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HC 3SAP T
COOKING AND CLEANING
RICHARDS and ELLIOTT
THE CHEMISTRY OF
COOKING AND CLEANING
A MANUAL FOR HOUSEKEEPERS
ELLEN H. RICHARDS
S. MARIA riELlOTT
REVISED AND ENLARGED
WHITCOMB AND BARROWS
By Estes & Lauriat
By Ellen H* Richards
Al<FRBD MUDOB & SON, INC., PRINTBRS,
Boston, Mass., U. S. A.
IN this age of applied science, every opportunity
of benefiting the household should be seized
The family is the heart of the country's life, and
every philanthropist or social scientist must begin
at that point Whatever, then, will enlighten the
mind, and lighten the burden of care, of every
housekeeper will be a boon.
At the present time,. when ^ev^ctric light and
the gas stove are familiar topics, ^i^e is, after all,
no branch of science which might', be of more
benefit to the community, ^If 7t ji'^ere prc^erly un-
derstood, than Chemistry — ^the Chemistry of Com-
mon Life. , . ^ , • r« ^ . - --
There is a space yet uhcK^upied for an elemen-
tary work which shall give to non-scientific read-
ers some practical information as to the chemical
composition of articles of daily use, and as to their
action in the various operations in which they are
The public are the more ready for the applica-
tion of this knowledge since Chemistry is taught
in nearly all High Schools, and most persons have
a dim idea of what some part of it means. To
gather up these indistinct notions into a definite
and practical form is the aim of this little book.
There is, lingering in the air, a great awe of
chemistry and chemical terms, an inheritance
from the age of alchemy. Every chemist can re-
call instances by the score in which manufacturers
have asked for recipes for making some substitute
for a well-known article, and have expected the
most absurd results to follow the simple mixing
of two substances. Chemicals are supposed by
the multitude to be all-powerful, and great ad-
vantage is taken of this credulity by unscrupulous
The number of patent compounds thrown upon
the market under fanciful and taking names is a
witness to the apathy of housekeepers. It is time
that they should bestir themselves for their own
protection. A little knowledge of the right kind
cannot hurt them, and it will surely bring a large
return in comfort and economy.
These mysterious chemicals are not so many
or so complicated in structure but that a little
patient study will enable any one to understand
the laws of their action, so far as they apply to the
common operations of the household.
No attempt is here made to cover the whole
ground of chemical science, but only to explain
such of its principles as are involved in the raising
of bread, and in a few other common processes.
To THE Second Edition.
THE science of chemistry has made rapid
strides in the past fifteen years. Biological
science has sprung from infancy to sturdy man-
hood during the same time, and a knowledge of
both with their relations to each other is necessary
to the right understanding of the manifold opera-
tions of life. All the sciences and all the arts are
taxed by thq intelligent home-maker for the
proper foundation and continuance of the complex
life of the home.
The establishment of more homes and their
right conduct when established, which results in
the better utilization of time, money and strength,
means the perpetuity, prosperity and power of the
Without trespassing upon the domain of house-
hold bacteriology, a knowledge of the chemistry
of cooking and cleaning must include some dis-
cussion of the sources of dirt, its composition and
its dangers, and the discussion of methods for its
removal, which shall at the same time be speedy,
safe and effectual.
Experience teaches that in domestic work there
is no best rule of universal application. Circum-
stances vary so widely that principles, alone, can
be laid down. Each case requires a large propor-
tion of judgment — ^a compound of more complex
composition than any chemical substance ever
If any housekeeper finds a method better for
her purpose than the one -specified here, let her
keep to its use and tell it to others. This work
will have accomplished its purpose if it interests
those who understand already the principles of
cooking and cleaning; gives a few answers to
those who continually ask "Why?" and "How?"
and stimulates to study and thought the many
who have long labored with willing hearts but
with untrained minds and hands.
Preface to First Edition iii
Preface to Second Edition v
I. Matter and Its Composition ... 5
II. Elementary Chemistry 12
III. Starches, Sugars, Fats, Their Preparation
as Food 24
Iv. Nitrogenous Constituents .... 47
V. Flavors and Condiments. Diet ... 56
I. Dust 71
II. Dust Mixtures (Grease -and Dust) . . 87
III. Stains, Spots, Tarnish 100
IV. Laundry 118
V. Chemicals, and Their Use in the House-
VI. Antiseptics, Disinfectants, Insecticides . 165
Books of Reference 181
To THE Revised Edition of 1907.
IN the thirty years since this little book was
written, the interpretation of many scientific
facts has been changed as more facts have been
discovered, and also, in many cases, the method
of expressing the well-established facts has been
changed to agree with newer theories.
Although at first sight this seems discourag-
ing, it should not prevent an attempt to under-
stand some of the fundamental laws upon which
every-day life and health depend. The author
has already learned three different systems of
expressing the same facts in chemistry and
expects to learn yet another.
In making this revision a medium course has
been chosen. It is not prepared for the scien-
tific man, but its mission is now, as it has been
heretofore, to the average intelligent housewife.
She needs to see that there are reasons for things
in order to lift the monotonous operations of the
kitchen in particular, and the household in gen-
2 THE CHEMISTRY OF
eral, from distasteful drudgery to a plane of
intelligent direction of scientific processes, the
results of which may be more or less controlled.
It is this sense of control, of power to pro-
duce desired results, which gives an interest to
daily duties. Since the good health and earning
capacity of the family depend upon the house-
mother's knowledge of the laws which govern
the daily making and baking and cleaning, surely
it will be worth her while to try to absorb the
spirit of modern scientific research, to observe
what goes on in her pots and pans, to watch
her oven, and especially to scrutinize her dish
Knowledge of foods and of chemical proc-
esses is increasing so rapidly that what is written
is out of date before the ink is dry, but a little
more or less exact information is not so im-
portant as that the spirit of inquiry, of open-
mindedness, shall pervade all departments of
household activity. .
Thirty years ago very few grown women had
received any training in chemistry. Chemical
nomenclature was worse than Greek to them.
Today the majority of young housewives have a
small remnant of school chemistry among iheir
store of miscellaneous knowledge. It is to be
feared that it is rather vague, but chemistry is
COOKING AND CLEANING. 3
not the bugbear it once was. The present day
housewife is not afraid of chemical substances.
The great difficulty in explaining chemical
results has been in showing the law of definite
proportions, that fundamental law, discovered
by Dalton, in and upon which the whole theory
has been built.
The law of exchange of different quantities
having different values not according ,to quan-
tity, but according to value, has always been
difficult to express.
One reason for dwelling upon the law of defi-
nite proportions is because the idea is so preva-
lent that if the effect of a teaspoonful is good,
that of a teaspoonful and a half is better, whereas
the extra half may be the cause of failure. The
long experience of a grocery clerk gives his hand
nerves such a response to weight that he may
dispense with scales in putting up a pound of
sugar. In this way the skilled cook tells the
proportions with the exactness of the balance,
but woe betide the unskilled housewife who
attempts the same trick.
One other fact in relation to science, and chem-
ical science in particular, must be borne in mind.
While much is known, there remains much more
still hidden. It is practical wisdom to use all
that is known and to accept results as far as they
4 THE CHEMISTRY OF
prove beneficial, without waiting to Jearn all the
reasons why. Not that the search for reasons
should be abandoned, but that each bit of knowl-
edge should be applied as fast as gained.
THE CHEMISTRY OF COOKING
Matter and Its Composition.
WE give the name matter fo the objects Matter,
which can be recognized by any one of
our senses. There are many kinds of matter and
many forms of one kind. Ice melts into water,
water changes into steam. In our stoves, the
hard, black coal disappears, leaving a soft, gray
ash, that weighs much less than the original coal.
Something has been taken away.
The leaf is covered by wind-blown soil and SStl^*"
soon no leaf is there ; but the matter of which it
was composed is still somewhere, for that is
never lost. Living matter is in constant change
from one form to another. Our bodies are com-
posed of matter, and to their continued existence,
as well as to their growth, material substances
are'necessary. Some changes come quickly, some
slowly. Years, ages even, are sometimes neces-
sary to bring about a result that is visible to us.
6 THE CHEMISTRY OF
A familiar substance, sugar, for example, may
be subjected to different changes. Put two table-
spoonfuls of white sugar into a scant half cup of
water. The sugar disappears. The clear water
changes to a syrupy liquid. If the water is
allowed to evaporate slowly, the sugar is found
A teaspoonful of sugar dropped upon the
warm stove changes in character. There ap-
pears a black mass, which is readily recognized
Add a solution of an acid to a solution of an
alkali, and observe that the acid substance and
the alkaline substance are no longer in existence
as such. There is, instead, a neutral saline sub-
stance dissolved in water. The new substance
. has the properties of neither of the others. The
acid and the alkali have lost their identity.
Dissolve a teaspoonful of sugar in a cupful of
water. Add a very little yeast and put the cup
in a warm place. Soon bubbles of gas rise and
break on the surface; while, on distilling the
liquid, a new acquaintance presents itself in the
form of alcohol. The first-mentioned change in
the sugar — the solution of it in water — is a
physical change; for the character of the sub-
stance is not permanently altered. The second
change — the charring — is a chemical change —
COOKING AND CLEANING. 7
the substance loses its individual character. The
third change in the* sugar — its fermentation —
which is most important for our present purpose,
is also a chemical change but one caused by the
action of life. When the syrup ferments, we
know that living organisms are at work in the
solution, changing the substance by their own
processes of growth. To this class, then, we may
apply the name biological change. Here belong
the changes in our own bodies which enable them
to live and grow. Death comes when these
"vital" changes can no longer proceed in a
normal, healthy manner.
Changes in matter, then, are of two kinds.
I. Physical. Change of form, without per-
manent loss of identity. This is brought about
by outside forces: heat, blows, etc.
II. Chemical. Complete change of character,
with or without change of form. This is brought
about by chemical agencies, by fire and electric-
ity — also forces from without.
Physical and chemical forces, working to-
gether, allow biological results, caused by living
cells producing energy by means of their life
Under these heads come the numerous changes
which every housewife observes and which all
should understand, so far as such understanding
is necessary for the true economy of the house.
8 THE CHEMISTRY OF
FoiTO^of ^^ j^ave seen that matter is subject to two
kinds of change. Experience teaches that matter
exists in three different forms — soUds, liquids
^nd gases. It teaches, also, that by the action of
outside forces some solids become liquids and
some liquids become gases. The reverse proc-
ess, also, is known — gases change into liquids
and liquids into solids. The chemist or physicist
is able to change matter from one form into
another in many more instances than are ob-
served in ordinary experience.
Causes of What causcs can be made to bring about these
Matter. changcs ? Bcforc an iron kettle or stove can be
made, the metal from which it is formed must
be subjected to intense heat, when it will become
a liquid and can be poured into molds of any
desired shape. Solid ice melts or becomes water
at a low temperature ; but at a higher degree of
temperature, the water becomes steam or gas.
Some solids, as camphor and iodine, sublime, that
is, pass directly into the gaseous form.
Heat, then, is one influence which brings about
a change of state in material substances. If heat
be abstracted from a liquid, the latter may be-
come a solid, as when water becomes ice. Like
changes are less readily brought about by pres-
sure, gases becoming liquids; liquids becoming
solids. Cold and pressure, acting together, are
COOKING AND CLEANING. 9
able to liquefy the air, and other gases once
Different degrees of heat produce varying Expansion,
degrees of liquefaction. Sometimes only a semi-
liquid state results, as in the melting of solder,
of gelatine and of tar. Almost all matter (ex-
cept water between 32° and 39° Fahrenheit)
expands or occupies more space under the action
of heat ; but in gases the proportion of expansion
is much the greatest. This expansion of gases
with heat makes possible the process of ventila-
tion by means of an open fire, and is one factor
in the rise of dough.
The solids may also be changed to liquids. Solution.
The degree of solubility of any substance de-
pends largely upon the temperature of the solv-
ent. Common salt dissolves nearly as well in
cold as in warm water. "Soda" and alum dis-
solve more readily in warm than in cold, while
cream of tartar requires hot water for its com-
The amount of solid which water will dissolve Saturation,
usually increases with the temperature to a cer-
tain degree. After this no more will dissolve
and the solution is "saturated." Gases readily
dissolve in water, but usually in cold solutions
The action of the liquid is more rapid if the
THE CHEMISTRY OF
solid be first powdered, for a greater area is thus
presented to the action of the Hquid. It is also
usually more rapid when the substance is placed
upon or near the surface. Under these condi-
tions each particle, while dissolving, is sur-
rounded by a thin envelop of syrup, which be-
comes heavier and sweeter. The film of syrup
sinks into the solvent liquid, so that a clean sur-
face is continually exposed to be acted upon.
Solution is a valuable agent in bringing about
chemical action during many processes of cook-
ing and cleaning.
Water is a nearly universal solvent. It dis-
solves larger quantities of more substances than
any other liquid. Some solids, however, dissolve
more readily in other liquids, as camphor in alco-
hol. Silver, copper and tin are not perceptibly
dissolved in pure water, while most of their com-
pounds, as nitrate of silver and sulphate of cop-
per, are thus soluble. Lead dissolves more read-
ily in pure water than in that containing some
impurities. Gold may be dissolved in a warm
mixture of two strong acids. Many of these
metallic solutions which may be formed in cook-
ing utensils and water pipes are poisonous, and
a knowledge of them becomes a matter of great
importance to all housekeepers.
A process of daily occurrence in the household
COOKING AND CLEANING, H
greatly resembles solution. It consists in the
taking up of water, which produces an increase
of bulk or "swelling," but no true solution. Gel-
atine swells in cold water and may then be dis-
solved in hot water. Starch "jells" by taking
up water; so we soak the cereals which consist
largely of starch, that they may be more quickly
acted upon by beat
OST substances with which we deal in or-
dinary life are compounds of two pr more
elementary constituents. The grain of wheat,
the flesh of animals, the dangerous poison, are
each capable of separation into simpler sub-
stances. Finally a substance is found which can-
not be further separated. A chemical element
is a substancie which cannot be decomposed into
Elements. Purc gold is au element from which nothing
can be taken different from itself, but gold coin
contains a little copper or silver or both. The
oxygen of the air is an element. Air is a mix-
ture of two or more elements. Oxygen and
hydrogen, both gaseous elements, unite in cer-
tain proportions to form the chemical compound,
There are 'about eighty of these elements
known to the chemist, while their compounds
are infinite. For his convenience the chemist
abbrevisites the nam^s of the elements into syn^^
tized by Google
COOKING AND CLEANING, 13
bols, which he uses instead of the names. Usu-
ally, the first or the first two. lett^r^ 9f the Latin
name are taken. These symtois mean much
more, however, than time saved, as we shall see.
Most of the elements unite with each other. Compounds.
Then in the resulting compounds, one or more
elements may be exchanged for others, so that a
multitude of combinations are formed out of few
elementary substances. The bulk of our food,
clothing and furniture is made up of only five or
six of these elements, although about twenty of »
them enter into the compounds used in the
household. The others are found in nature, in
the chemical laboratory or in the physician's
medicine case. A few are so rare as to be con-
Every housewife should understand something chemical Laws,
of these chemical substances — their common
forms, their nature and their reactions, that she
may not be cheated out of time and money, and,
more important still, that she may preserve the
health of those for whom she cares.
All chemical changes are governed by laws.
Under like conditions, like results follow. No
chemical sleight of hand can make one pound of
washing soda do the work of two pounds, or one
pound of flour make a third more bread at one
time than at another.
14 THE CHEMISTRY OF
i?^J)2rtiOTs?"*** ^"^ ^^ ^^^ "^^st important of these laws is
that known as the Law of Definite Proportions,
which states that the various elements do not
unite to form chemical compounds in any pro-
portions whatever, but only in perfectly definite
proportions. From this it follows that to the
elements can be assigned values which represent
the quantities of them which enter into combina-
tion with each other* These values are called
the combining weights or atomic weights of the
elements, the latter term having been introduced
since it is assumed that the elements are built up
of extremely small particles of matter called
atoms, and that compounds are made of groups
of these atoms called molecules, and since under
this assumption the relative weights of the ele-,
ments which unite represent the relative weights
of the atoms or multiples of them. Thus, in the
compound water, hydrogen and oxygen are
present always in perfectly definite proportions,
namely, in the relation of one part by weight of
hydrogen to eight parts by weight of oxygen;
and in the compound acetylene, the elements
carbon and. hydrogen are always present in the
proportion of one part of hydrogen to twelve
parts of carbon. It is customary to adopt as the
standard of reference one part by weight of
hydrogen and to ^dopt c^§ th^ cpmbining weight
COOKING AND CLEANING. 16
or atomic weight of other elements that quantity
of them which combines with one part of- hydro-
gen, or in some cases with two or more parts of
Upon this basis the atomic weight of oxygen
is sixteen and that of carbon twelve times the
atomic weight of hydrogen. The symbol of an
element is made to represent its constant atomic
weight; so that, while the word oxygen means
only the collection of properties to which is given
the name, the symbol O indicates a definite quan-
tity of oxygen which is sixteen times the weight
of hydrogen represented by the symbol H.
While it is always true that the elements com- Law of Multiple
bine with each other only in definite proportions, ^^ ***"*'
yet it is often true that they combine to form two
or more definite compounds. Such combinations
are governed by the Law of Multiple Propor-
tions: When elements form more than one com-
pound, they unite according to some multiple of
their combining weights.
Thus, sulphur and oxygen form two different
compounds represented by the symbols SO, and
SO3 — where the proportions of sulphur to oxy-
gen are thirty-two to thirty-two for the first and
thirty-two to forty-eight for the second, the com-'
bining weight* corresponding to the symbol S
16 THE CHEMISTRY OF
A partial list of atomic weights is as follows:
SymboU. fhe symbols, then, are the chemist's shorthand
alphabet, or his sign language. The non-scien-
tific reader is apt to look upon the acquisition of
this sign language as the schoolboy regards the
study of Chinese — as the work of a lifetime. He
would be near the truth were he to attempt to
remember the symbols of all the complicated
compounds known and constantly increasing;
but a study of the properties and combinations
of the few which make the common substances
of daily use need not frighten the most busy
• COOKING AND CLEANING. 17
housewife, for they can be comprehended in a
few hours of thoughtful reading. Then a little
practice will make them as familiar as the recipe
of her favorite cake. "To master the s)mibolical
language of chemistry, so as to fully understand
what it expresses, is a great step toward master-
ing the science."
The exchanges and interchanges among the
elements by which new compounds are produced
are called chemical reactions. The written ex-
pression of the reaction is called a chemical
equation. In all chemical equations there is just
as much weight represented on one side of the
sign of equality (=) as on the other.
C + O, = CO,
12 + 32 = 44
Carbon. Oxygen. Carbon Dioxide.
HCl + NaOH = NaCl + H,0
Hvdro- Sodium Sodium Water,
chloric Hydrate. Chloride,
Acid. * or Com-
36.5 + 40 = 58.5 + 18
76.5 = 76.5
This shows that the sum of the weights of
the two substances taken is equal to the sum of
the weights of the new substances formed as the
result of the reaction.
18 THE CHEMISTRY OF
It is this exactness in dealing with matter
which gives to the study of chemistry its great
value from an educational standpoint. In the
economy of nature nothing is lost. . Wood and
coal burn in our stoves. The invisible product
of their combustion, COg, passes into the air, but
adds a definite amount to the weight of the air.
Thus the symbol of this product shows that
twelve pounds of coal (which when free of ash
is nearly pure carbon) in burning take from the
air thirty-two pounds of oxygen and give back
to the air forty-four pounds of carbon dioxide.
Similarly the symbol of water, HgO (atomic
weights, H = I, O = i6), shows that for every
eighteen parts by weight of water produced,
there will be two parts by weight of H and six-
teen parts by weight of O required.
Although the phenomena themselves are found
to be unchangeable, our explanation of them may
be modified as our knowledge increases.
Present theories penetrate only a little into the
real essence of things, and the investigator soon
stumbles upon questions whose explanation does
not at present even seem to be a possibility.
(See late text-books on chemistry for the dif-
ference between ipns and atoms.)
Oxidation. One of the most important chemical changes
that takes place inside or outside the animal body
COOKING AND CLEANING. 19
is that union of oxygen (four-fifths of the air)
with carbon or hydrogen which we call oxida-
tion — under the steam boiler and in the stove it
is called combustion. It is the chief source of
available power or energy in either case. (See
pp. 25, 26.)
The same amount of heat is evolved when a
given amount of substance is oxidized, whether
the combustion takes place slowly or rapidly.
An appreciation of these fundamental laws of The
chemical combination is needed to realize the
significance of the recent work on the use of
food in the human body as demonstrated in the
Before a study of the chemical composition of
food materials and of the chemical and physical
changes occurring in the processes of cooking
as a preparation for the best utilization of these
food stuflfs could be insisted upon, it was neces-
sary to be convinced that the utilization of the
chemical compounds, such as sugar, starch, albu-
min, etc., was the same in effect within the body
as without, in stove or furnace.
For the proof that the law of the conserva-
tion of energy held in the life processes going
on in the human body, an examination of the
food and of the results of its consumption was
20 THE CHEMISTRY OF
For this purpose a "respiration calorimeter"
was set up.*
"This is a metal- walled chamber in which a
man lives, eats, drinks, works and sleeps. Pro-
vision is made for ventilating the chamber and
for regulating the temperature and moisture of
the air within it. The volume of the ventilating
air current is measured and samples for analysis
are taken before and after it passes through the
chamber, thus obtaining the amounts of carbon
dioxide and water in the respiratory products.
The food, drink, feces and urine are weighed
and analyzed, and their potential energy is deter-
mined, as is the kinetic energy given off from the
body in the forms of heat and external muscular
"The device^ for measuring the heat or loss
of heat given off from the body include: (i)
Arrangements to prevent gain or loss of heat
in the chamber either by the passage of heat
through the walls or the bringing in and taking
out of heat in the ventilating air current; (2)
arrangements by which the heat given off in the
chamber, by the body or otherwise, is carried
out by a current of water. . . . This current,
which is conveyed by copper pipes, comes into
the chamber at a low temperature, passes around
the interior, absorbs the heat, and goes out cor-
respondingly warmer. The quantity of the water
and the rise of temperature show how much heat
is carried out."
* " Description of a New Respiration Calorimeter and Experiments on
the Conservation of Energy in the Human Body," by W. O. Atwater, Ph.D.,
Professor of Chemistry, Wesleyan University, and E. B. Rose, Ph.D., Pro-
fessor of Physics, Wesleyan University.
COOKING AND CLEANING. 21
By means of such apparatus there may be de- Jsuc?^^*^"*
termined questions pertaining to the demands ExpcrimentB.
of the body for nutriment under different condi-
tions of work and rest ; the duties performed by
the different nutrients of food in supplying the
needs of the body; and finally the nutritive
values of food materials and the amount and
proportions best adapted to the needs of people
of different classes, with different occupations
and in different conditions of life.
By experiment it has been found that i gram
of carbohydrates (starch, sugar, etc.) or proteids
(lean meat, white of tgg, etc.) gives on an aver-
age about 4-1 calories,* and one gram of fats 9.3
calories. Therefore to find the value of a given
dish set upon the family table is simple when
the weights of the ingredients are known. For
instance, in a curry stew with rice, three pounds
of medium fat beef will yield 259 grams proteid
and 175 grams of fat, while ten ounces of rice
will yield 22.5 grams proteid, i gram of fat and
222 grams of carbohydrates. Adding together
the carbohydrate and proteid gives 503.5 grams.
Multiplying this number by the 4.1 calories per
gram we have 2,064 calories; while multiplying
the 176 grams of fat by 9.3 gives 1,636 calories
for the fat, a total of 3,700 calories, or as many
* For definition of calories, see yage 47.
Si THE CHEMISTRY OF
as shoidd be supplied by a dinner for three
The housewife well understands that she may
provide sufficient food, but that she cannot be
sure it will be eaten, or assimilated if it is eaten.
But she must also understand that power does
not come from nothing, and that if sufficient
nourishment is not provided, the body cannot
have its full due.
p^d^ ^"^ °^ ^^^ universal chemical operations in
the household is the use of cream of tartar and
baking soda or of baking powders. Advantage
has been taken of this fact to put upon the
market many substitutes and variations with the
natural result that the housewife is confused and
' uncertain. The table on page 23 may be helpful
in clearing up some of the mysterious ways of
the substances themselves and of their advocates.
Thus, 84 parts of cooking soda unite with 188
parts of cream of tartar — if both are pure — to
g^ve 44 parts of the gas COg. Cream of tartar
is a compact powder, however, so that a tea-
spoonful will weigh more than a teaspoonful of
soda, and illustrates the difference in accuracy
between weighing and measuring. Because
cream of tartar is so liable to cake, a starch is
added to the mixing for baking powder. For
home preparation 5 to 10 per cent will be enough.
COOKING AND CLEANING. 23
Starches, Sugars, Fats, Their Preparation for Food.
THE material world is divided into living and
lifeless matter. All living matter requires
food that it may grow, repair waste, and reproduce
itself, if the existence of its kind is to be continued.
This food must be made from the material elements
we have been studying. Food for the human body
must, therefore, contain such elements, in com-
bination, as are found in the body substance, in
order that new materials may be formed from
them by the processes of life.
Wherever there is life, there is chemical change,
and, as a rule, a certain degree of heat is neces-
sary, in order that chemical change may occur.
Vegetation does not begin in the colder climates
until the air becomes warmed by the heat of the
spring. When the cold of winter comes upon
the land, vegetation ceases. If plant life is to be
sustained during a northern winter, artificial
warmth must be supplied. This is done by heat
from a furnace or stove. In chemical terms, car-
bon and hydrogen from coal, wood, or gas are
caused to unite with the oxygen of the air to form
carbon dioxide (carbonic acid gas) and water, and
COOKING AND CLEANING, 26
by this union of two elements with oxygen, heat
C +Oa =C O.
C H4+O4 =C Oa +2H, O
These two chemical reactions indicate the Combuttioii.
changes which cause th^ production of artificial
heat generally used for domestic purposes. AH
living matter, whether plant or animal, is found
by analysis to contain carbon, oxygen, hydrogen,
and nitrogen. Other elements are present in small
and varying quantities, but "the great four*' are
the essentials. The plant is able to take all its
food elements from air, water and soil, and, in
its own cells, to manufacture those compounds
upon which it can feed; while an animal cannot do
this, but must accept for the most part the manu-
factured product of the plant. Man, therefore,
finds his food in both vegetable and animal subr
Since many animals Eve in temperatures in
which plants would die, it is evident that they must
have some source Of heat in themselves. This is
found in the union of the oxygen of the air
breathed, with carbonaceous matter eaten as food,
and the formation of carbonic acid gas (carbon
dioxide), and water (CO2 and HgO), just as
in the case of the combustion of the wood in the
grate. Only, instead of this union taking place in
THE CHEMISTRY OF
one Spot, and so rapidly as to be accompanied by-
light, as in the case of the grate fire, it takes place
slowly and continuously in each living cell.
Nevertheless, the chemical reaction seems to be
The heat of the human body must be main-
tained at 37° C — ^the temperature necessary for
the best performance of the normal functions. Any
continued variation from this degree of heat indi-
cates disease. Especially important is it that there
be no considerable lowering of this temperature,
for a fall of one degree is dangerous.
The first requirement of animal life is, then, the
food which supplies the heat necessary for the
other chemical changes to take place. The class
of foods which will be considered here as those
utilized for the production of animal heat among
other functions, -includes the carbon compounds,
chiefly composed of carbon, hydrogen and oxygen.
The slow combustion or oxidation of these car-
bonaceous bodies cannot take place without an
abundance of oxygen; hence, the diet of the ani-
mal must include fresh air — ^a point too often over-
looked. The amount of oxygen, by weight, taken
in daily, is equal to the sum of all the other food
elements. One-half of these consists of some form
of starch or sugar — ^the so-called carbohydrates,
COOKING AND CLEANING, 27
in which the hydrogen and oxygen are found in
the same proportions as in water. (The fats will
be considered by themselves.)
Starches, sugars and gums are among the con- starches,
stituents of plants, and are sometimes found in
animals in small quantities. Starch is found in
greater or less abundance in all plants and is laid
up in large quantities in the seeds of many species.
Rice is nearly pure, starch, wheat and the other
cereals contain sixty to seventy per cent of it.
Some tubers contain it, as potatoes, although in
less quantity, ten to twenty per cent. It is formed
by means of the living plant-cell and the sun's
rays, from the carbon dioxide and water contained
in the air, and it is the end of the plant life — ^the
stored energy of the summer, prepared for the
early life of the young plant another year. An
allied substance is called cellulose. This oc-
curs under numerous forms, in the shells
and skins of fruits, in their membraneous
partitions, and in the cell walls. Starch in its com-
mon forms is insoluble in water. It dissolves par-
tially in boiling water, forming a transparent jelly
Sugars, also, are a direct or indirect product of sugw.
plant life. Common sugar, or cane-sugar, occurs
in the juices of a few grasses, as the sugar-cane;
of some trees; and of some roots. Milk-sugar i$
28 THE CHEMISTRY OF
found in the milk of mammalia, while grape-sugar
is a product of the ripening processes in fruit
gg5^** Digestion is primarily synonymous with solu-
tion. All solid food materials must become prac-
tically soluble before they can pass through the
walls of the digestive system. As a rule, non-crys-
talline bodies are not diffusible, so that starch and
like materials must be transformed into soluble,
crystalline substances, before absorption can take
place. Cane-sugar, too, has to undergo a chemical
change before it can be absorbed; but grape and
milk sugars are taken directly into the circula-
tion. To this fact is due a part of the great nu-
tritive value of dried fruits as raisins, dates and
figs, and the value of milk-sugar over cane-sugar,
for children or invalids. Chemically pure milk-
sugar can now be obtained at wholesale for about
35 cents per pound. This may be used in certain
diseases when cane-sugar is harmful. The chemi-
cal transformations of starch and sugar have been
very carefully and scientifically studied with refer-
ence to brewing and wine-making. Several of the
operations concerned necessitate great precision in
respect to temperature and length of time, and
these operations bear a close analogy to the
process of bread-making by means of yeast. The
general principles on which the conversion of
starch into sugar, and sugar into alcohol, are con-
tized by Google
COOKING AND CLEANING, 29
ducted will therefore be stated as preliminary to la
discussion of starch and sugar as food.
There are two distinct means known to the surchCon-
chemist, by which this change can be produced.
One is by the use of acid and heat, which changes
the starch into sugar, but can go no farther. The
other is by the use of a class of substances called
ferments, some of which have the power of chang-
ing the starch into sugar, and others of changing
the sugar into alcohol and carbon dioxide. These
ferments are in great variety and the seeds of
some of them are always present in the air. Among
the chemical substances called ferments, one is
formed in sprouting grain which is called diastase
or starch converter, which first, under the in-
fluence of warmth, changes the starch into a sugar,
as is seen in the preparation of malt for brewing.
The starch (CeHioOg), first takes up water (HjjO),
and, under the influence of the ferment, is changed
into maltose. Cane-sugar is readily converted
into two sugars, dextrose and levulose, belonging
to the glucoses.
Cia H„ Oil +H, O +ferment=2C, 'Hi» Oo
Cane-Sugar. Water. Dextrose and Levulose.
Glucose and maltose are converted by yeast into Sugar .
alcohol and carbon dioxide. In beer, the alcohol
is the product desired, but in bread-making the
80 THE CHEMISTRY OF
chief object of the fermentation is to produce car-
bon dioxide to puff up the bread, while the al-
cohol escapes in the baking.
( 2G H. C
C. H» O. = J ^«'^*-
DextroM. | 2C 0%
\ Carbon Dioxide.
The alcohol, if burned, would give carbon dioxide
2C, H. O +12O =4C O, H-6H, O.
Alcohol. Oxygen. Carbon Dioxide. Water.
It will be seen, from the previous equations,
that nothing has been lost during the process.
The six atoms of carbon in the original starch
reappear in the carbon dioxide at the end,
2CO24-4CO2. Two atoms of hydrogen from the
water, and thirteen atoms of oxygen from the
water and the air have been added. Reckoning
the atomic weights of the starch used, the carbon
dioxide and the water formed, we find that, in
round numbers, sixteen pounds of starch will yield
twenty-six pounds of gas and ten pounds of water,
or more than double the weight of the starch.
These products of decomposition are given back
to the air in the same form in which those sub-
stances existed from which the starch was orig-
ComisioB The same cycle of chemical changes goes on in
5^^^ the human body when starchy substances are
COOKING AND CLEANING. . 31
taken as food. Such food, moistened and warmed
in the mouth, becomes mixed with air through
mastication, by reason of the property of the sa-
liva to form froth, and also becomes impregnated
with ptyalin, a substance which can change starch
into sugar as can the diastase of the malt. The
mass then passes into the stomach, and the
change, once begun, goes on. As soon as the
sugar is formed, it is absorbed into the circu-
latory system and, by the life processes, is oxi-
dized, i. e., united with more oxygen and changed
finally into carbon dioxide and water.
No starch is utilized in the human system as
starch. It must undergo transformation before it
can be absorbed. Therefore starchy foods must
not be given to children before the secretion of
the starch converting ferments, has begun, nor to
any one in any disease where the normal action of
the glands secreting these ferments is interrupted.
Whatever starch passes out of the stomach
unchanged, meets a very active converter in
the intestinal juice. If grains of starch escape
these two agents, they leave the system in the
same form as that in which they entered it.
Early man, probably, lived much like the beasts,
taking his food in a raw state. Civilized man re-
quires much of the raw material to be changed, by
the action of heat, into substances more palatable
and already partly digested.
S2 THE CHEMISTRY OF
The chemistry of cooking the raw materials is
very simple. It is in the mixing of incongruous
materials in one dish or one meal that complica-
'SsS^^ Since fully one-half of our food is made up of
starches and sugars^ it is pertinent to examine^
beside their chemical composition, the changes
which they may undergo in the processes of cook-
ing that can render them more valuable as food,
or which, on the other hand, may in large meas-
ure destroy their food value.
The cooking of starch, as rice, farina, etc., re-
quires little explanation. The starch grains are
prepared by the plant to keep during a season of
cold or drought and are very close and compact;
they need to be swollen and distended by moisture
in order that the chemical change may take place
readily, as it is a law, that the finer the particles,
the sooner a given change takes place, as has
been explained in a previous chapter. Starch
grains may increase to twenty-five times their bulk
during the process of hydration.
The cooking of the potato and other starch-con-
taining vegetables, is likewise a mechanical proc-
ess very necessary as a preparation for the chem-
ical action of digestion; for raw starch has been
shown to require a far longer time and more di-
gestiye power than cooked starch. Change takes
COOKING AND CLEANING. 83
place slowly, even with thorough mastication, un-
less the starch is heated and swollen, and, in case
the intestinal secretion is disturbed, the starch
may not become converted at all.
The most important of all the articles of diet Bread,
which can be classed under the head of starchy
foods is bread. Wheat bread is not all starch, but
it contains a larger percentage of starch than of
anything else, and it must be discussed under this
topic. Bread of some kind has been used by man-
kind from the first dawn of civilization. During
the earlier stages, it consisted chiefly of powdered
meal and water, baked in the sun, or on hot
stones. This kind of bread had the same charac-
teristics as the modern sea-biscuit, crackers and
hoe-cake, as far as digestibility was concerned. It
had great density, it was difficult to masticate,
and the starch in it presented but little more sur-
face to the digestive fluids than that in the hard
compact grain, the seed of the plant.
Experience must have taught the semi-civilized
man that a light porous loaf was more digestible
than a dense one. Probably some dough was ac-
cidentally left over, yeast plants settled upon it
from the air, fermentation set in, and the possibil-
ity of porous bread was thus suggested.
The small loaf, Ught, spongy, with a crispness
and sweet, pleasant taste, is not only aesthetically.
34 THE CHEMISTRY OF
but chemically, considered the best form in which
starch can be presented to the digestive organs.
The porous condition is desired in order that as
large a surface as possible shall be presented to
the action of the chemical converter, the ptyalin
of the saliva, and, later, to other digestive fer-
ments. There is also a better aeration in the proc-
ess of mastication.
The ideal bread for daily use should fulfill cer-
tain dietetic conditions:
1. It should retain as much as possible of the
nutritive principles of the grain from which it is
2. It should be priepared in such a manner as to
secure the complete assimilation of these nutri-
3. It should be light and porous, so as to allow
the digestive juices to penetrate it quickly and
4. It should be especially palatable, so that one
may be induced to eat enough for nourishment.
5. It should be nearly or quite free from coarse
bran, which causes too rapid muscular action to
allow of complete digestion. This effect is also
produced when the bread is sour.
Ordinary Graham bread, brown bread and the
black bread of Germany fulfill conditions i and 4,
but fail in the other three. Bakers' br^ad of fine
COOKING AND CLEANING. 85
white flour fulfills 2, 3 and 5, but fails in the other
two. Home-made bread often fulfills conditions
4 and 5, but fails in the other three.
Very early in the history of the human race
leavened bread seems to have been used. This was
made by allowing flour and water to stand in a
warm place until fermentation had well set in. A
portion of this dough was used to start the process
anew in fresh portions of flour and water. This
kind of bread had to be made with great care, for
germs different from yeast might get in, forming
lactic acid — the acid of sour milk — ^and other sub-
stances unpleasant to the taste and harmful to the
Butyric acid occurs in rancid butter and in many
putrified organic substances. A sponge made from
perfectly pure yeast and kept pure may stand for a
long time after it is ready for the oven and still
show no sig^ of sourness.
On account of the disagreeable taste of leaven
and because of the possibility that the dough might
reach the stage of putrid fermentation, chemists
and physicians sought for some other means of
rendering the bread light and porous. The search
beg^n almost as soon as chemistry was worthy the
name of a science, and one of the early patents
bears the date 1837. Much time and thought have
been devoted to the perfecting of unfer-
86 THE CHEMISTRY OF
mented bread; but since the process of beer-
making has been universally introduced, yeast has
been readily obtained, and is an eflfectual mean* of
giving to the bread a porous character and a pleas-
ant taste. Since the chemistry of the yeast fer-
mentation has been better understood, a change of
opinion has come about, and nearly all scientific
and medical men now recommend fermented bread.
The bacteriology of bread and bread-making is
yet somewhat obscure. The ordinary yeasts are so
mingled with bacteria that the part which each
plays is not yet understood. Only experiments
long continued will solve these problems,
a^s^li^*' The chemical reactions concerned in bread-
Bwad-Mak. raising are similar to those in beer-making. To
the flour and warmed water is added yeast, a mi-
croscopic plant, capable of causing the alcoholic
fermentation. The yeast begins to act at once, but
slowly; more rapidly if sugar has been added and
the dough is a semi-fluid. Without the addition
of sugar no change is evident to the eye for some
hours, as the fermentation of sugar from starch, by
the diastase, gives rise to no gaseous products. As
soon as the sugar is decomposed by the yeast plant
into alcohol and carbonic acid gas (carbon diox-
ide), the latter product makes itself known by the
bubbles which appear and the consequent swelling
of the whole mass.
COOKING AND CLEANING. St
It is the carbon dioxide which causes the sponge-
like condition of the loaf by reason of the peculiar
tenacity of the gluten, one of the constituents of
wheat. It is a well-known fact that no other kind
of grain will make so light a bread as wheat. It is
the right proportion of gluten (a nitrogenous sub-
stance to be considered later) which enables the
light loaf to be made of wheat flour.
The production of carbon dioxide is the end of
the chemical process. The rest is purely mechanical.
The kneading is for the purpose of rendering the
dough elastic by the spreading out of the already
fermented mass and its thorough incorporation
with the fresh flour. Another reason for kneading
is, that the bubbles of gas may be broken up into
as small portions as possible, in order that there
may be no large holes, only very fine ones,
evenly distributed through the loaf, when it is
The temperature at which the dough should be Temperature
maintained during the chemical process is an im- Making,
portant point. If the characteristics of "home-
made" bread are desired, it is found to be better to
use a small amount of yeast and to keep the dough
at a temperature from 55 degrees to 60 degrees for
twelve to fifteen hours, than to use a larger quantity
of yeast and to cause its rapid growth. The changes
which produce the desired effect are not fully under-
38 THE CHEMISTRY OF
stood. Above 90 degrees the production of acetic
acid — ^the acid of vinegar — ^is liable to occur: for
this temperature, while unfavorable for the yeast
plant, is favorable for the growth of the particular
bacterium which produces acetic acid.
C. H. O +0, =C, H4 O. +Hr O
Alcohol. Acetic Water.
After the dough is stiffened by a little fresh flour
and is nearly ready for the oven, the temperature
may be raised, for a few minutes, to 100 degrees
or 165 degrees F. The rapid change in the yeast is
soon stopped by the heat of the oven.
The baking of the loaf has for its object to kill
the ferment, to heat the starch sufficiently to render
it easily soluble, to expand the carbon dioxide and
drive off the alcohol, to stiffen the gluten, and to
form a crust which shall have a pleasant flavor.
The oven must be hot enough to raise the tempera-
ture of the inside of the loaf to 212 degrees R, or
the bacteria will not all be killed. A pound
loaf, four inches by four by nin6, may
be baked three-quarters of an hour in an
oven where the initial temperature is 400
degrees F., or for an hour and a half, where
the temperature during the time does not rise above
350 degrees F. Quick baking gives a white loaf,
because the starch has undergone but little change.
COOKING AND CLEANING. 39
The long, slow baking gives a yellow tint, with the
desirable nutty flavor, and crisp crust Different
flavors in bread are supposed to be caused by the
different varieties of yeast used or by bacteria,
which are present in all doughs, as ordinarily
The brown coloration of the crust, which gives
a peculiar flavor to the loaf, is caused by the forma-
tion of substances analogous to dextrine and cara-
mel, due to the high heat to which the starch is
One hundred pounds of flour are said to make
from 126 to 150 pounds of bread. This increase of
weight is due to the incorporation of water, pos-
sibly by a chemical union, as the water does not
dry out of the loaf, as it does out of a sponge. The
bread seems moist when first taken from the oven,
and dry after standing some hours, but the weight
will be found nearly the same. It is this probable
chemical change which makes the difference, to
delicate stomachs, between fresh bread and stale. A
thick loaf is best when eaten after it is twenty-four
hours old, although it is said to be "done" when
ten hours have passed. Thin biscuits do not show
the same ill effects when eaten hot. The bread
must be well baked in any case, in order that the
process of fermentation may be stopped. If this be
stopped and the mastication be thorough, so that
THE CHEMISTRY OF
the bread is in finely divided portions instead of in
a mass or ball, the digestibility of fresh and stale
bread is about the same.
The expansion of water or ice into seventeen
hundred times its volume of steam is sometimes
taken advantage of in making snow-bread, water-
gems, etc. It plays a part in the lightening of
pastry and crackers. Air, at 70 degrees, doubles
its volume at a temperature of 560° F., so that if air
is entangled in a mass of dough, it gives a certain
lightness when the whole is baked. This is the
cause of the sponginess of cakes made with eggs.
The viscous albumen catches the air and holds it,
even when it is expanded, unless the oven is too
hot, when the sudden expansion is liable to burst
the bubbles and the cake falls.
As has been said, the production of the porous
condition, by means of carbon dioxide, generated
in some other way than by the decomposition of
starch, was the study of practical chemists for some
A simple method for obtaining the carbon diox-
ide is by heating bicarbonate of sodium.
2Na H C O. +heat = Na* C O. +H, O +C Os
The bicarbonate splits up into sodium carbonate,
water, and carbon dioxide. The bread is light but
yellow. Some of the carbonate remains in the
COOKING AND CLEANING. 41
bread, and as it neutralizes the acid of the gastric
juice, digestion may be retarded. It also acts upon
the gluten producing an unpleasant odor.
Among the first methods proposed was one un-
doubtedly the b^st theoretically, but very difficult
to put in practice, viz., the liberation of carbon
dioxide from bicarbonate of sodium by means of
NaHC O. +HCl=Naa+H, O +C O,
" Soda." Hydrochloric Common Water. Carbon dioxide.
This liberation of gas is instantaneous on the con-
tact of the acid with the "soda," and only a skilled
hand can mix the bread and place it in the oven
without the loss of much of the gas. Tartaric acid,
the acid phosphates, sour milk (lactic acid), vinegar
(acetic acid), alum — ^all of which have been used —
are open to the same objection. Cream of tartar
is the only acid substance commonly used which
does not liberate the gas by simple contact when
cold. It unites with "soda" only when heated, be-
cause it is so slightly soluble in cold water. For the
even distribution of the gas by thorough mixing,
cream of tartar would seem to be the best; but as,
beside gas, there are other products which remain
behind in the bread in the case of all the so-called
baking powders, the healthfulness of these residues
must be considered.
42 THE CHEMISTRY OF
Common salt is the safest, and perhaps the resi-
dues from acid phosphate are next in order.
The tartrate, lactate and acetate of sodium are
not known to be especially hurtful. As the im-
portant constituent of Seidlitz powders is Rochelle
salt, the same compound as that resulting from the
use of cream of tartar and "soda," it is not likely to
be very deleterious, taken in the small quantities
in which even habitual "soda biscuit" eaters take it.
i^Sdu^' '^^ various products formed by the chemical de-
composition of alum and "soda" are possibly the
most injurious, as the sulphates are supposed to be
the least readily absorbed salts. Taking into con-
sideration the advantage given by the insolubility
of cream of tartar in cold water, and the compara-
tively little danger from its derivative — Rochelle
salt — it would seem to be, on the whole, the best
'Substance to add to the soda in order to liberate
the gas; but the proportions should be chemically
exact, in order that there be no excess of alkali to
hinder digestion. Hence, baking powders pre-
pared by weight and carefully mixed, are a great
improvement over cream of tartar and "soda"
measured separately. As commonly used, the
proportion of soda should be a little less than
half. The table on page 23 gives the chemical re-
actions of the more common baking powders.
COOKING AND CLEANING.
Another group of substances which, by their
slow combustion or oxidation in the animal body,
yield carbon dioxide and water and furnish heat
to the system, is called fats. These comprise the
animal fats — suet, lard, butter, etc. — ^and the vege-
table oilsr— olive oil, cottonseed oil, the oily matter
in com, oats, etc.
Fats, ordinarily so called, are simply solidified
oils, and oils are liquid fats. The difference be-
tween them is ope of temperature only; for, within
the body, all are fluid. In this fluid condition, they
are held in little cells which make up the fatty
These fatty materials all have a similar composi-
tion, containing, when pure, only carbon, hydro-
gen, and oxygen. They differ from starch and
sugar in the proportion of oxygen to the carbon
and hydrogen, there being very little oxygen rela-
tively in the fatty group, hence more must be
taken from the air for their combustion.
Cit H»« 0»
Stearic Add in Suet.
C« Hio O5
One pound of starch requires one and two-tenths
pounds of oxygen, while one pound of suet re-
quires about three pounds of oxygen for perfect
combustion. This combination of oxygen with the
44 THE CHEMISTRY OF
excess of hydrogen, as well as with the excess of
carbon results in a greater quantity of heat from
fat, pound for pound, than can be obtained from
starch or sug^. Recent experiments have proved
that the fats yield more than twice as much heat as
the carbohydrates; hence people in Arctic regions
require large amounts of fat, and, everywhere, the
diet of winter should contain more fat than that of
sourees of While the chemical expression of these changes
is that of heat produced, it must be remembered
that energy or work done by the body is included,
and that both fats and carbohydrates are the source
of this energy, and that they must be increased in
proportion as the mechanical work of the body in-
creases. If a quantity is taken at any one time
greater than the body needs for its work, the sur-
plus will be deposited as a bank account, to be
drawn from in case of any lack in the future supply
This double source of energy has a large
economic value, for it has been noticed that in com-
munities where fats are dear, the required amount
of heat-giving and energy-producing food is made
up by a larger proportion of the cheaper carbo-
hydrates. This prevents too large a draft on the
bank account. It has also been noticed that wage-
earners do use a large proportion of fat, whenever
it is within th^ir means,
COOKING AND CLEANING. 46
Fat in the
Numerous investigations into the condition of
the insane, as well as of the criminal classes, show ^'•'•
the results of too little nutrition and the absence of
sufficient fat. The diet of school children should
be carefully regelated with the fat supply in view.
Girls, esi)ecially, show, at times, a dislike to fat and
an overfondness for sugar. They should have the
proper proportion of fat furnished by butter, cream,
or, if need be, in disguised form. The cook must
remember that the butter absorbed from her cake
tin or the olive oil on her salad is food, as well as
the flour and eggs.
The essential oils, although very important, as
will be shown in the chapter on flavors, occur in
such small quantities that they need not be con-
sidered here, except by way of caution. These oils
are all volatile, and, therefore, will be dissipated by
a high temperature.
The digestion of fats is mainly a process of emul-
sion. With the intestinal fluids, the bile, especially,
the fats form an emulsion in which the globules
are finely divided, and rendered capable of passing
through the membranes into the circulatory sys-
tem. The change, if any, is not one destructive
of the properties of the fatty matters.
If we define cooking as the application of heat, iiic Digestion
then whatever we do to fats in the line of cooking
them is liable to hinder rather than help their diges-
46 COOKING AND CLEANING.
tibility. The flavor which cooking gives to food
materials containing fat is, in general, due not to
any flavor of the fat but to substances produced
in the surrounding tissues.
hSsPtLb. ^^^^ ^^y ^^ heated to a temperature far above
|entuf«oB that of boiling water without showing any change;
but there comes a point, different for each fat,
where reactions take place, the products of which
irritate the mucous membranes and, therefore, in-
terfere with digestion. It is the volatile products of
such decomposition which cause the familiar action
upon the eyes and throat during the process of
frying, and, also, the tell-tale odors throughout the
house. The indigestibility of fatty foods, or foods
cooked in fat, is due to these harmful substances
produced by the too high temperature. It must
not be inferred from what has been said that the
oxidation of starch and fat is the only source of
heat in the animal body. A certain quantity is un-
doubtedly derived from the chemical changes of
the other portions of food, but the chemistry of
these changes is not yet fully understood.
THE animal body is a living machine, capable
of doing work — raising weights, pulling loads,
and the like. The work of this kind which it does
can be measured by the same standard as the work
of any machine, i. e., by the mechanical unit of
energy — ^the foot-ton.
The power to do mechanical work comes from
the consumption of fuel, — the burning of wood,
coal or gas; and this potential energy of fuel is often
expressed in units of heat or calories, 2l calorie being
nearly the amount of heat required to raise two
quarts of water one degree Fahrenheit. The ani-
mal body also requires ?ts fuel, namely food, in
order to do other work — its thinking, its talking or
even its worrying.
The animal body is more than a machine. It
requires fuel to enable it not only to work but also
to live, even without working. About one-third of
the food eaten goes to maintain its life, for while
the inanimate machine is sent periodically to the
repair-shop, the living machine must do its own
Need of Body
48 ' THE CHEMISTRY OF
rq)airing, day by day, aiid minute by minute.
Hence it is that the estimations of the fuel and re-
pair material needed to keep the living animal body
in good working and thinking condition are, in the
present state of our knowledge, somewhat empir-
ical; but it is believed that, within certain wide
limits, useful calculations can be made by any one
willing to give a little time and thought to the sub-
ject. Our knowledge may be rapidly increased if
such study is made in many localities and under
waste-R^ The adult animal lives, repairs waste, and does
work; while the young animal does all these and
more — ^it grows. For growth and work something
else is needed beside starch and fat. The muscles
are the instruments of motion, and they must grow
and be nourished, in order that they may have
power. The nourishment is carried to them by the
blood in which, as well as in muscular tissue, there
is found an element which we have not heretofore
considered, namely, nitrogen. It has been proved
that the wear and tear of the muscles and brain
causes the liberation of nitrogenous compounds,
which pass out of the system as such, and this loss
must be supplied by the use of some kind of food
which contains nitrogen. Starch and fat do not
contain this element; therefore they cannot furnish
it to the blood.
COOKING AND CLEANING. 49
Nitrogenous food-stuffs comprise at least two ?iJ;y.gX
large groups, the Albumins or Proteids and the
The Albumins in some form are never absent
from animal and vegetable organisms. They are
more abundant in animal flesh and in the blood.
The typical food of this class is the white of egg,
which is nearly pure albumin. Other common arti-
cles of diet belonging to this group are the casein
of milk, the musculin of animal flesh, the gluten of
wheat, and the legumin of peas and beans.
Egg albumin is soluble in cold water, but coagu-
lates at about i6o degrees F. At this point it is
tender, jelly-like, and easily digested, while at a
higher temperature it becomes tough, hard and sol-
uble with difficulty.
The albumin of flesh is contained largely in the
blood ; therefore the juices of meat extracted in cold
water form an albuminous solution. If this be
heated to the right temperature the albumin is
coagulated and forms the "scum" which many a
cook skims off and throws away. In doing this
she wastes a large portion of the nutriment. She
should retain this nutrition in the meat by the quick
coagulation of the albumin of the exterior, which
will prevent further loss, or use the nutritive solu-
THE CHEMISTRY OF
tion in the form of soups or stews. "Clear soups"
have lost much of their nutritive value and, there-
fore, belong among the luxuries.
The animal skeleton — ^homs, bones, cartilage,
connective tissue, etc., contain nitrogenous com-
pounds which are converted by boiling into sub-
stances that form with water a jelly-like mass.
These are known as the gelatins.
The chief constituent of the connective tissues is
collagen. This is insoluble in cold water, but in hot
water becomes soluble and yields gelatine. Colla-
gen swells when heated and when treated with
dilute acids. Steak increases in bulk when placed
over the coals, and tough meat is rendered tender
by soaking in vinegar. Freshly killed meat is tough,
for the collagen is dry and hard. In time it becomeh*
softened by the acid secretions brought about
through bacterial action, and the meat becomes
tender and easily masticated. Tannic acid has the
opposite effect upon collag'en, hardening and
shrinking it. This effect is taken advantage of in
tanning, and is the disadvantage of boiled tea as
Cooking should render nitrogenous food more
soluble because here, as in every case, digestibility
means solubility. Therefore, when the white of
COOKING AND CLEANING. fil
egg (albumin), the curd of milk (casein), or the glu-
ten of wheat are hardened by heat, a much longer
time is required to effect solution.
As previously stated, egg albumin is tender and i^i^
jelly-like when heated from i6o degrees to i8o de*
grees. This fact should never be forgotten in the
cooking of eggs. Raw eggs are easily digested
and are rich in nutrition; when heated just enough
to coagulate the albumin or "the white,'' their di-
gestibility is not materially lessened; but when
boiled the albumin is rendered more difficultly
To secure the greatest digestibility in combina-
tion with palatibility, they may be put into boiling
water, placed where the temperature can be kept
below i8o degrees, and left from ten to fifteen min-
utes, or even longer, as the albumin will not harden
and the yolk will become mealy.
To fry eggs the fat must reach a temperature —
300 degrees or over — far above that at which the
albumin of the egg becomes tough, hard, and well-
The oyster, though not rich in nutrition, is read- Ofutn.
ily digested when raw or slightly warmed. When
fried in a batter, it is so protected by the Ayater in
the dough that the heat does not rise high enough
to render insoluble the albuminous morsel within.
Frying in crumbs (in which there is always 30 to 40
62 THE CHEMISTRY OF
per cent water, even though the bread be dry) is
another though less efficient method of protection
for the albumin. Com meal, often used as a coat-
ing, contains lo to 12 per cent of water.
Experiments on the digestibility of gluten have
proved that a high temperature largely decreases
its solubility. Subjected to artificial digestion for
the same length of time, nearly two and one half
times as much nitrogen was dissolved from the raw
gluten as from that which had been baked.*
When gluten is combined with starch, as in the
cereals, the difficulties of correct cooking are'many,
for the heat which increases the digestibility of the
starch decreases that of the gluten.
^^^*"* The same principle applies to casein — the albu-
minous constituent of milk. There seems to be no
doubt that boiling decreases its solubility, and, con-
sequently, its digestibility for persons of delicate
Legumin. ^he cooking of beans and all leguminous vege-
tables should soften the cellulose and break up
the compact grains of starch. Vegetables should
never be cooked in hard water, for the legumin of
the vegetable forms an insoluble compound with
the lime or magnesia of the water.
In the case of flesh the cooking should soften
*The Effect of Heat upon the Digestibility of Gluten, by Ellen H. Richaxds.
A. M., S. B., and Elizabeth Mason, A. B. Technology Quarterly, Vol. vii., 6^
COOKING AND CLEANING. 6d
and loosen the connective tissue, so that the little
bundles of fibre which contain the nutriment may
fall apart easily when brought in contact with the
teeth. Any process which toughens and hardens
the meat should be avoided.
Whenever it is desired to retain the juices within
the meat or fish, it should be placed in boiling water
that the albumin of the surface may be hardened
and so prevent the escape of the albumin of the
interior. The temperature should then be low-
ered and kept between i6o and i8o degrees
during the time needed for the complete breiak-
ing down of the connective tissues. When
the nutriment is to be used in broths, stews
or soups, the meat should be placed in cold
water, heated very slowly and the temperature
not allowed to rise above i8o degrees until the
extraction is complete. To dissolve the softened
collagen, a temperature of 212 degrees is necessary
for a short time.
The object of all cooking»is to make the food- object of
stuffs more palatable or more digestible or both
In general, the starchy foods are rendered more
digestible by cooking; the albuminous and fatty
foods less digestible.
The appetite of civilized man craves and custom
encourages the putting together of raw materials
64 THE CHEMISTRY OF
of such diverse chemical composition that the
processes of cooking are also made complex.
Bread — the staff of life — requires a high degree
of heat to4cai the plant-life, and long baking to
prepare the starch for solution; while, by the same
process, the gluten is made less soluble.
Fats, alone, are easily digested, but in the ordi-
nary method of frying, they not only become de-
composed themselves, and, therefore, injurious;
but they also prevent the necessary action of heat,
or of the digestive ferments upon the starchy ma-
terials with which the fats are mixed.
Pastry owes its harmful character to this inter-
ference of fat with the proper solution of the starch.
Good pastry requires the intimate mixture of flour
with solid fat. The starch granules of the flour
must absorb water, swell, and burst before they can
be dissolved. The fat does not furnish enough
water to accomplish this, and it so coats the starch
^anules as to prevent the sufficient absorption of
water in mixing, or from the saliva during mas-
tication. This coating of fat is not removed till
late in the process of digestion. The same effect is
produced by the combining of flour and fat in
Effect of The effect of cooking upon the solubility of the
Cooking. ^j^j.^^ important food-principals may be broadly
stated thus: —
COOKING AND CLEANING. 56
Starchy foods are made more soluble by long
cooking at moderate temperatures or by heat
high enough to dextrinize a portion of the starch,
as in the brown crust of bread.
Nitrogenous foods. The animal and vegetable
albumins are made less soluble by heat; the animal
albuminoids more soluble.
Fats are readily absorbed in their natural condi-
tion, but stre decomposed at very high temperatures
and their products become irritants.
The Art of Cooking.
Flavors and Condiments.
THE science as well as the art of cooking lies in
the production of a subtle something which
g^ves zest to the food and which, though infinites-
imal in quantity, is of priceless value. It is the
savory potage, the mint, anise and cummin, the
tasteful morsel, the appetizing odor, which is,
rightly, the pride of the cook's heart.
Flavors. The most general term for this class of stimu-
lating substances is, perhaps, flavor — the gout of
the French, the Genuss-Mittel (enjoyment-giver) of
The development of this quality in food — ^taste,
savor, relish, flavor or what not, which makes "the
mouth water,'' depends, in every case, upon chem-
ical changes more subtle than any others known
to us. The change in the coffee berry by roasting
is a familiar illustration. The heat of the fire causes
the breaking up of a substance existing in the berr}'-
and the production of several new ones. If the
heat is not sufficient, the right odor will not be
COOKING AND CLEANING. 67
given; if it is too great, the aroma will be dissipated
into the air or the compound will be destroyed.
This is an excellent illustration of the narrow . Nature oi
margin along which success lies. It is also chem-
ically typical of the largest number of flavors,
which seem to be of the nature of oils, set free by
the breaking up of the complex substances of which
they form a part Nature has prepared these essen-
tial oils by the heat of the sun. They give the taste
to green vegetables; while in fruits they are present
with certain acids, and both together cause the
pleasure-giving and therapeutic effects for which
fruit is noted.
It is probable that the flavors of roasted com,
well-cooked oatmeal, toasted bread, also belong to
this class. Broiled steak and roasted turkey are
also illustrations, and with coffee show how easily
the mark is overstepped — a few seconds too long,
a vefry few degrees too hot, and the delicate morsel
becomes an acrid, irritating mass.
From this standpoint, cooking is an art as exact
as the pharmacist's, and the person exercising it
should receive as careful preparation; for these
flavors, which are so highly prized, are many of
them the drugs and poisons of the apothecary and
are to be used with as much care. This is an addi-
tional reason for producing them by legitimate
means from the food itself, and not by adding the
THE CHEMISTRY OF
crude materials in quantities relatively enormous to
those of the food substances.
The chemistry of cooking is therefore largely the
chemistry of flavor-production — ^the application of
heat to the food material in such a way a3 to bring
about the right changes and only these.
The flavors produced by cooking, correctly done,
will be delicate and unobtrusive. Usually, except
for broiled meats, a low heat applied for a long
time, with the use of closed cooking vessels, de-
velops the best flavors; while quick cooking, which
necessitates a high temperature, robs the fine prod-
ucts of nature's laboratory of their choicest ele-
ments. Present American cookery, especially, sins
in this respect. Either the food is insipid from lack
of flavor or crudely seasoned at the last moment.
The secret of the success of our grandmothers*
cooking lay not solely in the brick oven — ^in the
low, steady heat it furnished — ^but in the care,
thought, and infinite pains they put into the prep-
aration of their simple foods. Compared with
these, the "one-minute^' cereals, the "lightning*'
pudding mixtures of the present are insipid, or
tasteless. Experience with die Aladdin Oven is an
education in flavor production.
Another source of stimulating flavor is found in
the addition of various substances called Condi-
ments. These consist of materials, of whatever
COOKING AND CLEANING. 60
nature, added to the food compounds, to give them
a relish. Their use is legitimate; their abuse, hattn-
ful. The effect of flavors is due to the stimulation
of the nerves of taste and smelL Condiments should
be used in a way to cause a like stimulation of the
nerves. If they are added to food materials before
or during the cooking process, a small quantity
imparts a flavor to the entire mixture. If added to
the cooked food, a larger quantity is used and the
effect lasts, not only while the food is in contact
with the nerves of the mouth, but also throughout
the digestive tract, causing an irritation of the
mucous membranes themselves. The tissues be-
come weakened, and, in time, lose the power of
Cayenne pepper directly applied to the food,
although sometimes a help, is oftener the cause in
dyspepsia. Highly seasoned food tends to weaken
the digestion in the end, by calling for more secre-
tion than is needed and so tiring out, as it were,
the glands. It is like the too frequent and violent
application of the whip to a willing steed — ^by and
by he learns to disregard it. Just enough to accom-
plish the purpose is nature's economy.
This economy is quick to recognize and be satis-
fied with a food which is easily digested without im-
pairing the functional powers of the digestive
fluids. A child seldom shows a desire for condi-
THE CHEMISTRY OF
ments unless these have been first unwisely added
by adults. Flavors are largely odors, or odors and
tastes combined, and act upon the nervous system
in a natural way. Condiments, in many cases, are
powerful, stimulating drugs, exciting the inner lin-
ings of the stomach to an increased and abnormal
activity. Medicinally they may act as tonics. The
skill of the cook consists in steering between the
two digestion possibilities — hinder and help.
Some relish-giving substances, as meat extracts,
the caffeine of coffee, theine of tea, theo-bromine of
cocoa, and alcohol of wines go directly into the
blood and here act upon the nervous system. They
quicken the circulation and, therefore, stimulate to
increased activity. The cup of coffee thus drives
out the feeling of lassitude from wearied nerves and
muscles. Wine should never be treated as an arti-
cle of diet, but as a Genuss-MitteL
The secret of the cooking of vegetables is the
judicious production of flavor. In this the
French cook excels. She adds a little meat juice to
the cooked vegetables, thus obtaining the desired
flavor with the cheaper nutritious food. This wise
use of meats for flavor, while the actual food value
is made up from the vegetable kingdom, is an im-
portant item in public kitchens* institutions, or
wherever expense must be closely calculated.
In the study of economy, flavor-creation is of the
tized by Google
COOKING AND CLEANING. 61
utmost importance. In foods, as everywhere,
science and art must supplement the purse, making
the few and cheaper materials necessary for nutri-
tion into a variety of savory dishes. Without the
appetizing flavor, many a combination of food ma-
teriiils is utterly worthless, for this alone stimu-
lates the desire or appetite, the absence of which
may prevent digestion. Food which pleases the
palate, unless this has been abnormally educated,
is usually wholesome, and judgment based on
flavor is normally a sound one.
Starch may be cooked according to the most ap- £ Di'***'Son.
proved methods; but, if there is no saliva, the starch
is without food value. The piece of meat may be
done to a turn; but, if there is no gastric juice in
the stomach, it will not be dissolved, and hence is
useless. A homely illustration will best serve
our turn, — z cow may retain her milk by
force of will. It is well known how much
a contented mitid has to do with her readi-
ness to give milk and the quantity of
milk she will yield. The various glands of the
human body seem to have a like action. The dry
mouth fails to moisten the food, and the stimulating
flavor is lost. On the other hand the mouth
"waters," and food is soon digested. The cow may
be utterly foolish and whimsical in her ideas — so
may persons. There may not be the least reason
02 THE CHEMISTRY ^ OF
why a person should turn away from a given food,
but if he does ? He suffers for his whims.
Hence the cook's art is most important, for its
results must often overcome adverse mental con-
ditions by nerve-stimulating flavors. The art
of serving, though out of place here, should be at-
tentively studied with the effect on the appetite
especially in view. This is of the utmost im-
portance in connection with hospital cooking.
Specific flavors, though agreeable in themselves,
should be used with discretion. In Norway, the
salmon is designedly cooked so as not to retain
much of its characteristic savor, for this is too de-
cided a flavor for an article of daily diet. In soups
and stews a "bouquet" of flavors is better than the
prominence of any one, although certain favorite
dishes may have a constant flavor. "
Nature has produced many flavors and guarded
well the secret of their production; but science is
fast discovering their sources, as bacterial life and
action are better understood. Now, the "June
flavor" of butter may be produced in December,
by inoculating milk with the right "butter
Cooking has thus become an art worthy the at-
tention of intelligent and learned women. The
laws of chemical action are founded upon the laws
of definite proportions, and whatever is added more
COOKING AND CLEANING, 68
than enough, is in the way. The head of every
household should study the condition of her fam-
ily, and tempt them with dainty dishes, if that is
what they need. Let her see to it that no burst of
ill temper, no sullen disposition, no intemperance
of any kind be caused by her ignorance or her dis-
regard ol the chemical laws governing the reactions
of the food she furnishes.
When this science and this art takes its place be-
side the other sciences and other arts, one crying
need of the world will be satisfied.
We have now considered the three classes of
food in one or more of which all staple articles of
diet may be placed — ^the carbohydrates (starch and
sugar), the fats and the nitrogenous material. Some
general principles of diet, indicated by science, re-
main to be discussed.
All preparation of food-stuffs necessary to make d?^?"*®'
them into suitable food for man comes under the s***^*-
head of what has been called "external digestion,"
The processes of internal digestion begin in the
mouth. Here the saliva not only lubricates the
finely divided portions of the food materials, but,
in the case of starch, begins the process of chang-
ing the insoluble starch into a soluble sugar. This
process is renewed in the small intestine. The fats
THE CHEMISTRY OF
are emulsified in the small intestine, and, with the
soluble carbohydrates, are here largely absorbed.
All the chemical changes which the nitrogenous
food stuffs undergo are not well understood. Such
food should be finely comminuted in the mouth,
because, as before stated, chemical action is rapid
in proportion to the fineness of division; but it is
in the stomach that the first chemical change
The chief agents of this change are pepsin
and related substances, aided by the acid of the
gastric juice; these together render the nitrogenous
substance soluble and capable of passing through
the membranes. Neither seems able to do this
alone, for if the acid is neutralized, action ceases ;
and if pepsin is absent, digestion does not take
Decompositions of a very complex kind occur,
peptones are formed which are soluble compounds,
and the nitrogen finally passes out of the system as
urea, being separated by the kidneys, as carbon di-
oxide is separated by the lungs.
One of tihe most obvious questions is: Which is
best for human food — starch or fat, beans and peas,
or flesh? As to starch or fat, the question has been
answered by experience, and science has only tried
to. explain the reason. The colder the climate, the
more fat the people eat. The tropical nations live
COOKING AND CLEANING,
chiefly on starchy foods, as rice. From previous
statements it will be seen that this is right in princi-
ple. Fat yields more heat than rice; therefore the
inference is plain that in the cold of winter fat is
appropriate food, while in the heat of summer rice
or some other starchy food should be substituted.
The diet of summer should also contain much
fruit. Increased perspiration makes necessary an
increased supply of water. This may be furnished
largely by fruits, and with the water certain acids
are taken which act as correctives in the digestive
No evident rule can be seen in the case of the
albuminous foods. At most, the class can be di-
vided into three groups. The first includes the ma-
terial of vegetable origin, as peas, lentils, and the
gluten of wheat. The second comprises the white
of egg and the curd of milk — material of anin^al
origin. The third takes in all the animal flesh used
by mankind as food.
Considering the question from a purely chemical
standpoint, without regarding the moral or social
aspects of the case, two views stand out clearly:
1st. If the stored-up vegetable matter has required
the force derived from the sun to prepare it, the
tearing apart and giving back to the air and earth
the elements of which it was built up will yield the
same amount of force to whatever tears it down;
ee THE CHEMISTRY OF
but a certain amount of energy must be used up in
this destruction. 2d. If the animal, having accom-
pHshed the decomposition of the vegetable and ap-
propriated the material, is killed, and the prepared
nitrogenous food in the form of muscle is eaten by
man, then little force is necessary to render the
food assimilable; it is only to be dissolved in order
that it may enter into the circulation. The force-
producing power is not lost; it is only transferred
to another animal body. Hence the ox or the
sheep can do a part of man's work for him in pre-
paring the vegetable food for use, and man may
thus accomplish more than he otherwise could.
This digestion of material outside of the body is
carried still further, by man, in the manufacture of
partially digested foods, — ^"'malted," "peptonized/^
"pre-digested,'' etc. Exclusive use of these is
fraught with danger, for the organs of digestion
lose power, if that which they have, however
little, be long unused,
^^of Nearly all, if not all, young animals live on food
Animals. of animal origin. The ypung of the human race
live on milk; but it has been found by experience
that milk is not the best food for the adult to live
upon to the exclusion of all else. It is not con-
ducive to quickness of thought or general bodily
^^i^J^ Experience leads to the conclusion that mankind
etablc Food. *
COOKING AND CLEANING. 67
needs some vegetable food. Two facts sustain this
inference. The digestive organs of the herbivorous
animals form fifteen to twenty per cent of
the whole weight of the body. Those of
the carnivorous animals form five to six
per cent, those of the human race, about
eight per cent. The length of the canal
through which the food passes varies in about the
same ratio in the three classes. A mixed diet seems
to-be indicated as desirable by every test which has
been applied; but the proportions in which the
vegetable and animal food are to be mingled, as
well as the relative quantities of carbonaceous and
nitrogenous material which will give the best effi-
ciency to the human machine are not so easily
Nature seems to have made provision for the ex- water and
cess of heat resulting from the oxidation of too
much starch or fat, by the ready means of evapora-
tion of water from the surface; this loss of water
being supplied by drinking a fresh supply, which
goes, without change, into the circulation. The
greater the heat, the greater the evaporation; hence
the importance of water as an article of diet, espe-
cially for children,, must not be overlooked. For
an active person, the supply has been estimated at
three quarts per day. Water is the heat regulator
of the animal body. An artick entitled "Water
Air as Food.
es THE CHEMISTRY OF
and Air as Food,"* by one of the authors of this
book, treats this subject more thoroughly.
Dangers of While dangerous disease seldom results from
eating an excess of starch or fat, because the por-
tion not wanted is rejected as if it were so much
sand, many of the most complicated disorders do
result from an excess of nitrogenous diet.
The readiness with which such substances under-
go putrefaction, and the many noxious products to
which such changes give rise, should lead us to be
more careful as to the quantity of this food.
From experiments made by the best investiga-
tors, it seems probable that only one third of the
estimated daily supply of food is available for ki-
netic force; that is, that only about one third of the
total energy contained in the daily food can be util-
ized in digging trenches, carrying bricks, climbing
mountains, designing bridges, or writing poems
and essays. The other two thirds is used up in the
internal work of the body — ^the action of the heart,
lungs, and the production of the large amount of
heat necessary to life.
Dietaries. It has been estimated that a growing person
needs about one part of nitrogenous food to four o(
starch and fat; a grown person, one part nitro-
genous to five or six of starch and fat. If this is
•Rumford Kitchen Leaflet, No. 6, American Kitchen Magazine, Vol. IV.,
COOKING AND CLEANING. 69
true, then we may make out a life ration, or that
amount of food which is necessary to keep the
human machine in existence.
For this cHmate, and for the habits of our people,
we have estimated this life ration as approximately:
Proteid. Fat. Carbohydrates. Calories.
75 grains. 40 grams. 335 grams. 2/xx>.
The amount of energy given out in the form of
work cannot exceed the amount of energy taken in
in the form of food ; so this life ration is increased
to make a maximum and minimum for a work
ration. For professional or literary persons the
following may be considered a sufficient maximum
For hard manual labor about one-third is to be
added to the above rations. An examination of the
actual dietaries of some of the very poor who eat
just enough to live, without doing any work,
shows that in twelve cases the average diet was :
Proteid. Fat. Carbohydrates. Calories.
31 grams. 8z grams. 273 grams. 2,257.
For further information on these points see the
list of works at the end of this book.
The first office of the food, then, is to keep the offices oi
human body in a high condition of health; the
second, to enable it to exert force in doing the work
70 COOKING AND CLEANING,
of the world; and a third, the value of which it is
hardly possible to estimate, is to furnish an im-
portant factor in the restoration of the body to nor-
mal condition, when health is lost In sickness,
far more than in health, a knowledge of the right
proportions of the essential food substances, and of
the absolute quantity or food value given, is im-
portant. How many a life has been lost because of
a lack of this knowledge the world will never know.
THE CHEMISTRY OF CLEANING.
MANY a housewife looks upon dust as her in-
veterate enemy against whom incessant war-
fare brings only visible defeat. Between the battles,
let us study the enemy — the composition of his
forces, his tactics, his ammunition, in order that
we may find a vantage ground from which to direct
our assault, or from which we may determine
whether it is really an enemy which we are fighting.
The Century dictionary defines dust as "Earth, Definition of
or other matter in fine dry particles so attenuated
that they can be raised and carried by the wind."
This suggests that dust is no modem product of
the universe. Indeed, its ancestry is hidden in
those ages of mystery before man was. Who can
say that it does not reach to that eternity which can
be designated only by "In the beginning?"
•72 THE CHEMISTRY OF
Neocssityof Tyndall provcd by delicate experiments that
when all dust was removed from the track of a
beam of light, there was darkness. So before the
command "Let there be light," the dust-condition
of light must have been present. Balloonists find
that the higher they ascend the deeper the color of
the sky. When at a distance of some miles, the
sky is nearly black, there is so little dust to scatter
the rays of light. If the stellar spaces are dustless,
they must be black and, therefore, colorless. The
moisture of the air collects about the dust-particles
giving us clouds and, with them, all the glories of
sunrise and sunset. Fogs, too, are considered to
be masses of "water-dust," and ships far out at sea
have had their sails colored by this dust, while sail-
ing through banks of fog. Thinking, now, of the
above definition, it may be said that the earth, in
its final analysis, must be dust deposited during
past ages; that to dust is due the light necessary
to life, and that without it certain phenomena of
nature — clouds, color, fog, perhaps, even rain and
snow could not exist.
It behooves us, then, as inhabitants of this dust-
formed and dust-beautified earth to speak well of
our habitation. We have found no enemy yet.
The enemy must be lurking in the "other matter."
This the dictionary says is in powdered form, car-
ried by the air, and, therefore, at times existent in
COOKING AND CLEANING.
it, as has been seen. A March wind gives sensible
proof of this, but what about the quiet air, whether
out of doors or in our houses?
An old writer has said: "The sun discovers
atonies, though they be invisible by candle-light,
and makes them dance naked in his beams." Those
sensible particles with these **atomes/- which be-
come visible in the track of a beam of light when-
ever it enters a darkened room, make up the dust
whose character is to be studied.
Astronomers find meteoric dust in the atmos-
phere. When this falls on the snow and ice fields
of the Arctic regions, it is readily recognized. The
eruption of Krakatoa proved that volcanic dust is
disseminated world-wide. Dust contains mineral
matter, also, from the wear and tear of nature's
forces upon the rocks, bits of dead matter given off
by animal and vegetable organisms, minute fibres
from clothing, the pollen of plants, the dry and pul-
verized excrement of animals. These constituents
are easily detected — are they all?
Let a mixture of flour and water stand out-of-
doors, leave a piece of bread or bit of cheese on
the pantry shelves for a week. The mixture fer-
ments, the bread and cheese mold. Formerly, these
changes were attributed to the "access of air" — i. e.,
to the action upon the substances, of the oxygen of
the air; later experiments have proved that if the
74 THE CHEMISTRY OF
air be previously passed through a cotton-wool
filter it will cause no change in the mixture. The
oxygen is not filtered out, so it cannot be the cause
of the fermentation. Now, such phenomena of
fermentation are known to be caused by minute
vegetable organisms which exist ever)rwhere in the
air and settle from it when it becomes dry and still.
They are molds, yeasts and bacteria. All are mi-
croscopic and many sub-microscopic .They are
found wherever the atmosphere extends — some
inches below the surface of the ground and
some miles above it, although on the tops of the
highest moiintains and, perhaps, far out at sea,
the air is practically free from earthly dust,
and therefore nearly free from these forms. The
volcanic dust of the upper air does not appear to
contain them. They are all spoken of as **germs,"
because they are capable of developing into grow-
ing forms. All are plants belonging to the fungi;
in their manner of life essentially like the plants
we cherish, requiring food, growing, and repro-
ducing their kind. They require moisture in order
to grow or multiply; but, like the seeds of higher
plants, can take on a condition calculated to resist
hard times and endure these for long periods; then
when moisture is furnished, they immediately
spring into growth. In the bacteria these spores
ar^ a resting stage, not primarily reproduc-
COOKING AND CLEANING, W
tive; while, in molds, they bring forth an active,
The common puff-baD (Lycoperdon), the "smoke'' Spoiw.
ball of the country child, well illustrates both v^e-
tative and spore stages. This belongs to the fungi,
is closely related to the molds, and consists of a
spherical outer wall of two layers, enclosing tissues
which form numerous chambers with membraneous
partitions. Within these chambers are formed the
reproductive cells or spores. When ripe, the mass
becomes dry, the outer layer of the wall scales off,
the inner layer splits open, allowing the minute dry
spores to escape as a "cloud of dust." These are
readily carried by the wind until caught on some
moist spot favorable for their growth. They are
found on dry, sandy soils, showing that very little
moisture is needed; but when this is found, the
spore swells, germinates, and grows into a new
vegetative ball, which completes the cycle.
Wheat grains taken from the wrappings of mum- viui
mies are said to have sprouted when given moist- *"***
ure and warmth. Whether this be true or not, there
can be no doubt that the vitality of some seeds and
spores is wonderfully enduring.
The spores of some of the bacteria may be boiled
and many may be frozen — still life will remain.
Aristotle declared that "all dry bodies become Dangerout
d?TOp and ?J1 damp bodies which are dried engen-
76 ' THE CHEMISTRY OF
der animal life." He believed these dust germs to
be animalcules spontaneously generated wherever
the conditions were favorable. How could he, with-
out the microscope, explain in any other way the
sudden appearance of such myriads of living forms?
Now, it is recognized that the air everywhere
contains the spores of molds and bacteria, and it
is this dust, carried in the air, which falls in our
houses. This is our enemy.
A simple housemaid once said that the sun
brought in the dust "atomes" through the window,
and the careful, old. New England housewife
thought the same. So, she shut up the best room,
making it dark and, therefore, damp. Unwittingly,
she furnished to them the most favorable conditions
of growth, in which tliey might increase at the rate
of many thousands in twenty-four hours.
"Let there be light" must be the ever-repeated
command, if we would take the first outpost of the
We live in an invisible atmosphere of dust, we
are constantly adding to this atmosphere by the
processes of our own growth and waste, and, finally,
we shall go the way of all the earth, contributing
our bodies to the making of more dust. Thus dust
has a decided two-fold aspect of friendliness and
enmity. We have no wish to guard ourselves
against friends; so, for the 'present purposes, the
tized by Google
COOKING AND CLEANING. Tl
inimical action of dust, as affecting* the life and
health of man, alone need challenge our attention.
The mineral dust, animal waste, or vegetable
debris, however irritating to our membranes, or
destructive of our clothing, are enemies of minor
importance, compared with these myriads of living
germs, which we feel not, hear not, see not, and
know not until they have done their work.
From a sanitary point of view, the most im-
portant of the three living ingredients of dust is
that called bacteria. They are the most numerous,
the most widely distributed, and perhaps the small-
est of all living things. Their natural home is the
soil. Here they are held by moisture, and by the
gelatinous character caused, in large part, by their
own vital action. When the surface of the ground
becomes dry, they are carried from it, by the wind,
into the air. Rain and snow wash them down;
running streams take them from the soil; so that, at
all times, the natural waters contain immense num-
bers of them. They are heavier than the air and
settle from it in an hour or two, when it is dry and
still. They are now quietly resting on this page
which you are reading. They are on the floor, the
tops of doors and windows, the picture frames, in
every bit of "fluff" which so adroitly eludes the
broom — in fact, everywhere where dust can lodge.
The second ingredient, in point of numbers, is Molds,
78 THE CHEMISTRY OF
the molds. They, too, are present in the air, both
outside and inside of our houses; but being much
lighter than the bacteria, they do not settle so
quickly, and are much more readily carried into the
air again, by a very slight breeze.
YeMtt. The third, or wild yeasts, are not usually trouble-
some in the air or in the dust of the house, where
ordinary cleanliness rules.
•-Dirt." To the bacteriologist, then, everything is dirty
unless the conditions for germ-growth have been
removed, and the germs, once present, killed.
All of this dirt cannot be said to be "matter in the
wrong place," only when it is the wrong kind of
matter in some particular place. The bacteria are
Nature's scavengers, ^very tree that falls in the
forest — animal or vegetable matter of all kinds is
immediately attacked by these ever-present, invisi-
ble agents. By their life-prpcesses, absorbing, se-
creting, growing and reproducing, they silently
convert such matter into various hairmless sub-
stances. They are faithful laborers, earning an
honest living, taking their wages as they go. Their
number and omnipresence show the great amount
of work there must be for them to do.
Then why should we enter the lists against such
opponents? Because this germ-community is like
any other typical community.
The majority of the individuals are law-abiding,
COOKING AND CLEANING, , W
respectable citizens; yet in some dark comer a thief
may hide, or a cut-throat steal in unawares. If
this happens, property may be destroyed and life
All of these forms destroy our property;
but a certain few of the bacteria cause disease
and death. In a very real sense, so soon as an or-
ganism begins to live it begins to die; but these are
natural processes and do not attract attention so
long as the balance between the two is preserved.
When the vital force is lessened, by whatever cause,
disease eventually shows itself. Methods for the
cure of disease are as old as disease itself; but
methods for the prevention of disease are of late
birth. Here and there along the past, some minds,
wiser than their age, have seen the possibilities of
such prevention; but superstition and ignorance
have long delayed the fruition of their hopes.
"An ounce of prevention is worth a pound of
cure," though oft repeated has borne scanty fruit
in) daily living. When the cause of smallpox,
tuberculosis, diphtheria, typhoid fever, and other
infectious diseases is known to be a living plant,
which cannot live without food, it seems, at first
sight, a simple matter to starve it out of existence.
This has proved to be no simple nor easy task; so
much the more is each person bound by the law
of self-love and the greater law, "Thou shalt love
80 THE CHEMISTRY OF
thy neighbor as thyself," to do his part toward
driving these diseases from the world.
Any one of these dust-germs is harmless so long
as it cannot grow. Prevent their growth in the
human body, and the diseased condition cannot
Prevention, then, is the watchword of modem
It may be asked: How do the germs cause dis-
Why do they not always cause disease?
Numerous answers have been given during the
short time the germ theory of infectious diseases
has been studied. If we follow the history of this
study, we may find, at least, a partial answer.
Action of A person is "attacked" by smallpox, diphtheria,
lockjaw, typhoid fever, or some kindred disease.
Common speech recognizes in the use of the word
"attacked" that an enemy from outside has begun,
by force, a violent onset upon the person. This
enemy — a particular bacterium or other germ, has
entered the body in some way. There may have
been contact with another person ill with the same
disease. The germ may have entered through food
on which it was resting, by water, or by dust as
it touched the exposed flesh, where the skin was
broken by a scratch or cut. It found in the blood
or flesh the moisture and warmth necessary for its
COOKING AND CLEANING. 81
growth, and, probably, a supply of food at once de-
sirable and bountiful. It began to feed, to grow,
and to multiply rapidly, until the little one became
a million. At this stage the patient knew he was
ill. It was thought, at first, that the mere presence
in the body of such enormous numbers caused the
Bacteria like the same kinds of food which we fpodot
like. Though they can and will live on starvation
rations, they prefer a more luxurious diet. This
fact led to the idea that they supplied their larder
by stealing from the food supply of the invaded
body; so that, while the uninvited and unwelcome
guest dined luxuriously, the host sickened of starva-
tion. This answer is now rejected.
The food of the bacteria is not only similar in
kind to our own food, but it must also undergo like
processes of solution and absorption.
Solution is brought about by the excretion of
certain substances, similar in character and in ac-
tion to the ferments secreted in the animal mouth,
stomach and intestines. These excretions reduce
the food materials to liquids, which are then ab-
The path:>genic or disease-producing germs are
. found to throw out during their processes of as-
similation and growth, various substances which
are poisons to the animal body, as are aconite and
82 THE CHEMISTRY OF
digitalis. These areabsorbed and carried by the blood
throughout the entire system. These poisons are
called toxines.' It is now believed that it is these
bacterial products, the toxines or poisons, which
•are the immediate cause of the diseased condition.
laocniataoiL Inoculation of some of the lower animals with
the poisoned blood of a diseased person, in which
blood no germ itself was present, has repeatedly
produced the identical disease. It is far easier to
keep such manufacturers out of the body than to
"regulate'' their manufactures after an entrance has
These faint glimpses into the "Philosophy of
Cleanness" lead to another question, namely: How
shall we keep clean?
The first requisite for cleanness is light — direct
sunlight if possible. It not only reveals the visible
dirt, but allies itself with us as an active agent
towards the destruction of the invisible elements of
uncleanness. That which costs little or nothing is
seldom appreciated; so this all-abundant, freely-
Suniighc given light is often shut out through man's greed
or through mistaken economy. The country dwell-
er surrounds his house with evergreens or shade
trees, the city dweller is surrounded by high brick
walls. Blinds, shades, or thick draperies shut out
still more, and prevent the beneficent sunlight from
acting its role of germ-prevention and germ-de-
COOKING AND CLEANING. 6S
struction. Bright-colored carpets and . pale-faced
children are the opposite results which follow.
"Sunshine is the enemy of disease, which thrives in
darkness and shadow." Consumption and scrofu-
lous diseases are well-nigh inevitable, when blinds
are tightly closed and trees surround the house,
causing darkness, and, thereby, inviting dampness.
As far as possible let the exterior of the house be
bathed in sunlight. Then let it enter every nook and
cranny. It will dry up the moisture, without which
the tiny diseiise germs or other plants cannot grow;
it will find and rout them by its chemical action.
Its necessity and power in moral cleanness, who
More plentiful than sunlight is air. We cannot PmeAir.
shut it out entirely as we can light; but there is
dirty air just as truly as dirty clothes and dirty
water. The second requisite for cleanness, then,
is pure air.
Primitive conditions of human life required no primitiTe
thought of the air supply, for man lived in the open ; yie.
but civilization brings the need of attention and
care for details; improvements in some directions
are balanced by disadvantages in others; luxuries
crowd out necessities, and man pays the penalty
for his disregard of Nature's laws. Sunlight, pure
air and pure water are our common birthright,
which we often bargain away for so-called com-
THB CHEMISTRY OF
Sunlight is purity itself. Man cannot contam-
inate it, but the air about him is what man makes it.
Naturally, air is the great "disinfectant, antiseptic
and purifier, and not to be compared for a moment
with any of artificial contrivance," but under man's
abuse it may become a death-dealing breath.
Charlemagne said: "Right action is better than
knowledge; but to act right one must know right."
Nature's supply of pure air is sufficient for all, but
to have it always in its pure state requires knowl-
edge and constant, intelligent action.
The gaseous products of the combustion carried
on within our bodies; like products from our arti-
ficial sources of heat and light — burning coal, gas
and oil; Waste matters of life and manufactures car-
ried into the air through fermentation and putre-
faction — all these, with the innumerable sources of
dust we have already found, load the air with im-
purities. Some are quickly recognized by sight,
smell or taste; but many, arid these the more dan-
gerous, are unrecognizable by any sense. They
show their actions in our weakened, diseased and
useless bodies. Dr. James Johnson says: "All
the deaths resulting from fevers are but a drop in
the ocean, when compared with the numbers who
perish from bad air."
The per cent of pollution in the country is much
smaller than in the city, where a crowded popula-
COOKING AND CLEANING. 85
tion and extensive manufactories are constantly
pouring forth impure matters, but by rapidly mov-
ing currents, even this large per cent is soon diluted
and carried away. Would that the air in country
houses, during both winter and summer, might
show an equally small per cent!
Air is a real substance. It can be weighed. It Air • Sub.
will expand, and may be compressed like other * ^'
gases. It requires considerable force to move it,
and this force varies with the temperature. When
a bottle is full of air, no more can be poured in.
Our houses are full of air all the time. No more
can come in till some has gone out. In breathing,
we use up a little, but it is immediately replaced
by expired air, which is impure. Were there no
exits for this air, no pure air could enter, and we
should soon die" of slow suffocation. The better
built the house the quicker the suffocation, unless
special provision be made for a current of fresh air
to push out the bad. Fortunately no house is air
tight. Air will come in round doors and windows,
but this is neither sufficient »to drive out the bad
nor to dilute it beyond harm. Therefore the air of
all rooms must be often and completely changed,
either by special systems of ventilation, or by in-
telligent action in the opening of doors and win-
Sunlight and pure air are the silent but powerful aiS^.
86 COOKING AND CLEANING,
allies of the housewife in her daily struggle toward
the ideal cleanness, i. e., sanitary cleanness, the
cleanness of health. Without these allies she may
spend her strei^glli for naught, for the plant-life of
the quiet, dust-laden air will grow and multiply far
beyond her powers of destruction. These dust-
plants or micro-organisms grow rapidly in wamv
places where there is moisture. Collections of
dtist in cracks and corners, lodged in depressions
of the surface, as in seams and carvings, or held
by rough, absorbent materials as fabrics, at all
times furnish the seed. All organic materials
ftu-nish soil or food. Therefore the half-dried
milk-can, the partly cleaned dripping-pan, the
dampened clothes in the laundry basket, the wet
dishcloth and damp towel will soon become a
A dust-garden suggests growth; growth of
dust means fermentation with its consequent
chemical changes. Fermentation is a process of
decomposition which may end in putrefaction.
This means economic waste.
Civilized man requires so many articles for his
convenience and comfort that the problem of
cleanness has grown to be most complex.
But dry dust is not the only enemy. The
mixture of dust with greasy, sugary or smoky
deposits makes the struggle twofold.
Grease and Dust.
THE various processes of housework give rise
to many volatile substances. These, the vapors
of water or fat, if not carried out of the house in
their vaporous state will cool and settle upon all
exposed surfaces, whether walls, furniture or fab-
rics. This thin film entangles and holds the dust,
clouding and soiling, with a layer more or less visi-
ble, everything within the house. Imperfect ven-
tilation allows additional deposits from fires and
lights — the smoky products of incomplete com-
Thorough ventilation is, then, a preventive meas-
ure, which ensures a larger removal not only of the
volatile matters, but also of the dust, with its possi-
ble disease germs.
Dust, abnCy may be removed from most sur-
faces with a damp or even with a dry cloth, or from
fabrics by vigorous shaking or brushing; but,
usually, the greasy or sugary deposits must first be
broken up and, thus, the dust set free. This must be
accomplished without harm to the material upon
THE CHEMISTRY OF
which the unclean deposit rests. Here is a broad
field for the application of chemical knowledge.
Cleaning, then, involves two processes: First,
the greasy film must be broken up, that the en-
tangled dtist may be set free. Second, the dust
must be removed by mechanical means. Disinfec-
tion sometimes precedes these processes, in or-
der that the dangerous dust-plants may be killed
To understand the methods of dust removal, it
IS necessary to consider the chemical character of
the grease and, also, that of the materials effectual
in acting upon it.
Grease or fats, called oils when liquid at ordinary
temperature, are chemical compounds made of dif-
ferent elements, but all containing an ingredient
known to the chemist as a fatty acid.
The chemist finds in nature certain elements
which, with the fatty acids, form compounds en-
tirely different in character from either of the orig-
inal ingredients. These elements are called the
alkali metals and the neutral compounds formed by
their union with the acid of the fat are familiarly
known to the chemist as salts.
The chemical g^oup of "alkali metals" comprises
six substances: Ammonium, Caesium, Lithium, Po-
tassium, Rubidium and Sodium. Two of the six —
Caesium and Rubidium — ^were discovered by means
COOKING AND CLEANING. 89
of the spectroscope, not many years ago, in the min-
eral waters of Diirckheim, and, probably, the total
amount for sale of all the salts of these two metals
could be carried in one's pocket. A third alkali
metal — Lithivmi — occurs in several minerals, and
its salts are of frequent use in the laboratory, but it
is not sufficiently abundant to be of commercial
importance. As regards the three remaining alkali
metals, the hydrate of Ammonium (NHJOH, is
known as "Volatile Alkali," the hydrates of Po-
tassium, KOH, and Sodium, NaOH, as "Caustic
Alkalies." With these three alkaHes and their
compounds, and these alone, are we concerned
in housekeeping. The volatile alkali. Ammonia, is
now prepared in quantity and price such that every
housekeeper may become acquainted with its use.
It does not often occur in soaps, but it is valuable .
for use in all cleansing operations — ^the kitchen,
the laundry, the bath, the washing of woolens, and
in other cases where its property of evaporation,
without leaving any residue to attack the fabric or
to attract anything from the air, is invaluable. The
most extensive household use of the alkalies is in
the laundry, under which head they will be more
Some of the fatty acids combine readily with Soap^
alkaHes to form compounds which we call soaps.
Others in contact with the alkalies form emulsions,
THE CHEMISTRY OF
" Finish '» of
so-called, in which the fatty globules are suspended,
forming an opaque liquid. .These emulsions are
capable of being indefinitely diluted with clear
water, and, by this means, the fatty globules are all
carried away. Most of the fats are soluble in ben-
zine, ether, chloroform, naphtha or alcohol.
If the housekeeper's problem were the simple
one of removing the grease alone, she would solve
it by the free use of one of these solvents or by
some of the strong alkalies. This is what the
painter does when he is called to repaint or to re-
finish; but the housewife wishes to preserve the
finish or the fabric while she removes the dirt. She
must, then, choose those materials which will dis-
solve or unite with the grease without injury to the
The greasy film which entangles the unclean and
possibly dangerous dust-germs and dust-particles
is deposited on materials of widely different char-
acter. These materials may be roughly divided
into two classes: One, where, on account of some
artificial preparation, the uncleanness does not
penetrate the material but remains upon the sur-
face, as on wood, metal, minerals, leather and some
wall paper; the other, where the grease and dust
settle among the fibres, as in fabrics.
In the interior of the house, woods are seldom
used in their natural state. The surface is covered
COOKING AND CLEANING,
with two or more coatings of different substances
which add to the wood durability or beauty. The
finish used is governed by the character of the
wood, the position and the purpose which it serves.
The cleaning processes should affect the final coat
of finish alone.
Soft woods are finished with paint, stain, oil,
shellac, varnish, or with two or more of these com-
bined; hard woods with any of these and, in addi-
tion, encaustics of wax, or wax with turpentine or
All these surfaces, except those finished with
wax, may be cleaned with a weak solution of soap
or ammonia, but the continued use of any such
alkali will impair and finally remove the polish.
Waxed surfaces are turned dark by water. Fin-
ished surfaces should never be scoured nor cleaned
with strong alkalies, like sal-soda or potash soaps.*
To avoid the disastrous effects of these alkalies the
solvents of grease may be used or slight friction
applied. Turpentine dissolves paint.
Kerosene and turpentine are efficient sohrents for
grease and a few drops of these on a soft cloth may
be used to clean all polished surfaces. The latter
cleans the more perfectly. and evaporates readily;
the former is cheaper, safer, because its vapor is not
so inflammable as that of turpentine, and it polishes
a little while it cleans; but it evaporates so slowly
*If the finish has become very greasy, smo^ or worn, it may be
economy to use as strong an alkali as sal-soda. The washing and rinsing
should be as rapid as possible. Refinishing may be necessary for clean
92 THE CHEMISTRY OF
that the surface must be rubbed dry each time, or
dust will be collected and retained. The harder the
rubbing, the higher the polish.*
Outside of the kitchen, the woodwork of the
house seldom needs scrubbing. The greasy layer
is readily dissolved by weak alkaline solutions, by
kerosene or turpentine, while the imbedded dust is
wiped away by the cloth. Polished siuiaces keep
clean longest. Strong alkalies will eat through the
polish by dissolving the oil with which the best
paints, stains or polishes are usually mixed. If the
finish be removed or broken by deep scratches, the
wood itself absorbs the grease and dust, and the
stain may have to be scraped out.
Woodwork, whether in floors, standing finish or
furniture, from which the dust is carefully wiped
every day, will not need frequent cleaning. A
few drops of kerosene or some clear oil rubbed or
with a second cloth will keep the polish bright and
will protect the wood.
Certain preparations of hon-drying oils are now
in the market, which, when applied to floors, serve
to hold the dust and prevent its spreading through
the room and settling upon the furnishings. They
are useful in school-rooms, stores, etc., where the
floor cannot be often cleaned. The dust and dirt
stick in the oil and, in time, the whole must be
cleaned off and a new coating applied.
* Continued use of kerosene on white paint tends to turn it yellow.
COOKING AND CLEANING. 93
Many housewives fear to touch the piano, how- acicmi
ever clouded or milky the surface may become. * ^
The manufacturers say that pianos should be
washed with soap and water. Use tepid water with
a good quality of hard soap and soft woolen or cot-
ton-flannel cloths. Wash a small part at a time,
rinse quickly with clear water that the soap may
not remain long, and wipe dry immediately. Do
all quickly. A well-oiled cloth wiped over the sur-
face and hard rubbing with the hand or with cham-
ois will improve the appearance. If there are deep
scratches which go through the polish to the wood,
first, cover them with oil and allow it to soak in,
or dark lines will appear where the alkali and
water touched the natural wood.
Painted surfaces, especially if white, may be paint,
cleaned with whiting, applied with a moistened
woolen cloth or soft sponge. Never let the
cloth be wet enough for the water to run or
stand in drops on the surface. Wipe "with
the grain" of the wood, rinse in clear
water with a second soft cloth and wipe
dry with a third. All washed surfaces should
be wiped dry, for moisture and warmth furnish the
favorable conditions of growth for all dust-germs,
whether bacteria or molds. Cheese cloth may be
used for all polished surfaces, for it does not
scratch and washes easily.
94 THE CHEMISTRY OF
Walls painted with oil paints may be cleaned
with weak ammonia water or whiting in the same
manner as woodwork; but if they are tinted with
water colors, no cleaning can be done to them, for
both liquids and friction will loosen the coloring
WaU-Pftpcr. Papered walls should be wiped down with cheese
cloth, with the rough side of cotton flannel, or some
other soft cloth. This will effectually remove all
free dust Make a bag the width of the broom or
brush used. Run in drawing strings. Draw the
bag over the broom, and tie closely round the han-
dle, just above the broom-corn. Wipe the walls
down with a light stroke and the paper will not be
injured. An occasional thorough cleansing will be
needed to remove the gjeasy and smoky deposits.
The use of bread dough or crumb is not recom-
mended, for organic matter may be left upon the
wall. A large piece of aerated rubber — ^the
"sponge" rubber used by artists for erasing their
drawings — may be used effectually, and will leave
no harmful deposit. "Cartridge" paper may be
scoured with fine emery or pumice powder, for the
color goes through. Other papers have only a thin
layer of color.
Varnished and waxed papers are now made
which may be wiped with a damp cloth.
Leather may be wiped with a damp cloth or be
tized by Google
COOKING AND CLEANING. 95
kept fresh by the use of a little kerosene. An occa-
sional dressing of some good oil, well rubbed in,
will keep it soft and glossy.
Marble may be scoured with fine sand-soap or MarWc.
powdered pumice, or covered with a paste of whit-
ing, borax or pipe-clay, mixed with turpentine,
ammonia, alcohol or soft soap. This should be left
to dry. When brushed or washed off, the marble
will be found clean. Polish with coarse flannel or
a piece of an old felt hat. Marble is carbonate of
Ume, and any acid, even fruit juices, will unite
with the lime, driving out the carbon dioxide,
which shows itself in effervescence, if the quantity
of acid be sufficient. Acids, then, should not touch
marble, if it is desired to keep the polish intact.
An encaustic of wax and turpentine is sometimes
applied to marbles to give them a smooth, shining
surface. These must not be scoured.*
Pastes of whiting, pipe-clay, starch or whitewash
may be put over ornaments of alabaster, plaster and
the hke. The paste absorbs the grease and, by rea-
son of its adhesive character, removes the grime
Most metals may be washed without harm in a Meiau.
hot alkaline solution or wiped with a little kerosene.
Stoves and iron sinks may be scoured with the
coarser materials like ashes, emery or pumice; but
copper, polished steel, or the soft metals, tin, silver,
and zinc require a fine powder that they may not
♦New marbles have a very hieh polish which is easily scratched.
These should be washed, not scoured,
96 THE CHEMISTRY OF
be scratched or worn away too rapidly. Metal
bathtubs may be kept clean and bright with whiting
and ammonia, if rinsed with boiling hot water and
wiped dry with soft flannel or chamois.
Porcelain. Porcclain or soapstone may be washed 4ike metal
or scoured with any fine material.
GiM*. Glass of windows, pictures and mirrors may be
cleaned in many ways. It may be covered with a
whiting paste mixed with water, ammonia or alco-
hol. Let the paste remain till dry, when it may be
rubbed off with a sponge, woolen cloth or paper.
Polish the glass ~by hard rubbing with news-
papers or chamois. Alcohol evaporates more
quickly than water and therefore hastens the
process; but it is expensive and should not touch
the sashes, as it might turn the varnish. Very good
results are obtained with a tablespoonful of kero-
sene to a quart of warm water. In winter, when
water would freeze, windows may be wiped with
clear kerosene and rubbed dry. Kerosene does not
remove fly specks readily, but will take off grease
and dust. Fly specks may be dissolved in alcohol
or strong alkali, or be scraped off with some
dull, hard edge, as a cent, nickel or the back of
Success in washing glass depends more upon
manipulation than materials. It is largely a matter
of patience and polishing. The outer surface of
COOKING AND CLEANING. 67
windows often becomes roughened by the dissolv-
ing action of rain water, or milky and opaque by
action between the sun, rain and the potash or soda
in the glass. Ordinary cleaning will not make such
windows clear and bright. The opaqueness may
sometimes be removed by rubbing with vinegar
or dilute muriatic acid. Polish with whiting.
Household fabrics, whether carpets, draperies Fabric
or clothing, collect large quantities of dust, which
no amount of brushing or shaking will entirely dis-
lodge. They also absorb vapors which con-
dense and hold the dust-germs still more firmly
among the fibres. Here the fastness of color and
strength of fibre must be considered, for a certain
amount of soaking will be necessary in order that
the cleansing material may penetrate through the
fabric. In general, all fabrics should be washed
often in an alkaline solution. If the colors will not
stand the application of water, they may be cleansed
in naphtha or rubbed with absorbents. The chem-
istry of dyeing has made such progress during the
last ten years that fast colors are more frequently
found, even in the cheaper grades of fabrics, than
could be possible before this time. It is now more
a question of weak fibre than of fleeting color.
Heavy fabrics may therefore be allowed to soak
for some time in many waters, or portions of naph-
tha, being rinsed carefully up and down without
THE CHEMISTRY OF
rubbing. All draperies or woolen materials should
be carefully beaten and brushed before any other
cleaning is attempted. Wool fabrics hold much of
the dirt upon their hook-like projections, and these
become knotted and twisted by hard rubbing. If
the fabric be too weak to be lifted up and down in
the liquid bath, it may be laid on a sheet, over a
folded blanket, and sponged on both sides with the
soap or ammonia solution or with the naphtha. If
the colors are changed a little by the alkalies, rinse
the fabrics in vinegar or dilute acetic acid; if affect-
ed by acids, rinse in ammonia water.
In the use of naphtha, benzine, turpentine, etc.,
gjeat caution is necessary. The vapor of all these
substances is extremely inflammable. They should
never be used where there is any fire or light pres-
ent, nor likely to be for several hours. A bottle
containing one of them should never be left un-
corked. Whenever possible, use them out-of-
With both dust and grease, prevention is easier
than removal. If the oily vapors of cooking and
the volatile products of combustion be removed
from the kitchen and cellar, and not allowe^d to dis-
sipate themselves throughout the house, the greasy
or smoky deposits will be prevented and the re-
moval of the dust-particles and dust-plants will be-
come a more mechanical process. Such vapors
COOKING AND CLEANING. 99
should be removed by special ventilators or by win-
dows open at the top, before they become con-
densed and thus deposited upon everything in the
house. Let in pure air, drive out the impure; fill
the house with sunshine that it may be dry, and the
problem of cleanness is largely solved.
Economy of time, labor and materials results
in removing dust and dust mixtures, frequently.
"One keep-clean is worth a dozen make-
clean" is as true now as it was generations ago.
The sooner a wrong condition can be removed
the easier will be its removal; less time will be
required; and much less harm done to the
The organic matter which is present in most
dirt tends to harden or to change in other ways
and, therefore, to become removable with diffi-
culty. It may undergo chemical changes which
make it. indelible.
In fabrics the fibres may even be destroyed.
Stains, Spots, Tarnish.
THESE three classes include the particular de-
posits resulting from accident, careless- .
nes9, or the action of special agents, as the
tarnish on metals. They are numerous in char-
acter, occur on all kinds of materials and their re-
moval is a problem which perplexes all women
and which requires considerable knowledge and
much patience to solve. A few suggestions may
help some one who has not yet found the best
way for herself.
Grease seems to be the most common cause of
such spots. Small articles that can be laundered
regularly with soap and water, give little trouble.
These will be discussed in the following chapter.
Spots of grease on carpets, heavy materials, or
colored fabrics of any kind which cannot be con-
veniently laundered, may be treated with absorb-
ents. Heat will assist in the process by melting
the grease. Fresh grease spots on such fabrics
may often be removed most quickly by placing
over the spot a piece of clean white blotting paper
or butcher's wrapping paper, and pressing the spot
with a warm iron. It is well to have absorbent
COOKING AND CLEANING. lOl
paper or old cloth under the spot as well. Heat
sometimes changes certain blues, greens and reds,
so it is well to work cautiously and hold the iron
a little above the goods till the effect can be noted.
French chalk, — a variety of talc, or magnesia,
may be scraped upon the spot and allowed to re-
main for some time, or applied in fresh portions, ,
repeatedly. If water ean be used, chalk, fuller's
earth or magnesia may be made into a paste with
it or with benzine and this spread over the spot.
When dry, brush the powder off with a soft brush.
For a fresh spot on fabrics of delicate texture or
color, when blotting paper is not at hand, a
visiting or other card may be split and
the rough inner surface rubbed gently over the
spot. Slight heat under the spot may hasten the
absorption. Powdered soapstone, pumice, whit-
ing, buckwheat flour, bran or any kind of coarse
meal are good absorbents to use on carpets or up-
holstery. They should be applied as soon as the
grease is spilled. Old spots will require a solvent
and fresh ones may be treated in the same way.
Grease, as has been said, may be removed in gJventsof
three ways, by forming a solution, an emulsion,
or a true soap. Wherever hot water and soap can
be applied, the process is one of simple emulsion,
and continued applications should remove both
the grease and the entangled dust; but strong
102 THE CHEMISTRY OF
soaps ruin some colors and textures. Ammonia
or borax may replace the soap, still the water may
affect the fabric, so the solvents of grease are safer
for use. Chloroform, ether, alcohol, turpentine,
benzine and naphtha, all dissolve grease. In their
commercial state some of these often contain im-
purities which leave a residue, forming a dark ring,
which is as objectionable as the original grease.
Turpentine is useful for coarser fabrics, while
chloroform, benzine and naphtha are best for silks
and woolens. Ether or chloroform can usually
be applied to all silks, however delicate.
Whenever these solvents are used, there
should be placed under the spot some absorb-
ent material, like a thick pad of cloth, blot-
ting paper or a layer of chalk to take up the
excess of liquid.
Then rub the spot from the outside toward
the center to prevent the spreading of the
liquid, to thin the edges, and, thus, to ensure
rapid and complete evaporation. The cleansing
liquid should not be left to dry of itself.
The cloth should be rubbed dry, but very
carefully, for the rubbing may remove the
nap from woolen goods and, therefore, change
the color or appearance. Apply the solvent
with a cloth as nearly like the fabric to be
cleaned, in color and texture, as possible,
COOKING AND CLEANING. 103
or, in general, use a piece of sateen, which does
not jg^row linty. On thick goods a stiff brush,
jtnd on thin goods a soft one, will reach into the
meshes. This should be struck against the cloth
more than rubbed across it. It is well to apply
all cleansing liquids and all rubbing on the wrong
side of the fabric. None of these solvents can be
used near a flame.
The troublesome "dust spot" has usually a neg- "Dust^
lected grease spot for its foundation. After the
grease is dissolved, the dust must be cleaned out
by thorough rinsing with fresh liquid or by brush-
ing after the spot is dry.
Our grandmothers found ox-gall an efficient Ox-gaii.
cleanser both for the general and special deposits.
It is as effectual now as then and is especially good
for carpets or heavy cloths. It may be used clear
for spots, or in solution for general cleansing and
brightening of colors. Its continued use for car-
pets does not fade the colors as ammonia or salt
and water is apt to do.
Cold or warm grease on finished wood can be ^"^^^'*
wiped off easily with a woolen cloth moistened
in soapsuds or with a few drops of turpentine.
Soap should never be rubbed on the cloth except,
possibly, for very bad spots round the kitchen
stove or table. Solutions of washing soda, potash,
or the friction, that may be used safely on unfin-
104 THE CHEMISTRY OF
ished woods, will take out the grease but will also
destroy the polish.
Hot grease usually destroys the polish and
sinks into the wood. It then needs to be treated
like grease on unfinished wood or scraped out
with fine steel wool or wire fibre, sandpaper or
emery paper. The color and polish must then be
renewed. When hot gjease is spilled on wood or
stone, if absorbents are not at hand, dash cold
water on it immediately. This will solidify the
grease and prevent its sinking deeply into the ma-
GreMeoB Grcase or oil stains on painted walls, wall-paper
Leather. or leather, may be covered with a paste of pipe-
clay, or French chalk and water. Let the paste
dry and after some hours carefully brush off the
powder. Sometimes a piece of blotting paper laid
over the spot and a warm iron held against this,
will draw out the grease. These pastes of absorb-
ent materials are good for spots on marbles. They
may then be mixed with turpentine or ammonia
or soft soap.
P*int. Paint is made of oil, lead or zinc oxide
and pigment. Spots of paint, then, must be
treated with something which will take out the oil,
leaving the insoluble coloring matter to be
brushed off. When fresh, such spots may
be treated with turpentine, benzine on naph-
COOKING AND CLEANING. 106
tha. For delicate colors or textures, chloroform
or naphtha is the safest. The turpentine, un-
less pure, may leave a resinous deposit. This
may be dissolved in chloroform or benzine, but
care should be exercised in the use of alcohol
for it dissolves some coloring matters. Old paint
spots often need to be softened by the application
of grease or oil; then the old and the new may be
removed together. Whenever practicable, let all
spots soak a little, that the necessity of hard rub-
bing may be lessened.
Paint on stone, bricks or marble, may be treated
with strong alkalies and scoured with pumice
stone or fine sand.
Varnish and pitch are treated with the same X^f^*
solvents as paint — turpentine being the one in
general use, — ^when the article stained will not
bear strong alkalies. Pitch and tar usually need
to be covered first with grease or oil, to soften
Wax spots made from candles should be re- Wax.
moved by scraping off as much as possible, then
treating the remainder with kerosene, benzine,
ether, naphtha, or with blotting paper and a warm
iron, as grease spots are treated. The soap and
water of ordinary washing will remove slight
spots. The spermaceti is often mixed with tallow
which makes a grease spot, and with coloring mat-
ters which may require alcohol.
106 THE CHEMISTRY OF
Food suiM. Spots made by food substances are greasy, sug-
ary or acid in their character, or a combination of
these. That which takes out the grease will gen-
erally remove the substance united with it, as the
blood in meat juices. The sugary deposits are us-
ually soluble in warm water. If the acids from
fresh fruits or fruit sauces affect the color of the
fabric, a little ammonia water may neutralize the
acid and bring back the color. Dilute alcohol
may sometimes be used as a solvent for colored
stains from fruit. Blood requires cold or tepid
water, never hot. After the red color is removed
soap and warm water may be used.
Blood stains on thick cloths may b6 absorbed
by repeated applications of moist starch.
Wheel Wheel-grease and lubricants of like nature are
^^' mixtures of various oils and may contain soaps or
graphite. The ordinary solvents of the vegetable
or animal oils will remove these mixtures from
colored fabrics by dissolving the oil. The undis-
solved coloring matter will, for the most part, pass
through the fabric and may be collected on thick
cloth or absorbent paper, which should always be
placed underneath. From wash goods, it may be
removed, readily, by strong alkalies and water, es-
pecially if softened first by kerosene or the addition
of more grease, which increases the quantity of
soap made. Graphite is the most difficult of re-
COOKING AND CLEANING. 107
Ink spots are perhaps the worst that can be en- i«k staim.
countered^ because of the great uncertainty of the
composition of the inks of the present day. When
the character of an enemy is known it is a compar-
atively simple matter to choose the weapons to be
used against him, but an unknown enemy must be
experimented upon, and conquest is uncertain.
Methods adapted to the household are difficult to
find, as the effective chemicals need to be applied
with considerable knowledge of proportions and
effects. Such chemicals are often poisons and,
in general, their use by unskilled hands is not to
Fresh ink will sometimes yield to clear cold oi
tepid water. Skimmed milk is safe and often ef-
fective. If the cloth is left in till the milk sours,
the result is at times more satisfactory. This has
proved effective on light colored dress goods
where strong acids might have affected the colored
printed patterns. Some articles may have a bit of
ice laid over the stain with blotting paper under
it to absorb the ink solution. Remove the satur-
ated portions quickly and continue the process till
the stain has nearly or quite disappeared. The last
slight stain may be taken out with soap and water.
Some colored dress goods will bear the applica-
tion of hot tartaric acid or of muriatic acid, a drop
at a time, as on white goods,
108 THE CHEMISTRY OF
Ink on carpets, table covers, draperies or heavy,
dark cloths of any kind, may be treated immedi-
ately with absorbents to keep the ink from spread-
ing. Bits of torn blotting paper may be held at
the surface of the spot to draw away the ink on
their hairy fibres. Cotton-batting acts in the same
way. Meal, flour, starch, sawdust, baking soda
or other absorbents may be thrown upon the ink
and carefully brushed up when saturated. If much
is spilled, it may be dipped up with a spoon or
knife, adding a little water to replace that taken
up, until the whole is washed out. Then dry the
spot with blotting paper. The cut surface of a
lemon may be used, taking away the stained por-
tion as soon as blackened. Usually it requires
hard rubbing to remove the last of the stain. Car-
pets may be rubbed with a floor brush, while a
soft toothbrush may be used for more delicate ar-
ticles. With white goods a solution of bleaching
powder may be used, but there is always danger
of rotting the fibres unless rinsing in ammonia
water follow, in order that the strong acid of the
powder may be neutralized.
Fresh ink stains on polished woods may be
wiped off with clear water, and old stains of some
inks likewise yield to water alone. The black col-
oring matter of other inks may be wiped off with
the water, but a greenish stain may still remain
COOKING AND CLEANING.
which requires turpentine. In general, turpentine
is the most effectual remover of ink from polished
The indelible inks formerly owed their perman-
ence to silver nitrate; now, many are made from
aniline solutions and are scarcely affected by any
chemicals. The silver nitrate inks, even after ex-
posure to light and the heat of the sun or of a hot
flat-iron, may be nemoved by bleaching liquor.
The chlorine replaces the nitric acid forming a
white silver chloride. This may be dissolved in
strong ammonia or a solution of sodium hyposul-
phite. Sodium hyposulphite, which may be
bought of the druggists, will usually remove the
silver inks without the use of bleaching fluid and is
not so harmful to the fibres. Some inks contain
carbon which is not affected by any chemicals.
The aniline inks, if treated with chemicals may AnOine ink&
spread over the fabric and the last state be Worse
than the first. Other chemicals are effective with
certain inks, but some are poisonous in themselves
or in their products, some injure the fabric, and
all require a knowledge of chemical reactions in
order to be safely handled. Dried ink stains on
silver, as the silver tops of inkstands may be
moistened with chloride of lime and rubbed hard.
Polished marble may be treated with turpen-
tine, "cQoking soda" or strong alkalies, remem-
110 THE CHEMISTRY OF
bering that acids should never touch marble if it
is desired to retain the polish. • If the stain has
penetrated through the polish, a paste of the alkali
and turpentine may be left upon the spot for some
time and then washed off with clear water.
Sometimes the porcelain linings of hoppers
and bowls become discolored with yellowish-
brown stains from the large quantities of iron in
the water supply. These should be taken off with
muriatic acid. Rinse in clean water and, lastly,
with a solution of potash or soda to prevent any
injurious action of the acid on the waste pipes.
Aioohoi. Alcohol dissolves shellac. Most of the interior
woodwork of the house, whether finish or furni-
ture, has been coated with shellac in the process
of polishing. If then, any liquid containing alco-
hol, as camphor, perfumes, or medicines, be spilled
upon such woodwork and allowed to remain, a
white spot will be made, or if rubbed while wet,
the dissolved shellac will be taken off and the bare
^••«- Heat also turns varnish and shellac white. A
hot dish on the polished table leaves its mark.
These white spots should be rubbed with oil till the
color is restored.
If a little alcohol be brushed over the spot with
a feather, a little of the surrounding shellac is dis-
solved and spread over the stained spot. HarcJ
COOKING And cleaning.
rubbing with kerosene will, usually, remove the
spot and renew the polish. If the shellac be re-
moved and the wood exposed the process of re-
newal must be the original one of coloring, shellac-
ing and polishing, until the necessary polish is ob-
Caustic alkalies, strong solutions of sal-soda,
potash and the like, will eat off the finish. Apply
sweet, olive, or other vegetable oils, in case of
such accidents. The continued use of oils or al-
kalies always darkens natural woods.
The special deposits on metals are caused by the
oxygen and moisture of the air, by the presence of
other gases in the house, or by acids or corroding
liquids. Such deposits come under the general
head of tarnish.
The metals^ or their compounds, in common use
are silver, copper and brass, iron and steel, tin,
zinc and nickel. Aluminum is rapidly taking a
prominent place in the manufacture of household
There is little trouble with the general greasy
film or with the special deposits on articles in daily
use, if they are washed in hot water and soap,
rinsed well and wiped dry each time. Yet certain
articles of food act upon the metal of tableware
and cooking utensils, forming true chemical salts.
The salts of silver are usually dark colored and in-
112 THE CHEMISTRY OF
soluble in water or in any alkaline liquid which will
not also dissolve the silver. Whether found in the
products of combustion, in food, as eggs, in the
paper or cloth used for wrapping, in the rubber
band of a fruit jar, or the rubber elastic which may
be rtear the silver, sulphur forms with silver a gray-
ish black compound — a sulphide of silver. All the
silver sulphides are insoluble in water. Rub such
tarnished articles, before washing, with common
salt. By replacement, silver chloride, a white chem-
ical salt, is formed, which is soluble in ammonia.
If the article be not washed in ammonia it will soon
turn dark again. Most of these metallic com-
pounds formed on household utensils being insolu-
ble, friction must be resorted to.
sarerware. The matron of fifty years ago took care of her
silver herself or closely superintended its clean-
ing, for the articles were either precious heirlooms
or the valued gifts of friends. The silver of which
they were made was hardened by a certain propor-
tion of copper and took a polish of great brilliancy
and permanence. The matron of to-day, who has
the same kind of silver or who takes the same care,
is the exception. Plated ware is found in most
households. The silver deposited from the battery
is only a thin coating of the pure soft metal — ^very
bright when new, but easily scratched, easily tar-
nished, and never again capable of taking a beauti-
tized by Google
COOKING AND CLEANING. US
ful polish. The utensils, being of comparatively
little value, are left to the table-girl to clean. She,
naturally, uses the material which will save her
In order to ascertain if there was any foundation saver
for the prevalent opinion that there was mercury or
some equally dangerous chemical in the silver pow-
ders commonly sold, samples were purchased in
Boston and vicinity, and in New York and vicinity.
Of the thirty-eight different kinds examined.
25 were dry powder.
ID " partly liquid.
3 " soaps.
Of the twenty-five powders, fifteen were chalk or
precipitated calcium carbonate, with a little color-
ing matter, usually rouge.
6 were diatomaceous earth.
2 " fine sand entirely.
2 " fine sand partly.
Mercury was found in none. No other injurious
chemical was found in any save the "electro-plating
battery in a bottle," which contained potassium
cyanide, KCN, a deadly poison; but it was labeled
poison, although the label also stated that "all salts
of silver are poison when taken internally." This
preparation does contain silver, and does deposit a
thin coating, but it is not a safe article for use.
THE CHEMISTRY OF
Of the nine polishes, partly liquid, five contained
alcohol and ammonia for the liquid portion; four,
alcohol and sassafras extract. The solid portion, in
all cases, was chalk, with, in one case, the addition
of a little jeweler's rouge.
The caution to be observed in the use of these
preparations is in regard to the fineness of the ma-
terial. A few coarse grains will scratch the coat-
ing of soft silver. Precipitated chalk, CaCOg, or
well-washed diatomaceous earth, SiOg, seem to be
of the most uniform fineness.
We may learn a lesson in this, as well as in many
other things, from the old-fashioned housewife.
She bought a pound of whiting for twelve cents,
sifted it through fine cloth, or floated off the finer
portion, and obtained twelve ounces of the same
material, for three ounces of which the modem
matron pays twenty-five or fifty cents, according to
the name on the box.
The whiting may be made into a paste with am-
monia or alcohol, the article coated with this and
left till the liquid has evaporated. Then the pow-
der should be rubbed off with soft tissue paper or
soft unbleached cloth, and polished with chamois.
Sometimes it is desirable to clean a large quantity
of silverware at one time, but the labor of scouring
and polishing each piece is considerable. They
may all be placed carefully in a large kettle — 3, clean
COOKING AND CLEANING. 116
wash-boiler is convenient for packing the large
pieces — ^and covered vv;i|th a strong solution of
washing-soda, potash or borax. Boil them in this
for an hour or less. Let them stand in the liquor
till it is cold; then polish each piece with a little
whiting and chamois. A good-sized piece of zinc
boiled with the silverware will help to clean away
any sulphides present, by replacing the silver in
them and forming a white compound.
Silver should never be rubbed with nor wrapped iwetioo oi
in woolen, flannel or bleached cloth of any kind,
for sulphur is commonly used in bleaching proc-
esses; nor should rubber in any form be present
where silver is kept. The unused silver may be
wrapped in soft, blue-white or pink tissue paper,
prepared without sulphur, and packed in un-
bleached cotton flannel cases, each piece separately.
Silver jewelry, where strong soap or other alkali surer
is not sufficient for the cleaning process, may be
immersed in a paste of whiting and ammonia, and
when dry, brushed carefully with a soft brush. If
there be a doubt as to the purity of the silver, re-
place the ammonia by sweet oil or alcohol. The
ammonia and whiting are also good for gold. Jew-
elry cleaned with water may be dried in boxwood
Care is necessary in the use of ammonia in or on Copper and
"silver*' topped articles, as vinaigrettes. These tops
lie THE CHEMISTRY OF
arc often made of copper with a thin layer of silver.
Whenever the ammonia remains upon the copper,
it dissolves it, forming poisonous copper salts.
Brass and copper must not be cleaned with am-
monia unless due care is taken that every spot be
rinsed and wiped perfectly dry. Nothing is better
for these metals than the rotten-stone and oil of old-
time practice. These may be mixed into a paste at
the time of cleaning or be kept on hand in quantity.
Most of the brass polishes sold in the market are
composed of these two materials, with a little alco-
hol or turpentine or soap, to form an emulsion with
the oil. Oxalic acid may be used to clean these
metals, but it must be rinsed or rubbed off com-
pletely, or green salts will be formed. Copper or
brass articles cleaned with acids tarnish much more
quickly from the action of moisture in the air than
when cleaned with the oil and soft powder. Small
spots may be removed with a bit of lemon juice and
hot water. An occasional rubbing with kerosene
helps to keep all copper articles clean and bright.
Indeed, kerosene is useful on any metal, as well as
on wood or glass.
Meuf$r*° °' The presence of water always favors chemical
change. Therefore iron and steel rapidly oxidize
in damp air or in the presence of moisture. All
metallic articles may be protected from such action
by a thin oily coating. Iron and steel articles not in
use may be covered with a thin layer of vaseline.
COOKING AND CLEANING.
Rust spots may be scoured off with emery and
oil, covered with kerosene or sweet oil for some
time and then rubbed hard, or in obstinate cases,
touched with muriatic acid and thexkwith ammonia,
to neutralize the acid.
A stove rubbed daily with a soft cloth and a few
drops of kerosene or sweet oil may be kept black
and clean, though not polished. Substances spilled
on such a stove may be cleaned off with soap and
water better than on one kept black with graphite.
Nickel is now used in stove ornaments, in the
bathroom, and in table utensils. It does not oxidize
or tarnish in the air or with common use. It can
be kept bright by washing in hot soap-suds and
rinsing in very hot water. It may be rubbed with
a paste of whiting and lard, tallow, alcohol or am-
Aluminum does not tarnish readily, and may be
rubbed with the whiting or with any of the fine
materials used for silver. It is darkened by
^ Kitchen utensils, with careful use, may be kept
clean by soap and water or a liberal use of am-
monia. Fine sand-soap must occasionally be used
when substances are burned on or where the tin
comes in contact with flame. Kerosene is a good
cleaner for the zinc stove-boards ; vinegar and
water, if there is careful rinsing afterward, or a
strong solution of salt and water may be used.
*HE health of the family depends largely upon
the cleansing operations which belong to the
laundry. Here, too, more largely perhaps than in
any other line of cleaning, will a knowledge of
chemical properties and reactions lead to econ-
omy of time, strength and material.
The numerous stains and spots on table linen
and white clothes are dealt with in the laundry,
and, also, all fabrics soiled by contact with the
Body clothes, bed linen and towels become
soiled not only by the sweat and oily secretions of
the body, but also with the dead organic matter
continually thrown off from its surface. Thus the
cleansing of such articles means the removal of
stains of varied character, grease and dust, and all
traces of organic matter.
The two most important agents in this purifica-
tion are water and soap.
Water. Purc watcr is a chemical compound of two
gases, hydrogen and oxygen (HgO). It has great
solvent and absorbent power, so that in nature
pure water is never found, though that which falls
COOKING AND CLEANING. 119
in sparsely-settled districts, at the end of a long
storm, may be approximately pure. The first fall
of any shower is mixed with impurities which have
been washed from the air. Among these may be
acids, ammonia and carbon in the form of soot
and creosote. It is these impurities which cause
the almost indelible stain left when rain-water
stands upon window-sills or other finished wood.
Cistern water, while soft, is liable to be colored wai"*^^^
from shingles, paint or moss on the roof. Spring
water and well water, having percolated a greater
or less distance through the ground, are filtered,
clear waters. But they have become mineralized
to a degree because of the great solvent power
of water. All ground waters contain more solid
residue than rain water, iand are more or less
hard when they contain compounds of lime and
magnesia. These form insoluble compounds
with soap and give curd-like masses on hands
or clothes. They waste the soap, therefore, in
proportion to the amount present.
The soft waters of the Atlantic seaboard use
up very little soap. One pound of standard Cas-
tile softens 409 gallons of water containing
twenty parts per million of hardening sub-
stances; one pound of Ivory soap softens 196
gallons of the same water, and one pound of
Gold Dust 65 gallons.
THE CHEMISTRY OF
In case of a moderately hard water, not uncom-
mon in wells, giving 200 parts hardness per
million, one pound of Castile soap softens 60
gallons, one pound of Ivory soap 29 gallons, and
one pound of Gold Dust 24 gallons. Therefore
the expense of securing a soft water supply is
partly met by a saving in soap.
Many hard waters may be softened by boiling.
The gaseous carbon dioxide escapes and calcium
carbonate falls to the bottom of the vessel. Or
the excess gas may be taken up by lime water in
the cold. Such hardness is often called tempo-
rary, because it may be removed easily.
Permanent hardness is given by sulphates,
chlorides, nitrates of calcium, which require
chemical action to remove. Such compounds
are converted into carbonates by the addition of
sal-soda, soda-ash, sodium carbonate, which gives
the precipitate of calcium carbonate and the
soluble sodium sulphate. Tri-sodium phosphate
may be used instead of the carbonate, and
calcium phosphate precipitated.
In many parts of the country city supplies are
"softened" by chemical treatment.
Another important material used in the laundry-
is soap. "Whether the extended use of soap be
preceded or succeeded by an. improvement in any
community-^whether it be the precvirsor or the re-
COOKING AND CLEANING. 121
suit of a higher degree of refinement among the
nations of the earth — the remark of Liebig must
be acknowledged to be true, that the quantity of
soap consumed by a nation would be no inaccur-
ate measure whereby to estimate its wealth and
civilization. Of two countries with an equal
amount of population, the wealthiest and most
highly civilized will consume the greatest weight
of soap. This consumption does not subserve sen-
sual gratification, nor depend upon fashion, but
upon the feeling of the beauty, comfort and wel-
fare attendant upon cleanliness; and a regard to
this feeling is coincident with wealth and civiliza-
Many primitive people find a substitute for soap Soap SuUti.
in the roots, bark or fruit of certain plants. Nearly
every country is known to produce such vegetable
soaps, the quality which they possess of forming
an emulsion with oily substances being due to a
peculiar vegetable substance, known as Saponin.
Many of these saponaceous barks, roots and fruits
are now used with good results — ^the "soap bark"
of the druggist being one of the best substances
for cleansing dress goods, especially black, wheth-
er of silk or wool.
The fruit of the soapberry tree — Papindus
Saponaria — a native of the West Indies, is said to
* Muspratt's Chemistry as Applied to Arts and Manufacturtu
122 THE CHEMISTRY OF
be capable of cleansing as much linen as sixty
times its weight of soap.
Wood ashes were probably used as cleansing
material long before soap was made, as well as
long after its general use. Their properties and
value will be considered later.
Compontioo Soaps for laundry use are chiefly composed of
alkaline bases, combined with fatty acids. Their
action is "gently but efficiently to dispose the
greasy dirt of the clothes and oily exudations of
the skin to miscibility with, and solubility in wash
Oily matters, as we have seen, are soluble in cer-
tain substances, as salt is soluble in water, and can
be recovered in their original form from such solu-
tions by simple evaporation. Others in contact
with alkalies, form emulsions in which the sus-
pended fatty globules make the liquid opaque, as
in soapsuds. The soap is decomposed by water,
the alkali set free acts upon the oily matter on the
clothes, and unites with it, forming a new soap.
The freed fatty acid remains in the water, causing
the "milkiness," or is deposited upon the clothes.
•Potash "and Certain compounds of two of the alkali metals,
potassium and sodium, are capable of thus saponi-
fying fats and forming the complex substances
known as soaps. For the compounds of these al-
* Chemistry applied to the Manufactuie of Soaps and Candles.— Morfit,
COOKING AND CLEANING. 128
kalies employed in the manufacture of soap, we
shall use the popular terms "potash'' and "soda,'' as
less likely to cause confusion in our readers' minds.
Potash makes soft soap; soda makes hard soap.
Potash is derived from wood ashes, and in the
days of our grandmothers soft soap was the uni-
versal detergent. Potash (often called pearlash)
was cheap and abundant. The wood fires of every
household furnished a waste product ready for its
extraction. Aerated pearlash (potassium bicar-
bonate), under the name of saleratus, was used for
bread. Soda-ash was, at that time, obtained from
the ashes of seaweed, and, of course, was not com-
The discovery by the French manufacturer, Le-
blanc, of a process of making soda-ash from the
cheap and abundant sodium chloride, or common
salt, has quite reversed the conditions of the use
of the two alkalies. Potash is now about eight
cents a pound, soda-ash is only three.
In 1824, Mr. James Muspratt, of Liverpool, first ^^,^^J*
carried out the Leblanc process on a large scale,
and he is said to have been compelled to give
away soda by ,he ton to the soap-boilers, before
he could convince them that it was better than the
ashes of kelp, which they were using on a small
scale. The soap trade, as we now know it, came
into existence after the soap-makers realized the
124 THE CHEMISTRY OF
value of the new process. Soda-ash is now the
cheapest form of alkali, and housekeepers will do
well to remember this fact when they are tempted
to buy some new " ine" or "Crystal."
In regard to the best form in which to use the
alkali for washing purposes, experience is the best
guide, — ^that is, experience reinforced by judg-
ment; for the number of soaps and soap substi-
tutes in the market is so great, and the names so
little indicative of their value, that only general in-
formation can be given.
In the purchase of soap, it is safest to choose
the make of some well-known and long-established
firm, of which there are several who have a repu-
tation to lose, if their products are not good; and,
for an additional agent, stronger than soap, it is
better to buy sal-soda or soda-ash (sodium car-
bonate) and use it knowingly, than to trust to the
highly-lauded packages of the grocery.
^ Use of Washing soda should never be used in the solid
Soda. form, but should be dissolved in a separate vessel,
and the solution used with judgment. The in-
judicious use of the solid is probably the cause of
the disfavor with which it is often regarded. One
of the most highly recommended of the scores of
"washing compounds" formerly in the market,
doubtless owed its popularity to the following di-
rections: "Put the contents of the box into one
COOKING AND CLEANING. 126
quart of boiling water, stir well, and add three
quarts of cold water; this will make one gallon.
For washing clothes, allow two cupfuls of liquid
to a large tub of water."
As the package contained about a pound of
washing soda, this rule, which good housekeepers
have found so safe, means about two ounces to a
large tub of water, added before the clothes are
Ten pounds of washing soda can^ be purchased
of the grocer for the price of this one-pound pack-
age with its high-sounding name. Nearly all the
compounds in the market depend upon washing
soda for their efficiency. Usually they contain
nothing else. Sometimes soap is present and,
rarely, borax. In one or two, a compound of am-
monia has been found.
Ammonia may be used with soap or as its sub- Amm<»ia
stitute. The ammonia ordinarily used in the house-
hold is an impure article and its continued use yel-
lows bleached fabrics. The pure ammonia may be
bought of druggists or of dealers in chemical sup-
plies and diluted with two or even four parts of
water. Borax, where the alkali is in a milder form
than it is in washing soda, is an effectual cleanser,
disinfectant and bleacher. It is more expensive
than soda or ammonia, but for delicate fabrics and
for many colored articles it is the safest alkali in
1S6 THE CHEMISTRY OP
Turpentine also is valuable in removing grease.
A tablespoonful to a quart of warm water is a sat-
isfactory way of washing silks and other delicate
materials. It should never be used in hot water,
for much would be lost by evaporation, and in this
form it is more readily absorbed by the skin, caus-
ing irritation and discomfort.
Preparation for General Washing.
White goods are liable to stains from a variety
of sources. Many of these substances when acted
upon by the moisture of the air, by dust, or al-
kalies, change their character, becoming more or
less indelible; colorless matters acquire color and
liquids become semi-solid. All such spots and
stains should be taken out before the clothes are
put into the general wash to be treated with soap.
Fruii-staiiu. Fruit stains are the most frequent and possibly
the most indelible, when neglected. These should
be treated when fresh.
The juices of most fruits contain sugar in solu-
tion, and pectose, a mucilaginous substance which
will form jelly. All such gummy, saccharine mat-
ters are dissolved most readily by boiling water,
as are mucilage, gelatine and the like. To remove
them when old, an acid, or in some cases, a
bleaching liquid, like "chloride of lime*' solution or
Javelle water will be needed.
COOKING AND CLEANING. 127
Stretch the stained part over an earthen dish and
pour boiling water upon the stain until it disap-
pears. How to use the acid and the Javelle water
will be explained later on.
Wine stains should be immediately covered
with a thick layer of salt. Boiling milk is often
used for taking out wine and fruit stains.
• Most fruit stains, especially those of berries, are Uieoisui-
bleached readily by the fumes of burning sulphur. ^ "' ""**
SOg. These fumes are irritating to the mucous
membrane and care should, therefore, be taken
not to inhale them. Stand by an open window
and turn the head away. Make a cone of stiff
paper or cardboard or devote a small tin tunnel to
this purpose. Cut off the base of the paper cone,
leaving it level and have a small opening at the
apex. On an old plate or saucer, place a small
piece of sulphur, set it on fire, place over it the
cone or tunnel, and hold the moistened stain over
the chimney-like opening. Have a woolen cloth
handy to put out the sulphur flame if the piece is
larger than is needed. A burning match sometimes
furnishes enough SO2 for small spots. Do not get
the burning sulphur on the skin.
Medicine stains usually yield to alcohol. Iodine Medicine,
dissolves more quickly in ether or chloroform.
Coffee, tea and cocoa stain badly, the latter, if Tea^CoHee,
neglected, resisting even to the destruction of the
128 THE CHEMISTRY OF
fabric. These all contain tannin, besides various
coloring matters. These coloring matters are
"fixed" by soap and hot water. Clear boiling
water will often remove fresh coffee and tea stains,
although it is safer to sprinkle the stain with borax
and soak in cold water first. (A dredging box
filled with borax is a great convenience in the laun-
dry.) Old cocoa and tea stains may resist the bo-
rax. Extreme cases require extreme treatment.
Place on such stains a small piece of washing-
soda or "potash." Tie it in and boil the cloth for
half an hour. It has already been said that these
strong alkalies in their solid form cannot be al-
lowed to touch the fabrics without injury. With
this method, then, there must be a choice between
the stain and an injury to the fabric,
jaydie Water. An alkaline solution of great use and conven-
ience is Javelle water. It will remove stains and
is a general bleacher. This is composed of one
pound of sal-soda with one-quarter pound of
"chloride of lime" — calcium hypochlorite — in two
quarts of boiling water. Let the substances dis-
solve as much as they will and the solution cool and
settle. Pour off the clear liquid and bottle it for
use. Be careful not to let any of the solid portion
pass into the bottle. Use the dregs to scour un-
painted 'woodwork, or to cleanse waste pipes.
When a spot is found on a white table-cloth.
COOKING AND CLEANING. 129
place under it an overturned plate. Apply Javelle
water with a soft tooth-brush. (The use of a brush
protects the skin and nails.) Rub gently till the
stain disappears, then rinse in clear water and
finally in ammonia. "Chloride of lime" always
contains a powerful acid, as well as some free
Blood stains require clear, cold or tepid water, Blood,
for hot water and soap render the red coloring
matter less soluble. When the stain is brown and
nearly gone, soap and hot water may be used.
Meat juice on the table linen is usually com-
bined with more or less fat. This also yields most
readily to the cold water, followed by soap.
Stains. made by mucus should be washed in am-
monia before soap is added. ^ When blood is mixed
with mucus, as in the case of handkerchiefs, it
is well to soak the stains for some hours in a solu-
tion of salt and cold water — ^two tablespoonfuls to
a quart. Double the quantity of salt for heavier
or more badly stained articles. The salt has a dis-
infecting quality, and its use in this way is a wise
precaution in cases of catarrh.
Milk exposed to the air becomes cheesy, and iiak.
hot water with milk makes a substance difficult of
solution. Milk stains, therefore, should be washed
out when fresh and in cold water.
Grass stains dissolve in alcohol. If applied im- Gnn.
130 THE CHEMISTRY OF
mediately, ammonia and water will sometimes
wash them out. In some cases the following meth-
ods have proved successful, and their simplicity
recommends them for trial in cases where colors
might be affected by alcohol. Molasses, or a paste
of soap and cooking soda, may be spread over the
stain and left for some hours, or the stain may be
kept moist in the sunshine until the green color
has changed to brown, then it will wash out in
MOdev. Mildew causes a spot of a totally different char-
acter from any we have considered. It is a true
mold, and like all plants requires warmth and
moisture for its growth. When this necessary
moisture is furnished by any cloth in a warm
place, the mildew grows upon the fibres. During
the first stages of its growth, the mold may be
removed, but in time it destroys the fibres.
Strong soapsuds, a layer of soft soap and pulver-
ized chalk, or one of chalk and salt, are all effec-
tive if, in addition, the moistened cloth be sub-
jected to strong sunlight, which kills the plant
and bleaches the fibres. Bleaching powder or
Javelle water may be tried in cases of advanced
growth, but success cannot be assured.
ou- Some of the animal and vegetable oils may be
taken out by soap and cold water or dissolved in
naphtha, chloroform, ether, etc.
COOKING AND CLEANING. 131
Some of the vegetable oils are only sparingly
soluble in cold, but readily soluble in hot alcohol.
The boiling, point of alcohol is so low that care
should be taken that the temperature be not raised
to the ignition point
Mineral oil stains are not soluble in any alkaline
or acid solutions. Kerosene will evaporate in time.
Vaseline stains should be soaked in kerosene be-
fore water and soap touch them.
Ink spots on white goods are the same in charac- ink.
ter as on colored fabrics. Many of the present inks
are made from aniline or allied substances instead
of the iron compounds of the past Aniline black
is indelible; the colored anilines may be dissolved in
alcohol. Where the ink is an iron compound the
stain may be treated with oxalic, muriatic or hot
tartaric acids, applied in the same manner as for
iron-rust stains. No definite rule can be given, for
some inks are affected by strong alkalies, others by
acids, while some will dissolve in clear water.
The present dyes are so much more stable than •
those of twenty-five years ago, that pure lemon
juice or a weak acid like hydrochloric, has no effect
upon many colors. Any acid should, however, be
applied with caution. If the color is affected by
acids, it may often be restored by dilute ammonia.
The red iron-rust spots must be treated with acid. R«* i««»-
These are the result of true oxidation — ^the union
132 THE CHEMISTRY OF
of the oxygen of the air with the iron in the pres-
ence of moisture. The salt formed is deposited
upon the fabric which furnishes the moisture. Or-
dinary "tin'' utensils are made from iron coated
with tin, which soon wears off, so no moist fabric
should be left long in tin unless the surface is entire.
Iron-rust is, then, an oxide of iron. The oxides
of iron, copper, tin, etc., are insoluble.. The chlor-
ides, however, are soluble. Replace the oxygen
with the chlorine of hydrochloric acid and the iron
compound will be dissolved. The method of apply-
ing the acid is very simple.
Fill an earthen dish two thirds full of hot water
and stretch the stained cloth over this. Have near
two other dishes with clear water in one and am-
monia water in the other. The steam from the hot
water will furnish the heat and moisture favorable
for chemical action. Drop a little hydrochloric
(muriatic) acid, HCl, on the stain with a medicine
dropper. Let it act a moment, then lower the cloth
into the clear water. Repeat till the stain disap-
pears. Rinse carefully in the clear water and,
finally, immerse in the ammonia water that any ex-
cess of acid may be neutralized and the fabric pro-
Salt and lemon juice are often sufficient for a
slight stain, probably because a little hydrochloric
acid is formed from their union.
COOKING AND CLEANING, 133
Many spots appear upon white goods which re- Bitti*«-
semble those made by iron-rust, or the fabrics
themselves acquire a general yellowish tinge. This
is the result of the use of bluing and soap, where
there has been imperfect rinsing of the clothes.
The old-time bluing was pure indigo. This is in-
soluble, but, by its use, a fine blue powder was
spread among the fibres of the cloth. It required
careful manipulation, which it usually had. Indigo
with sulphuric acid can be made to yield a soluble
paste. This is the best form pi bluing which can
be used, for a very little gives a dark, clear blue to
water, and overcomes the yellowish tinge which
cotton or linen will acquire in time unless well
bleached by sunshine. The expense and difficulty
of obtaining this soluble indigo has led to the sub-
stitution of numerous solid and liquid "blues" by
the use of which the laundress is promised success
with little labor. Most of these liquid bluings con-
tain some iron compound. This, when in contact
With a strong alkali, is broken up and the iron is
precipitated. If, then, bluing be used where all the
soap or alkali has not been rinsed from the clothes,
this decomposition and precipitation takies place,
and a deposit of iron oxide is left on the cloth. This
must be dissolved by acid like any iron-rust.
Some "blues" are compounds of ultramarine, a
brilliant blue silicate of aluminum. These are gen-
184 THE CHEMISTRY OF
erally used in the form of a powder which is insol-
uble, settles quickly and, thereby, leaves blue spots
or streaks. It is very difficult to prevent these when
insoluble powdered "blues'' are used. This silicate
combined with hydrochloric acid forms a jelly-like
mass from which a white precipitate is formed.
These ultramarine blues are sometimes recom-
mended because of this white precipitate, obviating,
as is said, the yellowish results of careless rinsing,
inevitable when iron "blues" are used. The advice
is misleading, for no precipitate is formed unless an
acid be added.
When solid bluing is used it should be placed in
a flannel bag and stirred about in a basin of hot
water. In this way only the finest of the powder is
obtained. After this blued water is poured into the
tub, it must be continually stirred, to prevent the
powder from settling in spots or streaks upon the
Bleaching. First, then, the removal of all dirt, and second,
the removal, by thorough rinsing, of all soap or
other alkalies used in the first process, and third,
long exposure to air and sunshine should render
the use of bluing unnecessary. The experience of
many shows that clothes that have never beea
blued, never need bluing. In cities where conveni-
ences for drying and bleaching in the sunshine are
few, and where clear water or clear air are often un-
COOKING AND CLEANING, 135
attainable, a thorough bleaching two or three times
a year is a necessity ; but in the country it is wiser to
abolish all use of bluing and let the great bleacher,
the sun, in its action with moisture and the oxygen
of the air, keep the clothes white as well as pure.
Freezing aids in bleaching, for it retains the
moisture, upon which the sun can act so much the
longer. The easiest household method of bleach-
ing where clean grass, dew and sunshine are not
available, is by the use of "bleaching powder." In
the presence of water and weak acids, even carbonic
acid, oxygen and chlorine are both set free from
the compound. At the moment of liberation the
action is very powerful. The organic coloring mat-
ters present are seized upon and destroyed, thereby
bleaching the fabric.
Directions for the use of the powder usually ac-
company the can in which it is bought. The woman
who knows that the acid always present in the pow-
der must be completely rinsed out or neutralized
by an alkali, may use her bleaching powder with
safety and satisfaction.
All special deposits should be removed before G«nerai
the general cleansing of the fabric is undertaken.
Grease and other organic matters are the undesir-
able substances which are to be disposed of in the
general cleansing. Grease alone is more quickly
acted upon by hot water than by cold, but other
186 THE CHEMISTRY OF
organic matter is fixed by the hot water. ' There-
fore, while hot water melts the grease quickly, the
mixture may be thus spread over the surface and
may not be removed by the soap.
An effective method, proved by many housewives '
of long experience, is to soap thoroughly the dirti-
est portions of the clothes, fold these together
toward the center, roll the whole tightly, and soak
in cold water. The water should just cover the
articles. In this way the soap is kept where it is
most needed, and not washed away before it has
done its work. When the clothes are unrolled the
dirt may be washed out with less rubbing.
Too long soaking when a strong soap is used,
which has much free alkali, would weaken the fab-
ric. Judgment, trained by experience must guide
in such cases, so that effective cleaning depends
upon careful manipulation.
"<**■«• Whether to boil or not to boil the clothes de-
pends largely upon the purity of the materials used
and the degree of care exercised. Many persons
feel that the additional disinfection which boiling
ensures is an element of cleanness not to be disre-
garded; others think it unnecessary under ordinary
conditions, while others insist that boiling yellows
" Yeiiownci./' Th^ causcs of this yellowness seem to be:
COOKING AND CLEANING. 137
Impure materials in the soap used;
The deposition, after a time, of iron from the
water or the boiler;
The imperfect washing of the clothes — ^that is,
the organic matter is not thoroughly removed.
The safest process seems to be to put the clothes
into cold water with little or no soap, let the tem-
perature rise gradually to the boiling point and
remain there a few minutes.
Soap is more readily dissolved by hot water than
by cold, hence the boiling should help in the com-
plete removal of the soap and may well precede the
Borax — ^A tablespoonful to every \gallon of
water — added to each boilerful serves as a bleacher
and an aid in disinfection. The addition of the
borax to the last rinsing water is preferred by
many. In this case, the clothes should be hung out
quite wet, so that the bleaching may be thorough.
"Scalding," or the pouring of boiling water over Scalding,
the clothes is not so effectual for their disinfec-
tion as boiling, because the temperature is so
The main points in laundry cleansing seem to Necessities
be : Cleansing,
The removal of all stains;
Soft water and a good quality of soap;
The use of strong alkalies in solution only;
THE CHEMISTRY OF
Not too hot nor too mtich water while the soap
is acting upon the dirt; much water to wash in;
Thorough rinsing, that all alkali may be re-
moved; and that no dirty water remain:
Long exposure to sunlight — ^the great bleacher
The fibres of cotton, silk and wool vary greatly
in their structure, and a knowledge of this struc-
ture, as shown under the microscope, may guide
to proper methods of treatment.
The fibres of cotton, though tubular, become
much flattened during the process of manufacture,
and under the microscope show a characteristic
twist, with the ends gradually tapering to a point
It is this twist which makes them capable of being
made into a firm, hard thread.
The wool fibre, Hke human hair, is marked by
transverse divisions, and these divisions are ser-
rated. These teeth become curled, knotted or
tangled together by rubbing, by very hot water, or
by strong alkalies. This causes the shrinking which
should be prevented. When the two fibres are
mixed there is less opportunity for the little teeth
to become entangled and, therefore, there is less
Linen fabrics are much like cotton, with slight
notches or joints along the walls. These notches
serve to hold the fibres closely together and enable
COOKING AND CLEANING, 139
them to be felted to form paper. Linen, then, will
shrink, though not so much as wool, for the fibres
are more wiry and the teeth much shorter.
Silk fibres are perfectly smooth, and when siik.
rubbed, simply slide over each other. This pro-
duces a slight shrinkage in the width of woven
All wool goods, then, require the greatest care washinRoi
^nr oolc lis*
in washing. The different waters used should be of
the same temperature, and never too hot to be
borne comfortably by the hand.
The soap used should be in the form of a thin
soap solution. No soap should be rubbed on the
fabric, and only a good white soap, free from rosin,
or a soft potash soap, is allowable. Make each
water slightly soapy and leave a very little in the
fabric at the end, to furnish a dressing as nearly
like the original as possible.
Many persons prefer ammonia or borax in place
of the soap. For pure white flannel, borax gives the
best satisfaction, on account of its bleaching qual-
ity. Whatever alkali is chosen, care should be ex-
ercised in the quantity taken. Only enough should
be used to make the water very soft.
The fibres of wool collect much dust upon their
tooth-like projections, and this should be thor-
oughly brushed or shaken off before the fabric
is put intQ the wat^r. AH friction should be by
140 THE CHEMISTRY OF
squeezing, not by rubbing. Wool should not be
wrung by hand. Either run the fabric smoothly
through a wringer or squeeze the water out, that
the fibres may not be twisted. Wool may be well
dried by rolling the article tightly in a thick dry
towel or sheet and squeezing the whole till all
moisture is absorbed. Wool should not be allowed
to freeze, for the teeth will become knotted and
Linen, like wool, collects much dirt upon the
surface which does not penetrate the fabric. Shake
this off and rub the cloth as little as possible.
Linen or woolen articles should not be twisted in
the drying process, as it is sometimes impossible
to straighten the fibres afterward.
Setting of Colored cottons should have their colors fixed
before washing. Salt will set most colors, but the
process must be repeated at each washing. Alum
sets the colors permanently, and at the same time
renders the fabric less combu3tible, if used in
strong solution after the final rinsing.
Very Dirty Dish cloths and dish towels must be kept clean
as a matter of health, as well as a necessity for
clean, bright tableware. The greasy dish cloth
furnishes a most favorable field for the growth
of germs. It must be washed with soap and hot
water and dried thoroughly each time. All such
cloths should also form a part of the weekly
COOKING AND CLEANING,
wash and be subjected to all the disinfection pos-
sible, with soap, hot water and long drying in sun-
shine and the open air. Beware of the disease-
breeding, greasy and damp dish cloth hung in a
warm, dark place!
Oven towels, soiled with soot and crock, may be
soaked over night, or for some hours, in just kero-
sene enough to cover, then washed in cold water
With very dirty clothes or for spots, where hard
rubbing is necessary, much strength may be saved
by using a scrubbing brush.
Laundry tubs should be carefully washed and
dried. Wooden tubs, if kept in a very dry place,
and turned upside down, may have the bottoms
covered with a little water.
The rubber rollers of the wringer may be kept
white by rubbing them with a clean cloth and a
few drops of kerosene.
All waste and overflow pipes, from that of the
kitchen sink to that of the refrigerator, become
foul with grease, lint, dust, and other organic mat-
ters that are the result of bacterial action. They
are sources of contamination to the air of the en-
tire house and to the food supply, thereby endan-
gering health. All bath, set-bowl and watei closet
pipes should be flushed generously once a day, at
least, the kitchen sink pipe with clear boiling
1^ THE CHEMISTRY OP
water; and once a week all pipes should have a
thorough cleaning with a strong boiling solution
of washing-soda and a monthly flushing with caus-
tic potash. The plumbers recommend the "stone"
or crude potash for the kitchen pipe. This is
against their own interests, for many a plumber's
bill is saved where the housewife knows the dan-
ger and the means of prevention of a grease-coated
sink drain. The pipe of the refrigerator should be
cleared throughout its entire length with the soda
solution. Avoid any injury to the metallic rims of
the waste pipes by using a large tunnel.
Old-fashioned styles of overflow pipes retain a
large amount of filth, and it is very difficult to dis-
lodge it A common syringe may be devoted to
this purpose. By its patient, frequent use even this
tortuous pipe may be kept clean.
g2^^ Ideal cleanness requires the cleanness of the in-
dividual, of his possessions, and of his environ-
ment. Each individual is directly responsible for
his personal cleanness and that of his possessions;
but over a large part of his environment he has
only indirect control. Not until direct personal
responsibility is felt in its fullest sense, and exer-
cised in all directions toward the formation and
carrying out of sufficient public laws, will sanitary
COOKING AND CLEANING.
cleanness supplant the cure of a large number of
diseases by their ^prevention.
Many of the diseases of childhood are directly
traceable to uncleanness, somewhere. By these dis-
eases the system is often so weakened that others
of different character are caused which, though
slow in action, may baffle all science in their cure.
The necessity of forming systematic habits of
cleanness in the young is the first step toward sani-
tary health. They should, then, step by step, as
they are able to grasp the reasons for the habits,
be educated in all the sciences which give them
the knowledge of the cause and effects of un-
cleanness, the methods of prevention and removal,
and the relation of all these to building laws and
The first environment to be kept clean is the
home. But personal cleanness and household
cleanness should not be rendered partially futile by
unclean schoolhouses, public buildings and streets.
The housekeeping of the schoolhouses, especially,
should be carried on with a high regard to all
hygienic details, since here the degree of danger
•is even greater than in the home. In public
schoolhouses the conditions favorable to the pres-
ence of disease germs abound. If present, their
growth is rapid, and the extent of contagion be-
yond calculation. The cooperation of all most in-
144 COOKING AND CLEANING,
terested — ^pupils and teachers — should be expected
and required as firmly as their cooperation in any
other department of education.
Public Qewi. The sanitary condition of every school building
should be a model object lesson for the home; then,
instruction in personal cleanness will carry the
weight of an acknowledged necessity.
Schoolhouses which are models of sanitary clean-
ness will cause a demand for streets and public
conveyances of like character; then a// public build-
ings will be brought under the same laws of evi-
Not till the right of cleanness is added to the
right to be well fed, and both are assured to each
individual by the knowledge and consent of the
whole people, can the greater gospel of prevention
make good its claims.
Chemicals and Their Use in the Household.
EVERY woman, whether she knows it or not, SSSiSLts
is every day performing simple experi- «>theHome.
ments in chemistry. Every match that is lighted,
every use of soap on the body, the clothes or the
utensils, depends upon chemical laws for the
reactions which take place.
There is no process of cooking or cleaning
that does not rest upon a foundation of chemical
or physical law. Therefore every house is a
laboratory. Each is presided over by a director
of greater or less intelligence.
When intellectual interest and manual dex-
terity unite, "drudgery" is eliminated.
There may be, too, at all times an attitude of
discovery. Many of the most important chem-
ical processes have been found out, it is said,
In most persons an experiment awakens in-
terest. The housewife should be a cautious
An understanding of simple chemical reac-
tions tends also to economy in household
146 THE CHEMISTRY OF
The thrifty housewife may not only save many
dollju-s by restoring tarnished furniture and
stained fabrics, but may also keep her belongings
fresh and "as good as new" by the judicious use
of a few chemical substances always ready at her
It is essential, however, that she know their
properties and the effect they are likely to have
on the materials to be treated, lest more harm
than good result from their use. A good exam-
ple is the instant disappearance of all red iron-
rust stains when treated with a drop of hydro-
chloric acid. If, however, the acid is not com-
pletely washed out, the fabric will become eaten,
and holes will appear, which, in the housekeeper's
eye, are worse than the stains. This danger may
be entirely removed by adding ammonia to the
final rinsing water, which neutralizes any remain-
ing acid, and the stained tray-cloth or sheet is
It is well that the household laboratory should
be supplied with the following substances. Not
all of these are strictly chemicals, but they are
included by courtesy, as it were, because so
closely connected with the chemical reactions.
Many of them act only mechanically.
Ail^aiies. I. Alkalies — substances with a soapy feeling
and which turn red litmus blue. In solutions
COOKING AND CLEANING. 147
they neutralize the effects of acids. When the
neutralization is complete the solution is said to
be neutral, and it will not change the color of
litmus. This neutral substance is a chemical
Alkalies, except ammonia, injure wool fibres,
hardening, roughening and shrinking them,
while the caustic alkalies dissolve them. Only
weak alkalies should be used on linen or silk.
I. Potassium hydroxide, KOH, caustic pot- Caustic PotMh.
ash. This can be bought in solid form to use in
drains for removing grease. It forms a soap,
which must be washed out of the pipes by thor-
ough flushing. It is one of the strongest alkalies
and must be used with caution. It is dissolved
in water with the evolution of great heat, caus-
ing rapid boiling. Spatters from it on fabrics
are liable to burn holes, on wood will darken the
color, and on the flesh may cause deep burns.
When got upon the flesh or upon fabrics it
should be quickly washed off and, if necessary,
treated with vinegar. It is usually bought in
cans as "concentrated lye."* It combines with
fat to make soft soap.
Potassium is a common ingredient of inland
vegetation. Caustic potash is derived from wood
ashes. By adding water to wood ashes, potash
* Today, however, this is more often caustic soda iYan /tftasA,
148 THE CHEMISTRY OF
(carbonate of potash) is dissolved and the result-
ing liquid, lye, may be used for purposes of
Many a country housewife "sweetens" the
tainted pork barrel, the butter firkin or pie plate
by soaking or boiling it with wood ashes. Ran-
cid fats are acid. This acidity can be neutral-
ized by the alkali.
Potash is often used to soften paint, shellac
and other woodwork finishes, to facilitate their
removal before refinishing. This has the disad-
vantage that the wood is darkened by the alkali
and the grain is raised.
Caustic Soda. 2. SodiufH hydroxidc, NaOH, caustic soda.
This compound resembles caustic potash, is ef-
fective in slightly less degree for the same pur-
poses; and, being cheaper, is much more exten-
sively used. The element sodium is common in
all marine and seashore plants, aiid is the metal
in common salt, from which it is now prepared.
Soda Ash. 3. Sodiuffi carbofiate, NagCOg, soda-ash
(originally from the ashes of seaweed). When a
hot solution of soda-ash is cooled, a crystalline
form is left known as sal-soda, washing soda,
soda crystals. The crystals lose water when ex-
posed to the air and crumble to powder. This
powder is, therefore, stronger than the crystals.
Sal-soda is used most commonly in softening
COOKING AND CLEANING. 140
hard water, for keeping the plumbitig pipes free
from grease and to remove grease and hardened
food from cooking utensils. A convenient way
to prepare sal-soda for general use is to put one
pound of the ash in one quart of water. Let
this boil until the soda is dissolved. Bottle when
cold. It is the second strongest alkaline cleaner,
cheaper and more safely used than potash.
4. Sodium bicarbonate, NaHCOg, cooking Cooking soda.
soda, carbonated soda-ash. In cooking it is used
to neutralize acids, to aerate dough and to pro-
duce effervescence in acid solutions by liberating
carbon dioxide. This is the saleratus of today.
The true saleratus or "pearlash" used seventy-
five years ago was the corresponding potassium
salt, KHCOg. This was often obtained by burn-
ing corncobs, mixing the ashes with water and
allowing the solution to evaporate to dryness.
In cleaning, sodium bicarbonate gives a mildly
alkaline action when dissolved in water. With
kerosene it is nearly insoluble and therefore
gives a soft friction. Used in this way it is
effective in scouring plumbing fixtures, where
the insoluble whiting might clog the pipes. For
cleaning purposes, the choice between borax and
bicarbonate would be one of their relative cost.
5. Borax, Na2B404. A weakly alkaline sub- Borax,
stance, most useful with hard water, as a
150 THE CHEMISTRY OF
bleacher and* as an antiseptic. It is much more
expensive than sal-soda, but is less liable to injure
fabrics and to irritate the skin. Its action on
colors is less than that of ammonia.
Ammonui. 6. Ammofiia. The gas NH, is dissolved in
water in varying proportions, forming ammo-
nium hydroxide, or aqua ammonia, NH^OH. It
is the only volatile alkali. It is a useful sub-
stance in nearly all cleaning processes, and to
"Household ammonia" is subject to impurities
due to processes of manufacture. These often
fade colors or cause white materials to turn yel-
low. It is safer and cheaper to buy the concen-
trated ammonia from a druggist or a dealer in
chemicals and add the water at home. This con-
centrated ammonia may be diluted one-half to
one-sixth and yet be sufficiently strong for most
It loses strength rapidly when open to the air,
therefore it should be bought in quantities pro-
portioned to its use, diluted one-half or more
and kept carefully corked. A glass stopper is
best, although rubber will serve. Cork is acted
upon by the fumes and will color the ammonia.
If the glass stopper tends to stick, it may be kept
slightly smeared with vaseline.
Ammonia should not be used on brass or
COOKING AND CLEANING. 161
copper, as it eats them rapidly. It discolors
aluminum; but the resultant compound is not
7. Soaps, Hard soap is sold in small cakes, ^***p*'
fthavings or powder; soft soap in semi-liquid,
or liquid soap solutions. There are many grades
from those that are neutral, like the best toilet
soaps, to those that have much free alkali. The
free alkali hastens the action, but is injurious to
the skin and to many other materials. Soap and
water has a greater solvent power than water
8. Ox-gall, the liquid contents of the gall- Ox-oaii.
bladder of beef creatures, is a natural soap. It
is excellent for cleaning colored fabrics. It may
be used clear or with tepid water. It decomposes
readily and, therefore, must be used while fresh.
II. Acids — substances with a sour taste and Add*,
which change blue litmus red. An acid will also
liberate carbon dioxide from cooking or washing
s6da. In general, weak acids lighten the color
of wood, while strong acids burn it. Acids act
injuriously on all metals if allowed to remain in
cbntact with them. The metallic salts that are
formed are often very poisonous.
When used with caution acids are effectual in
removing iron and fruit stains. They remove
color from some fabrics.
162 THE CHEMISTRY OF
Dilute, cold, acid solutions do not readily in-
jure cotton or linen, while hot, strong solutions
injure the fibre. No acid should be allowed to
dry upon cloth.
Acetic Add. I. Acctic add, C2H4O2, is the acid of vinegar
and for many purposes it may be used in this
form. For delicate processes, however, the other
substances present may stain or interfere with
the action, so that the pure acetic acid, much
diluted, is better. It is volatile, therefore any
excess is not likely to injure the fabric by con-
centration in it on drying, as will hydrochloric
and oxalic acids. While acids clean copper and
brass quickly by combining with the tarnishing
salts, thus exposing a fresh surface, this new
surface soon tarnishes again, and the process
must be repeated. .If any acid remains, as it is
likely to do in seams and grooves, metallic salts
will be formed. Copper acetate, which is formed
when- brass or copper is treated witb vinegar, is
^5k Acids Sour milk contains lactic acid; lemons, citric
acid, and this is perhaps the best natural acid to
use for cleaning purposes. It should be used
with caution, however, as it is strong enough to
affect some colors and reacts with metals, as
copper, brass and iron. Rhubarb, tomatoes, sor-
rel, etc., contain acid principles. They can be
COOKING AND CLEANING. 163
used in emergencies and are less liable to "eat"
2. Oxalic acid, H2C2O4, is found naturally in oxaiicAdd.
some plants, as oxalis and sorrel. It is bought
in crystals, which are quickly soluble in hot and
more slowly in cold water. It is very useful in
removing stains from white fabrics and may be
used on some colors (any acid to be used, on
colored fabrics should be tested first on a piece
of the goods or on some hidden part, as a seam).
Hot solutions of oxalic acid are more effective
than cold. When very strong it makes the finger
nails brittle and may irritate the skin tempo-
rarily. It must be labeled "Poison," and should
be kept out of the reach of children.
Note.— The strong acids destroy the coats of the stomach and there-
fore are poisonous in a general sense, although not in the strict sense in
which strychnine is.
3. Tartaric acid, H2(C4H406), the acid of Tartaric Acid,
.cream of tartar, and prepared from it by treat-
ment with milk of lime, is one of the safest acid
agents. The Rochelle salt of Seidlitz powders
is a sodium potassium tartrate. In "soda pow-
ders" one paper contains tartaric acid, the other
sodium bicarbonate. The crude tartar or argol
is formed as a hard crust or deposit on the
bottom and sides of vessels in which wine is
4. Hydrochloric or muriatic acid, HCl, most ^5?^**^°"*^
164 THE CHEMISTRY OF
valuable for removing iron stains from fabrics
and other materials. It sometimes injures silk
and must be used with caution on colored goods.
A twenty per cent solution is effective, but it will
lose its strength unless very tightly corked with
glass or rubber. The fumes escaping around the
stopper will rust metals and "eat" fabrics even
at some distance.
Whenever this acid is used there should be
thorough rinsing of the fabric in water, prefer-
ably warm, and then neutralization in ammonia.
Bleachers. jn, Blcachers. These are sometimes used
to remove color from colored fabrics, but more
often to remove the yellow or brownish discol-
oration from fabrics which are naturally yellow
or which were originally white.
Sometimes the action is the result of adding
oxygen to the coloring matter; sometimes it
takes oxygen away. In both cases colorless com-
pounds are left, and in both cases moisture is
Sunshine. The bcst blcachcr is sunshine with moisture.
The action here is very complex, resulting in the
formation of ozone, but there is never any harm
to the fabric. The best way of using "Nature's
bleach" is to spread the fabrics on the grass, wet
them frequently with soapy, or better with borax
or ammonia water, leave out over night for the
COOKING AND CLEANING. 155
dew to form on them, turn occasionally that all
parts may be acted upon, and continue this until
the desired whiteness is reached.
In "dog days," however, the fabrics must be
carefully watched, else they will mildew.
The best time for grass bleaching is during the
long days of June.
If grass is not available, any other means by
which the wet cloth can be exposed to direct sun-
shine will answer. The wet, yellow handkerchief
or lace may be kept by the sunny window until
Cloth laid on the snow bleaches fairly well.
When clothes freeze the moisture is retained so
much longer that even in. the short, sunny days
of winter considerable bleaching may be done.
All bleaching with chemicals is attended with
danger to the fibre ; but it is so much more rapid
and so convenient a method that not only its
dangers should be understood, but also how to .
When the chemical has completed its action
with the coloring matter, it attacks the fibre
unless quickly removed.
I. Hydrogen peroxide, HgOj, may be pur- Hydrogen
chased as a five per cent liquid. This is a power-
ful oxidizing agent. It loses the extra atom of
oxygen readily and should be kept in a dark place,
preferably closed with a rubber stopper.
THE CHEMISTRY OF
It may be safely used with all fibres, being
especially good for wool. The bleaching action
It is an excellent disinfectant for wounds, sore
2. Sulphur dioxide, SOg, is made by burning
sulphur in the air. With moisture the dioxide
forms sulphurous acid, H2SO3.
This is effective on moist silk, wool, straw and
paper. The fumes should not be breathed. The
country housewife attaches the wet, yellowed
straw hat to the bottom of a barrel, which is
then inverted over a small kettle of coals and
This is much less destructive to the fibre than
chloride of lime, but the color often returns.
The fumes from a burning match held under
the wet hand will remove the purple stains left
from black kid gloves. They are also very effect-
ive for blueberry and blackberry stains.
The common sulphur candle is a convenient
means of obtaining sulphur fumes. They may
be readily concentrated by inverting over the
candle a paper, cardboard or other funnel.
3. Calcium hypochlorite is called bleaching
powder and "chloride of lime." Its composition
is not definitely known, but approximately is
given as CaOClg. A similar compound is some-
COOKING AND CLEANING. 167
times called "chlorinated lime/' (Chlorinated
soda is also on the market.)
When treated with acids this gives off chlorine,
freely. The carbon dioxide in the air liberates
it slowly, so that its very presence in the house
(or its use as a deodorizer or disinfectant) is a
prolific source of rust and deterioration of cotton
and other fabrics.
Whether used for general bleaching or in the
removal of stains, thorough rinsing and neutral-
ization in ammonia water must follow, else the
fabric will suffer.
4. Javelle water y really sodium hypochlorite, JaveiieWata;
is a .compound made by mixing "chloride of
lime" and sodium carbonate. It is excellent
for the treatment of old or obstinate stains as
well as a general bleach. Ammonia or sodium
hyposulphite should be used afterwards.
5. Sodium thiosulphite — called also hyposul- Hyposulphite,
phite, NajSgOg + 5H2O, the "hypo" of the pho-
tographer — is especially effective in removing
the marks of indelible ink containing silver
6. Borax (see page 149). ^*"^*-
IV. Solvents. For grease there are naphtha, Solvents.
benzine, gasoline, ether, chloroform, extremely
volatile; kerosene, turpentine, carbon tetrachlo-
ride, coal tar benzine (C^He) , alcohol less volatile.
158 THE CHEMISTRY OF ..
The vapors of all these substances are heav-
ier than air, therefoi-e sink. They should be used
out-of-doors or by an open window, and never
where there is any Are. There should be a cur-
rent of air near the floor to ensure quick removal
of 'the vapor.
Turp«itine is a resinous oil which serves as a
solvent for paint, grease, tar and wax. Mixed
with oil, preferably boiled linseed, it makes the
best general furniture polish. It cleans more
readily than kerosene, but does not give so good
a polish. It removes ink stains from polished
woods, from which it usually removes the gloss
and should be followed by oil and hard rubbing.
It will remove some inks from colored fabrics.
In the laundry it tends to whiten clothes. When
fresh it is clear and has little odor. When ex-
posed to the air it takes up oxygen, darkens and
thickens. This should not be used on fabrics, as
it will itself stain.
The vapors of chloroform and carbon tetra-
chloride are non-inflammable and non-explo-
sive. These, like ether, should be used where
there is a good draft, as they produce anaesthesia.
Chloroform is least likely to injure colors,
although ether is usually safe.
Oiii. V. Oils. The most common vegetable oils
are raw and boiled linseed, sweet or olive and
COOKING AND CLEANING, 159
cottonseed. They are all good for polishing
woodwork and metals, for softening and bright-
ening leather (particularly olive oil), to imbed
frictional materials, as emery for iron, rotten-
stone or tripoli for brass and copper; to soften
pitch, tar, etc.
Mineral oils are kerosene, an excellent cleaner,
a good polisher, a solvent of vaseline, an insecti-
cide; and paraffin oil — less odorous than kero-
sene but a little more expensive. Mixed with
turpentine in equal parts it makes an excellent
furniture polish for very light-colored woods
when the linseed oil, which is usually used, might
darken them too much; coal tar benzine, CeH^,
is excellent for removing grease, pitch and resin.
VI. "Alcohols." Ethyl "alcohol, CgH^OH, AicohoU.
" grain .alcphol," is valuable for removing stains.
"Wood alcohol," CH3OH, is less effective and is
poisonous when taken internally. It should
therefore be labeled " Poison."
Denatured alcohol may or may not be effective
for use on fabrics, according to the foreign ^
substances which have been added.
Alcohol dissolves shellac and turns varnish
and wax white. White stains on shellaced wood
are removed by gentle tapping with a bit of
flannel cloth wet in alcohol.
VII. Stiffening Agents. Starch is obtained 5^^f^jy"«
160 THE CHEMISTRY OF
from many plants, but chiefly for laundry uses
from corn, wheat and rice. Potatoes and sago
also furnish it. Wheat starch is most satisfac-
. tory for general purposes. It gives a more flex-
ible stiffness and smoother surface than corn
Storch. Rice starch is excellent for delicate work, as
fine dress goods and laces. As was shown in the
previous pages, uncooked starch is not soluble in
In cold starching the spaces between the
threads of the fabrics are filled and the surface
coated with the fine powder. The heat of the
iron with the moisture brings about the change
of condition and great stiffness results.
It is better for general stiffening purposes to
cook starch thoroughly before apply-ing it to
the fabric. As this cooking may caramelize a
part, making it slightly yellow, a very little blu-
ing may be added to counteract it. Thoroughly
cooked starch should not stick to a hot iron ; but
a little turpentine, wax or paraffin added helps
the iron to slip over the surface more readily
and adds some gloss.
A little borax in the starch preserves the stiff-
ness of starched articles when they are exposed
to dampness, as at the seashore.
Starched articles should not freeze before
COOKING AND CLEANING. 161
Prepared starches are sometimes made soluble
by treatment with acids. These frequently affect
the color of colored fabrics upon whi^h they are
Some also have borax or other alkali combined
with them, and these also change colored fabrics.
Blues, pinks and greens seem to be most sus-
ceptible to these changes. If a blue is turned
pinkish it may be well to add a little ammonia or .
borax to the starch; if pink is turned blue, add
a little acid — clear vinegar or lemon juice. Per-
haps the safer way is better, i, e,, to use only the
starch bought in bulk.
Gum arable, sugar, glue and gelatine are all other Agents,
valuable for stiffening thin, delicate fabrics.
Black laces, straw hats and ribbons are often
stiffened sufficiently by rinsing them in alcohol
and water. This slightly dissolves the still
VIII. Bluings. These substances are used to Bluings,
counteract or cover by their blue color the yel-
lowness which results from imperfect washing or
rinsing; from too much or too strong alkali;
from iron in the water ; or from the action of the
air or the absence of light, as when fabrics are
unused and stored in dark places. Blue and
yellow, however, do not make white. The color
which results from the use of bluing varies from
gray to green or blue when compared with white.
162 THE CHEMISTRY OF
The bluings, act either mechanically by leaving
a fine, impalpable powder among the meshes as
ultramarine, or by a tint absorbed -by the fibre
from the blue solution.
The public laundries use almost exclusively an
aniline blue. This may be purchased solid or
liquid and is a real dye. It requires an acid
medium before it will set, and too many times
this acid injures the fabrics. As it is a dye, it is
difficult to remove the effects when too much is
A good blued water is excellent for preserving
the original color of blue fabrics. It also im-
proves the appearance of dull or blue-black
Frictionai IX. Frictioual Materials. These do not act
chemically, but are important agents in the proc-
esses of cleaning and preservation. They may
be combined with soap, oils or other substances
into solid or paste-like form.
The best of the frictionai materials are whit-
ing, silicon, rouge, rotten-stone, tripoli, emery,
pumice and common sand of various degrees of
coarseness. Coal ashes, sifted, make an excellent
The commercial, prepared forms are often
more convenient for use, but much more expen-
sive; and any undesirable, sharp, gritty parti-
COOKING AND CLEANING. 163
cles, which would scratch or mar the article
scoured, might not be detected until the injury
occurred. Again the temptation is strong to put
into these manufactured materials substances
which will "take hold quickly/' or "do the work
in half the time," and these are apt to be injuri-
ous to the articles cleaned.
X. Absorbent Materials. Pipe clay, Fuller's ^;^^
earth, French chalk, are perhaps the best.' It
should be remembered that starch, flour, meal,
sawdust, blotting paper and similar materials
have much absorbent power. These extract
liquids mechanically and therefore do not affect
XL Miscellaneous: i. Alum, a crystalline Aium.
double salt of potassium and aluminum. It is
used for clearing water from suspended organic
matter by coagulation, for "fixing" colors and
for making cotton fabrics less inflammable.
For the laundry, two ounces of alum to a
gallon of water is sufficient. Less than this will
set most colors.
Sugar of lead, lead acetate, fixes colors,
but it is a strong poison and its use is not
2. Litmus paper is convenient for testing Litmus Paper,
solutions, either for acidity or alkalinity. The
red paper will give a rough test of free alkali if
164 THE CHEMISTRY OF
it be moistened and laid on soap ; the blue paper
for acid, on bread dough, etc.
One piece may be used alternately in acid and
alkaline solutions an indefinite number of times,
sdt 3. Sodium chloride, NaCl, common salt, is
used as a condiment, an antiseptic; for friction
and absorption; to remove silver sulphide (see
p. 112); in the laundry for fixing colors tem-
porarily and to aid in removing red wine, blood
and iron-rust stains.
Its action in setting colors is chiefly in decreas-
ing the solvent power of the water.
New goods, liable to fade, should be rinsed in
it before being washed with soap.
Antiseptics, Disinfectants, Insecticides
FUNDAMENTALLY and ordinarily clean-
ness depends upon the prevention or re-
moval -of unclean conditions — both the presence
of the living agents and that of the organic
matter on which they feed. Rosenau says:
"While the old idea that filth and unsanitary
conditions breed disease de novo is wrong, it is
nevertheless true that these conditions keep
the infectious principles alive and favor their
When infectious material is present, danger
is imminent and safety may require that the
living agents be destroyed that they be not
If their growth can be prevented, a measure Antisepsis,
of safety is attained. This is the condition of
antisepsis. It is brought about by producing
unfavorable conditions of growth. For this pur-
pose positive or negative means may be em-
ployed. The addition of sugar in preserves
lessens the air and water supply of the ferments ;
lea THE CHEMISTRY OF
salt withdraws moisture; drying by any means,
as the admission of sunlight and fresh air —
these are all antiseptic measures. Or, substances
may be applied which will retard or prevent the
growth of the germs. These are called antisep-
tics; soap, salt, strong acids, essential oils,
smoke, all act in this manner. Weak solutions
of substances which when strong will kill the
germ usually prevent or retard its action. Boric
acid is one of the best of the chemical antiseptics.
But this is only partial immunity. Safety re-
quires that the living agent of infection be killed.
This is the office of disinfection. Substances
which kill disease germs are called disinfectants.
All disinfectants are germicides. Sterilization
means the absence of all life, whether by proc-
esses of removal or death. This is a much
broader term than disinfection. Disinfectants
may kill the pathogenic forms, while many harm-
less ones remain. Sterilization would affect all.
This is seldom necessary. The state of asepsis
is equivalent to sterilization.
An ideal disinfectant will destroy the patho-
genic germs without injury to the infected mate-
rial. This may be difficult to find, as no one
agent is applicable either to all germs or to all
materials'. Direct sunshine is Nature's best and
cheapest disinfectant. It will, however, fade
COOKING AND CLEANING. 167
color; but this should not be considered where
infectious material is liable to be present. It
destroys the superficial spores as» well as the
active forms; but cannot penetrate opaque ob-
jects, and not deeply into solutions. It is most
effective, then, on surfaces.
Dry heat, 300° F., is sufficient to destroy the pnrHeat.
common pathogenic germs, but this is far above
what can be used, without injury, in most cases.
Dry heat is not so effective as moist heat.
Anything that can be boiled or steamed can be
most surely made safe.
In "Disinfection and Disinfectants," Dr. Ros-
enau says, regarding dry heat, boiling and
"Most materials will bear a temperature of
iio*'C. (about 230° F.) without much injury,
but when this temperature is exceeded, signs of
damage soon begin to show. Scorching occurs
sooner in woolen materials, such as flannels and
blankets, than with cotton and linen. The over-
drying renders most fabrics very brittle, but this
injury may be lessened by allowing the materials
which have been subjected to dry heat to remain
in the air long enough to regain their natural
degree of moisture before manipulating them.
"The ordinary household cooking oven is as
good as any specially contrived apparatus for the
disinfection of small objects by dry heat. In the
absence of a thermometer it is usual to heat
les THE CHEMISTRY OF
the oven to a point slightly below the tempera-
ture necessary to brown cotton, and expose the
objects no less than one hour.
" Dry heat fixes many stains, so that they will
not wash out. This is especially marked with
albuminous materials coagulable by heat, and
the method should not be used for the disinfec-
tion of fabrics and objects soiled with blood,
sputum, excreta or similar substances."
The objection to such use of the oven lies in
the handling of infected articles in the kitchen,
the worst place in the house to set free these
''Steam is the most valuable disinfecting agent
we possess. It is reliable, quick, and may be
depended upon to penetrate deeply" if the appli-
cation is prolonged. "It does more than disin-
fect; it sterilizes. Bacteria are killed instantly,
spores are killed in a few minutes, and it may
therefore be used to destroy the infection of any
one of the communicable diseases. . . ."
"Steam is very apt to shrink woolens and in-
jure silk fabrics. It ruins leather, fur, skins of
all kinds, also rubber shoes, mackintoshes and
similar articles made of impure rubber."
Boiling. ''Boiling is such a commonplace, every-day
process that it is often neglected in practical dis-
infection, despite the fact that it is one of the
readiest and most effective methods of destroy-
ing infection of all kinds. An exposure to
boiling water at ioo° C, continued half an hour,
will destroy the living principles of all the
COOKING AND CLEANING. 169
known infectious diseases, even very resisting
" Boiling is particularly applicable to the dis-
infection of bedding, body linen, towels and
fabrics of many kinds ; to kitchen and tableware ;
to cuspidors, urinals ^nd a great variety of ob-
jects. Surfaces, such as floors, walls, beds, fur-
niture, etc., may be effectively disinfected by
mechanically cleansing them with boiling water.
The efficacy of boiling water, especially when
used under such circumstances, is greatly in-
creased by the addition of corrosive sublimate,
carbolic acid, or any one. of the soluble germi-
cidal agents. The addition of lye, borax or a
strong alkaline soap greatly increases the pene-
trating power of boiling water, when applied to
surfaces soiled with organic or oleaginous
" In using boiling water for the disinfection of
bright steel objects or cutting instruments, the
addition of one per cent of an alkaline substance
(bicarbonate of soda) will prevent rusting and
injury to the cutting edge."
"In the household, small objects, body and bed
linen, and other fabrics may be thoroughly disin-
fected by streaming steam by placing a large pot
or washboiler on the kitchen fire, and arranging
broom handles across the top to hold the mate-
rials to be disinfected. The whole should be
covered with a sheet or cloth to retain the heat,
and steamed for an hour or longer, depending
upon the degree of penetration required and the
energy with which the water boils."
170 THE CHEMISTRY OF
Here, again, excessive precautions must be
taken in handling such materials in the kitchen.
^^^ Fire is by all means the surest disinfectant.
Anything which can be burned is reduced to its
inorganic elements, and these are not food for
the pathogenic germs.
Whenever any infectious material is liable to
be produced, as in all discharges from commu-
nicable diseases, an effort should be made to
receive it in or upon combustible material^ of
little value which can be burned immediately.
Soiatknu. Solutious. Thcse must not only be strong
enough, but in such quantity that the strength
shall not be diluted by the infectious material
beyond the effective point. The time of action
is also an essential factor. If the microbes are
dry it will take a certain time to wet them before
the chemical action can take place. Unless the
infected material can be immersed in the disin-
fectant solution, it is difficult to keep the two in
contact long enough to effect safety. Tempera-
ture, also, is an important factor in successful
disinfection. It is always well to use warm —
hot, if possible — solutions and combine their
action with mechanical removal, or scrubbing.
FonuaUn. Formalin is a solution of formaldehyde. A
very small amount is antiseptic, even i in 25,000
or 50,000, while one to four per cent kills in a
short time. This method kills spores, also.
COOKING AND CLEANING, 171
Lime or quicklime, CaO, is an alkaline earth.
It is very caustic and therefore useful in destroy-
ing organic matter.
Calcium hydrate, slaked lime, Ca(OH)2, is siakedLUne.
made by adding one part of water to two parts
For a disinfectant, freshly slaked lime should
be used. When the slaked lime is exposed to
the air it readily takes up carbon dioxide and is
converted into calcium carbonate, which has no
particular disinfecting power.
Whitewash is slaked lime mixed with water. whitew«»h.
It is an excellent disinfectant for surfaces, and is
a form of milk of lime, which is slaked lime
with about four times its volume of water. Milk
of lime must be prepared from freshly slaked
lime and should be thoroughly stirred to .prevent
the insoluble hydrate from settling. At least
two hours' contact should be allowed when this
is used for disinfecting excreta, and it should be
thoroughly incorporated. Milk of lime as used
for the disinfection of excreta in the United
States Army posts is made from one part, by
weight, of freshly slaked lime to eight parts of
water. The excreta should stand in this at least
two hours before disposal.
Ferrous sulphate, green vitriol, as copperas, copperas.
FeSO^, so commonly depended upon as a disin-
172 THE CHEMISTRY OF
fectant, has been found to be practically useless.
It is a fairly good deodorant.
Carbolic Acid. CarboUc Gcid, QH5OH, phenol, does not co-
agulate albuminous matter so readily as corro-
sive sublimate. It cannot be depended upon to
kill spores, but is fairly good for the vegetative
stage. In the strengths necessary for disinfec-
tion it is not destructive to fabrics, colors, metals
It should be used in a 1-20 solution. If much
is required it will be cheaper to buy the con-
centrated, which is a ninety-five per cent solution,
and reduce it to the desired strength. Four
ounces of this strength with five pints of boiling
water will give the required 1-20 solution. The
strong acid is very corrosive and must not touch
Quoting again from Dr. Rosenau's book, we
find that "in general practice carbolic acid is
used in from three to five per cent solutions, and
an exposure of no less than half an hour. Cloth-
ing and fabrics require deep penetration, and are
usually left in the solution one hour."
cresois. Crcsols 3Xt a class of substances obtained from
coal tar, found as impurities in commercial car-
bolic acid or phenol.
Their value is variable. Creolin is a common
^nd cheap member of this class. It contains
COOKING AND CLEANING, 173 .
about ten per cent of cresols and a small amount
of phenol held in solution by soap. It is at least
equal to and usually superior to the phenol. A
one per cent solution is effective for ordinary
Potassiutn permanganate, KM4O4, the cham- J2SSi"™nate
aeleon minerale, as it was called by the early
chemists, is a powerful oxidizing agent and a
strong germicide under limited conditions. It is
readily reduced and rendered inert by organic
Swampy water may be purified by it if enough
is added to allow the faint pink color to remain
when the brown precipitate which has enmeshed
the bacteria is settled or filtered off.
There is a possible danger of internal irrita-
tion when this chemical is used continuously in
Mercuric chloride, HgCL, corrosive sublimate, Corrosive
. . - T « '11 1 1 • 1 Sublimate.
is a potent germicide. It kills both active and
spore forms. It is a virulent poison, corrodes
metals, and unless used with salt it coagulates
albuminous matter. For disinfection of excreta,
therefore, sMt must be added. It dissolves with
some difficulty in three parts of boiling water
or sixteen parts cold water. It should, there-
fore, be powdered before the water is added,
care being taken not to inhale the dust. The
174 THE CHEMISTRY OF
solution is colorless and odorless, and has been
mistaken for water when not properly labeled.
The commercial tablets contain salt and are often
colored blue. The solution may be slightly col-
ored with indigo, or any of the aniline dyes, and
this should be done always as a precautionary
The i-iooo strength is sufficient to kill non-
spore-bearing species if allowed to act for half
an hour. For spores the 1-500 solution and an
hour's exposure is required.
A gaseous disinfectant is ideal if it can be
made to penetrate thick fabrics when they are
slightly moist, so that the gas may be absorbed
and brought into intimate contact. This is diffi-
cult to accomplish for the housewife, because
the gas must be delivered under pressure.
Formaldehyde. At present, formaldehyde seems to approach
this ideal most nearly. It is non-poisonous, does
not injure fabrics, metals or mineral surfaces.
In disinfecting with formaldehyde, temperature
plays an important part. The gas is not effective
under 50° F. and increases in power with the
higher temperatures. Moisture, als©, is neces-
sary for its effectiveness. A basin of water, kept
boiling, may be used to furnish the moisture.
The gas does not penetrate thick masses or fab-
rics readily, unless it is delivered under pressure,
COOKING AND CLEANING, 175
therefore such articles should be spread out as
thin as possible, and more time should be allowed
than for ordinary disinfection.
When the disinfection of a room with a gas
is completed, the doors and windows should be
opened as quickly as possible. If a person enters
the room to do this, he should cover the eyes,
nose and mouth with a moist cloth to prevent
the irritation caused by the gas. Ammonia
sprinkled about the room will neutralize the gas,
but forms with it a substance having a very
Soaps have an antiseptic action, and it is Soaps,
asserted by many that pure white castile soap
According to Dr. Rosenau: "Medicated soaps
are for the most part a snare and a delusion so
far as any increased germicidal action is con-
cerned ; in fact, the addition of carbolic acid, bi-
chloride of mercury, and other substances which
have the property of combining with the soap,
seems actually to diminish the disinfecting value
of that substance. As a rule, a very small quan-
tity of the disinfecting substance is added to the
soap, and when it is called to mind what an ex-
ceedingly small quantity of soap is necessary for
the ordinary washing of the skin, and the further
dilution of this small amount by the water used,
176 THE CHEMISTRY OF
-. it is easy to understand that medicated soaps, as
ordinarily applied, cannot have an energetic
The value of soap is in its superficial cleansing,
the removal of objectionable matter.
Deodorants. Another class of substances which are often
used, and sometimes with danger, are those
which destroy odors. These are substances
which combine with the decomposing matter,
forming new and odorless compounds. Charcoal
is such a substance.
This is the office of a true deodorant. The
name is sometimes applied to other substances
which produce no chemical or physical changes,
but simply cover up the odor given off by the
- decaying matter by one stronger or more
Deodorants simply destroy smells; disinfect-
ants and germicides destroy germs. Most disin-
fectants are at the same time deodorants.
The question is constantly asked, "What disin-
fectants can I use that are common and cheap?"
The last published report of the American
Public Health Association speaks authoritatively
upon this question, and from this the following
quotation may be taken as a summary of the
present status of the subject:
ummSlule.*'^ " ''^e wcight of opinion seems to be that alco-
COOKING AND CLEANING, 111
hoi from 40-60% is quite a strong germicide,
but that lower and higher percentages are much
weaker in their action. Two observers class it
about midway between sublimate and carbolic
acid in strength.
"Whether it acts as a direct poison or indi-
rectly through the water present is not yet estab-
lished, but the weight of opinion seems to be that
it acts directly."
The vapor from boiling alcohol solutions
is more effective as a disinfectant than the
"There are a few common disinfectants the
efficiency of which has been firmly established,
namely, boiling water, hot soda solution (about
10% solution of sal-soda in water), milk of lime
(pieces of lime slacked to a milk), corrosive sub-
limate and formaldehyde. I would add some of
the cresol preparations except that they are pat-
ented and hence not cheap enough for common
use in the United States. I leave out carbolic
acid because of its poisonous properties, and
chloride of lime because of its uncertain compo-
sition. Nothing better or more effective is
needed to disinfect feces and such matters than
milk of lime; nothing to disinfect clothes than
steam, hot water or hot soda solution ; for quick
sterilization of the hands a i-iooo sublimate solu-
tion is the best; and as a room disinfectant,
formaldehyde properly used still holds the first
place. . . ."
Some insects are known to carry infectious ^**«^»-
178 THE CHEMISTRY OF
matter, and it is easy to understand how any
animal may convey such material from one place
to another and possibly to man. They certainly
do carry on their bodies minute infectious parti-
cles gathered from moist substances, as excreta,
pus, sputum, over which they have crawled.
They carry also the agents of decomposition
from decaying food, depositing them upon other
food and thus starting decomposition in it.
In some cases the infectious germ is intro-
duced into human beings from the body of the
insect as it stings or bites. This is the case with
the flea and the mosquito, which carry malarial
and yellow fever germs.
The flies, fleas, ants, etc., deposit the infectious
material on the skin with their excrement, and in
other ways. The virulent infection is rubbed
into the little wounds or scratched into the skin
as a result of the irritation caused by the bites,
thereby setting up the disease.
Therefore all insects may be looked upon with
suspicion, while mosquitoes, flies, roaches, bed-
bugs and fleas should receive no quarter in the
clean and healthful house.
Insecticides. Most germicidcs are insecticides. Yet formal-
dehyde is a notable exception. It has slight
eflFect upon insect life.
Sulphur dioxide. This gas holds first place
COOKING AND CLEANING. 179
for killing insects and vermin. As an insecticide
it can be used dry, while as a germicide, as has
been said, moisture is necessary.
Bisulphide of carbon, CSg, and hydrocyanic
acid gas, HCN, are both powerful insecticides.
They are also deadly poisons to all animal life.
They should therefore never be used except by
experts. The United States Government has
published some valuable bulletins upon the use
of these substances.
Kerosene kills bedbugs and their eggs. Ap-
plied to the surface of water at the rate of an
ounce to fifteen square feet of surface it destroys
mosquitoes and their larvae. It is therefore use-
ful in covering all moist matter in which they
''Insect powder I' or "Persian or Dalmatian in-
sect powder," is usually the powdered flowers of
two species of chrysanthemum, C. roseum and
C. carneum. They are also sold under the names
of pyrethrum and buhack. The powder acts
mostly by . filling the breathing holes, causing
suffocation. It will kill, but too often only stu-
pefies the insects, which should then be gathered
and burned. Water bugs and fleas are driven
from their lairs to be caught while stupefied.
The powder may be burned, and in this form
is quite effectual for mosquitoes.
180 THE CHEMISTRY OP
The poisonous fly papers kill the insects, but
they fall everywhere about the house, and the
presence of these arsenical compounds is dan-
gerous wherever there are children.
The sticky fly papers do not kill but hold the
insects, and they die from exhaustion.
BOOKS OF REFERENCE.
Approved Methods for Home Laundering. M. B. Vail.
Art and Practice of Laundry Work. M. C. Rankin.
Bacteria, Yeasts and Molds in the Home. H. W. Conn.
Care of a House. T. M. Clark.
Chemistry of the Household. M. £. Dodd.
Chemistry of Plant and Animal Life. Harry Snyder.
Clean Milk. S. t). Belcher.
Disinfection and Disinfectants. M. J. Rosenau.
Domestic Economy in Theory and Practice. Bidder and
Drinking Water and Ice Supplies. T. M. Prudden.
Dust and Its Dangers. T. M. Prudden.
Elementary Laundry Work. Calder and Mann.
Expert Cleaner. H. J. Seaman.
Garment Dyeing and Cleaning. G. H. Hurst.
Handbook of Domestic Science and Household Arts.
L. L. W. WUson.
Handbook on Sanitation. G. M. Price.
Home Furnishing. A. M. Kellogg.
Home Sanitation. Richards and Talbot.
House and Home. M. £. Carter.
House that Jill Built. £. C. Gardner.
Household Bacteriology. S. M. Elliott.
Household Economics. Helen Campbell.
Household Hygiene. . S. M. Elliott.
How to Drain a House. G. E. Waring, Jr.
liygi^n^ and Public U^^thf U Qf PM^k«9t
182 BOOKS OF REFERENCE,
Laboratory Notes in Household Chemistry. Vult^ and
Laundry Manual. Balderston and Limerick.
Laundry Work. J. L. SheppanL
Outlines of Rural Hygiene. H. B. Bashore.
Principles of Sanitary Science and Public Health. W. T.
Sanitary and Applied Chemistry. £. H. S. Bailey.
Sanitation of a Country House. H. B. Bashore.
School Sanitation and Decoration. Burrage and Bailey.
Story of the Bacteria. T. M. Prudden.
Story of Germ Life. H. W. Conn.
Story of the Living Machine. H. W. Conn.
Text-Book of Physiological Chemistry. Hammerst^n.
Text-Book of Physiology. William HowelL
Absorbents of grease, 100, 101, 163
Acids, 41, 151
Acetic, 38, 162
for iron stains, 132
Hydrochloric or Muriatic, 17, 41,
Oxalic, 116, 153
Air, as food, 67
not the agent of change, 73
pollution of, 84
a substance, 85
Alcohol, 30, 36, 169
Alcohol, as solvent, 102, 110, 107
Alkalies, caustic, 89, 111, 146
Alkali metals, 88
Ammonia, 89, 160
uses of, 73, 93, 102, 126, 139, 160
Ammonium, 88, 89
Animal body, a living machine, 47
repair of, 48
Art of cooking, 56, 62
AtCHns, 14 «
Atomic weight, 14, 16
, of hydrogen, 14
Bacteria, 36^ 39, 74, 76, 77, 81
action of m disease, 80
as flavor producers, 62
food of, 81
spores of, 75
Bacteriology of bread-making, 36
Baking powder, 22, 23 -
Beans, 52, 64
Benzine, 98, 102, 157
Bleachmg, 134, 135
Bleaching powder, 136, 166
Blood stains, 106, 129
Blotting paper for ink, 108
Bluing, 133, 134, 161
Books for reference, 181
Borax, 125, 128, 137, 139, 149
Bread-making, chemical reactions iui
Bread, as food, 33
flavor in, 39 *
object of baking, 38
reason for kneading, 37
temperature of baking, 37, 38, 39, 64
of fermentation, 37
Butyric add, 35
Calcium hypochlorite, 128, 156
Cane sugar, 28, 29
Carbohydrates. 26, 44, 63
Carbolic acid, 172
Carbon bisulphide of , 179
Carbon dioxide (carbonic add gas),
17, 18, 19, 25, 30, 36, 37
method of obtaining, 40
Carbon tetrachloride, 167
Caustic alkalies, 89, 147, 148
ChecM cloth for d ,
dMoical arithmetic, 17
CWmiail dumf e, 7
prodnoet heat, 9S
Cfiemical elements, 12, 16
Chemical equatiooa, 17
Chemical experimenu in the home, 145
Chemical Uwa, 18. 14, lA
Chemical reactions, 17, 25
in bread and beer making, 81
Chemical symbols, 16
Chemicals for housefcold naa, 146
Chloride of lime, 126, 127, 128, 139,
OOoroform, 102, 157, 158
CWaninf of bcass, 116
fabrics, 97, 98
problems of, 90
processes of, 88, 90
silver. Ill, 116
wood, 90, 91, 92, 98
Qfannesa. ideal Md aanitary, 143
philoeopny of, 82, 88
of schoolhoases, 144
Cdboa and coffee stains, 137, 138
Colors, setting of, 140, 146
Combining weights, 14
Combustion of food, 35, 36
products of, 84
Conversion of starch. 28, 80
Cooking, American, 06
art oC 66, 57, 62
chemistry of, 58
economy in, 60
effect of, 64
nitrogenous fasd, fO, 58
object of, 58
Copper. 115, U6
Corrosive sublimate, 178
Cottonseed oil, 48
Cream of tartar, 23, 41, «2
Definite proportions, law of, 14
Development of flavor, 56
Diet, 63, 65
Diet, fat hi, 4ft
Dietaries, 68, 69
Digestion, 28, 61, 63, 68
is solution, 28
Dirt, definition <rf, 78
prevention of, 96
prevention of. 79
Dish cloths and towels, 14it
Disinfectants, 166, 176
Dry heat, 167
Dust, 71, 72, 73, 75, 87, 88
in air, 72, 76
composed jqIj 77
on fabrics, 97, 98
on wood, 92
Economy in Moktag, 69
of mixed 4lct, 65
Effect of condiments, 68
of cooking, 64
Etements. chemical, 12, 16
Energy, lOfachinM unit of, 47
sources of, 44
Ether, 108, 167,1^
E3q>an8ion of eues, 9
of water, 40^
Fabrics. 97. 96
Fat, digestion of, 44
in diet, 44
effect of high tempera!
Fermentation, 35, 39
Finish of woods, 90
Flavor, 46, 66, 57. 58,. 60
Flour, me 9f , in vmA, 88
Food, office of, ai, 69
water and air as, 68
Frendi chalk, 163
Frictional materials, 162
Fruit stains, 1^, 127
Fuel in body, 47
Fuller's tax^ 163
Germs, 74, 80, 81
Grass stains, 120
Grea«i, «7, 98, IflO, 101. lOB, 104, 136
solvents for, 91, 167
on wood, 108
Growth, nitrogenous food required
Hard water, 119, 120
Heat, dry, 167
produced by chemical change, 24
source of in animals, 26
Hydrochloric acid, 41. 153
Hydrogen, 14, 27, 44
Hydrogen peroxide, 155
Ideal bread, 34
Inflsunmable substances, 98
Ink indelible, 100
stains, lOT, 108, 131
Insect powder, 179
Insecticides, 178 '
Iron rust, removal of, 117, 131, 132,
JaveUe water, ^, 127, 128, 129. 130,
Kerosene,91,92,96, 111, 116,117, 131,
141, 167, 179
Kitchen utensils, 117
Law of definite proportioDS, 14
multiple proportions, 15
Lime, slaked, 171
Lithium, 88, 89
Litmus pifp^, 16§
Marble, 95, 100
Matter, chants in, 5
definition of, 6
fonns of, 8
Mercuric cMonAe, US
Metals, 96, 111, 116
Milk stains, 129
Mixed diet, 66
Molds, 74, 77, 79
Molecular weight, 11
Mucous stains, 129
Multiple proportions, law of, 15
Muriatic a^i^. 1^
Nature's scavfi^gers, 78
Nitrogenous food, 47, ^, 6jB
cooking of, 60, t^
OU stains, 130
Olive oil, 44, 45
Oxalic acid, 147
Ox-gall, 103, 161
Oxygen, 16, 26, 43
Paint, 93, 104
Pathogenic germs, ^
Physical change, 7
Pipe clay, 163
Plated silverware, 112
Plumbing, care of, 141
Porcelain, 96, 110
Potash, lOB, 122, 123, 147
Potassium hydroxide, 147
Potassium permanganate, 173
Preparation tor food, of starch, sugar
and fat, 24
Prevention. 80, 96
Products of decMnpositiott, 64
Proportion of nitrogenous food re-
Punuce, 96, 102
Removal of dnstj^spots and stains, 87
Rust of iron, 117
Salt, 17, 41, 42
Schoolhouse sanitation, 148
Seasonable diet, 65
Shellac, dissolved by alcohol. 111
Silver, cleaning of, HI, 113, 114, 115
Silver nitrate, 167
Silverware, 112, 116
Soap, 89, 120, 122, 124, 137, 139, 151,
berry tree, 121
Soda, 42, 122, 124, 148, 149
Soda ash, 17, 123, 124, 148
Sodium carbonate, 148
Sodium chloride, 17. 164
Sodium hydroxide, 148
Sodium thiosulphite, 167
Soft water. 119, 120
Solution, 9,28, 50
Solutions, disinfecting, 170
Solvents, 10, 78, 91. 101, 102» 106, 167
Source of energy, 44
Spots, 100, 118
Stains, 100, 106. 118, 126. 127, 128
Starch, 24, 27, 28, 29, 30, 31, 160
cooking of, 32, 66, 61, 160
Stearic add, 43
Stiffening agents, 160, 160
Stoves, care of, 117
Sugar, 24, 27, 29
of lead, 163
mUk, 27. 28
Sulphur dioxide, 166, 178
Sunlight, 82, 83, 84, 86, 164, 106
Tables, 16, 23
Tarnish, 100, 101
Tea stains, 127. 128
Temperature, 26, 46, 49, 02, 63
Turpentine, 91, 102, 103, 126, 168
Ultramarine, 133, 134, 162
Utensils, kitchen. 117
Varnish, 91. 106
Wall paper, 94
Washing soda. 124, 126, 148
Water, 118, 119, 120
as food, 67
hard and soft, 119, 120
Wax, 91, 106
Whiting, 114, 162
Wine stains, 121
Wood finish, 90, 91, 92
Woolens, washing of, 139
Yeast, 33, 36. 36, 37, 38, 74, 78
HC 35AP T
llM MMMHi^ Of OOMHRI MM
3 2044 045 173 671
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