of floating soap a high proportion of cocoanut oil is

necessary. A most suitable composition is one part cocoanut oil to one

part of tallow. This is an expensive stock for the highest grade of soap

and is usually cheapened by the use of cottonseed or various other

liquid oils. Thus it is possible to obtain a floating soap from a kettle

stocked with 30 per cent. cocoanut oil, 15 per cent. cottonseed oil and

55 per cent. tallow. With this quality of soap, however, there is a

possibility of sweating and rancidity, and of the soap being too soft

and being poor in color.

The process of manufacture is to boil the soap in an ordinary soap

kettle, after which air is worked into the hot soap by a specially

constructed crutcher, after which the soap is framed, slabbed, cut into

cakes and pressed.

Concerning the boiling of the soap, the saponification must be carefully

carried out, as the high proportion of cocoanut oil may cause a violent

reaction in the kettle causing it to boil over.

The method of procedure is the same as for a settled soap up to the

finishing. When the mass is finally settled after the finish, the soap

should be more on the "open" side, and the object should be to get as

long a piece of goods as possible.

Due to its high melting point, a much harder crust forms on the surface

of a floating soap and in a greater proportion than on a settled soap

during the settling. In a large kettle, in fact, it has been found

impossible to break through this crust by the ordinary procedure to

admit the skimmer pipe. Much of the success of the subsequent operations

depends upon the completeness of the settling, and in order to overcome

the difficulties occasioned by the formation of the crust everything

possible should be done in the way of covering the kettle completely to

enable this period of settling to continue as long as possible.

When the soap is finished it is run into a specially constructed U-shape

crutcher, a Strunz crutcher is best adapted to this purpose, although a

rapidly revolving upright screw crutcher has been found to give

satisfaction upon a smaller scale, and a sufficient quantity of air

beaten into the soap to make it light enough to float. Care must be

taken not to run the crutcher too rapidly or the soap will be entirely

too fobby. During this operation the mass of soap increases in bulk,

and after it has been established how much air must be put into the soap

to satisfy the requirements, this increase in bulk is a criterion to

estimate when this process is completed.

It is of course understood that the longer the crutching continues the

greater quantity of air is incorporated and the increase of volume must

be established for a particular composition by sampling, cooling the

sample rapidly and seeing if it floats in water. If the beating is

continued too long an interval of time, the finished soap is too spongy

and useless.

The temperature of the mass during crutching is most important. This

must never exceed 158 degrees F. At 159 degrees F. the operation is not

very successful, yet the thermometer may indicate 140 degrees F. without

interfering with this operation. If, however, the temperature drops too

low, trouble is liable to be met with, by the soap solidifying too

quickly in the frames.

When the crutching is completed, the soap is allowed to drop into frames

through the valve at the bottom of the crutcher and rapidly crutched by

the hand in the frames to prevent large air spaces and then allowed to

cool. It is an improvement to jolt the frames as they are drawn away as

this tends to make the larger air bubbles float to the surface and thus

reduce the quantity of waste. When the soap has cooled, the frame is

stripped and the soap slabbed as usual. At this point a layer of

considerable depth of spongy soap will be found to have formed. This of

course must be cut away and returned to the kettle. The last few slabs

are also often rejected, inasmuch as the weight of the soap above them

has forced out so much of the air that the soap no longer floats. As a

fair average it may be estimated that not more than 50 to 60 per cent.

of the soap in the kettle will come out as finished cakes. the

remaining 40 to 50 per cent. being constituted by the heavy crust in the

kettle, the spongy tops, the bottom slabs and scrapings. This soap is of

course reboiled and consequently not lost, but the actual cakes obtained

are produced at a cost of practically double labor.

It is advisable to add a small quantity of soap blue color to the mass

while crutching to neutralize the yellowish tint a floating soap is

liable to have.

Some manufacturers add a percentage of carbonate of soda, about 3 per

cent., to prevent the soap from shrinking. Floating soap may also be

loaded with sodium silicate to the extent of about 5 per cent.

TOILET SOAP.

It is not a simple matter to differentiate between toilet soaps and

various other soaps, because numerous soaps are adaptable to toilet

purposes. While some soaps of this variety are manufactured by the cold

made or semi-boiled process, and not milled, the consumer has become

accustomed to a milled soap for general toilet use.

The toilet base most extensively employed is a tallow and cocoanut base

made as a full boiled settled soap. The manufacture of this base has

already been outlined and really needs no further comment except that it

is to be remembered that a suitable toilet soap should contain no great

excess of free alkali which is injurious to the skin. Cochin cocoanut

oil is preferable to the Ceylon cocoanut oil or palm kernel oil, to use

in conjunction with the tallow, which should be a good grade and color

if a white piece of goods is desired. The percentage of cocoanut oil may

be anywhere from 10 to 25 per cent., depending upon the kind of lather

required, it being remembered that cocoanut oil increases the lathering

power of the soap.

In addition to a tallow base, numerous other oils are used in the

manufacture of toilet soaps, especially palm oil, palm kernel oil, olive

oil and olive oil foots, and to a much less extent arachis or peanut

oil, sesame oil and poppy seed oil, oils of the class of cottonseed,

corn and soya bean oils are not adapted to manufacturing a milled soap,

as they form yellow spots in a finished cake of soap which has been kept

a short time.

Palm oil, especially the Lagos oil, is much used in making a palm base.

As has already been stated, the oil is bleached before saponification. A

palm base has a yellowish color, a sweetish odor, and a small quantity

added to a tallow base naturally aids the perfume. It is especially good

for a violet soap. The peculiarity of a palm oil base is that this oil

makes a short soap. By the addition of some tallow or twenty to

twenty-five per cent. of cocoanut oil, or both, this objection is

overcome. It is a good plan in using a straight palm base to add a

proportion of yellow color to hold the yellowish tint of this soap, as a

soap made from this oil continues bleaching upon exposure to air and

light.

Olive oil and olive oil foots are used most extensively in the

manufacture of castile soaps. The peculiarity of an olive oil soap is

that it makes a very slimy lather, and like palm oil gives the soap a

characteristic odor. An olive oil soap is usually considered to be a

very neutral soap and may readily be superfatted. Much olive oil soap is

used in bars or slabs as an unmilled soap and it is often made by the

cold process. Peanut oil or sesame and poppy seed oil often replaces

olive oil, as they form a similar soap to olive oil.

In the manufacture of a toilet soap it is hardly practical to lay down a

definite plan for the various bases to be made. From the combination of

tallow, palm oil, cocoanut oil, palm kernel oil, olive oil and olive oil

foots, a great many bases of different proportions might be given. The

simplest method is to make a tallow base, a palm base and an olive oil

base. Then from these it is an easy matter to weigh out any proportion

of these soap bases and obtain the proper mixture in the mill. If,

however, as is often the case, a large quantity of soap base of certain

proportions of these, four or even more of these fats and oils is

required, it is not only more economical to stock the kettle with the

correct proportion of these oils, but a more thorough mixture is thus

obtained by saponifying these in the kettle. In view of the fact that it

is really a question for the manufacturer to decide for himself what

combination of oils he desires for a particular soap we will simply

outline a few typical toilet soap bases in their simplest combination.

It is understood that these soaps are suitable for milled soaps and are

to be made as fully boiled settled soaps. Palm kernel oil may be

substituted for cocoanut oil in all cases.

TALLOW BASE.

Tallow 75-90 parts

Cocoanut oil 25-10 parts

PALM BASE.

Bleached Lagos palm oil 75-80 parts

Cocoanut oil 25-20 parts

or

Tallow 30 parts

Palm oil 60 parts

Cocoanut oil 10 parts

OLIVE OIL BASE (WHITE).

Olive oil 75-90 parts

Cocoanut oil 25-10 parts

or

Olive oil 40 parts

Tallow 40 parts

Cocoanut 20 parts

Where a green olive oil base is desired, olive oil foots are substituted

for the olive oil. Peanut oil may replace the olive oil or part of it,

the same being true of sesame oil and poppy seed oil.

PALM AND OLIVE BASE.

Palm oil 50 parts

Olive oil 30 parts

Cocoanut oil 20 parts

or

Palm oil 20 parts

Olive oil 10 parts

Tallow 50 parts

Cocoanut oil 20 parts

CHEAPER TOILET SOAPS.

It is often necessary to manufacture a cheaper grade of soap for toilet

purposes to meet the demand of a certain class of trade as well as for

export. To accomplish this it is of course necessary to produce a very

inferior product and run down the percentage of fatty acids contained in

the soaps by the addition of fillers or to use cheaper oils in

manufacturing. The most simple method of filling a soap is to load it at

the mill with some substance much less expensive than the soap itself.

Many of the cheaper toilet soaps, however, are not milled and it is,

therefore, necessary to follow out some other procedure.

Milled soaps, as has just been stated, are loaded at the mill. The

consumers of cheaper toilet soaps in this country are accustomed to a

milled soap and this grade of soap for home consumption is very often

filled with numerous substances, but most generally by adding starch

and talc. The addition of such materials of course later exhibit

themselves by imparting to the cake of soap a dead appearance. Talc is

more readily detected in the soap than starch by washing with it, as

talc is insoluble and imparts a roughness to the soap, like sand or

pumice, as the soap wears down. It may readily be added to 20 per cent.

by weight. Starch is to be preferred to talc, in loading a soap, as it

is not so readily noticeable in washing. It leaves the cake itself

absolutely smooth although the lather formed is more shiny. This

substance may be employed to as high a percentage as one-third the

weight of the soap. It is, of course, possible to cheapen the best soap

base by this method and the price may be further lowered by using the

less expensive oils and fats to make the soap base.

RUN AND GLUED UP SOAPS.

A very cheap grade of soap may be made by making a run soap and adding

the filler e. g. sodium silicate in the kettle during saponification.

The percentage of fatty acids may be brought down to 10 per cent.,

although of course a soap of this type shrinks a whole lot upon

exposure.

In making a "glued up" soap the procedure is the same for making the

soap itself as with a settled soap, except that the soap is finished

"curd" and later filled in the crutcher. The percentage of fatty acids

in a soap of this type is seldom below 50 per cent.

The method of "gluing up" a soap is best illustrated by a typical soap

of this character in which the kettle is charged with the following

stock.

Bleached palm oil 5 parts

Distilled grease 2 "

Cotton oil foots stock, 63% fatty acid 1 "

Rosin 4 "

The palm oil is first run into the kettle, saponified and washed to

extract any glycerine, then the rest of the fats and finally the rosin.

The soap is then finished and settled as with a boiled settled soap. To

assure success it is absolutely necessary that the soap settle as long a

period as possible, or until the temperature is about 150 degs. F. The

ideal temperature for carrying out the "gluing up" process is 140 degs.

F., as at a lower temperature than this the soap is liable to cool too

quickly and not be thoroughly glued up. A higher temperature than 150

degs. F. causes delay in that the soap does not properly take the filler

at a higher temperature and the soap must be kept in the crutcher until

the temperature drops to the right point.

The soap is run into the crutcher and the percentage of fatty acids run

down to 50-55 per cent. with one of the following mixtures:

Sodium silicate, 59-1/2deg. B. 1 part

Potassium carbonate, 51deg. B. 1 "

or

Sodium silicate, 59-1/2deg. B. 1 part

Potassium carbonate, 51deg. B. 1 "

Sodium sulfate, 28deg. B. 1 "

From 230 to 300 pounds of either of these mixtures are required for a

crutcher holding 2,600 pounds of soap.

The crutching is continued until the mass is well "spiked," that is to

say, a freshly broken surface of the soap, as the crutcher blade is

jerked away, stands up like shattered sheets in triangular form

[Transcriber's note: three triangles]), which retain their shape

perfectly. When this condition is realized the soap is run into frames

which are carefully crutched by hand to remove any air spaces. The

surface of the soap is then smoothed down and heaped up in the center.

After standing a day to contract, the surface is again leveled and a

snugly-fitting board placed on the top of the soap upon which a weight

is placed or upon which the workman treads and stamps until the surface

is flat, thus assuring the further removal of air spaces. The soap

remains in the frame from six to eight days and is then slabbed, barred

and pressed by the usual method employed for soaps thus handled without

milling.

In a soap of this nature no hard and fast rule can be laid down as to

the quantity of solution to be used for "gluing up" or the strength of

the solution. In a soap of the type described the most satisfactory

appearing cake will be obtained from a soap containing 58 per cent.

fatty acids. That is to say, about 8 per cent. to 10 per cent. filling

solution is added per hundred pounds of soap. The filling solutions

given are very satisfactory. Carbonate of soda should be avoided in

connection with sodium silicate as the property of efflorescing on the

surface of the finished cake after a short time will prove detrimental.

To assure successful gluing up it is advisable to experiment upon a

small scale to determine the exact extent to which the filling solution

should be diluted. Various proportions of water are added to a certain

quantity of the filled soap. After the soap has been filled in a small

receptacle a sample is taken and rubbed between the fingers. If the

freshly exposed surface is smooth and glossy, the filling solution is

weak enough, if rough it is too strong. It is of course understood that

the temperature must be correct, 140 degs. to 150 degs. F., or the soap

will be rough. By this means the operator can readily judge the correct

strength of his filling solution. When properly carried out a perfectly

satisfactory soap is obtained.

CURD SOAP.

The object of a soap which is finished "curd" or grained, is to obtain a

harder piece of goods from low titer fat or to increase the percentage

of fatty acids in the finished soap. This is still another method of

producing a cheap grade of soap as by its adoption the cheaper oils and

fats may be used to obtain a firm piece of soap.

A typical charge for curd soap is:

Red oil 63 parts

Tallow 10 "

Rosin 27 "

Cotton seed foots may be employed in place of red oil and a tallow of

too high titer is not suitable for this kind of soap.

The red oil and tallow are first saponified with 15 degs. B. lye, boiler

pressure 80-90 pounds, 18 degs. B. lye for lower steam pressure, and two

washings given to extract the glycerine. The rosin is added at the

strengthening change and at the finish the soap is "pitched," that is to

say, the soap is settled over night only. The next day the lyes are

drawn off and a portion of the nigre pumped to another kettle which

prevents later streaking of the soap. The soap is then boiled with 18

degs. B. lye as with another strengthening change under closed steam.

Salt brine or "pickle," 15 degs. B. is then added and the mass boiled

with closed steam until the brine reaches a density of 18 degs. B. and

the kettle pumped the next day. A soap of this type requires either hand

or power crutching to assure homogeneity and prevention of streaks. To

obviate any air spaces it is advisable to place over the top of the

frame a tightly-fitted board which is heavily weighted down. This soap

is also pressed without any milling.

COLD MADE TOILET SOAPS.

Comparatively little toilet soap is made by the cold or semi-boiled

processes. While these are the simplest methods of manufacturing soaps

the drawbacks of using them are numerous and only in a few cases are

they very extensively employed. To make a toilet soap by the cold

process a combination of good grade tallow and cocoanut oil is required.

It requires 50 per cent. by weight of 36 degs. B. lye to saponify a

given weight of tallow and 50 per cent. of 38 degs. B. lye for cocoanut

oil. The lyes are used full strength or may be reduced slightly with

water and the method of procedure is the same as already given in the

general directions for cold made soaps.

Cold made soaps are readily filled with sodium silicate which is added

at the same time the stock is put into the crutcher. In adding the

silicate it is necessary to add additional lye to that required for

saponifying the fats, about 20 per cent. of 36 degs. B. lye is the

proper amount. There is of course a certain amount of shrinking due to

the addition of this filler and the finished cake is exceedingly hard,

yet the author has seen a good looking cake of cheap soap made from as

high a proportion as 420 parts of tallow to 600 parts of silicate.

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

circumstances 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 assurance 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 circumstances is it advisable to add these in such a

quantity 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.

Phenol (Carbolic Acid) is most extensively used in soaps of this kind,

which are called carbolic soaps. Carbolic soaps are generally colored

green and contain from 1 to 5 per cent. phenol crystals.

The cresols are also extensively used for making soaps named carbolic.

These substances impart more odor to the soap and really have more

disinfecting powers than phenol when incorporated with soap.

Other soaps, containing the phenol group, which are well known are

resorcinol soap, salol soap, thymol soap, naphthol soap, etc. From one

to five per cent of the compound after which the soap is named is

usually incorporated with the soap.

PEROXIDE SOAP.

Hydrogen peroxide in itself is an excellent disinfectant. It loses all

its medicinal value, however, when added to the soap. To overcome this

objection various metallic peroxides are added to the soap, as sodium

peroxide, zinc peroxide and barium peroxide. These generate hydrogen

peroxide by the addition of water. Sodium perborate is also used in

peroxide soaps, as this substance is decomposed by water into hydrogen

peroxide and sodium metaborate.

MERCURY SOAPS.

Mercuric chloride (corrosive sublimate) is most extensively used for the

production of mercury soaps. Because of its extremely poisonous

properties care should be taken in using it. Since it really eventually

loses any antiseptic value in the soap through forming an insoluble

mercury soap it might better be omitted entirely.

LESS IMPORTANT MEDICINAL SOAPS.

While the above mentioned soaps are probably the best known medicated

soaps, there are numerous other soaps which may be classed under these

kinds of soaps. Thus we have cold cream soap, which can be made by

adding Russian Mineral Oil, 1 to 5 per cent., to the soap; witch hazel

soap, made by the addition of extract of witch hazel; iodine soap, made

by adding iodine or iodoform; formaldehyde soap, made by adding

formaldehyde; tannin soaps, made by adding tannin. In fact, there have

been incorporated in soap so great a number of substances that the list

might be greatly enlarged.

Medicated soaps are not only used in solid form, but in powder, paste

and liquid soap as well. The only difference in a soap like those just

referred to is that the medicant is incorporated with these forms of

soaps as convenience directs.

CASTILE SOAP.

A pure castile soap should be made from olive oil. This, however, is not

always the case, as a number of oils as well as tallow are used to

adulterate this oil to cheapen it, and there are even some soaps called

castile which contain no olive oil at all. Most of the pure castile soap

used in this country is imported, as it is a difficult matter for the

American manufacturer to compete with the pure imported castile soap,

since both labor and oil itself are so much cheaper in the vicinities of

Europe where this oil is produced, that this advantage is more than

compensated by the carrying and custom charges by importing the castile

soap.

Castile soap may be made either by the full boiled or cold process.

There are numerous grades of olive oil, and those used for soap making

are denatured to lower the duty charges. Olive oil makes a hard white

soap, usually sold in bars, and olive oil foots a green soap, due to the

coloring matter contained in this oil.

To make a boiled castile soap, a composition of 10 per cent. Cochin

cocoanut oil and 90 per cent. olive oil may be used. To cheapen this,

peanut oil (Arachis oil) may entirely replace the olive oil, or about 20

per cent. of corn or soya bean oil may be added. The oils are saponified

as usual in making a settled soap and to prevent rancidity the soap is

boiled near the finish for some time in the closed state with

sufficient excess of alkali to give it a sharp taste, then grained with

lye, the lye drawn off, closed with water and then grained with salt.

This process is repeated until the desired strength is reached. The last

graining should not be too great, and on the last change the soap should

not be thinned out, as it will contain too great a quantity of water

when slabbed.

In making a cold castile soap the usual method is pursued as already

directed under cold made soap. When the soap is taken from the crutcher

it is advisable, however, to keep the soap in the frame well covered to

assure complete saponification. Some manufacturers use very small frames

which are placed into compartments, well insulated to retain heat.

Several formulae for cold made castile soaps, follow. It may be noted

that some of these contain practically no olive oil.

I

Olive oil 2030

Palm kernel 674

Soda lye, 35 per cent. B. 1506

II

Olive oil 2030

Cochin cocoanut oil 674

Soda lye, 36 per cent. B. 1523

Sodium Silicate 82

III

Palm kernel oil 1578

Tallow 940

Olive oil 7

Sodium silicate, 20 per cent. 190

Soda lye, 36 per cent. B. 1507

IV

Olive oil (yellow) 1000

Soda lye, 37 per cent. B. 500

V

Olive oil 90

or

Palm kernel } 10

Cochin or cocoanut oil } 10

Lye, 37 per cent. B. 51

If any of the soaps containing a high proportion of cocoanut oil are

boiled the soap will float. It is therefore necessary to keep the

temperature as low as possible.

ESCHWEGER SOAP (BLUE MOTTLED).

Eschweger soap is a colored mottled or marbled soap made to a very

slight extent in this country. Inasmuch as it has been introduced to the

export trade, it is made for this purpose by some manufacturers. A high

percentage of cocoanut oil is usually used together with tallow and

grease. About one-third of each is a typical formula. In a soap of this

character the fact that cocoanut oil soap takes up a large quantity of

water and salts of various kinds and is difficult to salt out is made

use of. The tallow and grease are first saponified as usual, then the

cocoanut oil is pumped and saponified. When the saponification is nearly

completed either silicate or carbonate of soda or common salt are added

to make the soap "short" so as to form the mottle. The finishing of a

soap of this type can only be gained by practice and it is rather

difficult to explain the exact appearance of the kettle at this stage.

The surface of the soap should be bright and lustrous with the steam

escaping in numerous places in rose-like formation. A sample on the

trowel should have a slight sharpness to the tongue and be plastic. When

the soap slides from the trowel it should break short. When the soap has

reached this stage the desired coloring matter, usually ultramarine, is

added to the soap either in the kettle or crutcher and the soap framed.

The yield is 200-215 pounds per hundred pounds of stock.

Several modifications of this general method for Eschweger soap are used

by adopting the half boiled or cold process.

TRANSPARENT SOAP.

Transparent soap is really not a most desirable soap for toilet

purposes, as it contains an excess of free alkali. It has, nevertheless,

met with public approval because of the fact it is novel in being

transparent. Except for this fact very little merit can be claimed for a

soap of this kind.

The transparency of soap is generally due to the presence of alcohol,

sugar or glycerine in the soap when it is made. It is very essential in

a soap of this character, where lightness and clearness of color are

desired, that the material for making the soap be carefully selected as

to color and purity. The perfumes also play an important part in the

color of the soap and many of the tinctures, balsams and infusions used

in perfuming soap may eventually cause trouble by spotting. If the soap

is artificially colored, which is almost always the case, the dyestuffs

used for this purpose should have careful attention and only those

should be used which are known to resist the action of alkalis. Where

rosin is used this product must be of the better grade. Distilled water

is always preferable for use in transparent soap. The government permits

the use of a specially denatured alcohol. This alcohol is not taxed and

consists of grain (ethyl) alcohol denatured with 5 per cent. wood

(methyl) alcohol. Some soapmakers prefer to use a more expensive refined

methyl alcohol, but outside of adding to the cost of the soap, there is

no particular advantage. The glycerine should be chemically pure. As to

the oils and fats these should be low in acid and of good color. Under

no circumstances should the crutcher or kettle in which the soap is made

be rusty or unclean in any way. For a light soap enameled utensils are

to be preferred.

To obtain transparency in soap the following general methods may be

given.

1. Where the transparency is due to sugar.

2. Where alcohol and glycerine produce transparency.

3. Where (1) or (2) is supplemented by the use of castor oil.

4. Where transparency depends upon the percentage of fatty acid in a

soap and the number of times the soap is milled.

Under the first method at least 25 per cent. of the charge should be

cocoanut oil, the other constituent being tallow or any fat or oil

capable of giving a sufficiently hard soap. The soap is boiled and

finished as usual, then run to the crutcher to be mixed with a strong

cane sugar solution, containing 10-20 per cent. sugar of the weight of

the soap. The sugar is dissolved in its own weight of water and the

solution heated to 175 degs. F. before being very slowly added to the

soap. As the water evaporates, soaps of this type show spots due to the

sugar thus being thrown out of solution.

Transparent soap made under the second method may be saponified as usual

and consist of any good toilet base. The soap is run to the crutcher and

mixed with 95 per cent. alcohol in the proportion of one part alcohol to

two parts of fatty acid contained in the soap together with glycerine in

the same proportion.

By the third method castor oil alone may be used to make the soap or

added to any of the above bases up to 33-1/3 per cent. of the charge. If

castor oil only is used, but 2 per cent. or 3 per cent. of sugar is

required.

In the last method a combination of 80 per cent. tallow, very low in

free acid, 20 per cent. cocoanut oil and 5 per cent. W. W. rosin is a

suitable charge. The saponification and finishing is carried out as with

a full boiled soap. The soap is then placed into a jacketed vessel,

provided with dry-steam coils, by which the excess water is evaporated

from the soap until it contains 73 per cent. fatty acids. When the thick

mass reaches this stage it is framed and when cool is suitable for

obtaining a semi transparency which now depends upon the number of times

the soap is milled, it being, of course, inferred that no solid matter

of any sort be added to the soap.

COLD MADE TRANSPARENT SOAP.

While transparent soaps may be made by the above general methods they

are usually made by the semi-boiled or cold process. By this process a

more satisfactory soap is obtained and it is more simple to carry out. A

detailed description of this method is best and most easily given by

using a typical formula.

Charge:

Tallow 193-1/2 lbs.

Cochin Cocoanut Oil 169-1/2 "

Castor Oil 89-1/2 "

Soda Ash 7-3/4 "

Soda Lye, 36 degs. B. 256 "

Sugar (Cane) 198 "

Alcohol 126 "

Water (Distilled) 80 "

To proceed, first place into a crutcher or jacketed kettle the oils and

fat and heat to 140 degs. F. Then add the soda ash dissolved in about 30

pounds of the water, after which the lye is added and the mass stirred

until a finger or stick run over the surface leaves an imprint. Where

the soap has reached this stage, it is well covered and allowed to stand

about two hours or until it bulges in the center, after which the rest

of the water which should contain no lime or other mineral substance and

which is preferably distilled water, is added. The sugar is then slowly

shoveled in while the mass is stirring and finally the alcohol is poured

in. The heat is then increased to 160 degs. F. by dry steam and the soap

crutched until dissolved. Under no circumstances should any soap be

allowed to remain above the surface of the mass on the sides of the

mixer. This crutching operation consumes about one hour, and when

finished the soap should stand in the vessel about half an hour when a

small sample is taken out to cool. This sample should be clear and show

an excess of alkali. If it is not clear more alcohol is added, if not of

sufficient strength more lye put in until the desired condition is

reached. The perfume and color are now added.

The soap is then framed and allowed to set after which it is cut,

allowed to dry slightly and then pressed. To obtain a polished cake

transparent soaps are often planed before pressing and after pressing

polished with a soft cloth, dampened with alcohol. Instead of framing

this soap, it is sometimes "tubed," that is to say, the soap from the

crutcher is run into specially constructed tubes of a shape near that of

the desired cake and allowed to cool, after which it is cut and pressed.

All scraps are returned to the crutcher, but in so doing the soap is

slightly darkened in color. It is advisable to expose a finished cake of

transparent soap to the air for some time as by so doing it becomes

clearer.

Other formulae for cold made transparent soaps made as just outlined

follow:

I.

Bleached Tallow 134 lbs.

Cochin Cocoanut Oil 88 "

Castor Oil 20 "

W. W. Rosin 7 "

Cane Sugar 64 "

Water 32 "

Glycerine 34 "

Soda Lye, 38 degs. B. 135 "

Alcohol 16 gal.

II.

Tallow 211 lbs.

Cochin Cocoanut Oil 185 "

Castor Oil 97-1/2 "

Soda Ash 8-1/2 "

Water 106 "

Soda Lye, 38 degs. B. 279 "

Sugar 216 "

Alcohol 137 "

III.

Castor Oil 60 lbs.

Cochin Cocoanut Oil 195 "

Tallow 120 "

Alcohol 115 "

Sugar 90 "

Water 53 "

Glycerine 53 "

Soda Lye, 38 degs. B. 205-1/2 "

IV.

Tallow 100 lbs.

Cochin Cocoanut Oil 100 "

Castor Oil 60 "

Glycerine 20 "

Rosin, W. W. 20 "

Sugar 40 "

Water 50 "

Soda Lye, 36 degs. B. 164 "

Alcohol 8 gal.

V.

Tallow 174 lbs.

Cocoanut Oil 114 "

Soda Lye, 38 degs. B. 170 "

Sugar 80 "

Water 72 "

Alcohol 16 gal.

Rosin may be added in this formula up to 20 per cent. of fats used and

the tallow cut down correspondingly.

SHAVING SOAPS.

The requirements of a shaving soap are somewhat different than those of

other soaps. To be a good shaving soap the lather produced therefrom

must be heavy, creamy, but not gummy, and remain moist when formed on

the face. The soap itself should be of a soft consistency so as to

readily adhere to the face when used in stick form. It should

furthermore be neutral or nearly so to prevent the alkali from smarting

during shaving.

Shaving soap is made in the form of a stick, and a tablet for use in the

shaving mug. Some shavers prefer to have the soap as a powder or cream,

which are claimed to be more convenient methods of shaving. While a

liquid shaving soap is not as well known because it has not yet become

popular, some soap for shaving is made in this form.

Formerly shaving soap was extensively made from a charge of about 80

parts tallow and 20 parts cocoanut oil as a boiled settled soap, but

either making the strengthening change with potash lye or using potash

lye in saponifying the stock and graining with salt. Soaps for shaving

made in this manner are very unsatisfactory, as they do not produce a

sufficiently thick or lasting lather and discolor very materially upon

ageing. Potassium stearate forms an ideal lather for shaving, but

readily hardens and hence needs some of the softer oils, or glycerine

incorporated with it to form a satisfactory soap for shaving.

The selection of materials for making a shaving soap is important. The

tallow used should be white and of high titer. Cochin cocoanut oil is to

be preferred to the other kinds, and the alkalis should be the best for

technical use that can be purchased--76 per cent. caustic soda and 88-92

per cent. caustic potash are suitable. By the use of stearic acid it is

a simple matter to reach the neutral point which can be carefully

approximated.

The following are shaving soap formulae which have been found to give

good satisfaction:

I. lbs.

Tallow 360

Stearic acid 40

Soda lye, 41deg. B. 147

Potash lye, 34deg. B. 87

Water 32

Gum tragacanth 1

II. lbs.

Tallow 282

Cocoanut oil 60

Stearic acid 50

Bayberry wax 18

Soda lye, 41deg. B. 147

Potash lye, 34deg. B. 90

Water 32

III. lbs.

Tallow 400

Cocoanut oil 176

Stearic acid 415

Caustic soda, 40deg. B. 182

Caustic potash, 38deg. B. 108

To proceed, first run into the crutcher the tallow, cocoanut oil and

bayberry wax when used, and bring the temperature of the mass up to

140deg.-160deg. F. by dry steam. Then add the caustic soda lye and keep on

heat with occasional mixing until it is all taken up. When this stage is

reached gradually add all but about 5 per cent. of the potash lye, and

complete the saponification. This point having been reached, the heat is

turned off; the crutcher is run and the stearic acid, previously melted

by dry steam in a lead-lined or enameled vessel, is run in in a

continuous stream and the crutching continued for fifteen minutes to

half an hour. Samples are taken at this time, cooled and tested by

alcoholic phenolphthalein solution. If too alkaline more stearic acid is

added, if too acid more potash lye from that previously reserved. After

each addition of lye or stearic acid the mass is crutched from 10 to 15

minutes longer, another sample is taken, cooled and again tested. When

the phenolphthalein shows a very light pink after several minutes, the

soap is practically neutral, although at this point one can better judge

by dissolving a sample in hot neutralized alcohol made by putting into

the alcohol a few drops of phenolphthalein, and then adding weak alkali

drop by drop from a burette until a slight pink, not yellow, tint is

obtained, and noting the color of the solution. The solution should show

a very light pink when the soap is properly neutralized. When this stage

is arrived at the gum tragacanth, previously softened in water, is

crutched in if it is to be added. The soap is then framed, stripped in

three or four days, dried and milled.

The formulae as given are for shaving sticks, and do not readily press

unless thoroughly dried. A more satisfactory result is obtained by

adding at the mill 25 per cent. of white tallow base to obtain a

satisfactory mug soap.

SHAVING POWDER.

Shaving powder differs from the soaps just described in being

pulverized, usually adding up to 5 per cent. starch to prevent caking.

Any of the above soaps, dried bone dry, with or without the addition of

tallow base make a satisfactory powder for shaving.

SHAVING CREAM.

Shaving cream is now a very popular shaving medium due to the rapidity

and convenience with which one can shave by the use of this product.

Formerly shaving cream was made from the liquid oils like olive oil and

a soft fat like lard, together with cocoanut oil. Now, however, most of

the popular shaving creams are made from stearic acid and cocoanut oil,

as a far superior product is obtained by the use of these substances. By

using these a more satisfactory cream is obtained, and it is far more

convenient to make. The lather also produced therefrom is more suitable

for shaving, being thick, creamy and remaining moist.

A few typical formulae for shaving creams of this type are as follows:

I. lbs.

Cochin cocoanut oil 26

Stearic acid 165

Caustic potash lye, 50deg. B. 69

Glycerine C. P. 76

Water 38

II. lbs.

Cochin cocoanut oil 18

Stearic acid 73

Caustic potash lye, 39deg. B. 54

Glycerine 33

Water 27

III. lbs.

Cochin cocoanut oil 18

Stearic acid 73

Caustic potash lye, 39deg. B. 54

Glycerine 20

Water 40

and lbs.

Stearic acid 60

Glycerine C. P. 85

Water 165

Sodium carbonate 50

Borax 1

To make a shaving cream by Formula I or II, the cocoanut oil and

glycerine are first put into a suitable mixing apparatus or crutcher,

and heated to 120deg. F. A part or all the potash lye is then added and the

cocoanut oil saponified. The rest of the potash lye and the water are

then added, and with the mixer running the stearic acid, previously

melted in a lead-lined or enameled vessel, is then poured in in a stream

and the mass stirred until smooth, care being exercised not to aerate it

too much. The cream is then tested for alkalinity, the best method being

by that described under shaving soap, in which the sample is dissolved

in alcohol. Because of the large quantity of water present,

phenolphthalein is unsatisfactory, as dissociation of the soap may show

a pink indication in spite of the fact the mass is on the acid side. For

a quick method of testing the bite on the tongue is a satisfactory

criterion. If a cooled sample bites the tongue more stearic acid is

added until there is a 3% excess of this. When the proper neutralization

has taken place the cream is perfumed and framed in a special frame, or

it may be allowed to cool in the mixer and perfumed the next day. When

cool the cream is strained, or put through an ointment mill, after which

it is ready to fill into tubes.

The procedure for the first part of Formula III is the same as that just

given. The second part of the formula is made the same as a vanishing

cream for toilet purposes. To make this, first melt the stearic acid as

already directed. Dissolve the sodium carbonate and borax in water and

when dissolved add the glycerine and stir. Then heat this solution to

about 100deg.-120deg. F. and while stirring in a suitable mixing machine

into which this solution has been poured after being heated, or better

still in which it has been heated by dry steam, add the stearic acid.

Continue mixing until smooth and then allow to cool, or run into frames

to cool.

When the shaving cream and vanishing cream are both cool, they are mixed

in the proportion of one of the former to two of the latter. It is

claimed that in thus making a shaving cream a smoother product is

obtained, although it may be said that the vanishing cream is merely a

soft soap and the ultimate result is the same as though the various

ingredients were added in one operation, rather than making two separate

products and then mixing them, thereby considerably increasing the cost

of manufacture.

PUMICE OR SAND SOAPS.

Pumice and sand are at times added to soap to aid in the removal of dirt

in cleansing the hands. In some cases these soaps are made in the form

of a cake, in others they are sold in cans in the form of a paste.

A hand paste is usually made by merely dissolving ordinary tallow base

in two or three times its weight of hot water and mixing in the desired

quantity of pumice or sand and in some instances adding a little

glycerine to keep it soft or a solvent of some kind for grease. It may

also be made by directly incorporating any of these in a potash soap.

A cold made or semi-boiled cocoanut or palm kernel oil soap is the base

used to add the pumice or sand to in making a cake soap of this sort.

The following formulae serve as a guide for these soaps.

I.

Palm Kernel or Ceylon Cocoanut Oil 705 lbs.

Pumice (Powdered) 281 "

Soda Lye, 38deg. B. 378 "

II.

Cocoanut Oil 100 "

Soda Lye, 38deg. B. 55 "

Water 6 "

Silver Sand (fine) 60 "

To proceed place the oil in a crutcher and heat to 140deg. F. Sift in the

pumice and mix thoroughly. The lye is then added which causes a curdling

of the grain. The stirring is continued until the grain closes and the

soap is smooth, after which the desired perfume is added and the soap

dropped into a frame and crutched by hand. When the soap is set, it is

slabbed, cut into cakes, dried slightly and pressed.

LIQUID SOAPS.

Liquid soaps are merely solutions of a potash soap, usually cocoanut oil

soap, although corn oil is used to make a cheap soap. One of the

difficulties encountered in liquid soap is to keep it clear. At a low

temperature a sediment is often formed, but this can be overcome by the

use of sugar and filtering the soap through a filter press at a low

temperature. In order to prevent the soap from freezing, it is necessary

to lower the freezing point by the addition of glycerine or alcohol.

To make liquid soap by any of the formulae given below, the oil is first

run into a jacketed kettle with a stirring device, and heated to about

120deg. F. The potash lye is then added and the oil saponified. When the

saponification takes place, especially when cocoanut oil is used, the

mass swells rapidly and may foam over the sides of the kettle unless

water is used to check this, or a kettle of about four to five times the

capacity of the total charge of soap is used. When the saponification

has occurred, the sugar, borax and glycerine are added, the water run in

and the mixture stirred until the soap is thoroughly dissolved. Heat

aids materially in dissolving the soap. The soap is then allowed to cool

and if color or perfume is to be added this is stirred in, after which

the soap is cooled and filtered or else run directly into barrels.

Tallow is not suitable for making a clear liquid soap since it is too

high in stearine which when formed into the stearate makes an opaque

solution. The formulae herewith given have been found to give good

practical results.

I. lbs.

Cocoanut oil 130

Caustic potash lye, 28deg. B. 135

Sugar 72

Borax 2

Water 267

II. lbs.

Corn oil 130

Caustic potash lye, 26deg. B. 135

Sugar 72

Borax 2

Water 267

III. lbs.

Cocoanut oil 100

Caustic potash lye, 28deg. B. 102

Glycerine 100

Sugar 70

Water 833

Formulae I and II contain about 20 per cent. fatty acids. It is

possible, of course, to either increase or decrease the percentage of

fatty acid by varying the amount of water. The water used in making

liquid soaps, of course, should be soft, for hard water forms insoluble

soaps which precipitate and cause a sediment.

USE OF HARDENED OILS IN TOILET SOAPS.

While the introduction of the hydrogenation of oils is a decided advance

in the production of suitable cheaper oils for soap making,

comparatively little hardened oil is employed for soap making in America

up to the present time. In Europe, however, considerable advance has

been made by the use of such oils for manufacturing soap therefrom and a

number of plants turn out large quantities of hydrogenated oils for soap

making as well as for edible purposes. Recently a company has been

formed in this country for hardening oils and it is very probable that

the future will see this material extensively used in our own country,

as these appear to be the one present hope of the soap manufacturer as a

check on the ever increasing cost of fats and oils now used in making

soap.

It is an unfortunate condition that hydrogenated oils produced abroad

are sold under names which give absolutely no indication as to the oil

which has been hardened. The softer and cheaper oils like fish oil,

linseed oil, cottonseed oil, etc., are generally hardened for soap

manufacture to different degrees of hardness. While it is impossible to

definitely state just what products as Candelite, Talgol, Krutolin or

several other coined names of hardened oils are, various investigators

have experimented with them as to their adaptability for producing

toilet soaps and found that suitable toilet soaps may be made from them.

While many objections were at first met with concerning soaps made from

these products, as to their unsatisfactory saponification, the poor

lathering quality of the soaps and their odor and consequent difficulty

in perfuming, the results of most investigators along these lines

indicate that these in many cases were due to prejudice against or

unfamiliarity with handling oils of this type for soap making.

In manufacturing soap from hardened oils it is usually necessary to

incorporate with the charge lard, tallow, tallow oil or some other soft

oil of this nature. Satisfactory bases for toilet soaps, made as boiled

settled soap by the use of Talgol (undoubtedly hardened fish oil), are

said to be made by the formulae[10] below.

I.

Tallow 45 parts

Talgol 40 "

Cocoanut Oil 15 "

II.

Cocoanut Oil (Ceylon) 6 "

Tallow 12 "

Talgol, Extra 12 "

The method of boiling a soap of this type does not differ materially

from that of making settled tallow soap base. The soap itself has a

different odor than a straight tallow base, but is said to make a very

satisfactory soap for milling and to be of good appearance.

Satisfactory transparent soaps are made from the hardened oil Candelite,

which replaces the tallow in transparent soap formulae such as have

already been given in the section under "Transparent Soaps." The method

of manufacturing a soap by the use of this product varies in no way from

the usual method employed for making these soaps.

Since hydrogenated oils are high in stearine, their use in shaving soaps

is a decided advantage. It has previously been pointed out that

potassium stearate forms an ideal lather for shaving, and in the

hydrogenating process the olein is converted to stearine. Thus a

hardened oil is advantageous in a shaving soap. As an example of a cold

made soap for shaving the following may be taken.[11]

Talgol Extra 50 lbs.

Cocoanut Oil 10 "

Lard 10 "

Soda Lye, 38deg. B. 20 "

Potash Lye, 37deg. B. 21 "

This soap may be made in a crutcher by the method generally used in

making soap by the cold process.

TEXTILE SOAPS.

Soap is a very important product to every branch of the textile

industry. For woolen fabrics it is used for scouring, fulling and

throwing the wool; in the silk industry it is necessary for degumming

the raw silk, as well as for dyeing; in the cotton mills it is used to

finish cotton cloth and to some extent in bleaching; it is, furthermore,

employed in a number of ways in the manufacture of linen. Large

quantities of soap are thus consumed in an industry of so great an

extent and the requirements necessitate different soaps for the

different operations. We will, therefore, consider these in detail.

SCOURING AND FULLING SOAPS FOR WOOL.

The soaps used to scour wool and for fulling the woven cloth are usually

made as cheaply as possible. They are, however, generally pure soaps, as

filling material such as sodium silicate does not readily rinse out of

the wool and if used at all must be added very sparingly. Both cold made

and boiled settled soaps are made for this purpose. The soap is

generally sold in barrels, hence is run directly to these from the

crutcher or soap kettle. As cold made soaps the following serve for wool

scouring or fulling.

I.

Palm Oil 200 lbs.

Bone Grease 460 "

Soda Lye, 36deg. B. 357 "

Water 113 "

Soda Ash 50 "

Citronella 2 "

II.

Palm Oil (Calabar, unbleached) 155 "

House Grease 360 "

Soda Lye, 36deg. B. 324 "

Water 268 "

Sodium Silicate 83 "

III.

House Grease 185 "

Palm Oil (unbleached) 309 "

Soda Lye, 36deg. B. 309 "

Water 391 "

Soda Ash 70 "

Sodium Silicate 60 "

Corn Starch 10 "

These soaps are made in a crutcher by the usual process for cold-made

soaps, crutched until smooth, dropped into a barrel and crutched by hand

the next day or just before cooling.

As a settled soap for these operations the following charge is typical:

Palm Oil 34 parts

Cottonseed foots or its equivalent in fatty acids 33 "

Rosin 10 "

House Grease 23 "

The method of boiling such a soap is the same as for any settled soap up

to the strengthening change. When this stage is reached, sufficient lye

is added to strengthen the kettle strongly. It is then boiled down with

closed steam on salt brine or "pickle" until a sample of the lye taken

from the bottom stands at 16deg.-22deg. B. The soap is then run into

barrels and after standing therein for a day is hand crutched until cool

to prevent streaking of the soap.

Besides a soap of this type a settled tallow chip soap is used.

WOOL THROWER'S SOAP.

Soaps for wool throwing are sometimes made from olive oil foots but

these are often objected to because of the sulphur-like odor conveyed to

the cloth due to the method by which this oil is extracted with carbon

disulphide. A potash soap hardened somewhat with soda is also used. As a

formula for a suitable soap of this type this may be given.

Olive Oil Foots 12 parts

Corn Oil 46 "

House Grease 20 "

Soda Lye, 36deg. B. 3 "

Potassium Carbonate (dry) 5-3/4 "

Potassium Hydrate (solid) 23 "

This soap is made as a "run" soap by the general directions already

given for a soap thus made. The kettle is boiled with open and closed

steam, adding water very slowly and aiming to obtain a 220-225 per cent.

yield or fatty acid content of the finished soap of 46 per cent. When

the soap is finished a sample cooled on a plate of glass should be

neither slippery or short, but should string slightly. The finished soap

is run directly into barrels.

A soap for wool throwing by the semi-boiled process may be made from

olive oil foots in a crutcher thus:

Olive Oil Foots 600 lbs.

Potash Lye, 20deg. B. 660 "

The oil is heated to 180deg. F., the lye added and the mass stirred until

it bunches, when it is dropped into barrels.

WORSTED FINISHING SOAPS.

For the finishing of worsted cloth soaps high in cocoanut oil or palm

kernel oil are preferred. These soaps are finished very neutral, being

made as settled soaps, but given an extra wash change after

strengthening strongly. They are then finished as usual and run into

barrels. If framed too hot, the high percentage of cocoanut oil causes

mottling, which is prevented by crutching by hand until the temperature

of the soap is 140deg.-145deg. F. Some typical charges, all of which are

saponified with soda lye, follow:

I.

Palm Kernel Oil 60 parts

Corn Oil 40 "

II.

Palm Kernel Oil 30 "

Red Oil (single pressed) 70 "

III.

Red Oil 33-1/3 "

Corn Oil 33-1/3 "

Cocoanut Oil or Palm Kernel Oil 33-1/3 "

SOAPS USED IN THE SILK INDUSTRY.

Soap is used to a very large extent in silk mills, both for degumming

the raw silk and in silk dyeing. Raw silk consists of the true silk

fibre known as fibroin and a gummy coating, sericin, which dulls the

lustre of the silk unless removed. For this purpose a slightly alkaline

olive oil foots soap is best adapted, although palm oil and peanut oil

soaps are sometimes used, as well as soaps made from a combination of

house grease to the extent of 30 per cent., together with red oil or

straight olein soaps, both of which are artificially colored green. In

using house grease, if 30 per cent. is exceeded in combination with red

oil, the titer is raised to such an extent that the soap does not

readily rinse from the silk nor dissolve readily. They are also not

advisable because they impart a disagreeable odor to the silk.

To make a soap for this purpose from olive oil foots it is made as a

settled soap, care being taken to thoroughly boil the mass on the

saponification change in the closed state to assure proper

saponification. The kettle is usually grained with lye and given a good

wash change to remove the excess strength. The change previous to the

finish should not be too heavy or too large a nigre results. The lighter

the grain is, the better the finished kettle is. A yield of 150 per

cent. is usually obtained. This soap is generally run to a frame,

slabbed upon cooling and packed directly into wooden cases.

For silk dyeing the above soap is suitable, although any well-made soap

of good odor and not rancid is useable. While soap alone is often used

in the bath for silk dyeing, certain dyestuffs require the addition of

acetic or sulphuric acid, which sets free the fatty acids. If these be

of bad odor it is taken up by the silk and is difficult to remove. The

most generally used soaps are the just mentioned olive foots soap or a

soap made from a good grade red oil.

Both kinds are extensively used.

SOAPS USED FOR COTTON GOODS.

In the manufacture of cotton goods, as compared to the wool and silk

industries, very much less soap is used and it is only applied to the

finished fabric either to clean the cloth preparatory to dyeing or to

aid in dyeing with certain colors. It is also used in calico printing.

For cleansing the cloth ordinary chip soap is suitable although a more

alkaline soap finished as a curd soap is an advantage in that the free

alkali contained therein aids in removing the dirt and has no harmful

effect on the cotton. For dyeing cotton goods or to brighten certain

colors after dyeing an olive oil foots soap is most generally employed.

In calico printing soap is used to wash and clear the cloth after

printing. A soap for this purpose should be easily soluble in water and

contain no free alkali, rosin or filler. The best soaps for use in

calico printing are either an olive oil foots soap or an olein soap.

SULPHONATED OILS.

While sulphonated oils are not used to any great extent in the

manufacture of soap, they are used very largely in the dyeing and

printing of turkey and alizarine reds on cotton as well as other colors.

Just what action these oils have is not known. Turkey red oil or

sulphonated castor oil is the best known sulphonated oil.

The process of making these oils is simple. The equipment necessary is a

wooden tank or barrel of suitable capacity, approximately two and a half

times the amount of oil to be treated. There are furthermore required

other tanks or vessels to hold the solutions used such as caustic soda,

ammonia and acid. The tank to be used for the preparation of sulphonated

oil should be provided with a valve at the bottom of the tank and a

gauge to measure the quantity of liquid therein.

The process is carried out as follows:

Three hundred pounds of castor oil are placed in the tank and 80 pounds

at 66 deg. B. sulphuric acid are weighed out in another vessel. The acid

is run into the tank containing the oil in a very thin stream while the

oil is well stirred. At no time should the temperature exceed 40 deg. C.

This operation should consume at least an hour and stirring should be

continued half an hour longer to insure the thorough mixing of the oil

with the acid. The mass is then allowed to settle for 24 hours, after

which 40 gallons of water are added and the mixture stirred until it has

a uniform creamy color indicating no dark streaks. This mixing process

should be carefully carried out and when completed allowed to settle 36

hours. At this point the mass will have separated into two layers, the

lower layer consisting of a water solution of acid and the upper layer

of oil. The former is run out through the valve located at the bottom of

the tank. Another wash may now be given or dispensed with as desired. In

this wash the addition of salt or sodium sulphate at the rate of 1-1/2

pounds per gallon of water is advisable. A 24 deg. B. caustic soda

solution is prepared and added slowly to the acidified oil with constant

stirring. The mass first turns creamy, then becomes streaked, increasing

in streaks as the caustic solution is poured in, and finally becomes

clear and transparent. Water is now added to bring the volume to 75

gallons. The oil is now milky in appearance, but the addition of a

little more soda solution restores the transparency.

In some cases ammonia is used in addition to caustic soda in

neutralizing the oil. Three-fourths of the amount of caustic soda

required to complete the neutralization is first added and then the

neutralization is completed with a one to one liquid ammonia and water

solution.

FOOTNOTES:

[9] Seifensieder Ztg., 40, 47, 1266 (1913).

[10] Seifensieder Ztg. (1913), p. 334 and 338.

" " (1912), p. 1229 and 1257.

[11] Seifensieder Ztg. (1912), p. 954.