DOMESTIC SCIENCE
A BOOK FOR USE IN SCHOOLS AND FOR
GENERAL READING,
BY
JAMES E. TALMAGE. D. 8. D., Ph. d.
President of Latter-day Saints' College, Salt Lake City, Utah;
Member of American Chemical Society.
" Till, by experience taught the mind shall learn
That, not to know at large of things remote
From use, obscure and subtle, but to know
That which before us lies in daily life.
Is the prime wisdom."— i>/t?/o«.
\
m 6 1891
PUBLISHED AT
THE JUVENILE INSTRUCTOR OFFICE,
Salt Lake City, Utah.
1891.
<:
Copyrighted January, 1891.
/
7'^
sy
DEDICATORY.
TO
KARL G. MAESER, D. L. D.,
General Superintendent of Latter-da ij Saint
Schools, and Pioneer Teacher
in Such Schools;
To whom the Author, in common with all the
youth of this people, owes so much, this unpre-
tentious volume is respectfully and affectionately
inscribed.
ENDORSKNIEKTS.
Salt Lake City, Dec. 1, 1890.
To All Concerned :
With the growth of our Church school system, and
of the Mutual Improvement Associations among our
people, the need of text -books specially adapted for
use under those organizations becomes very apparent.
A short time ago, Dr. J. E. Talmage was requested
by us to prepare a work of medium size and scope on
subjects of practical and scientific interest ; and as a
result he has written a small volume entitled Domestic
Science.
A committee appointed to examine the book has
heartily endorsed it as a worthy work, representing an
extended array of useful facts expressed in simple but
forcible style, and imbued throughout with the spirit
of our religion.
AVe take pleasure in recommending the little work
to our people as well adapted for use in our Church
schools, also in the Mutual Improvement Associations,
and for general reading.
Your brethren in the gospel,
WiLFORD Woodruff,
Geo. Q. Cannon,
Jos. F. Smith.
Provo CiTr, Utah, Dec. 1, 1890.
The study of Domestic Science, recognized as an
essential feature of education, has received in this
work by Dr. J. E, Talmage such a thorough and sys-
tematic treatment as will entitle the work to the careful
consideration of all educators ; I earnestly recommend
it, therefore, to all our Church schools for adoption.
Karl G. ]VL\eser, D. L. D.,
Gen. Supt. L. D. S. Schools.
PREFACE.
SEVERAL years ago, the author introduced to his
students a brief course of instruction upon topics
of practical, everyday interest, under the name of
Domestic Chemistry. The class has since held a
permanent place on his program of science teaching ;
and he is pleased to note that with the increase in the
number of Church schools among the Latter-day
Saints, and with the growth of the Mutual Improve-
ment Associations among the young people of this
region, many other classes of the same nature have
been established. The need of a text-book, embody-
ing the principal facts of such a course, has been felt
for some time ; and, in consequence, the appointment
which led to the production of this little volume was
made.
The author has endeavored to bring together, in a
simple manner, such topics as have a direct bearing
upon the science of domestic operations. His object
has been to direct attention to daily household affairs,
— affairs indeed, which to many are too common to be
deemed worthy of earnest thought. The kitchen and
the pantry may be made a laboratory for the elucida-
tion of many important facts of science ; and as
11 PREFACE.
interest is aroused in the necessary labors of the
household, much of the unwelcome air of drudgery
will vanish from such work. As it is plain that the
duration of our mortal existence permits the exploration
of but a small fraction of the domain of knowledge,
careful judgment should be exercised in the selection
of subjects of study ; the practical and utilitarian
aspect of modern systems of education testifies to the
wide recognition this fact has received among the peo-
ple in general.
In this book, no effort has been made to secure an
unduly elaborate or an exhaustive treatment ; a large
work would be poorly adapted for class use, and much
detail might discourage the general reader in his
study. Liberal reference has been made to the works
of recognized authorities on the subjects treated ; in
such cases, acknowledgment has been made in the body
of the work. A few passages are reprints of articles
that have appeared over the author's signature in local
periodicals.
J. E. T.
Salt Lake City, Utah.
Jan. 24, 1891.
ANALYSIS OF CONTENTS.
DF^jPlPS-T I.
AIR AND VENTILATION, WITH CHAPTERS ON HEATING AND
LIGHTING.
CHAPTER 1.
Some physical properties of air; impenetrability of air; pres-
sure; air-pump, and experiments with same - - 9
CHAPTER 2.
Simple instruments utilizing atmospheric pressure; simple bar-
ometer; siphon barometer; wheel barometer; aneroid
barometer; storm glass; syringe; pumps, lifting, and
force; pipette; siphon - - - - 21
CHAPTER 3.
Composition of the atmosphere ; dittusion of gases ; nitrogen ;
oxygen; carbon-dioxide; vapor of water - - 33
CHAPTER 4.
Permanency of the atmosphere ; plants as agents of atmospheric
purification ; fungi and chlorophyle-bearing plants ; mol-
lusks and corals as removers of carbon dioxide - - 44
CHAPTER 5.
The air of rooms; contamination resulting from presence of
human beings; proximity of stables, etc.; rate of con-
tamination ; effect of lights and fires ; cellars beneath
dwellings ------ 51
CHAPTER 6.
Ill effects of impure air; human respiration; foul air productive
of scrofula; tuberculosis; tonsilitis; dysentery; effect of
foul air on mental powers - - - - 61
iv ANALYSIS OF CONTENTS.
CHAPTER 7.
Dust in the air ; effects of dust in respiratory passages ; dust-
inhaling occupations; coal miners and tin miners; poison-
ous dust; natural defences against dust; vibrissas and
ciliated membranes of respiratory passages; living organ-
isms in dust; household dust; carpets, curtains, etc., as
dust-traps ; wall papers, arsenical papers - - 70
CHAPTER 8.
Ventilation: dependent on temperature changes; entering and
outgoing currents of a room; opposite currents; mine
ventilation; Lyman's ventilator; open fire-places as ven-
tilators; mechanical aids to ventilation; exhaust fans;
revolving cowls ; entering currents through windows and
transoms - - - - - - 81
CHAPTER 9.
Some properties of heat: expansion of solids by heat; force ex-
erted by expanding solids; compensation pendulums,
gridiron, and mercurial bob ; expansion of liquids and
gases by heat; thermometers, Fahrenheit and Celsius - 92
CHAPTER 10.
Communication of heat; latent and specific heat; conduction in
solids; conductors of heat; convection in fluids; radia-
tion of heat; latent heat and specific heat; latent heat of
water; beneficial effects of same - - - 101
CHAPTER 11.
Production of heat; fuels and flame; chemical processes of com-
bustion; moisture formed by combustion; carbon-dioxide
formed by combustion; nature of flame; hollow condi-
tion of flame; fuels; woods; coal; lignite; cannel coal; bit-
uminous coal, semi-bituminous coal; anthracite coal;
charcoal; coke; coal gas; matches - - - 109
CHAPTER 12.
House warming; open flreplace, ancient and modern; stoves;
double case stove; warmed air; steam warming; warm-
water heating; low pressure system, high pressure system 119
CHAPTER 13.
Light and lighting; candles; candle flame; simple lamp; Argand
lamp; hollow wick lamp - _ - - 129
CHAPTER 14.
Lighting, continued; common illuminants; illuminating oils;
flashing point and fire test of oils: coal gas, water gas,
electric lamps,— arc and incandescent - - - 137
ANALYSIS OF CONTENTS.
IF'jPlK.T II.
WATER.
CHAPTER 15.
Water— its occurrence;— in minerals; in plants, fresh and air
dried; absorption of water by plants; water in animal
bodies; in human bodies - - - - 144
CHAPTER 16.
Water, some of its uses and properties: as liquid, as solid, as
vapor; freezing of water; ice crystals - - * - 151
CHAPTER 17.
Sources of water; rainwater; springs; hill-side springs; fissure
springs; artesian well; equilibrium of liquids; intermittent
springs; water of rivers; of wells - - - 156
CHAPTER 18.
Water— a solvent for solids; solids in natural waters; hardness
of water; goitre prevalent in regions of hard water occur-
rence - - - - - - - 164
CHAPTER 19.
Water— a solvent for gases; atmospheric gases in water; am-
monia gas and hydrogen sulphide in water; carbon di-
oxide in water; soda water; water in the sick-room - 171
CHAPTER 20.
Organic impurities in water; free ammonia and albuminoid am-
monia in water; chlorine in water; ill effects of organic
contamination of water; suspended matter in well water;
living organisms in potable water - - - 176
CHAPTER 21.
Simple tests for purity in potable water; chemical analysis of
water; color; clearness; odor; taste; tests for chlorine,
and organic matters; filthy state of grave-fed waters - 183
CHAPTER 22.
Purification of water; boiling; distillation; filtration; domestic
filters; Clark's process for softening water; alum and
tannin in water; waters of Marah - - - 188
VI ANALYSIS OF CONTENTS.
CHAPTER 23.
Mineral waters; sulphur waters; carbonated waters; calcium
waters; chalybeate waters; alum waters; saline waters;
thermal w^aters - - - - - 197
CHAPTER 24.
Composition of pure water; electrolysis of water; preparation
and properties of hydrogen; oxy-hydrogen flame - 202
r^jPLK.T III.
FOOD AND ITS COOKERY.
CHAPTER 25.
Food, its nature and uses: classification of foods,— inorganic,
organic, and auxilliary; advantages of mixed diet; condi-
tions of digestibility; object of cooking - - - 207
CHAPTER 26.
Mineral ingredients of food: water, salt, lime, iron, sulphur, and
phosphorus - - - - - - 214
CHAPTER 27.
Organic ingredients of food: amyloid group of food substances,
—starch, sugar, gum; sources, preparation, and use of
starch; sugar,— saccharine and glucose; vegetable gum - 222
CHAPTER 28.
Carbonaceous ingredients of food; vegetable acids— citric acid,
tartaric acid, malic acid, oxalic acid; pectin; fats and oils
— vegetable fats, animal fats, olein, palmitin, stearine - 230
CHAPTER 29.
Nitrogenous ingredients of food : albuminoids or proteids,— al-
bumen, fibrin, gelatin, casein, gluten - - - 237
CHAPTER 30.
Vegetable foods and their cookery: tubers, bulbs and roots,—
potatoes, onions, turnips, carrots, parsnips, beets, rad-
ishes; leaves and leaf-stems,— cabbage, salads: fruits;
seeds - - - - - - - 245
CHAPTER! 31.
Vegetable foods, continued: wheat— bread and bread-making;
yeast, effect of; baking powders; new and stale bread;
barley; rye; oats; buckwheat; rice - - - 254
ANALYSIS OF CONTENTS. Vll
CHAPTER 32.
Animal foods and their cookery: use of water-bath; meats, fish,
eggs ; seething, roasting, broiling or grilling, frying - 265
CHAPTER 33.
Animal foods, continued: milk, butter, artificial butters, cheese 273
CHAPTER 34.
Some auxilliary foods: condiments; vinegar; pickles; lemon and
lime juices; essential oils as flavoring agents; spices; ar-
tificial drinks— tea, cofliee, cocoa, chocolate - - 278
CHAPTER 35.
Preservation ol food stuffs: cause of decay: preservation by
freezing,^ by hermetic sealing, by drying, by chemical
antiseptics,— salt, sugar, alcohol, creosote, boric acid - 286
CLEANSING AGENTS; AND POISONS AND THEIR ANTIDOTES.
CHAPTER 36.
Cleansing agents: water; soaps,— hard soaps, soft soaps, marine
soap, Castile soap, glycerine soaps; adulterations of soap;
aqua ammonia and other detergents - - - 293
CHAPTER 37.
Bleaching; explanation of process: light and air as bleaching
agents; sun bleaching; art of bleaching as practiced in
Holland; chlorine as a bleaching agent; bleaching pow-
der; sulphur dioxide as bleaching agent - - 299
CHAPTER 38.
Disinfectants; true disinfectants, absorbents, and deodorizers;
charcoal and lime as absorbents ; chlorine as a disinfect-
ant; chloride of lime; sulphur dioxide; carbolic acid;
thymol; copperas; corrosive sublimate; zinc salts; lead
chloride; heat; instructions for disinfection - - 304
CHAPTER 39.
Poisons and their antidotes: nature of a poison; general treat-
ment n\ poisoning cases; common poisons and antidotes:
—mineral acids, organic acids, alkalies, antimony, ar-
senic, copper, iron, lead, mercury, silver, zinc, phosphor-
us; narcotic poisons; irritant vegetable poisons; poisonous
meat, fish, cheese; animal venom - - - . 313
Index - - - - - - 321
DOMESTIC SCIENCE.
i='jPi.:e^t I.
AIR AND VENTILATION, WITH CHAPTERS ON HEAT-
ING AND LIGHTING.
CHAPTER I.
SOME PHYSICAL PROPERTIES OF AIR.
IT IS generally believed that the earth's surface is
covered to a depth of several miles with a gaseous
substance known as air or atmosphere. Owing to its
transparency, this covering is not apparent to our powers
of sight ; yet there are other means by which we may
become convinced of its existence. When the air is in
motion, it gives rise to the phenomenon of winds,
some effects of which are familiar to all of us. The
speed with which the moving air travels determines the
difference between the pleasant zephyr, and the destruc-
tive hurricane.
The following simple oper-
ation will conclusively prove
the existence of the atmos-
phere :
Place a cork on water con -
tained in a large bowl or bas -
in ; take now a good sized
glass tumbler or goblet, and
while holding it vertically,
with the open end down-
ward, lower it over the float-
ing cork, pressing down-
ward until the glass is en- Fig. i.
tirely submerged. As the Showing the impenetrability of
10
DOMESTIC SCIENCE.
cork does not rise within the glass, we know that tlie
water has not entered.
Now, a ver}^ simple, yet proper question is, what
keeps the water from lilling the inverted tumbler?
Liquids, it is correctly said, show a tendency to seek
their levels. There must be something inside the
tumbler, which presses against the water, and prevents
its entrance. Had it not been for the pressure ex-
erted by this invisible something inside the glass, the
water would have risen to the same height within the
vessel as without, or until the glass was entirely filled.
This may be made much clearer by another ex-
periment.
Take an ordinary lamp
chimney, which, of course,
is open at both ends ; and,
while holding it in a verti-
cal position, push the chim-
ney into the water as was
done with the tumbler in
the former experiment. The
liquid will be found to stand
at the same level inside and
outside the chimney. The
water, in this case, pushed
the air from the* open glass,
and took its place. If the
chimney had been previously
filled with smoke from a bit of bin-ning rag or thick
coarse paper, the movements of the escaping air as it
overflowed the chimney would be clearly visible.
The following is a very pretty illustration, suitable
Fig. 2.
Water expelling air
THYSICAL PROPERTIES OF AIR.
11
for the lecture table, and one that can be performed by
any body who will provide himself with a few simple
requisites in the way of apparatus, and who will
exercise a moderate degree of patience and persever-
ance.
In the figure, A represents a wide-mouth bottle, which
should hold a pint or more. This is x^rovided
12 DOMESTIC^ SCIENCE.
with a tightly fitting (;ork, through which two holes
are bored.
B is a funnel -tube passing through one of the per-
forations in the cork. A piece of wide glass tubing-
could be employed, though less conveniently, instead
of the funnel tube.
C represents a delivery tube of glass ; this can be
easily shaped from a piece of glass tubing of the
required length, first softened in a lamp flame.
D is a basin or any suitable vessel containing water,
beneath the surface of which the delivery tube C
terminates.
E is an ordinary bottle, which is to be first filled
with water, and then inverted over the end
of the delivery tube, and there supported on any con-
venient stand, or held in position by the experi-
menter.
Now, as water is poured through the funnel tube
into the bottle, air is forced there -from and escapes
through the delivery tube into the inverted vessel.
It may be shown by measurement that just as much
air is crowded out, as water is poured in.
Thus we see that this transparent invisible air
possesses in its own degree many of the properties of
other heavier matter. It occupies a definite amount
of room, and prevents other things occupying that
space at the same time.
The atmosphere also possesses weight. By carefully
weighing a closed vessel filled with air, and then
weighing it again after the air has been drawn out b}^
means of a pump, the weight of air has been accurately
PHYSICAL PROPERTIES OF AIR. 13
clctcrniined. By .such means it has been found, that a
cubic inch of dry air at the surface of the sea weighs
.31 grains. A hundred cubic inches wouhl weigh
therefore 31 grains; and a cubic foot would weigli
535.68 grains, or about 1.11 ounces. About 14.4
cubic feet of dry aii- would be required to weigh a
pound.
A sitting room of ordinary size, say 14 feet long,
12 feet wide, and 9 feet high, would contain about
105 pounds of air; and a large room suitable for
l^ublic assemblies, say 40 feet by 40 feet, and 18 feet
high, would hold about a ton of air.
These calculations apply only to air at the sea level ;
at greater altitudes the atmosphere is less dense, so
that fewer particles are contained in a given space. At
the altitude of Salt Lake City, a cubic inch of dry air
weighs only .26 grains ; a cubic foot weighs .93 ounces ;
and 17.2 cubic feet weigh but one pound. An ex-
ample of the weight of large masses of air may be
made in the case of the large Tabernacle at Salt Lake
City. This immeijse building holds 1,825,588,174
cubic feet of air, weighing 53,069 tons. The same
l)ulk of air at the sea level would weigh 63,388
tons.
It is well known that liquids exert a definite pressure
on bodies immersed in them, A forcible demonstra-
tion which may readily be performed by ocean voyagers
is as follows: A stout bottle is tightly corked, and
then attached to a long cord, weighted and thrown
overboard, the string being paid out as fast as the
weighted bottle sinks. After a consideral)li' depth has
been reached, the cord is drawn in. In most cases
14
DOMESTIC SCIENCE.
the cork will be foiiiid forced into the bottle through
the great pressure of the water. If, however, the cork
used was of the ''Tom Thumb" pattern, so that it
could not enter, the bottle may be crushed.
In ail analogous way the air presses upon every
object upon which it rests. To illustrate : Completely
till a tumbler with water ; lay over the top a piece of
glazed note paper ; hold the latter firmly in position
by jjlacing the palm of the hand over it, and invert
the glass. The pressure of the air will hold the paper
in position against the mouth of
the tumbler after the hand has been
removed, and in spite of the down-
ward pressiire of the water which
rests upon the paper. This is illus-
trated in figure 4 .
This illustration may be very
prettily varied by first tying a piece
of coarse muslin over the top of the
tumbler. The vessel should be
filled with water, covered with a
piece of paper, and inverted as be-
fore. If the paper be then carefully drawn away, the water
is still kept within the vessel by the upward atmospheric
pressure, which is exerted on the water within ihQ
vessel, Avhile the bottom of the rigid tumbler receives
the downward pressure, but does not communicate it
to the liquid within. The upward pressure therefore
operates without the downward pressure to counter-
balance it.
Another experiment should follow :
Instead of a glass vessel use a common fruit can.
Fig. 4.
Upward pressure of
the air.
PHYSICAL PROPERTIES OF AIR.
15
the cover having been removed, a piece of muslin tied
over as before, and a small hole punched in the opposite
end, as shown in the illustration, figure 5.
Now place the finger over the small opening ; fill the
vessel with water, cover with a piece of glazed paper,
and invert as before. When satisfied that the pressure
of the air sustains the water within the can, remove
the finger, and immediately the liquid flows out, be-
cause the downward atmos])heric pressure is communi-
cated to the contents of the vessel through the tiny
Fig. 5.
Atmospheric pressure.
aperture, and this downward pressure together with
the weight of the water is evidently greater than the
upward pressure of the atmosphere alone. The latter
is overcome, and therefore the liquid falls.
An interesting demonstration may be made by taking
a hard boiled egg, from which the shell has been (*arc-
fully removed. A bottle, with a mouth sufficiently
large to partially but not completely admit the egg is
to be provided. Place now in the bottle a bit of
burning paper, or hold within it by means of tongs
16 rXJMESTIC SCIENCE.
a ''live" coal. The effect of the heat is to expand
the air, causing much of it to pass entirely out of the
bottle. Now put the egg in position, like a stopper
within the mouth. As the air within the bottle cools,
it contracts ; the outer air in its endeavor to enter the
bottle presses on the Ggg, and forces it inward, fre-
(luently with a loud report.
The expansion of air by heat may be further illustrat-
ed in this way :
Take a small cup, burn a bit of paper within it, or
hold a glowing coal by tongs as in the case of the egg
and bottle experiment, described above= The air be-
comes heated, and expanded, and a portion is driven
out. Now remove the lire, and press the mouth of
the cup on the fleshy part of the arm. As contraction
by cooling occurs, the experimenter is made aware of a
strong, and even painful tendency of the flesh to enter
the vessel. This is a crude illustration of the surgical
operation of "cupping," which was in general use
years ago. By such means, blood and other matter
could be drawn from an affected part of the body
without the use of the lancet.
Many other demonstrations, no less instructive than
impressive may be made by the aid of an Ai7' Pump.
The essential points in the construction of this useful
instrument will be understood by reference to the
sketch. Figure 6 shows the complete instrument. C is
the cylinder, within which a piston works, operated by
the lever L. As the piston is raised, air is drawn
fi-om the large globe or receiver on the left. The mode
of operation will be seen by a study of flgure 7, which
shows the air ])ump in section. A valve, r, is (connect-
PHYSICAL PROPERTIES OF AIR.
17
ed with the piston, within the cylinder; a second
valve, h, is situated at the bottom of the cylinder ; these
valves open only in an upward direction : a tube, a,
leads from the receiver -plate to the cylinder. As the
tio-ht- fitting piston is raised, air passes through the
Fig.'G.
Air-pump.
tube a, opens the valve h, and fills the space between
the piston and the bottom of the cylinder. With the
first down -stroke, the air confined within the cylinder
becomes compressed, it forces open the piston valve,
and escapes. In subsequent strokes more air is drawn
through the tube a, and a globe or receiver placed
upon the plate over the entrance to a would soon be-
come exhausted.
18
DOMESTIC SCIENCE.
As an impressive illustration of atmospheric pressure,
place a hand glass, which is simply a hollow cylinder
open at both ends, over the aperture in the air pump
iliiM^M;i$^^%MM?i^^^^3y;'
Fig. 7.
Section of air-pump.
plate; and cover the upper opening with the hand.
As the air is exhausted, the hand is firmly held against
the vessel.
A piece of sheet rubber may be tied
over the open glass ; as shown in fig-
ure 8 ; as the air is drawn out, the
rubber is forced into the jar so as
almost entirely to cover the inside. If
instead of the rubber, a piece of blad -
der be tied over the jar, the air pres-
sure from above will burst the bladder inward with a
loud report.
Fig. 8.
Sheet rubber
under pressure.
Fig. 9.
Magdeburg hemispberes.
PHYSICAL PROPERTIES OF AIR.
19
A still more striking effect of atmospheric pressure
is shown by the Madgeburg hemispheres.
These are two hollow half globes, made to accurately
fit each other at the edges. The air is exhausted from
within by attaching the pair to the air pump ; after
which the stop -cock is turned to prevent a re -entrance
of air. The pressure of the atmosphere is so strong,
that very great force is required to pull the hemispheres
apart, (see figure 9.) The apparatus derives its
specific name from the fact that the first experiment of
the kind is supposed to have been made at Magdeburg
by Otto von Guericke in 1654. It is said that he used
hemispheres so large and effective that, after the air
had been exhausted, twenty horses were unable to
pull them apart.
Take now a bottle, fill it completely with water, and
invert it with its mouth just below the surface of water
in a larger vessel (see figure 10). The water remains in
the bottle, although far above the level in the outer
vessel ; it is held there by the downward pressure of
the air which is received on the surface of the liquid in
Fig. 10.
Air pressure supporting a column of water.
20 DOMESTIC SCIENCE.
the outer vessel, and thence transmitted to the contents
of the bottle. It is very readily seen, that, as the
mouth of tlie inverted bottle is below the surface of
the water in the larger vessel, air could not enter the
bottle from without, even if the contained water could
be mthdrawn. This phenomenon was discussed as
long ago as the days of Aristotle, the noted Grecian
philosoj)her, who has been dead now about twenty-
one centuries. He taught the people, that ^'■Nature
dislikes a vacuum.'" By "vacuum" is meant an empty
space, one that is devoid even of air.
ATMOSPHERIC PRESSURE.
21
CHAPTER 2.
SIMPLE INSTRUMENTS UTILIZING ATMOSPHERIC PRESSURE.
WE may very properly ask if there is a limit to this
supporting power of the air ; or if the atmospheric
pressure which sustains the water in the bottle, as last
described, would be able to hold a column of liquid of
an indefinite height.
This question has
been answered by ex-
periments which are
not convenient for
us to repeat. If we
could take a tube, say
thirty -six feet long,
closed at one end,
fill it with water, and
invert it with its
open end beneath
the surface of water,
the liquid would sink
to the level of thir-
ty-four feet, leaving
a vacuum in the up-
per part of the tube
jPjg 11 for the space of two
Air Pressure Supporting Column of feet. This fact caused
Mercury. Galileo who lived in
the earlier part of the seventeenth century to gravely as-
sert : ''Nature does not dislike a vacuum beyond thirty-
22 DOMESTIC SCIENCE.
four feet." The true explanation evidently is that the air
pressure is just powerful enough to support a column
of water thirty -four feet high. If a tube be filled with
mercury ((luicksilver), and inverted in a vessel of the
same liquid, the column will be sustained at the level
of thirty inches. If the tube be longer than thirty
inches, the mercury will fall to that level, and a vacuum
will be formed in the upper part ; this is illustrated in
figure 11. Now mercury is 13.6 times heavier than
water; and 34 feet, which is the height at which the
water column was sustained, is 13.6 times 30 inches,
which latter is the height at which the mercury column
stood. In other words, a column of mercury 30 inches
high, would weigh the same as a column of water of
equal diameter 34 feet high. Here then is a very con-
venient method of measuring the pressure of the atmo-
^ sphere. Suppose the tube used in the experiment with
quicksilver described above, had a cross -section of 1
square inch ; the mercury stood 30 inches high ; there-
fore the tube contained 30 cubic inches of the liquid ;
and this amount of mercury is found by trial to weigh
about 15 pounds. We may conclude, therefore, that
the pressure of the air is equal to 15 pounds to the
square inch.
This statement, however, is strictly true only under
the conditions prevailing at the sea level ; for the atmo-
spheric pressure is found to vary greatly at different
altitudes. The higher we proceed above the sea level,
the less becomes the air pressure. By carefully noting
the height at which the mercury stands in a tube ar-
ranged as above at different stations, the relative alti-
tudes of those places may be determined with fair ac-
ATMOSPHERIC PRESSURE.
23
curacy. At a height of four miles above the sea level,
the mercurial column would be about half its ordinary
height, or fifteen inches, and at an elevation of twenty
miles it is supposed the pressure would not support a
column higher than one inch.
At the altitude of Salt Lake City, the mean height of
the mercurial column is 25.6 inches ; this corresponds to
a pressure of 12.8 pounds per square inch. At this alti-
tude the body of a man of medium size, possessing 2000
square inches of surface, n
would sustain a weight
of 25,600 pounds, or over
one and a quarter tons ; at
the sea level such a person
would be under a pressure
of 30,000 pounds, or ful-
ly a ton and a half. How-
ever, there is air within
the body so that this enor-
mous pressure is equably
balanced.
The roof of the Latter-
day Saints' Tabernacle at
Salt Lake City measures
4 2,500 square feet; the
air pressure thereon
amounts to 39,168 tons;
at the sea level, with the
mercury column at 30
inches, such a surface would be under an atmos-
pheric jiressure of 45,900 tons.
Such an instrument as that alreadv described — a _
Fig, 12.
Showing fluctuations of tlie
mercurial column. .
24
DOMESTIC SCIENCE.
tube of proper length filled with mercury and inverted
in a cistern of the same liquid, is usually called a Bar-
ometer, the term meaning "weight measurer." Many
different forms of barometers are now in use ; the most
accurate being the mercurial barometer similar in prin-
ciple to the kind already described. To demonstrate
the effect of varying air pressure on the
barometric column, proceed as follows,
(see figure 12) : Invert a barometer tube
filled with mercury in a bottle of the
same liquid. Provide a doubly perfor-
ated cork, which tightly fits the bottle
mouth ; insert the cork with the inverted
tube passing through, and place a short
tube in the other perforation. By blow-
ing through the short tube, an increased
pressure is exerted on the mercury with -
in the bottle, and the column rises. By
applying suction, some air is drawn from
the bottle, the pressure upon the con-
tained mercury is lessened, and the
column falls. Thus we may see illus-
trated within a room such barometric
differences as exist between the mount-
ain-top and the sea -level.
A very good instrument is the siphon
barometer, illustrated in figure 13. This
consists of a glass tube of proper length,
curved upward at the bottom so as
to form two arms of unequal length. The short arm is
open, the long arm closed. When the tube is filled
with mercury and inverted, a vacuum is formed in the
Fig. 13.
Siphon
barometer,
ATMOSrilEKIC PRESSURE.
26
upper part of the long arm, the height of the liquid
column depending upon the prevailing atmospheric
pressure. The tube is permanently graduated above
and below a point, selected near the middle of the long
tube and marked zero (0). The height of the column
Fig. 14. Wheel barometej-
2(t
DOMESTIC SCIENCE,
is determined by reading the level of the mercury in
the long- arm above 0, and that in short arm below 0,
and adding the two figures.
An interesting variation in the siphon form of bar-
ometer is the wlieel barometer, the operation of which
will be understood from ligure 14. Resting on the
mercury in the short arm of the tube is a float, which
rises and falls with the liquid. By means of a rack and
pinion, or by a string and pulley, these movements are
communicated to an axis upon which a needle is fixed.
This needle moves in front of a graduated disc on which
the different states of the weather, such as "change,"
"fair," "stormy," "rain," etc., are marked.
Another fairly reliable instrument, and a very con-
venient form is the so-
called aneroid barometer,
(figure 15), in general
shape not unlike a watch.
The air pressure is trans-
mitted from a very thin
and flexible metallic casing
to a system of levers acting
upon the dial finger.
Even at a fixed station
the barometric reading is
seldom constant for any
great length of time, from
which fact we learn that
the atmospheric pressure is
Sudden and violent weather
changes are usually accompanied by fluctuations in the
barometric column. But the common belief that a de-
Fig. 15. .
Aneroid barometer,
continually varying.
ATMOSPHERIC PRESSURE. 27
creasing pressure, as indicated by a fall in the bar-
ometric height, is an infallible indication of approach-
ing storms, and that a " rising barometer" is surely
indicative of fair weather, can scarcely be relied upon.
We have not yet mastered the true science of weather
indications. The wind still " bloweth where he list-
eth," irrespective of our artificial rules. Our confi-
dence in the barometric indications should not be
impaired on this account. That little instrument
simply informs us of changes in atmiospheric pressure ;
if we interpret such information to mean rain, wind, or
fair weather, we do so of our own accord : the bar-
ometer told us no such thing.
There is an instrument known as the storm glass,
now in common use. It consists of a sealed tube con-
taining a chemical solution, in which crystals appear
with varying profusion. It is plain that the pressure
of the air can in no way affect the contents of the
tube, as the latter is hermetically sealed. The author
has made systematic observations on a number of
the instruments, and finds them entirely unreliable
as indicators of atmospheric pressure. The solvent
power of the contained liquid is affected by changes
in temperature, and the instrument has a stronger
semblance to claim as a thermometer than as a bar-
ometer. The "storm glass" is well designed as a
selling aricle and as a wall ornament.
The pressure of the atmosphere is turned to practical
account in the construction and operation of many
simple instruments, among which the Pump is prom-
inent. An essential feature of the pump is illustrated
by the common syringe. In figure 1(5, a vessel of
28
DOMESTIC SCIENCE.
water is shown ; in it are inserted two cylinders, each
provided with a tightly -fitting- piston and a convenient
handle. In the figure on the left the piston is at the
Fig 16. Fig. 17.
Syringe. Lifting pi:mp.
bottom of the cylinder ; in the right hand sketch the
piston is partly raised, the water following it.
The Lifting Pumji (figure 17) consists essentially of
a barrel containing a piston, which is o"perated by
means of a lever handle. A pipe passes from the
pump barriel to the well. At a is placed a valve, so
constructed asjto open only upward. Any pressure
ATMOSPHERIC PRESSURE.
29
received from above tightly closes the valve. An-
other valve, similar in action, is placed in the piston
at b. As the piston ascends, the water follov^^s it,
owing to the pressure being relieved within the barrel,
while the atmosphere presses with ordinary intensity
on the water surface in the well. The force of the in-
flowing water is suflflcient to force open the valve a.
As soon as the down stroke of the piston begins, how-
ever, the pressure closes the barrel valve, while the
water forces up the piston
valve, and fills the space above
the piston. This water is
lifted to the spout at the next
up stroke.
As before explained, the
atmospheric pressure at the
sea level is about 15 pounds
to each square inch, and this
is sufficient to raise and sus-
tain a column of water 34
feet high. Under the
most favorable circumstances
therefore, if the full pressure
of 15 pounds to the square
inch were realized, water
could not be raised by a lift-
ing pump from a greater
depth than 34 feet; and in
actual practice, through im-
perfect action of the pump,
this theoretical efficiency is
never attained. Lifting pumps are seldom able to
Fig. 18.
Force pump.
so
DOMESTIC SCIENCE.
raise water more than 28 feet. This is equal to a little
more than 12 pounds to the square inch.
At this altitude (Salt Lake City) under exceptionally
favorable circumstances, lifting pumps may raise water
to a height near 22 feet; but, as a rule, 18 feet is
considered a maximum, and 16 feet is the general
limit of efficiency.
If it be desired to lift water to a greater height than
Fig. ]9.
The dropping tube or pipette.
this, a Force Pump must be employed. This device
is pro^dded with a solid piston and a pair of valves ;
one valve being set in the barrel, as in the case of
the lifting pump, and the other being connected with
a discharge pipe, through which the water is driven
1>\ the down sti'okc of the piston. The limitations to
the operation of the force pump lie in the strength of
ATMOSPHERIC PRESSURE.
31
the material from which the pump is constriictetl and
in the power applied.
The Dropping Tube or Pipette is based on the ap-
plication of air pressure (see figure 19). By applying
suction at one end, while the other end is immersed in
liquid, the tube may be filled ; the finger then being so
placed as to close the upper opening, the liquid can be
held in the tube and be allowed to escape as desired.
Such tubes may easily be made from ordinary glass
tubing (figure 20). Pipettes will be found of great
service in many simple operations of the
household, such as the measuring of flavoring
extracts, medicines and the like.
Fig. 20.
Simple pipette.
Fig. 21.
The siplion.
The Siplion consists essentially of a bent tube, with
arms of unequal length. If the short arm be inserted
in any liquid, and suction be applied at the end of the
long arm, the liquid may be drawn through the tube,
and will continue to flow after the suction has ceased
(see figure 21). This simple device may be made of
32
DOMESTIC SCIENCE.
Fig. 22.
Siphon transferring liquid wittiout disturbing sediment.
much practical service in the kitchen and cook-room.
Liquids may he drawn off in a clear condition without
disturbing bottom sediment (figure 22), or top scum
(figure 23). Milk may be taken from the setting
pans without disturbing the cream, by inserting the
tube beneath the cream layer.
Fig. 23.
SiplHiii traiislci ring I'Kiuid without disturbing top layer.
COMPOSITION OF AIR. 33
CHAPTER 3.
COMPOSITION OF THE ATMOSPHERE.
UNTIL comparatively recent times, the atmosphere was
supposed to be elementary in its composition, that
is, composed of but one simple substance. Now, how-
ever, it is known to be made up of several components
the most plentiful ingredients being nitrogen^ oxygen^
carbon dioxide, and ivater. The last named substance
exists in the form of vapor. The first two, namely,
nitrogen and oxygen, are present in much the largest
proportions, there being about four -fifths or 80 per
cent, nitrogen and one -fifth or 20 per cent, oxygen.
The carbon dioxide and the watery vapor are present
in very small and variable quantities. In its condition
of ordinary purity there is about one cubic inch of car-
bon of dioxide in a cubic foot of air.
It has been calculated that if the atmosphere
could be compressed to a total depth of five miles,
the vapor of water being condensed to the liquid form,
and the atmospheric constituents being arranged in
sejjarate strata, the relative amounts would be shown
as follows : The water would form a sheet over the
earth about five inches deep ; above this would be a
layer of carbon dioxide thirteen feet in depth, then a
stratum of oxygen nearly one mile deep, and lastly,
one of nitrogen four miles in thickness. Such an illus-
tration is intended for comparison only ; the constitu =
34
DOMESTIC SCIENCE.
cnts of the air are not so separated ; on the contrary,
tliere is a most intimate mixture of all ; the heavy and
the light ingredients being mingled at the surface in
practically the same way as at the greatest heights.
This perfect mixing is brought about by the operation
of that wonderful law of nature, called by man the
"Law of the diffusion of gases." To illustrate, we
may perform the following experiment : Let us take
two large bottles placed mouth to mouth, (as in figure
24), the upper one containing a very
light gas, dry hydrogen for instance,
and the lower one a comparatively
heavy gas, ordinary air will answer.
In a very short time part of the heavy
gas will have risen into the upper
bottle, and a portion of the light
gas will have sunk into the vessel
below, and the two will be uniformly
mixed. We can easily determine that
the air and the hydrogen have become
mixed by separating the bottles, and
applying a flame to the mouth of
each ; an explosion occurs. Nei-
ther pure hydrogen nor air is ex-
plosive of itself, but a mixture of air
and hydrogen explodes with vigor when a flame is ap-
plied. Xow, air is about 14^ times heavier than hydro-
gen ; yet the tendency toward diffusion is so strong
that the heavy air rises and the light hydrogen sinks
till a perfect intermixture is effected. By such a pro-
cess of diffusion the composition of our atmosphere is
rendered practically luiiform throughout. Air has been
Fig. 24.
Dillusion of gases.
COMPOSITION OF AIR.
35
analyzed from mines and deep valleys, as well as from
mountain tops ; from above the sea as well as from the
land surface, and from the upper deeps of the atmos-
pheric ocean as reached by balloon ascents ; yet the
only differences thus far discovered are such as are due
to accidental contamination ; the proportions of the
essential ingredients being practically constant in all
cases.
We should learn something regarding the individual
characteristics of each of the principal ingredients of the
atmosphere.
Nitrogen is the one present in greatest quantity.
This is a colorless gas, without apjjreciable taste or
odor. It may be prepared in a
comparatively pure state by re-
moving the oxygen of the air,
and this can be done through
combustion.
Provide any convenient stand,
as shown in the illustration
(figure 25). This must be set
in a bowl of water, so as to pro-
ject several inches above the
water surface. Place on the top
of the stand a bit of phosphorus*
about the size of a No. 3 shot.
Light the phosphorus by touch-
ing it with a heated wire, and
then quickly invert over it a large wide -mouth bottle,
* Pliosplioinis should be handled only by those who have some
knowledge of its properties. It is intensely poisonous and very easily
inflannnable. In fact it must be kept always under water, and even
while being handled it must be kept covered with water to prevent its
taking fire. The fumes of burning phosphorus are very injurious,
and phosphorus burns in the flesh are deep and painful.
Fig. 25.
Preparation of nitrogen
3(; DOMESTIC SCIENCK.
which is, of course, tilled with air. Lower the bottle
over the burning phosphorus so as to keep the mouth
of the vessel sealed by the water. Dense white clouds
appear in the bottle ; these consist in reality of a fine
white powder formed by the union of the burning-
phosphorus with the oxygen of the air within the jar.
After a short time this powder dissolves in the water,
and the bottle is found to contain about one -fifth of
its full capacity of water, which has risen from below;
the remaining four -fifths are o(*cupied by a colorless
gas ; this proper tests w^U prove to be nitrogen.
The fact that the bottle bectomes about one -fifth full
of water is significant. As the burning phosphorus
removed the oxygen of the enclosed air by uniting with
it to form phosphoric acid, which was dissolved in the
water, evidently the space formerly occupied by the
oxygen would be left unfilled, unless the water passed
in. As one -fifth of the space originally occupied by
the air is found filled with water, it is clear that
one -fifth of the original substance has been removed ;
and this amount must have been the oxygen. The
remaining gas, four-fifths in amount, is nitrogen.
When the contents of the bottle have become entirely
clear, we may place a plate of glass under the mouth
of the vessel, remove from the bowl and invert.
If now a burning taper or a briskly flaming splinter
be introduced into the bottle, the flame will be im-
mediately extinguished, thus proving the inability of
nitrogen to support combustion. A further experiment
has been performed, but we need not re])cat it. It is
cruel, though it embodies a lesson. If a small ani-
iiiial, amouse, for instance, be placed In a bottle of uitro-
COMrOSITION OF Allf.
o /
geu, the little creature quickly dies with all evidences of
suffocation. Nitrogen, then, is a passive, inert gas,
incapable of supporting combustion or of sustaining
life. Its chief value as an ingredient of the atmo
sphere seems to be that of a dilutent for the more
vigorous oxygen associated with it.
Oxygen, the second ingredient of the atmosphere in
point of abundance, is not so easily prepared in a
state of purity. The removal of the nitrogen of the
air so as to leave the oxygen is almost an impossi-
bility. But other methods may be employed.
Make an intimate mixture of potassium chlorate and
manganese dioxide; place the same in a flask pro-
vided with a delivery tube and a collecting bottle,
connected with a pneuijiatic trough, as in figure 26,
Fig. 26.
Preparing oxygen.
and apply heat to the flask. Soon a gas is delivered
through the tube with considerable rapidity ; this gas
is oxygen. If a lighted taper or splinter be introduced
into the oxygen, the flame is greatly increased in bril-
liancy. A bit of phosphorus if lighted and introduced
38 DOMESTIC SCIENCE.
into oxygen burns with blinding brightness. A piece
of steel wire may be made to burn in this gas as easily
as a shaving of wood. In demonstrating the combus-
tion of metallic wire, a bit of wood is to be first
fastened to the wire and lighted ; the wire then takes
tire from the wood. An animal placed in pure oxygen
gives signs of feverish exhilaration, and if compelled
to breathe the gas for any great length of time the
creature dies from excessive excitement.
A greater chemical contrast could scarcely be found
than that which exists between inert nitrogen and
active oxygen. If the oxygen were taken from the air,
men and animals would speedily die of suffocation ; if
the air consisted of pure oxygen the tissues of our
bodies would soon be worn out, and death would re-
sult from the unnatural energy of the vital processes.
In an atmosphere of undiluted oxygen a combustion
once started would soon become universal ; the metal
of our lire-places would burn with the fuel, and nothing-
would escape the general conflagration but that which
had already been burned. The fact that combustion
is possible in the air points to the presence of oxygen ;
the additional fact that such combustion is far less
energetic than in pure oxygen suggests the presence of
a diluting ingredient, such as nitrogen.
Carbon Dioxide is itself a compound substance,
consisting of the elements carbon and oxygen. It may
be prepared for study by pouring a strong acid on
marble or on sodium carbonate, and catching the es-
cai)ing gas. A bottle is to be ])rovided with a doubly per-
forated cork, carrying a funnel tube and a delivery pipe
arranged as in figure 27. Into the bottle a tablespoon-
COMPOSITION OF AIR.
39
fill ot marble dust, or better still, the same quantity of
baking soda, is to be placed. A little dilute muriatic
Fig. 27.
Preparation of carbon dioxide.
acid is to be poured through the funnel tube upon the
marble dust or soda. A gas is given off with vigor,
and may be collected as was the oxygen over the
pneumatic trough. If a lighted
taper be introduced into a vessel
containing carbon dioxide, the
flame is extinguished as speedily
as if plunged into Avater. A
living animal placed in the gas
dies very speedily after a few in-
effectual gasps for relief. This
carbon dioxide is considerably
heavier than air. The gas may
be ])Oured from one vessel to
another, as shown in figure 28.
It may be dipped by a small
vessel from a larger one as readily
Fig. 28.
Pouring carbon dioxide
as could water
Owing to its great weight the gas
40
DOMESTIC SCIENCE.
may be collected, as illustrated in figure 27, by dis-
placement instead of over water. The delivery tube in
such a case is to be passed to the bottom of the col-
lecting bottle. A lighted candle held at the mouth
will be extinguished as soon as the vessel is filled. If
we continue to pass the gas into a vessel after the latter
has become full, the gas will run over as water
would do under similar
circumstances. True, the
substance is transparent
and colorless, and there-
fore entirely invisible, but
a candle flame held along-
side the receiving vessel
will reveal the overflow
(see figure 29).
The writer once visited
a large vinegar -factory in
the State of Maryland.
The vats in which the
mash was placed to fer-
Fig. 29.
Carbon dioxide overflowing.
ment were each as large as a sitting room. These vats
were only half filled with mash, the upper space being
left for the gathering of the carbon dioxide which is
given off in the process of fermentation. On the oc-
casion of the visit referred to, a double quantity of
mash had by mistake been pumped into one of the
large vessels. There was, of course, no room for the
carbon dioxide to collect, and it ran over the sides of
the vat as fast as produced. Several workmen who
were engaged in repairing the floor around this
])arti(iilar vat were cjuickly cnvelo])ed in the siiffo-
COMPOSITION OF AIR. 41
eating gas, and died before assistance could be ren-
dered.
Its power of extinguishing a flame is a usual
method for determining the presence of carbon di-
oxide; but it will be remembered that nitrogen j)os-
sesses the same property. A more reliable test may-
be made as follows :
Prepare a little dear lime water, by adding water to
good lime and afterward filtering. Pour a little of
this into a bottle containing carbon dioxide, and
shake. The lime water becomes at once milky from
the formation of insoluble lime carbonate, resulting
from a union of the lime and the carbon dioxide. By
exposing a dish of lime water to the atmosphere, with
occasional shaking, after a time a turbid appearance
is produced, indicating the presence of carbon dioxide,
which must have existed in the air.
Watery Vapor. The existence of vapor of water
in the atmosphere is a fact scarcely to be wondered
at. If a vessel of water be exposed freely to the air,
after a short time the liquid is found to have dis-
appeared. The particles of water have not been de-
stroyed. They have, in fact, been lifted into the air
by the process of evaporation, and afterward they float
as freely as the other constituents of the atmosphere.
A very simple proceeding will prove the presence of
watery vapor in the air about us.
Provide a glass of ice water for observation. See
that the outside of the vessel is perfectly dry. Set the
glass in a warm room, and observe. In a short time
the outside of the glass becomes covered with drops of
liquid looking not unlike dew. This moisture could
3
42 DOMESTIC SCIENCK.
have come only from the atmosphere of the room.
Under all circumstances water can be condensed from
the atmosphere if the temperature be sufficiently lower-
ed. The quantity of moisture which the air can absorb
and hold in suspension depends largely upon the
temperature. AVarm air has a much greater capacity
for moisture than has cold air ; and the process of
cooling the air results in the deposition of much of the
water which it had held. When the air contains all
the moisture it is capable of holding at any given tem-
perature, it is said to be saturated.
At the freezing point of temperature, (32° F.) the
air is saturated with moisture when it contains 2.3
grains of water to the cubic foot. At the ordinary
temperature of rooms (60° F.) a cubic foot of air will
hold 5.8 grains of moisture ; at 90° F. it will hold 14.3
grains ; and at 100° F. it may contain 19.1 grains. In
the cold season, therefore, the air may appear
moist because it is near its saturation point, though in
reality it contains at such time much less moisture than
under conditions of greater warmth. Evidently, the
drying power of the atmosphere will depend upon its
capacity to take up more moisture than it already
holds. It is customary to express the drying power
of the atmosphere in degrees, the determination being
made by finding the difference between the temperature
of the air and the dew point.
IVlien under any circumstances the air becomes
charged with moisture beyond its i)oint of saturation,
some form of precipitation is the result. The deposit
may occur in the form of dew, or, if larger quantities
of water are condensed at the time, as by a sudden
COMPOSITION OF AIR. 43
cooling of a heavily laden clond, the fall msLj be one
of rain, snow, or hail, as the temperature may deter-
mine.
Summary. Let it be remembered then that the air
contains four essential, constant, ingredients : — nitrogen,
oxygen, carbon dioxide, and vapor of water; and be-
side these certain other accidental constituents, such as
gaseous emanations from decaying matter, the volatile
materials of fuel, the aroma of flowers, and the like.
The nitrogen and the oxygen form the bulk of the
atmosphere. These are present in the proportions here
shown : —
BY WEIGHT. BY VOLUME.
Nitrogen - - - 23.1 per cent. 20.9
Oxygen - - - 76.9 " " 79.1
100. 100
The average quantity of water present in the at-
mosphere is perhaps near 1 per cent., and that of carbon
dioxide is about ,,„\f, of 1 per cent by weight.
44 DOMESTIC SCIENCE.
CHAPTER 4.
PERMANENCY OF THE ATMOSPHERE.
''PHE uniform and constant composition of tlie atmos-
1 phere appears all the more remarkable, when we
consider the many influences of change to which most
of the ingredients are subject. As has been already
seen, the nitrogen of the air is an inert constituent.
Though mixed Avith other substances, it takes no part
in the transformations which they so readily undergo.
Air is taken into the lungs of men and animals, and
though the oxygen is there exchanged for carbon diox-
ide, the nitrogen passes out again in an unchanged
state. In all lires, oxygen combines with the fuel, and
thus adds to the energy of the blaze, but the nitrogen
remains still passive and free. The oxygen and the
carbon dioxide, however, are continually undergoing
change by an endless series of rapid combinations and
decompositions. Let us, then, turn our attention to
these.
In breathing, men and animals inhale by drawing a
portion of air into the lungs, and after an interval they
exhale or expel about the same quantity of gaseous
matter, though of a composition far different from that
taken in. Expired air contains more carbon dioxide,
and a far lower proportion of free oxygen than does
air before respiration. Blow through a small tube, a
straw will answer well, into a vessel of clear lime
water : the milky appearance before explained indicates
the presence of carbon dioxide in the breath. This is
PERMANE^rCY OF THE ATMOSPHERE. 45
true of thp breath of animals as well as of human
beings. When we strive to think of the number of
living beings constantly breathing, and thus removing
oxygen from the air and supplying carbon dioxide
thereto, the causes of the permanency of the atmos-
phere become still more perplexing.
It would seem to us at first thought, that after a time
all the oxygen of the air would be consumed and in its
place would be a superabundance of the deadly carbon
dioxide. Beside the respiration of animal bodies, there
are many other causes by which atmospheric oxygen is
consumed and carbon dioxide produced ; such as the
combustions in lights and fires, the decay of organic
matter, and all common processes of fermentation. In
some portions of the earth, vast volumes of carbon
dioxide are thrown into the air from volcanic fissures
and rents, from carbonated mineral sj^rings, and the
ke. It is calculated that over 300,000,000 tons of
coal are annually burned in the world under present
conditions. This alone would produce upward of
800,000,000 tons of carbon dioxide gas. A century
ago but ah insignificant
fraction of this amount
was consumed ; yet the
composition of the atmos-
phere seems not to have
been altered by this im-
mense supply. There must
^p\^_ be some powerful influen-
Fig. 30. ces in operation, through
Leaves exhaling oxygen. ^ymch oxygen is restored
to the air and carbon dioxide abstracted therefrom.
46 DOMESTIC SCIENCE.
An experiment on this subject was made in 17 74 by Dr.
Priestly, an English chemist, and it has been repeatedly
verified since that time. Each of ns may make the
demonstration his own by proceeding as follows :
Place some freshly -plucked green leaves in a bell
jar or large bottle, and till the vessel so as to cover
the leaves, with water that has been charged
with carbon dioxide. Then invert the bottle in
a larger vessel ^of water, as in figure 30, place
the whole in direct sunlight, and watch results.
Very soon, bubbles of gas are seen rising from
the leafy surfaces ; and being lighter than the water
these bubbles collect at the top of the bottle, the
heavier liquid sinking to give them space. When a
surticient quantity of gas has been collected, ^^lace a
piece of glass beneath the mouth of the bottle, and set
the vessel right side up. Now introduce a lighted
candle or splinter into the gas ; the increased brilliancy
of the flame declares the substance to be oxygen.
The carbon dioxide with which the water was originally
charged has disappeared in the process. It is there-
fore clear to us, that, under the influence of sunlight,
the leaves have absorbed the carbou dioxide, and have
exhaled oxygen in its place.
If compelled to re -breathe their own exhalations,
animals would soon die for want of oxygen ; yet
the foulest emanations of animals' lungs, the suffocat-
ing carbon dioxide, forms the chief support of the
plant. Under the influence of sunlight, the green
leaves of plants, through their multitudes of tiny
pores, draw in the carbon dioxide from the atmos-
phere, and exhale the life-giving oxygen. Says
PERMANENCY OF THE ATMOSPHERE. 47
Professor Joliuson, "On a single square incli of
the leaf of, the common lilac as many as 120,000
(breathing pores) have been counted ; and the rapidity
with which they act is so great that a current of air
passing over the leaves of an actively growing plant is
almost immediately deprived of the carbonic acid it
contains." And again, "A common lilac tree, with a
million of leaves, has about four hundred thousand
millions of pores or mouths at work, sucking in
carbonic acid; and on a single oak-tree as many as
seven millions of leaves have been counted."
This power of the leaves is exerted only under the in-
fluence of sunlight, direct or diffused. The active
principle of the leaf b)^ which the decomposition of
carbon dioxide is effected is technically known as
chlorophyle, a word meaning "leaf -green," and so
used because the substance is usually of a green color,
and by its presence imparts the prevailing hue to
foliage. The word scarcely expresses the whole nature
of this potent compound, for in the case of multi-
colored leaves, as for example, the petals of flowers,
the varied tints are apparently imparted by a substance
identical in most respects other than color with the
chlorophyle of green leaves. Plants that contain no
chlorophyle, (fungi), such as the mushroom, toad-stool,
and the like, exhibit none of the colors of the higher
plants, and they flourish when entirely deprived of light.
Such plants do not decompose the carbon dioxide of
the atmosphere, but they exhale this gas, and consume
oxygen as do animals.
Chlorophyle -bearing plants, when deprived of light
act somewhat similarly to the fungi, thus rather vitiat-
48 DOMESTIC SCIENCE.
ing than purifying" the air. In the open air, the carbon
dioxide evolved during the hours of darkness by grow-
ing plants would be of but slight effect upon the
purity of the atmosphere ; but in closed spaces, as
the rooms of houses, the result would be different ;
and therefore it is considered injurious to sleep in
rooms containing growing house-plants. Though
during the bright hours these beautiful growths are
alike pleasing in their effects upon the mind and body,
in darkness they tend, however slightly, to increase
the contamination which is so constant a feature of
animal and human existence. In marshy districts,
growing plants exert another influence of great l)enefit,
since by the absorption of water through their roots
they aid in drying the soil. The sun -flower and the
E]ucalyptus tree have been used in experiments of the
kind with very satisfactory results.
If we have read at all aright concerning the past
history of our earth, there was a time when the de-
composition of carbon dioxide through the agency of
plant life took place on a scale vastly greater than that
of the present. In that period of the earth's growth
which is known as the Carboniferous Age, one of the
l)reparatory stages through which the earth passed be-
fore it was fitted for animal life, the air was strongly
charged with carbon dioxide. At that time, however,
vegetation flourished on the earth with a luxuriance
far beyond any comprehension based on present cir-
cumstances. In that age there existed extensive forests
of mammoth ferns, gigantic club -mosses, and huge
trees of many strange growths. All lived by decom-
posing the carbon dioxide of the air, fixing its carbon,
PERMANENCY OF THE ATMOSPHERE. 49
and returning its oxygen in the gaseous state. That
carbon has ever since been buried deep in the stony
fastnesses of the globe, there undergoing change until
converted into coal. Of the importance of coal, but
little need be said. Without it, thev^^orld could not be
what it is to-day. Now, by burning the coal its
carbon unites once more with oxygen to form carbon
dioxide, and thus the air receives again the substances
taken from it through the subtle agency of plant life
ages ago.
But lest the carbon dioxide should become too
plentiful for animal welfare, the Creator has wisely
directed other influences to operate in again removing-
this ingredient of the atmosphere as fast as it is pro -
duced. Go walk upon the sea beach, and there watch
the mollusks, great and small — shell fish as we usually
term them — living in such profusion ; observe them
carefully, and see what they are about. The stone -
like shell forming the creatures' home, consists
principally of calcium carbonate : and of this substance
two -fifths, or forty per cent., is carbon dioxide. Then
let us sail into warmer climes, and there observe the
myriads of coral polyps so successfullv fighting the
battle of life with the angry breakers of their ocean
home. The substance that we ordinarily call coral is
indeed nothing but the shell in which the tiny
creatures lived ; and this shell is composed mainly of
calcium carbonate taken from the waters, and contain-
ing the proportion of carbon dioxide already named.
The beautiful marbles which man ever has been de-
lighted to polish and admire, and the massive lime-
stone pillars, buttresses of the mighty hills — are made
50 DOMESTIC SCIENCE.
also of calcium carbonate, holding its proportion of
carbon dioxide imprisoned by the powerful bonds of
chemical force.
Upon such a plan does the Creator maintain the
equable balance of the elements. Is it not wonderful
that the animal in the unconscious exercise of its own
vital processes, contributes to the support of the
humble plant ? And the plant is not unmindful of the
aid thus received. The field of growing corn, while-
preparing aliment for the support of a higher life, the
rose-bush perfecting its flowers with which to please
the eye, adorn the home, and inspire the heart of man,
the vine laboring to ripen its tempting clusters, eai^h,
all are purifying the atmosphere, and preserving the
equilibrium without which animal life would soon
cease to exist on earth. AYhat then is independent in
nature? The mighty oak, and the gay squirrel which
finds food and shelter beneath the hospitable branches
of the tree, are mutually dependent. Neither the
animal nor the plant can say to the other, "I have no
need of thee." Each has been prepared by its Creator
to be a support to the other. Could any power pos-
sessing aught less than infinite wisdom have planned
and executed so perfect, so admirable a design?
THE AIR OF ROOMS. 51
CHAPTER 5.
THE AIR OF ROOMS.
'^PHE contaminating influences to which the atmos-
1 phere is subject through human and animal respira-
tion have been already referred to. The atmosphere
of closed rooms shows the effects of such influences to
a much greater extent than does the open air, for the
chief reason that enclosed air possesses far less oppor-
tunity of purifying itself. Combustion of lights and
fires within the room, and the respiration of the in-
mates work together in consuming oxygen and pro-
ducing carbon dioxide.
But this is not the only change. Large quantities of
water, in the form of vapor, are being continually thrown
into the air, from the lungs and the skin of living
beings. That this is true of the lungs may be made
clearly apparent by breathing upon any cold polished
surface. To prove that the same statement applies to
the skin, the following simple experiment may be
made : Take a large dry bottle, with the mouth sufli-
ciently wide to admit your hand. Sec that the hand
is clean and dry, and introduce it into the bottle ; after-
ward wrap a cloth around the wrist to seal the mouth.
After a short time, the inside of the bottle becomes
dimmed with moisture, which will increase till it
gathers in drops and trickles down the sides of the
vessel. The skin over the whole body is pierced
with innumerable tiny openings, through which vapor
is continually escaping, unless these pores have become
closed through uncleanliness or disease. As a result
of numerous experiments, it is believed that the quantity
52 DOMESTIC SCIENCE.
of fluid matter escaping in one day from the skin of an
adult personis not less than from two to three pounds.*
But this liquid excretion from the skin and the lungs
is not i)ure water ; it is indeed strongly charged with
the products of animal decay. By way of proof as
to the impure nature of the liquid matters in the
breath, proceed in this way : Take a clean dry bottle
having a wide neck : hold it before your mouth, and
breathe into it for some time. Then close it tight-
ly, and set it in a warm place for an hour or so ;
after this, remove the stopper, and apply the nose
with critical care. A foetid odor will be experienced ;
most probably of a convincing strength, t
A few years ago, an experimenter caused a number
of persons to breathe through tubes into a closed
vessel surrounded with ice, by which means the vapor
of the breath was condensed in considerable quantity.
Some of this liquid was injected into the blood
vessels of dogs and other animals. The process was
followed in almost every case by speedy death of the
victims with all appearances of poisoning.
* Dr. Faraday, of well merited fame, said upon this subject: — "I
think an individual may find a decided difference in his feelings when
making part of a large company, from what he does when one of a
small numher of persons, and yet the thermometer may give the same
indication. When I am one of a large number of persons, I feel an
oppressive sensation of closeness, notwithstanding the temperature
may be about 60 degree or G5 degrees, which 1 do not feel in a small
company at the same temperature, and which I cannot refer altogether
to the absorption of oxygen, or the inhalation of carbonic acid, and
probably depends upon the effluvia from the many present."
tSuch putrescible matter is constantly formed in the air of inhabited
rooms ; it settles upon the walls and furniture and its thorough re-
moval, if indeed at all possible, is a difficult undertaking. Upon these
ollcnsive sul)stauces lliose natural and necessary scavengers, the great-
ly abused house flies, largely feed, and but for these useful little crea-
tures we would be in a still worse plight.
THE AIR OF ROOMS. 53
Though the organs of smell are of exquisite delicacy
in enabling us to detect the presence of foul or offensive
matters, the sense may be easily dulled, so that we
become oblivious to the most disgusting odors. Note
the sickening effect which one experiences on re-enter-
ing a close bedroom, after having been in the open air
for a time, though perhaps the person may have occupied
that room during the entire night with complete un-
conciousness of its foul condition.
It is proper that every person should seek to preserve
the delicacy of each of his senses. No power of sen-
sation has been implanted within the human organism
without a definite use and purpose for the benefit of
the possessor. It is probable that we do not compre-
hend the full purpose of the power of smell ; yet it is
easy to perceive how we are warned against inhaling
many poisonous emanations, through their disagre-
able odor. Though there are some gaseous poisons
which are utterly devoid of odor, nearly all foetid and
disgusting smells indicate the presence of poisonous
matters.*
Many serious disorders have been directly traced to
the breathing of the foul gases arising from decaying
matters. The close proximity of stables, cow-houses,
pig pens, and the like is a constant menace to the in-
tThe delicacy of the sense of smell in detecting inconceivably small
particles of matter diffused through the air, is illustrated by the oft-
quoted statement of Dr. Carpenter:— "A grain of musk has been kept
freely exposed to the air of a room, of which the doors and windows
were constantly open for a period of ten years, during all which time,
the air though constantly changed, was completely impregnated with
the odor of musk, and yet, at the end of that time, the particle was
found not to have sensibly diminished in weight."
54 DOMESTIC SCIENCE.
mates of any house so situated. However, contami-
nation of the air from such causes may surely be
detected by a keen sense of smell.*
In wet localities, quantities of the injurious carbur-
ctted hydrogen (marsh gas) originate from the rotting
matters in the soil, and though this gas is itself with-
out odor yet when arising from such source it is always
associated with ill smelling gases.
In such localities, too, and more especially in vol-
canic regions and in the vicinity of "sulphur springs,"
the air is rich in sulphuretted hydrogen, sometimes
called from one of its very un -inviting sources
"rotten -egg gas.'' It is characterized by a most
disgusting odor, and when inhaled even in small
quantities produces severe headaches, nausea, and
general prostration, and in larger amounts it excites a
stupefying effect, which may terminate fatally. This
substance is a constituent of the gases of sewers, and
sometimes finds its way into dwellings from defective
drain pipes, there, by its soothing effect upon
the inmates its presence is to their senses im-
perceptible though its effects are positively deadly.
Having seen that contamination of air in our dwell-
ings is constantly taking place, it is of interest to enquire
as to the rate at which such processes are operating.
*"The offensive trades mentioned in tlie Tublic Health Act of 1875"
(England) "are those of blood-boiler, bone-boiler, fell-monger, soap-
boiler, tallow melter, tripe-boiler. The model byelaws of the local
Government Board include in addition, those of blood-dryer, leather-
dresser, tanner, fat-melter or fat-extractor, glue-maker, size-maker
and gut-scraper as being trades for which regulation by sanitary
authority is desirable."— Farkes. These occupation^ are all attended
l)y foul odors, and such i)ursuits the sanitary authorities of England
li ive found advisable to restrict.
THK AIR OF ROOMS. 55
Many attempts have been made to determine the average
quantity of air vitiated by the respiration of a single
person during a specified length of time; but the re-
sults are widely different owing to the varying rapidity
of the breathing act, and the absence of uniformity in
lung capacity.
We may safely say, as the result of numerous and
elaborate experiments that an adult person of average
size in a state of restordinarilly expires 0.6 cubic foot of
carbon dioxide per hour. The amount of this gas
naturally present in the outer air is found by analysis
to be about 0.04 per cent., or 0.4 parts per thousand.
From the experimental labors of Dr. Chammont and
others, we learn that a disagreeable smell is perceptible
in the air of rooms as soon as the carbon dioxide has
reached 0.06 per cent, or 0.6 parts per thousand.*
This amount, which is 0.2 j^arts per thousand above
that contained in pure air is considered by reliable
authorities as the maximum quantity to be tolerated in
the air of inhabited rooms.
Suppose an adult person to be confined in an air-
tight enclosure containing 3000 cubic feet of space.
In an hour he would give to the enclosed air 0.6 cubic
foot of carbon dioxide ; this added to the amount of the
gas present in pure air would make the total quantity
1.8 cubic feet, thus: — 0.6 -f (0.4 X 3 = 12) = 1.8.
*Tlie bad smell here referred to is not due to tlie carbon dioxide it-
self, this being an odorless gas, but arises from the foul organic matters
of the expired air, and these contaminating ingredients increase in
l)roportion to the carbon dioxide. As no strictly accurate methods of
determining the amount of such putrescible substances have been
devised, it is a rule with chemists to determine the carbon dioxide in
*ihe air under examination, and then to estimate the amount of organic
matter from this result.
56 DOMESTIC SCIENCE.
This being distributed among 3000 cubic feet would
represent 1.8-^-3=0.6 cubic footper thousand, and here
we see the permissable limit is exactly reached. In order
to keep the air within this limit of impurity, during a
second hour 3000 cubic feet of fresh air should be
admitted to replace the contaminated air of the chamber.
From such deductions as these, it is stated by many
authorities that, to be properly ventilated a dwelling
house should receive 3000 cubic feet of fresh air per
hour for each of its inmates. This amount may seem
excessive ; yet in determining it, no allowance has been
made for the many contaminating influences beside the
exhalations of the occupants. Dr. Billings places the
requisite supply of air at one cubic foot per second, o»
3600 cubic feet per hour.
If fires and lights are burning in the rooms, additional
allowance in the supply of fresh air should be made.
It is not possible to make an accurate measurement of
each of the many sources of contamination, it is
necessary, therefore, to make liberal allowance for di-
ficiencies in providing for the air supply of houses.
The more closely we can cause the air within doors to
approach in composition the atmosphere without, the
more beneficial will be its effect upon health. Children
expire a lower proportion of carbon dioxide, than do
adults. Persons engaged in physical exertion exhale
much more than the ordinary amount; sick people re-
quire a greater supply of fresh air than is indispens-
able to the healthy. It is therefore plain to us that
buildings used for different purposes require varying
allowances for the proper supply of air.
At the rate of contamination already stated, the air
THE AIR OF ROOMS. 57
ill an ordinary bedroom, say 12 by 14 by 11 feet, con-
taining 1848 cubic feet of space, would be contaminated
by the exhalations of a single occupant in a little less
than 37 minutes. A school room 28 by 35 by 14 feet
would contain 13,720 cubic feet of air. Suppose such
a room to be occupied by 60 children, allowing each of
them only 2000 cubic feet of air per hour, the contained
atmosphere would become vitiated in less than 7
minutes.
Fortunately for most of us, the doors and windows
of ordinary dwellings are seldom made to close
tightly ; consequently they permit some passage of air,
and the evil results of neglect in ventilation ai-e delayed
beyond the theoretical indications.
The amount of space necessary to the well being of
the inmates of a room is a subject requiring attention.
If the space be made inadequately small, the entrance
of a proper amount of air within a given time may cause
injurious draught. *
The figures already given as indicating the necessary
supply of fresh air are based upon the investigations
of many leading authorities. On this subject however
there is a wide discrepancy of opinion, and some writers
*Parkes has furnished us the following good illustration. For in-
stance, suppose in a dormitory occupied by 10 persons the amount of
space per head is only 300 feet ; to supply 3000 cubic feet of fresh air
per hour, 30,000 cubic feet must be admitted in this period, and the air
of the room will be completely changed 10 times, a proceeding which
would cause in cold weather unless the entering air was warm, a most
disagreeable draught, for the cold air could not be properly distributed
before reaching the persons of the occupants. But if the cubic space
per head be lOOO cubic feet, then the air of the dormitory need be
changed only 3 times per hour, and if such renewal is effected steadily
and gradually, the cold entering air is broken up, and mixing with the
warm air of the apartment creates no draught." The same author has
5S r)OMtestic sOifiNcE.
give figures whicli by comparison would seem dispro-
portionately low.
Among builders there is a woeful lack of uniformity
in ideas as to the requisite air su^Dpl}' for health. The
writer has applied to a number of prominent architects
for such information, some answers obtained indicated a
belief in the figures above quoted ; others gave very
low estimates. One architect considered necessary
16.6 cubic feet per minute, and one gave 4 cubic feet
per minute as a liberal estimate, adding that 4.5 cubic
feet would be an exceptionally good. Chemical
analysis would show the air of occupied rooms so
supplied, to be truly filthy, and buildings so constructed
are far from healthful.
It is well to set our ideal conditions of atmospheric
purity fairly high, and then approach them as closely a
the prevailing conditions may permit.
Another prolific source of contamination to the air of
dwellings arises from the hurtful custom of digging
cellars beneath the floors of houses. Cellars are usually
damp and musty, even if nothing be stored in them ;
but such places are commonly made receptacles for the
most perishable of organic products. The foul gases
) is perforated, and a gutter and waste pipe (c) are
arranged below, to catch the water from the meltiiig
ice, a large flue (d) conducts the cold descending air
into the rooms ; an upper box (e) usually made of wire
contains charcoal, which serves to purify the entering
air and also to retard the melting of the ice.*
Even within closed rooms, moving currents with
consequent draughts are frequent. During cold weather,
the windows are considerably colder -than the thicker
* Youman's says of this ventilator, "Tliis arrangement on a small
scale has been mounted on secretaries, to secure a cool and refreshing
iiir while writing; over heds to cool the air while sleeping; and over
cradles to furnish pure air for sick children."
86
DOMESTIC SCIENCE.
walls, consequently the inside air in contact with the
cold glass becomes chilled and falls ; while a warmed
current from other parts of the room sets in to fill the
space vacated by the descending cold air. A person
sitting by a window under such circumstances would
be entirely enveloped in the falling cloud of cold air,
with great detriment to his health. To lessen this
danger, builders now plan double windows consisting
of an outer and an inner
sash, with a few inches
space between. The air
within this space serves as
a non-conducting wall
separating the outer cold
atmosphere from the
warmer air of the room.
By holding a candle flame
near windows, and along-
side the walls, the presence
of complicated currents
within the room will be
at once revealed. Most
of the simplest methods
of ventilation are associat-
ed with the means of
warming the apartments ;
indeed the subjects of
ventilation and warming-
are so closely related, that to consider them independ-
ently of each other would be almost impossible.
A good fire in an open grate necessitates an ample
chimney draught ; the rising current within the flue cx-
Fig. 35.
Lyman's ventilator.
VENTILATION. 8 7
ferts a powerful aspirating effect, which results in the
ready removal of air from the room. A correspond-
ing quantity of other air must ent^r, to replace that
which has been taken away. This incoming air causes
a powerful current through the room toward the
grate ; indeed, in the case of the wide open grates of
olden times, the draught was so great that our worthy
ancestors found it necessary to provide specially con-
structed seats, called settles, with high close backs, for
use before their roaring fires.
In comparison with these high fire places^ capable
of admitting the Yule logs without difficulty, the open
grates of modern times seem very much contracted ;
the space above the fire bars, — and this largely determ-
ines the aspirating power of the grate, — being now re-
duced to the smallest possible dimensions. Many
forms of "ventilator -stoves" have of late appeared for
sale. Such a stove is constructed with a double casing ;
air enters below, and after becoming warmed it escapes
into the room through a perforated top.
The aspirating effects of a chimney increases in pro-
Xjortion to the energy of the fire ; though observation
has proved that a decided draught is noticeable in chim-
neys even when no fire is in the grates. If a chimney
be constructed with a double flue, one division may be
used specially as a ventilating shaft ; the air within it,
being warmed through proximity to the heating flue,
will rise with vigor. An objection to the use of double
flues has been found in the fact that, if of improper
construction, or if there be no adequate inlet for air to
the apartment, they are apt to permit downward currents ,
and thus to draw into the room smoke from the fire flue.
88
DOMESTIC SCIENCE.
The apertures that lead from the room into the flue
^re usually guarded by adjustable registers, the com-
monest form of which consists of an iron grating and a
movable back, so arranged that the passage may be
opened or closed at pleasure. The efficiency of such a
register may be greatly increased by attaching to the
inside of the bars a flap of thin oil cloth or of oiled
silk ; this will yield to pressure from the room toward
the chimney, but the least impulse in an opposite di-
rection will cause
i^i£ ^i>ry^^^y/.^^^7^ \ %,::^2^^^ the curtaiu to be
pushed in close
contact with the
inside of the regis -
ter, thus prevent-
ing the entrance of
back currents into
the room. Perhaps
the best contriv-
ance of the kind
is the Arnott valve,
which consists of
a movable door of
metal, set in the
chimney aperture,
and so delicately
adjusted as to yield
to the slightest cur-
rent toward the
chimney, and to
close firmly and easily when pressed in an opposite
direction.
For the ventilation of large buildings many devices
Fig. 36.
Gillis system of ventilating.
VENTILATION. 89
depending upon the expansion of air by warming have
been proposed. A very efficient method is known as
the Gillis system ; this however can be used only in
steam warmed buildings. As is shown in figure 36, a
large [shaft extends from the lowest floor through the
roof. Up the center of this shaft a steam pipe is car-
ried. In each room, two openings, one at the top and
the other near the floor, communicate with the shaft ;
these apertures are provided with registers and auto -
matic valves. The heat of the steam pipe causes a
powerful upward current, by which air is drawn from
the rooms.
MECHANICAL AIDS TO VENTILATION.
Many forms of air -propellers have been proposed for
purposes of ventilation. Most of them possess some merit,
and some of them rank among the most efficient of ventil -
ators. The exhaust fan seems to be a favorite device.
Dr. Mott speaking of the Blackburn fan, one of the most
efficient kinds, states that a single 48 inch fan, if
made to run at the rate of 500 to 600 revolutions per
minute, will carry off 30,000 cubic feet of air per minute.
Revolving cowls on chimney tops, if properly con-
structed, serve to increase the aspirating effects of
chimney flues.
Thus far our attention has been applied to methods
for removing the air from rooms ; adequate means for
introducing a supply of fresh air are also to be con-
sidered. Many common forms of inlets are objection-
able because of the injurious draughts to which they
give rise.
In the ventilation of large buildings, pipes are often
employed for conveying air to the interior ; these can
90
DOMESTIC SClfeNCtei
be easily operated with good results ; but in small
dwellings, windows and transoms are usually relied
upon for admitting air. Where inlet pipes are used,
however, a great advantage is possessed in the ease with
which the incoming air may be warmed. The pipes
may be passed through a heating box connected with
the furnace ; and if the air thus warmed be found
deficient in moisture, evaporating pans of water may
be placed in the course of the stream.
By opening the upper sash of a window, a strong
entering current may be established. The cold air
however, will fall rapidly, without diffusing itself suf-
ficiently throughout the room. If there be a fire in the
room, this current of
cold air w ill continue its
course to the grate, and
thus be speedily taken
from the room, having
served but little the pur-
poses of ventilation.
It has been proved to
be advantageous to
place a board at an ang-
le on tri3 upper part of
the sash, so as to de-
flect the entering cur-
rent toward the ceiling;
(see figure 3 7.)
On the same principle,
the efficiency of tran-
soms may be greatly
increased by hinging them at the bottom, so that
Fig. 37.
Entering current of air deflected to-
ward ceiling.
VENTILATION.
91
they may be set obliquely
Fig. as.
Transom hinged so as to deflect
„ currents toward r eiling.
Fig. 39.
(Jurrents entering between window
sashes.
towards the ceiling, as
in figure 38.
With ordinary win-
dows it is a good plan,
and one that is widely
practiced, to raise the
lower sash, and place
beneath it a strip of
board, from four to six
inches wide and of length
sufficient to extend across
the window^ opening,
see figure 3 9 . This leaves
a space between the
sashes, through which
air will enter the room,
the current being direct-
ed upward. Before fall-
ing, the fresh air will
have been diffused.
For breaking up the
entering current so as to
aid in its diffusion,
sheets of finely perfor-
ated metal may be in-
serted in the upper sash
in place of the ordinary
glass panes, or gratings
with inclined slots may
be used to advantage.
It is possible to utilize
windows both as inlet
and outlet air passages.
92 DOMESTIC SCIENCE.
CHAPTER 9.
SOME PROPERTIES OF HEAT.
''PHE close relation existing between the processes of
1- ventilation and those of house warming has been
already mentioned. Incidental reference has been
made to some methods of domestic warming, but be-
fore attempting any detailed consideration of the sub-
ject, it will be well to turn attention to some of the
simple principles by which the form of energy known
as heat is controlled.
Heat is that force which, when operating upon the
nerves of the living body, produces the sensations of
warmth and cold. The true nature of heat, as indeed
of all other forms of force, is very imperfectly under-
stood by mankind ; but it is a general belief among
experimenters and thinking men, that heat in a body
is a manifestation of motion among the particles. The
plausibility of this view is strengthened by the fact
that motion may be transformed with heat; and con-
versely, heat may be made to originate motion, with
but little unaccounted loss of energy in either case.
There is good reason for believing that as a body
grows warm its particles are made to move within
certain limits, with increasing speed, and at the same
time they are driven farther apart, and thus the size of
the bodv is increased. In the case of a fusible solid,
iron for example, the temperature may be raised till
^he particles are so far separated that their cohesion is
SOME PROPERTIES OF HEAT. 93
greatly diminished, and the liquid state results. If
the molten material be still more highly heated, the
gaseous condition may be reached, vapor of iron
corresponding in physical state to steam being pro-
duced.
The general effect of heat when applied to bodies is
to cause expansion. This is true of solids, liquids, and
gases. Figure 40 illustrates a common experiment
upon this point.
A ring and a ball
of metal are pro-
Fig. 40. vided ; they are of
Ball enlarged by heat. g^^j^ relative sizes
that the ball while cold will readily pass through the
ring. By heating the ball, however, it becomes en-
larged, and is not able to pass through the ring.
The blacksmith applies a practical knowledge of
this principle when he heats the tires of wheels before
fitting them about the felloes ; the iron, he knows,
will contract in cooling and thus the tires will fit the
more tightly.
The force exerted by the expansion of solids through
increasing temperature, is enormous. The iron rods
and cables of which suspension bridges are made, move
through considerable distances in the course of a
season's range of temperature.*
A difference of 81° F. between summer and winter is
by no means uncommon ; yet such a change of
* Of the huge Brittania bridge an observer has said, "The ponderous
iron tubes writhe and twist lilce huge serpents under the varying in-
fluences of the solar heat. The span of the tube is depressed only a
quarter of an inch by the heaviest train of cars, while the sun lifts
it two and a half inches."
94 DOMESTIC SCIENCE.
temperature operating on a bar of wrought iron 10
inches long, would increase its length about 1-200 inch ;
this force is equivalent to a strain of 50 tons. It has
been shown by careful trial, a bar of iron measuring
1 square inch in cross -section, in being warmed from
the freezing point to dull red heat, will elongate about
()-1000 of its original length. The mechanical strain
needed to stretch such a bar this amount is about 90
tons.
Many practical illustrations of this principle may be
observed in household operations. The pendulum
rod of a clock is sure to elongate during warm weather
and to shorten during the cold season. Xow the
office of the clock pendulum is that of a regulator to
the time piece ; by its swinging it controls the speed
of the machinery. Observation proves that a long
pendulum requires greater time to vibrate than does a
short one. In warm weather, therefore, the pendulum
is apt to swing more slowly and thus cause the clock
to fall behind in its indications. In cold weather, on
the other hand, the fast -moving pendulum causes the
clock to run ahead of the true time. These irregularities
may be in some degree corrected by raising or lower-
ing the pendulum "bob" in accordance with the pre-
vailing conditions of temperature. Some pendulums
are so constructed as to partially regulate themselves.
These are known as compensation pendulums, the
simplest form of which is the gridiron penduhim,
sketched in figure 41. The pendulum rod consists of
bars of two different metals, usually steel and brass,
so arranged that the bars of one material can elongate
only in a downward direction, they being fixed above ;
SOME PROPERTIES OP HEAT.
95
While the other bars can expand only in an opposite
direction. Thus the upward and downward expansion
may be made to compensate each other, and the pen-
dulum be kept of the
same actual length.
Another form of
compensation pendu-
lum is the mercurial
bob, shown in figure
42. In this the lower
part of the pendulum
consists of a frame-
work or box, within
which a number of
glass vessels, contain-
ing mercury may be
set. Two such ves-
sels are shown in the
figure. As the pen-
dulum rod elongates
through increasing
temperature, the
mercury in the open
vessels, also expands
and consequently
Fig. 41.
Gridiron compensa-
tion pendulum.
Fig. 42.
rises. These opposite Mercurai pendu-
lum bob.
expansions may neu-
tralize each other's effect, and the "center of oscilla-
tion," which determines the true length of the pendu-
lum, may remain unchanged.
Although we observe fewer illustrations of the ex-
pansion of liquids and gases under the influence of
96
DOMESTIC SCIENCE.
Fig. 43.
Liquid expanding by
lieat.
heat, yet careful experiment will show that these
bodies, too, obey the general law. Take a glass
bulb attached to a stem or a small glass flask as
as in figure 43, provided with a tight-fitting cork
through which passes an open
tube ; fill the vessel with water
and gently warm. The liquid
rises in the tube under the ex-
pansive influence of the heat.
Now take a similar bulb or
flask, empty and dry ; invert and
place the stem in a vessel of water
(see figure 44). Grasp the
bulb in the hand ; the warmth
will cause the air within to ex-
pand till it drives the water from the hollow stem and
escapes in bubbles through the liquid in the tumbler.
Now remove the hand ; as the air cools it tends to
resume its former dimen-
sions ; but as a portion has
escaped, a corresponding
quantity of water enters the
bulb.
Upon the expansion of
liquids by heat depends the
action of the ordinary Ther-
mometer. The word is de-
rived fron the Greek thermos — heat, and metron,
measure, therefore a measurer of temperature. As
commonly constructed, it consists of a bulb of thin
glass with which a long hollow stem of fine caliber is
continuous ; this is shown in figure 45. A quantity of
Fig. 44.
(lases expanding wlien warm
SOME PROPERTIES OF HEAT.
97
mercury (quicksilver) or of alcohol fills the bulb and
extends some distance into the tube.
The stem is hermetically sealed at the
top, and the space above the fluid is a
vacuum, the air having been removed
therefrom before the tube was sealed.
A rise of temperature causes the liquid
within the bulb to expand ; the only
direction in which it is free to move is
the upward one ; the liquid therefore
rises. A cooling effect will result in a
contraction of the fluid, and a conse-
^^ quent fall of its level within the tube.
Fig. 45.
Thermometer-bulb Such an instrument will reveal the
and stem. p^^^j^ ^j ^ difference of temperature ;
but the degree of difference cannot be determined till
the thermometer is graduated. The inventor of the
instrument was a German scientist, one Gabriel
Fahrenheit, who lived in the early part of the last
century. He set his thermometer in ice, and marked
upon the tube the level at which the mercury stood :
this degree of temperature he properly called the
''freezing point." The instrument was then trans-
ferred to a bath of boiling water, and the level at
which the mercury then stood was marked on the tube,
and the temperature was named "boiling point."
In a somewhat arbitrary manner, Fahrenheit then
divided the space between the marks on the tube into
180 sections; these he called "degrees." Fahrenheit
knew that ice was not the coldest thing in existence ;
by mixing snow or cracked ice and salt he produced a
much lower temperature ; so in a mixture of this kind
98 DOMESTIC SCIENCE.
he immersed the thermometer, and the level of the
merciuy was marked and called "zero." The space
between that point and the freezing point was divided
into 32°. On the Fahrenheit scale, therefore, the
freezing point is 32° above 0°, and the boiling point
is (180° + 32° =) 212° above 0°. AYith a tube of
uniforrii caliber, the graduations may be carried above
and below these points. This scale of thermometric
readings, though very arbitrary in its nature, is the one
most generally used among English speaking nations ;
though for scientific and technical purposes another
system has been adopted.
A Swedish scientist named Celsius, proposed to call
the freezing point 0°, and the boiling point 100°, the
space OM the thermometer stem between the points
thus indicated being divided into 100 equal parts ;
and the graduation being continued both above and
below these fixed points. The Celsius graduation is
sometimes called the centigrade scale. The heat
needed to raise a quantity of water from the freezing
Ijoint to the boiling temperature will cause the mercury
in a thermometer graduated after the Fahrenheit system
to rise from 32° to 212° or through a space of 180
degrees ; and the same heat would raise the mercury
in a Celsius thermometer from 0° to 100°, or through
a space of 100 degrees. It will be seen then that:
1S0° F. correspond to 100° C.
Then '.)° F. •• >••' 5° C.
5'
1° F. corresponds " ^g^C.
, And 1° C. •' •• :' F.
o
SOME PROPERTIES OF HEAT.
99
Now, although as shown above, 180 of the Fahren-
heit degrees correspond to 100 of the Celsius degrees,
it does not follow that the 180th degree above 0° F.
should correspond to the 100th degree adove 0° C,
because the of the Celsius scale marks the freezing
point, while the of the Fahrenheit scale is 32
Fahrenheit degrees below the freezing point. An
allowance for this must be made in transforming the
readings of one scale into terms of the other. The
truth of the following formulae will be seen without
difficulty by the thoughtful student :
F.
C.
32.
mi
C. -f
(F.— .H2).
Figure 46 shows a thermometer
of simple construction, with scales
attached after both the Fahrenheit
and the Celsius (or centigrade)
systems.
The thermometer is an instru-
ment of great utility, and it certain -
ly deserves a more extended service
than is commonly allowed it in
domestic operations. We are apt
to place too much reliance in the
indications of our organs of sense
as to temperature, and t>ese indi-
cations are often deceptive.
Fig 4G. *Tlie old-time demonstration will i
^*^^™th?F^andthe'^^^ the point. Provide three bowls orb,
C. systems. medium size; into the middle one pu .
of medium temperature, say about G
into one of the remaining vessels put some ice water ; with the
ace water as hot as can be borne without injury when in con
rate
^f
100 DOMESTIC SCIENCE.
Many cheap thermometers are inaccurately gradu-
ated ; their error, however, seldom exceeds 2°. For
domestic purposes a thermomemter possessing the fol-
lowing characteristics will be found most generally use-
ful :
(1) The graduation markings should be on the glass
stem rather than upon an attached scale.
(2) If set in a frame the tube should be readily re-
movable that it may be used when so needed, to de-
termine the temperature of liquids.
(3) The graduations should extend at least from
0° to 212° F.
with the flesh. Now immerse one hand in the hot liquid, the other in
the ice water ; take notice of the sensations, then plunge both hands
into the bowl of water at ordinary temperature. To the hand that
came from the hot water this seems unendurably cold; to the hand
just taken from the ice water, the contents of the middle bowl seem
to be intensely hot. Neither of these sensations indicates the truth.
COMMUNICATION OF HEAT. 101
CHAPTER 10.
COMMUNICATION OF HEAT LATENT AND SPECIFIC HEAT.
IF A BAR of Iron be set with one end in a fire, after
a very short time the other end will have become
hot. It is plain that in this case the heat must have
come from the fire : it must have been communicated
along the line of particles from one end of the bar to
the other. To be more accurate in expression, we
should say the heat has been conducted along the iron :
in consequence of the property here shown the metal
is said to be a conductor of heat, and this process of
heat -communication is known as conduction.
An impressive illustration of this effect may be pro-
duced as follows :— Provide a thick iron or copper
-. about a foot long (see figure 47), by means of wax
the bar at equal distances a number of mar-
bles V, ' Mllets. Insert one end of the bar in a
Fig. 47.
LHeat being conducted along a bar of iron.
flame : one by one the balls are melted off, showing by
their successive falls the invasion of the particles by
the heat.
102 DOMESTIC SCIENCE.
An apparatus designed to demonstrate the relative
conductivity of different metals is shown in figure 48,
it consists of a brass box, carry-
ing a number of rods of differ-
ent substances. The free ends
of the rods are first covered
with wax : the box is then
tilled with hot water, and the
Fig. 48. order in which the wax on each
Condiictometer. t ,. .^ . , -,
rod liquifies is noted.
The common metals and alloys are arranged in the
following order with respect to their conducting pow-
ers : (1) silver; (2) copper; (3) gold; (4) brass;
(5) tin ; (6) iron ; (7) lead ; (8) platinum ; (9) Ger-
man silver: (10) bismuth.
To these may be added several common substances
other than metals, arranged on the same plan : (11)
marble; (12) porcelain; (13) clay; (14) woods;
(15) fats; (16) snow; (l7) air; (18) silk; (19^
charcoal; (20) cotton; (21) lampblack; (22'^^
Most liquids are poor conductors «^^
statement may seem strange when ue iact
that heat seems to be uni^^r ' ■ .^i throughout
liquid masses. Su'^^ . ^i. heat is effected by
other means thr.. ..ction as above described.
When licr ■ ^re heated they become specific -
"''v jnsequently they rise, thus making
■■'- ar most efficient fabrics for clothing are poor conductors of lieat.
A coat of fur or of woven wool, if wrapped about a living being will retain
the bodily lieat: if wrapped around a block of ice the same garment
keei)S the ice cold. In the one case the wrapping prevents tlie escai)e
of lieat from the waruier body to the cooler air: In the other It guards
the ice against access of warm air.
COMMUNICATION OF HEAT.
103
Fig. 49.
Convection of heat in a body
of liquid.
room for colder particles, which in turn become
warmed and rise. The course of these rising currents
of warm water and descend-
ing streams of cold may be
followed in the warming of
a flask or beaker containing
water, to which a small quan-
tity of sawdust or other finely
divided, opaque matter has
been added, (see figure 4 9).
Such a mode of diffusing
heat by the successive warm-
ing of separate particles, is
known as convection. If
Avater were a good conductor of heat it would trans-
mit heat as well in a doAvnward as in an upward direc-
tion. The inability of the liquid
to do this may be thus shown : A
funnel (figure 50) with a wide
throat is fitted with an " air ther-
mometer " passing through its
neck and dipping in a vessel of
water below. Water is poured
into the funnel till the thermome-
ter bulb is covered ; a little ether
is then poured upon the water and
ignited. Though the flame be
within half an inch of the bulb, the
Fig. 50. heat is conducted downward so
^^^ condJc^ heat"1n ^a ^^^wly as scarcely to cause an ex-
downward direction, pansion within the bulb.
There is a third method bv which heat is diffused, as
104 DOMESTIC SCIEMCE.
may be shown by holding the hand in front of a fire.
The flesh soon becomes warmed ; not by conduction,
for between the hand and the fire there is no material
connection, except the air, and air like all gases,
is of but slight conductivity ; neither is the hand
warmed by convection, for warm convection currents
are ascending ones. It is plain that the heat must have
penetrated the intervening air ; must have traveled
from the fire to the flesh. Such mode of heat com-
munication is known as radiation, and the heat so
transmitted is called radiant heat. Radiant heat passes
outward from its source, along straight lines in all
directions ; the heat rays fall upon objects in their
course and warm them, without, however, raising the
temperature of the intervening air. Radiant heat may
be transmitted in a vacuum, thus proving its inde-
pendence of air as a medium of conveyance. The laws
of its motion ai'e similar to those of light ; it comes to
us from the sun associated with light, both traveling
at the rate of 185,000 miles per second. The intensity
of radiant heat diminishes as the square of the distance
from its source increases ; therefore a person sitting
within two feet of a fire would receive four times as
much radiant heat as would fall upon a second person
situated four feet from the fire.
HIDDEN HEAT : LATENT AND SPECIFIC.
In speaking of the measurement of heat, we have
thus far dealt only with thermometric indications ; yet
there are many operations in the course of which heat
changes are not revealed bv the thermometer. Thus a
COMMUNICATION OF HEAT. 105
vessel containing ice at the freezing temperature may
be exposed to heat, but until the ice has become thor-
oughly liquified the thermometer would indicate no
rise. The energy has not been lost however ; it has
been expended in separating the ice particles, and in
overcoming the cohesion between them so as to pro -
duce the liquid state ; and this energy will be again
freed as heat when the liquid returns to the solid
condition.* The heat so escaping thermometric
measurement is known as latent heat. The heat thus
rendered latent in the melting of ice is about 80 times
that required to warm the same amount of water 1° C.
Heat is also rendered latent in changing substances
from the liquid to the gaseous state. In the boiling of
water much heat is absorbed, the steam being no
warmer according to the thermometer than was the
water at the instant of its transformation. Experi-
ment shows that to vaporize a given quantity of water
at the boiling temperature requires about 537 times
as much heat as is needed to raise that same quan-
tity of water through a range of 1° C.
Under all circumstances, water appears compara-
tively sluggish in responding to the in'fluences of heat.
The amount of heat that would raise a pound of water
1° in temperature, would warm 30 lbs. of quicksilver
through the same range. We perceive then that dif-
* Though paradoxical, it is true that the freezing process is associ-
ated with the liberation of heat, and is therefore in one sense a warm-
ing process. In passing from the liquid to the solid state, water gives
out all of the heat acquired by it and rendered latent in melting. This
principle is often made use of to prevent the freezing of vegetables and
fruits during cold weather. Open vessels of water placed in proximity
to such perishable articles in a closed room, will liberate sufficient heat
to warm the air of the room through a range of several degrees.
5
lOfi DOMESTIC SCIENCE.
ferent substances possess varying capacities for heat.
If to warm a quantity of water through a given range
of temperature requires 30 times as much heat as would
serve to similarly warm an equal amount of mercury,
then in cooling, the water would give out 30 times as
much heat as would the mercury. The relative capa-
city of substances for holding and retaining heat
is known as specific heat.
An instructive demonstration of specific heat may be
made thus (figure 51) : Procure
a number of small balls of equal
weight, one each of iron, copper,
silver, tin, lead, and bismuth.
Heat all to the same tempera -
ture by immersing them in a
Fig. 51. bath of hot oil ; then place them
^''"SiiS^^'liilS^^'way on a cake of paraffin or of bees
through wax with vary- ,^„^^ T'v.r. ii^^n o/->^ii mr.ifc. ifo
ing rapidity, because of ^^^x. Ihe iron soon melts its
hS '"''''^''''^ '^'''^' way through the wax ; then fol-
low in order the copper, the silver, the lead and
the bismuth. Some of the metals therefore are much
better absorbents of heat than are others.
Considering water as the standard, the specific heat
of several common substances may be expressed as
follows :
*Water - - - - - - 100
Air ------ - 23.75
* " It is hecause water is capable of receiving so much heat that it is
better adapted than any other substance to quench thirst. A small
quantity of it will go much farther in absorbing the feverish heat of
the mouth and throat than an^(iual amount of any other liquid. When
swallowed and taken into the stomach, or when poured over the in-
flamed skin, it is the most grateful and cooling of all substances. For
the same reason, a bottle of hot water will keep the feet warm much
longer than a hot stone or block."'— Dr. YoijM.\xs.
COMMUNICATION OF HEAT. 107
Oxygen ------ 21.75
Sulphur ------ 20.26
Iron ------- 11.38
Copper ------ 9.52
Silver ------ 5.70
Tin ------ - 5.62
Mercury ------ 3.33
Lead ------- 3.14
Bismuth ------ 3.08
Alcohol ----- - 5.05
Ether _.---- 5.4(;
The beneficial effects resulting from the operation
of these laws of latent and specific heat are of the
highest order. Suppose for a moment that the princi-
ple of latent heat did not exist. As spring time ap-
proached, the vast masses of ice and snow of lakes
rivers and mountains would become warmed to the
temperature of 32° F., the melting and freezing point
of water ; and the least further rise would result in an
immediate mighty bursting of the bonds of frost ; the
ice and snow would become almost instantaneously
liquified, and wide -spread destruction would be in-
evitable. But the All -seeing One has wisely decreed
that much heat shall be required to change the physical
state of matter ; such changes must then of necessity be
gradual ; and in orderly march, with the precision of
prisoners under full control, these frost-bound parti-
cles return to their condition of liquid liberty. So, too,
the advances of winter are restrained and the severity
of the season is tempered by reason of the great
amount of latent heat escaping from freezing water.
But for the operation of this principle, a fall of tem-
perature only one degree below the freezing point,
would result in the instantaneous formation of ice on
a stupendous scale. Try to think of the possible re-
sults, if as soon as the boiling point were reached,
108 DOMESTIC SCIENCE.
water was instantly converted into steam. Such a
prodigious expansion would be followed by demonstra-
tions of explosive violence, such as man cannot con-
ceive of. And but for its high specific capacity for
heat, water would respond with alarming readiness to
the slightest changes of temperature ; and the result could
not be other than destructive. But such dire calamities
are prevented through the operation of the laws of
nature, which are the laws of God. These stupendous
forces are under perfect control ; the Mighty One holds
them in His power.
PRODUCTION OF HEAT. lOO
CHAPTER 11.
PRODUCTION OF HEAT ; FUELS AND FLAME.
THE earth is warmed by the heat rays that come to
it from the sun. That brilliant orb has been con-
stituted by the Creator as the source of warmth and
light and chemical energy for our globe. During the
cold season, when we receive less directly these ener-
gizing rays, and during the night, when the hemi-
sphere on which we live is turned away from the
glowing sun, and for special purposes at other times,
it is necessary to provide for the production of arti-
ficial heat. The common methods of accomplishing
this depend upon the chemical energy of combustion,
and when employed for such purposes combustible
substances are known abs fuels.
To aid us in comprehending the chemical processes
attending the burning of fuel, let us examine a small
flame ; that of a candle will answer our purpose well ;
but first — a word as to the candle itself. A candle
consists of a solid cylinder of wax or tallow, or some
such easily fusible and combustible material ; this is
the fuel. In the middle of this cylinder a wick is
placed ; this serves by its porous nature to convey
the melted wax from the little cup at the top of the cyl -
inder to the region of the flame. In the burning pro-
cess a union occurs between the carbon and the hydro -
gen of the fuel and the oxygen of the air.
Hydrogen in burning with oxygen produces water ;
no
DOMESTIC SCIENCE.
carbon in so combining forms carbon dioxide. Hold
over a candle flame a dry cold tumbler (figure 52) ;
water from the flame con-
denses on the inside of the
glass. A similar thing oc-
curs when a cold lamp chim-
ney is placed in position
over the freshly lighted wick.
Soon, however, tumbler and
lamp chimney become so
Fig 52. warm as not to allow the de-
Moisture formed by tlie caudle position of water,
flame, condensing on a cold
jSTow arrange an apparatus
The gases rising from the
burning candle are drawn through the bottle, in which
tumbler.
as shown in figure 53.
Fit?. 5.H.
Gases rising from a candle flame, being drawn through lime water.
is a quantity of clear lime water. This lime water
soon becomes turbid from the formation within it of
PRODUCTION OF HEAT. Ill
insoluble lime carbonate. This, it will be remenabered,
is a proof of the presence of carbon dioxide.
The Jfame of the candle is due to the combustion of
gaseous matters. Fuels containing large quantities of
volatile combustible matters burn with large flames ;
such is the case with resinous woods, soft coals, tar,
pitch, oils and the like ; while fuels that consist mostly
of fixed carbon, such as charcoal, coke and anthracite
coal, burn with a steady glow, but with little flame.
Indeed, flame may be regarded in all cases as burning
gas. To demonstrate this fact, let us return once
more to our candle. When it is burning brightly, blow it
out by a sudden puff ; a stream of vapor is now seen
rising from the wick ; this consists of the volatile
part of the wax, which had been carried to the re-
gion of the flame, but now that the candle is extin-
guished it cannot burn and therefore it escapes. Now
apply a light to this rising column of vapor ; the flame
runs along the line and re -ignites the wick.
That this combustible va-
por is produced through the
action of heat on the wax,
may be proved by warming
a quantity of wax in a glass
tube provided with an es-
cape jet ; vapor rises and
Fig. 54. may be burned as it issues
Combustible vapors of volatilized n ,-, • , ^^ ^,x
wax. from the ]et (figure 54).
The hollow nature of the flame may be shown by
placing a splinter of wood across the flame, as in
figure 55. A charring action will occur where the
outer shell of flame touches the wood ; but between
112
DOMESTIC SCIENCE.
these points the wood is unscorched. By deft action
a match head may be introduced into the flame centre,
Fig. 55,
Showing that the candle flame is
hollow.
Fig. 56.
Match head in centre of flame re-
maining unburned.
and there held unlighted-, though the heat may be suf-
ficient to melt the ignition material (see figure 56).
A strip of paper may be depressed upon the flame, as
in figure 57. On being
removed, a blackened
ring enclosing an un-
scorched centre will be
seen.
The processes operat-
ing in and about the
larger flames may be thus
understood from a study
Eig. 57.
Showing that flame is hollow. of the burnmg candle.
The hydrogen and the carbon of wood and coal unite
with the oxygen of the air, and in so doing they evolve
a large and measurable quantity of heat. Fuels are
etticient in proportion to the amount of hydrogen and
carbon they contain. All natural fuels, however, con-
tain a considerable quantity of incombustible matter ;
the solid portions in the form of ash remain after the
burniiia'.
PRODUCTION OF HEAT. 113
Another cause of diminution in the heating- vahie of
fuels lies in the amount of water contained by them.
"We all know that green woods, rich in sap, are far less
eflScient fuels than are dry woods. Water in fuels
lowers the percentage of available hydrogen and car-
bon ; its presence retards the combustive process, by
absorbing much heat as the burning proceeds ; and
when the boiling temperature is reached, the water is
converted into steam, and thus a large amount of heat
is rendered latent, and is carried off by the escaping
vapor.
Woods may be ranged in the following order with
respect to their heating powers, the poor kinds being
named first: White pine, poplar, soft maple, cherry,/-
cedar, elm, hard maple, walnut, beech, apple, ash,
white oak, hickory. Hydrogen in burning produces
over three times as much heat as does the same weight
of carbon. The calorific or heating power of fuels de-
pends upon the amount of oxygen with which thev
unite in the course of combustion. Thus, 1 lb. of hy-
drogen while burning will combine with 8 lbs. of oxy-
gen ; while 1 lb. of carbon unites with but 21 lbs. of
oxygen. The practical efficiency of hydrogen as a fuel
is lowered, however, by the fact that the water pro-
duced by its combustion absorbs and renders latent a
large proportion of the heat. The carbon dioxide re-
sulting from the burning of carbon, having compara-
tively little capacity for heat, and undergoing no chano-e
of state, absorbs much less of the heat of combustion.
For practical purposes, therefore, the proportion of
fixed carbon in fuels largely determines their relative
efiiciency.
114 DOMESTIC SCIENCE.
Coal exists in many forms, and of widely varying
degrees of efficiency as fuel. There is much evidence
to support the view that mineral coal is but trans-
formed vegetable matter. The remains of many plants
are found in mines ; the microscope reveals, even in
the ash of the hardest coal, a cellular structure similar
to that known to exist in plants ; a substance very sim-
ilar to coal has been artificially made through the
operation of heat and pressure upon sawdust and other
finely divided vegetable matter. Coals are usually
classified according to the degree of metamorphism to
which they have been subjected, as shown by the vary-
ing amounts of volatile matter which they still contain.
The chief varieties are lignite, cannel coal, bituminous
coal, semi -bituminous coal and anthracite.
Lignite, often callecl brown coal, plainly shows the
woody structure. It is soft and lustreless, and so dif-
ferent in appearance from the common forms of coal,
that at first sight one scarcely considers it as belonging
to the same family. A typical sample from Saxony
was analyzed by the writer and found to consist of :
Moisture, 8.24 i)er cent. ; volatile combustible matter,
49.96; fixed carbon, 38.31; ash, 3.45.
Cannel coaZ, which in some places is known as pa^rof
coal, is usually grayish black in color, dense and lus-
treless. AVhen broken it shows a conchoidal or shell -
shaped fracture. It contains a tolerably large percent-
age of volatile matter, and is consequently Avell adapted
for the manufacture of gas ; in England it is known as
gas coal. The name cannel is due to a practice still
followed in Scotland, of using thin pieces of the coal
in place of candles (Scottish pronunciation — can-
PRODUCTION OF HEAT. 115
nels). A good sample of cannel coal from Virginia
yielded to the author's analysis: Moisture, 0.243 per
cent. ; volatile combustible matter, 60.818 ; fixed car-
bon, 35.135 ; ash, 3.882.
Bituminous coal contains from 40 to 50 per cent,
volatile matter. This constitutes the commonest class
of coals. It is a black, lustrous, friable solid, and burns
with a large flame. Varieties of this coal that are es-
pecially rich in volatile substances are described as fat
bituminous coals. A sample of bituminous coal from
Pleasant Valley, Utah, proved upon analysis to possess
this composition: Moisture, 4.56 per cent.; volatile
combustible matter, 39.05; fixed carbon, 54.68; ash,
1.70. Another variety from Weber County, Utah,
yielded: Moisture. 8.117; volatille combustible matter,
42.748; fixed carbon, 46.444; ash, 2.689.
Coal containing fully 50 per cent, of volatile ingred-
ients softens much in burning. Such kinds are popu-
larly called colling coals.
Semi-bituminous coal contains from 15 to 20 per
cent, volatile matters. It is richer in hydrogen than is
anthracite, and it contains more fixed carbon than does
bituminous coal proper. Owing to its ready inflam-
mfibility and the comparatively little smoke attending
its burning, it is in high favor as a fuel for engines and
boiler fires, and is often called steam coal.
, Anthracite is a hard, brittle and highly lustrous coal.
In structure it is very dense, and in breaking shows a
conchoidal fracture. It may contain upwards of 90
per cent, fixed carbon, leaving therefore small room for
volatile ingredients. In burning it evolves great heat,
but no flame. Coke formed from anthracite differs in
116 DOMESTIC SCIE^^CE.
appearance but very slightly from the coal itself. In
different sections of our own country, anthracite is
popularly known as glance coal, stone coal, and hard
coal; in Ireland it is commonly called Kilkenny coal;
in Scotland it is called from its flameless burning blind
coal. The varieties of coal here named are but the chief
or typical kinds. Numerous others are known, differ-
ing in degree from the ones here named. Beside the
natural fuels certain forms of artificially prepared car-
bon are also used ; the chief of these are charcoal and
coke.
Charcoal is produced from wood by distilling off the
volatile matters ; it remains after the process as a black,
brittle solid, containing all the fixed carbon and ash of
the wood. It has many uses beside those of fuel ; some
of these will be subsequently referred to.
Coke results from the distillation of coal. It is
made in large quantities as a by-product in the prepar-
ation of coal gas. It is a porous, friable solid, grayish
in color, and of medium lustre. It is largely used as
a fuel in metallurgical operations.
A very convenient and an efficient artificial fuel is coal
gas. However, the cost of its production and distri -
butiou prevents its use as a heating medium becoming
general. As furnished by its manufacturers, coal gas
may be regarded as the partly purified volatile matter
of coal. Its use is attended by considerable danger,
owing to its poisonous properties and the explosive
nature of mixtures of gas and air. Coal gas is in more
general use as an illuminant, though gas stoves for
heating purposes are in frequent service. Gasoline
or vapor stoves are now in common use. They depend
PRODUCTION OF HEAT. 117
for efficacy upon the burning of the light vapors of pe-
troleum, such as benzine and gasoline, between which
substances, as found in the market, there is very little
difference other than that of the prices charged for
them.
The mode of starting fire is an interesting subject for
study. In very early times, it is said our ancestors
developed fire by forcibly rubbing together pieces of
dry wood ; this method was laborious and its results
uncertain, though it is still employed among savage
tribes. An advance was made in the use of flint and
steel with which to produce a spark, and tinder to be
inflamed thereby. In the early part of the present cen-
tury the tinder-box was a household necessity. Sul-
phur matches, consisting of a globule of sulphur on
the end of a splinter of dry wood, were used in con-
nection with the tinder, the low igniting point of
sulphur making it possible to readily procure a flame
from the smoldering tinder. The matches of the pres-
ent day depend for their inflammability upon the pres -
ence of phosphorus. Common matches are made by
dipping the bits of wood in melted sulphur, and after-
wards in a paste of phosphorus, potassium nitrate
(nitre) and glue. Slight friction inflames the phos-
phorus ; this ignites the sulphur, while the nitre de-
composes and furnishes oxygen to aid the combustion.
The glue forms a hard coating impermeable to air, so
that the phosphorus within the match head is protected
from oxidation till by friction the outer layers are worn
away. In the crackling or explosive matches, potas-
sium chlorate is used in place of nitre ; such matches
burn quickly. If a colored match head be desired, a
118 DOMESTIC SCIENCE.
pigment, usually vermillion, red lead, or Prussian blue
is stirred into the paste.
Manj^ serious results have followed the accidental
ignition of matches, and as a partial safeguard safety
matches were invented, though their use has not become
general. Safety matches are capped with a mixture of
potassium chlorate, antimony sulj^hide, and glue ; they
ignite only when rubbed on a prepared plate contain -
red phosphorus and fine sand or powdered glass. The
red or amorphous phosphorus is far less dangerous than
is the ordinary waxy phosphorus.
HOUSE WARMING. 119
CHAPTER 12.
HOUSE WARMING.
'^PHROUGHOUT the temperate and colder regions of
JL the earth, man finds it necessary to employ means
for artificially warming his home. In this he aims to
secure an indoor temperature which will give comfort
and be conducive to health. No exact temperature
can be definitely named as being under all circum-
stances most advantageous. The bodily susceptibilities
and requirements of different persons for heat vary
considerably, a middle-aged vigorous man may find
no discomfort from cold in a room heated only to 59
or 60 degrees, while an enfeebled or sickly person may
shiver at 70°. It is evidently advisable, therefore, that
a medium temperature should be secured, and the indi-
vidual peculiarities be met as[nearly as possible by suit-
able amounts of clothing. For the majority of human
beings, a house temperature of 02° to 68° will be found
most agreeable and beneficial.
Many methods of warming dwellings are known, of
these the open Jire-place properly claims our first atten-
tion, by reason of its great antiquity. Among ancient
nations the open fire was the only known means of
house warming, and the primitive fire-place was a very
crude affair. The chimney even is a modern invention,
being now but about 600 years old. Before the 13th
century, dwellings were warmed by a method which is
still exemplified in the huts of the Esquimaux — the fire
being on the floor near the middle of the room, and
120 DOMESTIC SOll*>NCte»
the smoke escaping as best it may by the doorway and
through a hole in a roof.
Even among the classical Greeks and Romans, but
little real advancement was made over this primitive
and dirty practice. It is true tliey had vessels specially
provided as fire -holders ; these were known as braziers,
and consisted each of a pan mounted on a tripod of
convenient height, the whole being ornamented mth
carving and symbolical devices.*
The invention of chimneys was soon followed by
that of fire-places proper. The first of these consisted
of a huge square opening in the wall ; but a small part
of this space, however, was actually used for the fire^
the remainder being occupied by seats along the sides.
Count Rumford pointed out some of the many defects
of such a structure ; he showed that the jambs or side
walls, if built so as to directly face each other, that is,
at right angles to the back of the fire-place, would
simply reflect the heat rays back and forth between
them ; whereas, if the walls were placed at a widening
angle with the back, according to the laws govern-
ing the reflection of rays of force, much of the heat
and light would be thrown into the room. He con-
cluded that the best angle at which the jambs could be
set was 135° with the back of the hearth.
* Dr. Youman says of the Roman fire-place: "They (the Greeks and
Romans) kept fires in open pans called braziers. Those of the Romans
were elegant bronze tripods, supported by carved images with a round
dish above for the fire. A small vase below contained perfumes, odor-
ous gums and aromatic spices, which were used to mask the disagree-
able odor of the combustive products. The portions of the walls most
exposed were painted black, to prevent the visible effects of smoke,
and the rooms occupied in winter had plain cornices and no carved
work or mouldings, so that the soot might be easily cleared away."
ttousfc Warming. 121
The modern fire-place is by comparison a dwarfish
structure ; the open space leading into the chimney
above the grate is reduced to a minimum, and the grate
itself is made to project into the room. Much has been
said in favor of the open grate as a heating device, but
the fact is undisputed that its use is rapidly declining.
The brilliant glare of the burning fuel, fully exposed
to our view, imparts a cheerful influence ; it is in the
nature of man to love warmth and light, and therefore
he has pleasant preferences for the open grate — and
there are many substantial benefits arising from its use.
The heat derived from a clear open fire is almost en-
tirely radiant heat, the air of the room never becom-
ing burnt or excessively heated, and, farther, the fire
does much to promote efficient ventilation. On the
other hand, open fire-places are dusty and dirty addi-
tions to a room ; ashes and soot are sure to escape
from them into the apartments ; the radiant heat
warms chiefly the side of persons and objects that is
directed toward the fire, and in the coldest weather,
when the efficiency of our heating appliances is taxed
the most, this inequality of warmth will be found most
distressing. In addition, open grates do not secure to
the room a uniform temperature ; but very inadequate
regulators ofthecombustion,such as dampers and valves,
are provided, and the varying intensity of the burning
when the fuel in the grate is low and is then replen-
ished, will effect rapid chahges in the temperature of
the room. As regards economy of fuel, nothing can be
said in favor of the open hearth ; experience has demon-
strated that the best grates of modern construction
allow fully 70 "per cent, of the heat to escape up the
12 -2 DOMESTIC SCIENCE.
chimney, and in poorly constructed grates the propor-
tion of loss may reach even 90 per cent.
In England, the open grate remains still in general
use, and some improvements are there being intro-
duced. The following features are considered by many
English authorities (notably Parkes and Teale) as es-
sential in good fire-places: The back of grate should
be about one-third as vride as the front; the sides set
at the angle of 135° ; the sides and back should be of
fire brick ; the back should be inclined forward, that
the flames may play upon it, the whole fire-place
being carried well forward into the room. The chim-
ney throat should be narrowed as much as possible,
and the fire-place and chimney should be built in the
inner walls of the house, so that the escaping heat
may do some good in warming the upper rooms.
Stoves of various forms are now in common use for
domestic warming. A stove may be described as a
box, usually of metal, so constructed as to favor the
combustion of fuel placed within it, and allow the
ready removal of the gaseous products of the burning.
Stoves communicate heat to the room, partly by radia-
tion but mostly by convection. The air in contact
with the heated surface becomes warm, in consequence
of which it rises and gives place to a quantity of
colder air. The air of these rising currents coming in
contact with the colder ceiling and walls, contracts and
sinks ; thus circulating currents are created within the
room. The pipe which leads from the stove to the
chimney opening imparts much heat to the room ; and
this effect is materially increased if elbows are placed
in the pipe. The reason for this is simpl'e — the cooling
HOUSE WARMING
123
Ihf .fo-Hxits \
Opt nines under
OpeniTtas for Cold J' '
Double-case stove.
of the heated gaseous contents of the pipe can occur
only at the surface of the column ; such process will be
necessarily slow, and much of the heat will be carried
to the chimney, whereas, if the current be broken up
as by passing it by angles in the pipe, a circulation
within the moving column will be caused, and more
124 DOMESTIC SCIENCE.
air will come in contact with the pipe walls, thus allow-
ing more heat to escape into the room. Figure 58
illustrates the essential parts and action of the double -
case stove.
Stoves, are of but slight appreciable benefit in room
ventilation, indeed, it is said to their discredit that they
are of actual detriment through allowing the escape of
injurious gases from the fire. In stoves of poor con -
struction, and in the best of stoves badly managed,
this charge is certainly well founded ; but good stoves
under efiicient control are not necessarily as detri-
mental to health as has been claimed. However, if the
iron walls of the stove become too highly heated, pois-
onous gases, especially carbon monoxide, will escape
from the fire into the room. Hot iron, especially if it
be cast iron, is readily permeable to the deadly carbon
monoxide, as also to other gaseous products from the
fire box. Heated iron surfaces are apt to char the
organic impurities of the air that come in contact
therewith, imparting to it a foul smell, and other in-
jurious properties. These ill effects may be prevented
in a great measure by using stoves with large radiating
surfaces, so that no necessity exists of over -heating
any part. The fire-box of heating stoves should be
surrounded by fire brick or other non-conducting ma-
terial : such a casing would assist in regulating the
temperature changes resulting from the varying inten-
sity of the fire. Another decided disadvantage attend-
ing the use of stoves lies in the consequent dryness of
the atmosphere. As air becomes warmed, its capacity
for moisture increases, and the relative humidity of the
air is greatly diminished. This may be partially Qver-
HOUSE WARMING. 125
come by placing open vessels of water on the stove or
about the room. Though the use of stoves is attended
by many serious disadvantages, it is safe to say that
their demerits have been in some cases over- stated to
the raising of a strong popular prejudice against them.
Good stoves may be so operated as to be of far better
effect than are open grates of best construction if inju-
diciously managed.
By the use of anthracite coal stoves it is possible to
retain a fairly constant temperature even for days.
Such stoves, if large and well supplied with draught-
valves and dampers,* may be used with great success ;
and are well suited to houses of medium size, in which
no appliances exist for the more efficient methods of
steam and water warming.
With all the heating arrangements thus far described,
the upper parts of the rooms will be warmer than the
floors, which condition is directly opposite to the re-
quirements of health ; cold feet are the precursors of
many forms of illness. The methods yet to be referred
to promote the distribution of heat at the floor.
Warmed air is extensively used as a medium in
house heating. Fresh air from without is carried to the
furnaces by means of pipes : there it is raised to the
proper temperature; thence it is carried through dis-
tributing pipes to the rooms to be warmed, and then
discharged through register apertures in walls and
* The method of placing a damper or regulating valve in the pipe is
a bad one, since when such a valve is closed the gaseous products of
combustion will surely be thrown into the room. The draught regulators
should be so placed as to control the admission of air to the fire, not
arranged to check the escape of gases.
126 DOMESTIC SCIENCE.
floors. The most serious defect of the warm -air sys-
tem lies in the fact that the air becomes relatively dry,
being in some cases actually scorched, and consequently
tainted from the charring of the contained organic
matter.
Steam-warming is held in high favor as a means for
heating dwelling houses and large buildings. The es-
sential features of the process are these : steam is gen-
erated in a properly constructed boiler ; the vapor is
conveyed through pipes to the apartments that are to
be warmed ; there the steam is passed through one or
more radiators, consisting of a pipe arranged in many
parallel sections. In condensing, the steam imparts its
heat to the air of the room. The latent heat of vapor-
ization has been already explained, (see page 105) It
will be remembered, that in passing from the liquid
state at the boiling temperature (212° F. or 100° C.)
to steam at the same temperature, 537 times as much
heat is absorbed as would be required to raise the tem-
perature of the same amount of water 1° C. This
latent heat, though not measureable by the thermome-
ter, is retained by the steam and in the condensation
of the latter, the whole amount of heat will be again
liberated. Thus water may be vaporized in the cellar,
and the steam be made the carrier of heat into the most
distant parts of the house. How admirable is the
operation of this principle ; how cleanly, efficient and
economical is this method over that of grates or stoves
in rooms, with their inevitable accompaniments of dust
and dirt, irregular temperature, uncontrollable draughts,
woeful waste of energy ! The boiler may be situated at
anv reasonable distance from the ¥ooms to be warmed.
HOUSE WARMING. 127
If far removed, however, it is necessary to protect the
pipes with coatings of non-conducting material, else
much heat will be lost on the way. The conducting
pipes are usually wrapped with many layers of asbestos
fibre ; then with hair felt, and outside of this with several
thicknesses of stout paper ; on this strips of wood are
laid lengthwise and the whole is bound together by
wire. The pipe thus wrapped is enclosed in a wooden
tube, usually a hollowed log. Such insulation is not
needed in small buildings, or in any case wherein the
pipes are not exposed for any great length.
The warming of houses through the medium of warm
ivater depends for its efficacy upon the high specific
heat of water (see page 106), by virtue of which it ab-
sorbs for a given rise of temperature a greater amount
of heat than does any other liquid, and in cooling
through a given range of temperature a correspond-
ingly large amount of heat is given out.
In the loiv pressure system of heating by water, the
pipes are so connected with the boiler as to allow a
complete circulation ; the water returning to the boiler
after having traversed the circuit of pipes. From the
highest point in the course of the pipes a vent is pro -
vided for the escape of steam and heated air. The
water in this system can never exceed in temperature
the boiling point — 212° F., and therefore no scorched
or excessively^ry state of the air is possible.
The method known as the high pressure system re-
quires the use of very stout pipes without a vent. No
boiler being used, the pipes pass directly through the
furnace, and no escape is provided ; the enclosed water
becomes heated under pressure ; its temperature may
158 DOMESTIC SCIENCE.
therefore be raised far above the ordinary boiling
point ; still, as there is no room for expansion ^ steam
is not produced. In this system the water may be
heated above 300° F.
LIGHT AND LIGHTING. " 129
CHAPTER 13.
LIGHT AND LIGHTING.
DURING the daytime we depend for light directly
upon the rays that come to us from the sun ; this
we call natural light ; throughout the dark hours, we
adopt various means for the local production of light ;
this we call artificial light. In reality these terms
are misleading ; the light of lamp and candle is natural
light; it results from the combustion of various ani-
mal and vegetable matters, all of which grow under
the influence of the sun's energy.
Daylight is free to all ; we are only required to pro-
vide for its admission to our homes. It is not doled
out to us by the pound or the quart; no company's
agent calls to read the metre and prepare the bill of
our indebtedness. Light, the purest and the best that
the physical eyes of man have ever come to know, is
showered with a Creator's liberality upon the world. It
floods all places that are open to it. Yet how careless
we grow as to its distribution and use ! Physiologists
declare to us that light is as essential as is warmth to
the welfare of the body. Our homes then should be
well lighted.
It is true that the delicate organs of sight may be
seriously impaired through exposure to light of un-
usual brilliancy ; though the eye strain induced by de-
ficient illumination, is a far more frequent cause of sight
deterioration. The illumination within dwelling rooms
should be such as to produce in the eye a feeling of
130 DOMESTIC SCIENCE.
ease and comfort; no strain should be experienced
when closely viewing any object within the range of
vision. For a person sitting at the table reading or
writing, the light should come from above as through
a skylight, or from the left and back. In this way
the paper or book is well illuminated, and the shadow
is thrown away from the right hand.
For artificial illumination, the methods most com-
monly employed depend upon the combustion of cer-
tain substances, whereby a luminous flame is produced.
An exception to this is seen in the case of the electric
light.
As has already been stated, flame is the result of
the combustion of gases ; solid fuels may evolve great
heat and yet their combustion is flameless. Yet many
flames are but slightly luminous ; for example, hydro-
gen burning with a very intense heat emits but a very
feeble light. - The flame of the common spirit lamp,
depending upon the combustion of the vapor of alcohol,
is almost entirely non -luminous. The luminosity of
flame is due to the incandescence of solid particles
which are present with the gas. The most intense
artificial lights are produced by the incandescence of
solids. Many of the carbon particles in the candle
vapor are heated to incandescence, the supply of oxy-
gen is insuflScient to burn them with undue rapidity ;
they therefore shine. In an ordinary flame (figure 59)
several distinct parts are discernible ; (a) a dark,
central core, in which region no combustion is possi-
ble because of the absence of air; (b) a luminous
cone; and (c) an outer envelope.
Figure HO represents an ordinary mouth blowpipe;
LIGHT AND LIGHTING,
131
such as is used by jewelers, chemists and others. By
means of such a pipe, additional air may be blown
Fig. 59.
Parts of candle flame.
Fig. 61.
Blowpipe flame.
into the flame; the flame then be-^
comes a solid one, the combustible
materials are more rapidly and com-
pletely burned ; few solid particles
have time to become incandescent be-
fore they are consumed ; the result is
a bluish, hot, but iion -luminous
flame. In flgure 61, a represents
the end of the blowpipe inserted in
the flame.
There was a time, and that within
the memory of the middle-aged
among us, when candles were the
commonest of household illuminants.
The structure of candles and the
general nature of their flame have been already
noticed. The place of candles in domestic lighting
Fig. GO.
Moutli blowpipe.
132
DOMESTIC SCIENCE.
Fig. 62.
Simple form of lamp.
has now been taken by Ja7nps in which certain
inflammable oils are burned.
A lamp of modern construction (figure 62) con-
sists essentially of a cistern, h,
for holding oil ; supported on a
base or pillar, a ; a wick, c, for
conveying the fluid to the place of
burning ; a burner, e, for the sup-
port of the wick and the proper
distribution of air about it ; this
is usually provided with a rachet,
d, by which the wick may be
raised or lowered ; and a chimney
of glass, /, to shield the flame
from the disturbing effects of
draughts. The wicks that were first
made were shaped like a solid cylinder ; those of later
times are flat. Dr. Franklin demonstrated in the case
of candles, that two small wicks burned side by side
gave greater light than would a single wick of double
size ; this fact is due to the greater surface exposed by
the double wick. The advantage of spreading out
the wick fibres thereby enlarging the surface will be
readily seen.
About 1790, A. D., one Argand, of Geneva, in-
vented a lamp in which the wick was arranged as a
hollow cylinder ; this is still in use, and is known as
the Argand lamp. The general features of this lamp
will be understood from an inspection of figure 63,
which shows the complete lamp, and a section of the
same. With such a wick a large circular flame is
produced ; by a peculiar construction of the burner
LIGHT AND LIGHTING.
133
air is iutroduced into the interior of the flame, so that
a more perfect combustion with a consequent increase
of light is the result. The wick may be raised or
lowered so that the size of the flame will be pro-
portional to the air current. A valuable improvement
on the original Argand lamp was made by Lange, a
Frenchman. He proposed a narrowed chimney tube,
Fig. 63.
Argand lamp and section of same.
one having a shoulder in the region of the flame. The
effect of such a chimney is to deflect the outer air
current upon the flame, whereby an increased efii-
ciency is secured.
With a lamp of this construction it is possible to
burn without difiiculty the heavier and poorer oils, be-
cause the free supply of air favors a very complete
combustion of the carbon without the production of
134 DOMESTIC SCIENCE.
smoke. The Argand lamp is noted for the steadiness
of its flame ; it is well adapted to the writing table,
and is commonly and appropriately called the student's
lamp.
The reservoir of oil is set on the side so as to be
safely removed from the heated region of the flame.
The reservoir proper is inverted in an outer vessel,
and the contained liquid is held in position through
pneumatic pressure, and is conveyed to the wick only as
fast as used.
A serious objection to the use of the Argand lamp
for general illumination is based on the shadow thrown
by the oil reservoir. The cistern of common, flat-
wick lamps is sometimes so shaped as to throw an
objectionable shadow. The larger the cistern is the
more extensive will be its shadow ; yet small oil
holders are objectionable, because the level of their liquid
contents falls rapidly as the burning proceeds, thus
increasing the distance between the oil and the burner,
with a consequent diminution of the supply through
the wick, and a very marked decrease of light.
Many forms of hollow wick lamps are now in the
market. The appearance and construction of an
efficient kind may be understood from flgure 64.
The large wick is placed around the hollow cylinder,
through which air is carried from below. The base at
its place of support is either scalloped or perforated,
so as to allow the ready passage of air into the central
channel (a). A funnel-shaped distributor deflects the
inner column of air against the flame. Lamps of this
construction afford much light ; they are not well
adapted for the writing desk or reading table because
LIGHT AND LIGHTING.
135
of the great heat resulting from the large consumption
of oil.
It is advisable to surround the lamp chimney with a
convenient shade, so as to moderate the intensity of
-the rays that reach the eye. It is not desirable that
Fig. 64.
Hollow-wick lamp.
light pass in an unbroken line from its source to the
eye ; its efficiency depends upon the illumination of
the objects to be viewed ; and experiment has
demonstrated that if the eye in viewing an object re-
ceives from other sources any rays of light of greater
intensity than those reflected from the object, the usual
impression is weakened, and the organ of sight is un-
naturally strained. The value of a shade in deflecting
the light downward upon the table will be readily
seen. The best shades are made of ground glass or
porcelain, and are colored on the inside sky-blue.
Artificial light from candles or oil lamps is deficient in
136 DOMESTIC SCIENCE.
certain of the component colors of white light, and
the blue shade will partly supply the missing tints.
Shades so colored give less intense but purer illumina-
tion.
COMMON ILLUMINANTS. 137
CHAPTER 14.
LI(;HTIN(i continued: common ILLUMINANTS.
REFERENCE has already beeu made to caudles as
sources of light, let us uow cousider other illum-
iuauts.
Among the common illuminating fluids, are fish
oil, lard oil, colza oil, turpentine, and kerosene. The
last named is the common household illuminator.
Kerosene is a product of the distillation of petroleum,
and, as offered in the market, is of specific gravity lower
than that of water, clear and transparent, the best grades
showing a blue tint by reflected light.
In burning, the oil is first converted into vapor ; this
takes fire at a temperature which varies for different
kinds of oil ; this degree of temperature is known as
the Jiashin.g point ; at a somewhat higher temperature
the liquid burns continuously, this is known as they're
test point. Evidently the use of oil of a low flashing-
point is attended by great danger from the liability of
the mixture of air and vapor within the oil cylinder
to explode. In many parts of the United States and
in Europe, there are legal enactments specifying the
lowest flashing point that is permitted in oils offered
for public sale. The writer has found in the market
varying grades of kerosene, of flashing points ranging
from 75° F. to 135° F. ; and of fire test as low as 110°
F., and as high as 300° F.
6
138 DOMESTIC SCIENCE.
The stringency of the laws has done much to restrict
the sale of light oils ; and it is pleasing to contemplate
that accidental explosions in lamps are now infrequent.
With the best of oil, however, careless management of
the lamp may lead to disastrous results. The common
practice of extinguishing the flame by blowing down
the chimney often causes an ignition in the oil chamber,
in which case an explosion is almost inevitable. Allow-
ing a lamp to burn itself out, is a dangerous practice.
The wick smoulders, and a spark or a glowing ember
may reach the oil chamber, and cause a destructive ex-
plosion. Some improved forms of lamps are provided
with extinguishers ; and others have an automatic
attachment by which the flame is put out if the lamp be
overturned. With the best of contrivances, and under
the most favorable conditions, great care in the manage-
ment of the lamp is essential to safety.
Coal gas is used in large towns as an illuminant. It
consists of the volatile matter of coal. The production
of gas is carried on at the central works, the gas being
then distributed through underground mains to the
consumers. Good gas is a cleanly, convenient, and an
eflScient material for illumination ; though its presence
in the house entails certain dangers demanding con-
stant vigilance on the part of the inmates. An acci-
dental escape of gas into the rooms may form with the
air an explosive mixture ; and the smallest amount of
coal gas in the air of the house, must be regarded as a
poisonous addition. The inhalation of any consider-
able amount of coal gas produces asphyxia and speedy
death. It is well for us that the substance possesses a
disagreeable odor ; for by.it we may often recognize the
COMMON ILLUMINANTS. 139
presence of the poison, and we should seek to preserve
our sensitiveness to its effects. The gas is consumed
at convenient points along the line of the supply pipes,
burners of different forms being employed, named
from the shape of the flame produced by them ; the
commonest burners are the fishtail, the bat's -wing,
and the Argand. Gas burners may be provided with an
electric attachment, so that the passage of a current from
a local battery opens the valve, thus allowing the gas
to pass, and ignites it as it issues. With such a con-
trivance, it is only necessary to press the current button,
Avhich may be located in any convenient place, and the
gas is turned on and lighted. A second push stops
the flow of gas, and, of course, extinguishes the
light.
Water gas is the name of another illuminant, which
is produced- by the decomposition of steam through
contact with incandescent carbon. The oxygen from
the steam unites with the carbon to form carbon mon-
oxide, while the hydrogen of the steam is freed. Such
a mixture of hydrogen and carbon monoxide burns
with considerable heat, but with little light ; it is
necessary therefore to enrich the gas, and this is
accomplished by mixing it with the vapors of naphtha,
gasoline, or other highly volatile mineral oils.
Another method of using the vapors of light oils as
illuminants consists in passing a current of air through
such liquids, whereby the air becomes saturated with
combustible vapors ; in this state it is conveyed through
pipes to the place desired and there burned in ordinary
gas burners. The apparatus used in the production of
this vapor gas is simple and portable, it may be operat-
140 DOMESTIC SCIENCE.
ed in any dwelling house. Dangerous explosions have
occurred from the premature lighting of the vapor
laden air.
All the methods of house lighting thus far consider-
ed possess the serious defect of contributing largely to
the pollution of the atmosphere. *
Various forms of ventilator burners have been pro-
posed ; these are designed to carry away through flues
the objectionable products of combustion ; but all of
such contrivances are expensive and inconvenient, and
none of them have come into very general use. Vitiation
of the atmosphere is inevitable while illuminative
methods are dependent upon processes of combustion.
Such objections are inapplicable in the case of electric
lighting. Electric lamps are of two kinds, the arc
lamp and the incandescent lamj^. In the first,
(figure 65) the light results from the passage
of a strong current through rods of gas car-
bon set end to end, which are separated at the place
of contact. Some carbon particles become volatilized
through the great heat caused by the current, these
form an incandescent bridge between the separated rods.
The arc light is in favor for illuminating streets and
* Dr. Youmans says:— "A candle (six to the pound), will consume
one-third of the oxygen from 10 cubic feet of air per hour, while oil
lamps with large burners will change in the same way 70 feet per
hour. As the degrees of change in the air correspond with the
amount of light evolved, it is plain that gas illumination alters the air
most rapidly. A cubic foot of coal gas consumes from 2 to 2 and a
half cubic feet of oxygen, and produces l to 2 cubic feet of carbonic
acid. Thus every cubic foot of gas burned imparts to the atmosphere
1 cubic foot of carbonic acid, and charges 100 cubic feet with 1 per
cent, of it making it unfit to breathe. A burner which consumes 4
cubic feet of gas per hour spoils the breathing qualities of 400 cubic
feet of air in that time,"
COMMON ILLUMINANTS.
141
large buildings ; but for illumination on a smaller scale
the incandescent lamp (figure 66) is preferable. This
consists of a globe of glass, sealed, and containing some
inert gas such as nitrogen or carbon dioxide, which
will not support combustion. A fine hair- like filament
Fig. 65.
Electric arc lamp.
Fig. 66.
Incandescent electric lamp.
of carbon is placed within the globe, the ends connect-
ing with binding screws to which the line wires of the
electric circuit can be joined. As the illuminating
effect is not due to the chemical energy of combustion,
it is plain that this method of lighting does not result
in vitiation of the air. Incandescent lamps may be
operated under water, and in this way aquaria may be
beautifully and brilliantly illuminated.
142 DOMESTIC SCIENCE.
Even the best of our methods of artificial illumina-
tion are woefully wasteful of energy. This is largely
due to the fact that much of the energy developed by
combustion or through electrical resistance, manifests
itself as heat instead of as light. Lamps are intended
primarily as sources of light, and not as heating
apparatus, yet the results of experiments recently re-
ported (August. 1890,) by Professor Langley, showthat
99 per cent, of the energy of candle and lamp flames is
lost as far as illuminating effect is concerned ; and that
in electric lighting, fully 50 percent, of the total energy
never appears as light. Experiments are now in pro-
gress to test various methods of producing light
with a minimum of loss through heat radiation. Upon
this subject considerable interest has of late been
stirred by the phenomena attending the fire-fly's glow,
and other examples of natural phosphorescence. At
present, man is unable to produce light equal in
intensity to that of the fire -fly, without an ac-
companying temperature of nearly 2000° F. ; yet
the light -giving power of the insect named is ex-
ercised without development of sensible heat.
Referring to his experiments on the fire -fly's light.
Professor Langley says: "We repeat, that Nature
produces this cheapest light at aljout one four-
hundredth part of the cost of the energy which is
expended in the candle-flame, and at but an in-
significant fraction of the cost of the electric light, which
is the most economic light that has yet been devised : and
that finally there seems to be no reason why we are forbid-
den to hope that we may yet discover a method (since
such a one certainly exists, and is in use on the
COMMON ILLUMINANTS. 143
small scale), of obtaining an enormously greater re-
sult than we now do from our present ordinary
means for producing light."
144 DOMESTIC SCIENCE.
P^jPlK.T II.
WATER.
CHAPTER 15.
WATER ITS "OCCURKENCE.
WATER is indisj)eiisable in many of the processes
of life ; and in domestic operations it is a prime
necessity. Without it, the intricate machinery of
civilization would be inactive ; and all physical forms of
life, the bodies that serve as tenements for deathless
spirits, Avould cease to exist. Indeed the structure of
even the dead things of earth depends largely upon the
presence of water.
In each of the three great divisions of created things,
minerals, plants, and animals, water is present as an
essential constituent. In Minerals it forms a very
considerable proportion of the total composition, and
in many cases gives to the mineral bodies their character-
istic color and form. To illustrate this, take a crystal
of copper sulphate, — blue vitriol, or blue stone as it is
commonly called : carefully heat it in an iron spoon,
or better, in a clean dry test tube. Very soon, steam
is seen rising from the crystal ; in the tube this vapor
condenses on the colder part of the glass, and may
there accumulate till it gathers in drops and trickles
down tlie tube in a stream. Now that the water has
WATER ITS OCCURRENCE. 145
been expelled, instead of the beautiful, transparent
"blue stone", we have left only a grayish powder,
entirely undeserving of the popular name. A drop of
water added to this powder will partially revive the
azure tint, but the transparency, and the symmetrical
form have gone forever. The experiment teaches us
that the presence of water is essential to the crystal -
ine arrangement of particles within the mass. A
transparent piece of alum heated in the same way will
evolve large quantities of liquid, and will assume the
appearance of a white, opaque powder — the ""burnt
alum'- of the druggists. Chemical analysis has proved
that water is ordinarily present in the minerals named
below, as specified :
Per cent, water.
Calcium sulphate (gypsum) - - 20.9
Copper nitrate . . . 39.1
Copper sulphate, (blue vitriolj - - 36.1
Zinc sulphate (white vitriol) - - 43.9
Iron sulphate, (gi;een vitriol) - -, 45.3
Borax . - _ . 47 j
Soda alum . . - . 47 3
Magnesium sulphate (Epsom salts) - 51.2
Sodium sulphate (Glauber salts) - 55.9
Sodium carbonate (washing soda) - G2.9
The common designation of water so combined in
minerals is "water of crystallization." By mere ex-
posure to dry air, many of the salts named in the table
allow some part of the contained water to escape ;
such process is called efflorescence. To observe this,
take a few clear crystals of Glauber salts, or of washing
soda ; put them in an open dish, and set in a warm dry
atmosphere ; the substance soon loses its transparency
and becomes opaque and friable. This property of
146 DOMESTIC SCIENCE.
solids containing water of crystallization is well known
to /the dealers in such substances ; grocers and druggists
usually store efflorescent salts in tight cases so as to
prevent the escape of the water of crystallization, and
a consequent decrease in weight. Washing soda if ex-
posed in open vessels may lose over half its weight.
Beside the water commonly combined in mineral
bodies, and forming an essential constituent of the
same, large quantities of the liquid are sometimes
absorbed and mechanically retained by minerals.
Coal frequently contains even ten per cent, of water.
Ores taken from the mines, though seemingly dry, are
often so heavily laden with water as to necessitate a
drying process preliminary to the furnace treatment.
In the kingdom of Plants, water is no less widely
distributed nor less essential as an item of their com-
position. Its presence in vegetable bodies may be
easily demonstrated. Place within a dry test tube a
chip of wood, a little saw dust, starch, or any other
plant product — better select an apparently dry substance,
that the illustration may be the more impressive ; — now
apply heat, taking care not to char or blacken the sub-
stance ; soon water is evolved as steam, this condenses
upon the cold .portion of the tube.
The following table exhibits the proportion of water
in certain fresh vegetable substances, the figures being
the average results of numerous analyses :
Per cent, water
Pine wood
40
Timothy
70
Meadow grass
72
Lucerne
75
Potatoes
75
WATER ITS OCCURRENCE
147
Red clover
White clover
Grapes
Beets
Apricots .
Apples
Carrots
Gooseberries
Strawberries
Cabbage .
Turnips .
Cucumbers
Water melons
Per cent, water.
79
81
81
82
83
84
85
86
87
89
91
97
- 98
Through exposure to the air, part of this constituent
water will be lost, but even in air -dried vegetable
products very large proportions of water remain , as
will be seen from this table ; the figures represent
average amounts as foundby examinations of numerous
samples :
Per cent, water
Meadow grass hay . . •
15
Red clover hay
16
Dried pine wood
15
Dried wheat straw .
16
Wheat kernel
15
Indian corn
13
Rye kernel
15
Barley
14
Oats
13
Buckwheat .
13
Peas
14
Rice
13
Water is the medium by which the nutritive. matters
of the soil are carried into the body of the plant. The
roots of common plants ramify through the soil in great
abundance ; the main root giving off many branches,
which in turn divide, and subdivide till they become
finer than hairs.
148
DOMESTIC SCIENCE.
The root hairs are in close contact with the soil ; so
close indeed that in many cases it is possible to separate
the adherent soil from a root that has been taken from
the ground, only l)y vigorous shaking and thorough
washing.
Figure 6 7 (right sketch) shows the appearance of a
wheat rootlet with adhering soil just as it was taken
Fig. 67.
Rootlet with rootliairs ; rootlet
with adhering soil.
Fig. 68.
Pressure guage attached to a
growing plant.
from the earth ; and the left sketch exhibits the same
after thorough washing to remove the soil. The
numerous root -hairs are distinctly shown. Through
the roots, large quantities of water are absorbed.
The liquid rises through the vessels of the stem in the
form of sap, and in doing so exerts a surprising force.
There is a method of forcibly demonstrating this (see
WATER— ITS OCCURRENCE. 149
figure 68). If a pressure guage consisting of a bent
tube 6, with mercnry in the bulb c, be attached to the
stem of a growing plant a cut off near the ground, the
rising sap will lift the column of mercury. In an
operation of this kind, Dr. Hales found that the pressure
exerted during the spring of the year by a young grape
vine supported a column of mercury 32^ inches high.
This corresponds to a column of water 36^ feet in high
or to a pressure of 16^ pounds to the square inch.
Hofmeister found that a common stinging nettle simi-
larly tested, supported a column of mercury 14 inches
high, due to a pressure of 7 pounds per square inch.
The water so absorbed is distributed throughout the
entire structure of the plant ; many of the solid matters
which enter the plant in solution are retained within
the vegetable cells ; while the water itself escapes through
the countless stomata of the leaves.
In the bodies of Animals water abounds. A very
large proportion of the meats, eggs, and milk we buy
is water ; this will be seen from the following table :
Per
cent, water.
Fresh mutton contains
-
71
" beef
-
-
73
" veal
-
-
75
'" pork
-
-
7G
" flsh
-
-
80
" fowl
-
-
73
" egg
-
-
74
" milk
-
-
87
The bodies of many of the lower animals consist
mainly of water. Agassiz, a scientist of high repute,
examined the body of an aurelia or sun fish, from the
Atlantic coast of this country ; when alive the creature
150
DOMESTIC SCIENCE.
weighed 30 lbs., but when thoroughly- dried its body
yielded but half an ounce of solid matter, — showing
over 99.8 water.
It has been proved that the average human body
contains water to the extent of from two -thirds to three -
fourths of its weight. The proportion of water present
in different organs of the body will be seen from the
following exhibit :
Per cent, water
Human teeth
10
,, bones
13
muscles
75
,, brain
79
,, blood
79 to 80
„ bile
88
,, milk
88 to 89
„ gastric juice
97 to 98
,, perspiration
98 to 99
„ saliva
99 to 99.5
To supply the body with the requisite amount of
water, a man of average size has to imbibe about three
and a half pounds of the liquid daily ; this would
amount in a year to over 127 gallons. It is not
necessary that this quantity of water be actually drunk,
as a very large part of it is supplied from the food.
WATER SOME OF ITS USES. 151
CHAPTER 16.
WATER SOME OP ITS USES AND PROPERTIES.
ASIDE from forming so extensive and important a
constituent of minerals, plants, and animals, the
uses of water are many and varied. In each of its
three physical states, as a liquid (water itself), as a
solid (ice), and as vapor (steam), it proves of inesti-
mable service to man.
In the form of running streams it furnishes us a
continual source of power. Each tiny drop pushes
against the wheel, and the current grinds our corn
and weaves our cloth ; drives our saws and planes,
and forces open the vaults in which Nature has stored
her wealth of sugar and nectar, of oil and of wine. In
its ocean depths it forms an efficient and easilj'^ used
road of travel between distant lands ; and in both
stream and sea it constitutes a home for countless
forms of animal life of value to us for food and orna-
ment.
As ice, it is to us a cheap and an effective protection
against decomposition ; it stands guard over things
most perishable, and successfully repulses the ever
eager spirits of decay and destruction. In this form,
too, it is held in reserve upon the mountain tops till
its presence is most needed on the fields and farms be-
low ; and then, bursting away its frozen bands, it
hastens down with a merry babble and a joyous laugh,
like the voice of a happy child awakening from peaceful
152 DOMESTIC SCIENCE.
dreams to pleasant play. It carries joy and comfort
in its course ; the thirsty plants lift up their heads at
its approach and smile with thankfulness ; the laden
beast is refreshed, and the heart of man is gladdened.
As steam, it propels the wheel of civilization, and
has done much to put the stamp of progress upon the
present age, and to establish the superiority, of God-
given mind, over all else upon earth. Its effects have
surpassed the ac^hievements of the fabled giants of old,
who were said to run a mile at a stride, and to carry
houses upon their backs.*
In physical properties, water is the perfection of
adaptability to the needs of man. In the most of its
characteristics, it is the type of neutrality, odorless,
without color, and devoid of taste. High flavors and
sweets are not always pleasant to the palate, and the
most subtle perfumes are at times sickening and even
injurious in their effects. If water possessed positive
properties of taste and smell, all our foods, into the
* "Water is the common carrier of creation. It dissolves the ele-
ments of the soil, and, climbing as sap up through the delicate
capillary tubes of the plant, furnishes the leaf with the material of its
growth. It flows through the body as blood, floating to every part of
the system the life-sustaining oxygen, and the food necessary for
repairs, and for building up the various parts of the 'house we live in.'
It comes in the clouds as rain, bringing to us the heat of the tropics,
and tempering our northern climate, while in spring it floats the ice of
our rivers and lakes away to warmer seas to be melted. It washes
down the mountain side, levelling its lofty summit, and bearing
mineral matter to fertilize the valley beneath. It propels water-
wheels, works forges and mills, and thus becomes the grand motive
power of the arts and manufactures. It flows to the sea, bearing on its
bosom ships conducting the commerce of the world. It passes through
the arid sands, and the desert forthwith buds and blossoms as the
rose. It limits the bounds of fertility, decides the founding of cities,
and directs the flow of trade and wealth."
Du. Steelk.
WATER SOME OF ITS USES. 153
composition of which water so largely enters, and in
the cookery of which it plays so important a part,
would partake of the universal llavor, their qualities
would be in all cases modified, and in many instances
destroyed thereby.
The properties of water under the influence of heat
have been dwelt upon in a preceding chapter. Its high
specific heat, whereby its temperature changes are
modified and retarded, the great amount of hea
rendered latent in the fusion of ice and in the formation
of steam, with some of the resulting good effects have
also received attention.
In passing from a liquid to a solid form, that is in
freezing, water observes a strange and an anomalous
behavior. Solidification, or freezing, is the result of
cooling, and is usually attended by contraction in bulk.
The principle that "heat causes expansion and cold
causes contraction," applies to water at certain tem-
peratures only. Above 4° C. or 39.2° F., water ex-
pands by heating : below that temperature it expands
by cooling ; so that a piece of ice is larger than the
mass of water from which it was produced. The ice
is therefore specijically lighter than the water ; and as
a consequence ice floats in water. If the contraction
of water by cold continued to the point of congelation,
there would be a constant rise of warm, and a fall of
cold water in the body of the liquid undergoing the
freezing process, till the whole would become solid, and
in the case of alake, sea or ocean, all living things therein
would be killed. Farther, — if ice sank as fast as
fornaed in lakes and seas, it would be beyond the
reach of the sun's rays, and many tropical summers
154
DOMESTIC SCIENCE.
would be required to thaw the ice of one temperate
winter. As it is, however, ice being a poor conductor
of heat, the surface layer actually protects the warmer
water below from undue cooling.
By reason of the expansion of freezing water, frost
is a most valued servant to the farmer, breaking up the
hardened clods, and exposing large surfaces of soil to
the vivifying action of tho air. In an analogous way
the rock -masses of the hills are burst asunder, and
thus they are prepared for rapid disintegration and
speedy conversion into fresh and fertile soils.
Fig. 69.
Crystals of ice.
Freezing is essentially a crystallizing process, and
the microscope will reveal in the snow-flake and the
ice block a symmetry of parts analogous to that of the
stony crystals of earth. The unaided eye perceives the
beauties of the hoar frost on pavement and window
pane ; the glistening spangles suggest flowers, fruity and
WATER SOME OF ITS USES. 155
leaves ; surely the winter is not without its flora. To
examine the snow flowers microscopically, choose a
cold day when comparatively dry flakes are falling ;
catch them upon cold pieces of colored glass ; do not
touch them or breathe upon them ; then examine with
a low magnifying power. Figure 69 shows a very few
of the almost infinite forms of the crystals of frozen
water. Each of them is composed of six main parts or
groups of parts, all arranged upon a plan of seeminglj^
perfect symmetry.* The prevailing angle at which the
spangles are set with regard to each other is the same
in all. Why this constancy? Surely the Great Creator
delights in order ; and we His children can at least
learn to appreciate the beauties of His wondrous work-
manship.
It would be difficult to find a substance that does
more than water does in beautifying and diversifying
the surface of our earth and its surroundings. The
heavenly tints of morn and eve, the glorious bow,
which seals the covenant of the Creator with his chil-
dren, and which must ever remain an object of our
deepest wonder and admiration ; the varying effects of
cloud and mist — all are largely due to the water drops
suspended in the air. The pretty spangles of the hoar
frost, the ferns and leaves of the winter window, the
stars and flowers of the snow flake and the ice block,
show the operations of the building forces of Nature
according to the laws of strict and perfect science.
* Professor Tyndall describes a certain fall of snow crystals wit-
nessed by liim as " a shower of frozen flowers; all of tliem were six-
leaved ; some of the leaves threw out lateral ribs like ferns ; some were
rounded, others arrowy and serrated ; but there was no deviation from
the six-leaved type."
156 DOMESTIC SCIENCE.
CHAPTER 17.
SOURCES OF WATER.
IN view of the many and diverse uses of water in the
operations of life, it is gratifying to note that Nature
has supplied it in unstinted quantity, liberally distrib-
uted throughout the world. The water we use is pri-
marily derived from the clouds, through the medium
of rain and snow fall. A part of the water that falls
upon the surface of the earth speedily returns to the
vaporous condition, and is again lifted into the atmos-
phere. The inclination of the ground surface and the
nature of the soil with respect to its permeabilit)^ to
liquids, will determine what proportion of the re-
mainder will run off in the form of streams, and what'
part will sink and percolate through the soil. That por-
tion of the surface water that flows away in streams goes
to swell the rivers of the neighborhood ; and a part of
that which sinks into the soil serves to supply the roots of
growing plants ; the rest of the percolating water will
probably reappear at some distant place in the form of
springs. In the case of porous soil, this percolation is
rapid, so that in some regions it is found necessary to
collect the rain water in cisterns as it falls, and store
it for general use.
Rain ivater is especially serviceable for many house-
hold operations on account of its softness, which is a
result of its freedom from mineral impurities. To
procure pure rain water, the collection should be made
in an open space ; the water that comes to us from the
SOURCES OF WATER.
157
roof pipes is usually almost black from the impurities
that it has washed from the roof.
Much of the water that serves our domestic purposes
is derived from springs. These are numerous in hilly
Fig. 70.
Hillside spring.
regions, providing the rainfall is adequate and the soil
of proper kind. As the water falls from the clouds
upon the hills, a part of it sinks into the soil and des-
cends till it reaches a stratum that is impermeable to the
Fig. 71.
Fissure spring b, and artesian well c.
passage of water. Here its downward course is
checked, and the water flows along the impermeable
layer as along a floor. If this should lead it to the
surface of a hill, there the water will issue as a hill -side
158
DOMESTIC SCIENCE.
spring (see figure 70). If, however, the course of the
floor -stratum should be such as to carry the water be-
low the land surface in the valley, (as illustrated in
figure 71) the liquid may continue beneath the earth
till it finds or forms a fissure in the earth ; from this it
escapes as a fissure spring, or main spring (6). By
boring or driving into the soil such subterranean
streams may be tapped, the water then rises through
the pipe, which may be regarded as an artificial fissure,
this constitutes the artesian icell (c).
Fig. 72.
Equilibrium of liquids.
The force that causes a rise of water through the fis-
sure or pipe will be understood from the following
simple observations. If a tube of glass open at both
ends be inserted in a vessel of water, the liquid rises
within the tube to the level at which it stands in the
outer vessel.*
* If the tube be of small caliber the water will rise to a level higher
than that of the liquid in the vessel; this is due to the adhesion be-
tween the glass and the water. Such adhesive force when operating
in very small tubes is known as capillary aiiraction, the;term "capillary"
being derived from the Latin capUhis, meaning a hair, and so applied
SOURCES OF WATER.
159
The sketch (figure 72) represents a vessel commun-
icatiug with a number of tubes of different sizes and
shapes. If water be poured into such a vessel it will
come to rest at the same level in each of the tubes.
This fact warrants the oft-used expression, "Liquids
vrill find their level."
It is impossible to carry
a liquid by its own
pressure alone above
the level of its source.
By way of further
illustration, prepare
the apparatus sketched
in figure 73. Provide
a good -sized funnel,
and attach to it a rub -
ber tube. At the other
end of the rubber in -
sert a glass pipe. Hold
the attached tube as
shown in the figure
Fig. 73.
Liquid rising to the level of its source, ^nd pour water into
the funnel : the liquid rises to the same height in the
tube. Now lower the tube, so that the opening is
below the water level in the funnel : the water now
issues as from a fountain, and leaps nearly to the level
of its source in the funnel. The friction of the flow-
because the phenomenon manifests itself most strongly in small or
hair-like tubes. It is by capillary attraction that a piece of bread ab-
sorbs milk when dipped in the liquitl; that a sponge absorbs water ;
that a towel dries our flesh. We know how efficient is an un-glazed
towel over one in which the pores are closed by an impermeable gloss
160
DOMESTIC SCIENCE.
iiig liquid against the tube, the resistance of the air
through which it rises, and the force of the descending
drops as they strike the rising stream, prevent the true
level being fully reached. So in the case of the fissure
spring or the artesian well : the tendency of the escap-
ing stream is to throw itself to the level of its source
in the surrounding hills.
Fig. 74.
Possible cause of intermittent springs.
There are some springs that discharge water at cer-
tain seasons only. These are known as mtermittent
springs. It is believed that they are due to some such
a formation as is shown in figure 74. During a wet
season water would percolate through the soil and
gather in the cavern, a ; as soon as it rose above the
highest point in the exit passage, b, the water would
flow to the opening and there appear as a spring.
The flow would continue till the water sank below the
SOURCES OF WATER.
161
entrance to the tube ; and then would cease till the
cavern had again filled to the former level. This oper-
ation is explained by the principle of the siphon, page
31. The action may be well illustrated with the sim-
ple apparatus here shown (figure 75). A glass vessel
is provided with a
bent delivery tube:
if water be poured
into the receptacle
till the level of the
liquid is above the
Fig. 75. Vi* V. f • f f
Apparatus to illustrate a possible cause of highest point 01
intermittent springs. the tube, the water
will run through the tube and the flow will continue
till the liquid in the large vessel has sunk below the
entrance to the pipe.
Intermittent springs may be due to other conditions
than the occurrence of such a cave. In a case similar
Fig. 76.
Intermittent springs.
to that shown in figure 76, during high water season
the level of the subterranean water may reach a,
then a flow would occur at S : as the underground
water level sank, however, the spring would cease.
Potable water from springs is generally well adapted
Ifi2 DOMESTIC SCIENCE.
for domestic purposes ; the chief cause of objection
to its use being its hardness. Water from fissure
springs and artesian wells is generally free from sur-
face filth, the subterranean supply being deeply set.
Good spring water is generally clear and well aerated.
The water of rivers usually contains much mineral
matter, and is, in consequence, hard ; it is seldom free
from organic impurity. This contamination is the
direct consequence of the drainage exercised by rivers
upon the land through which they flow. Large quan-
tities of organic filth reach the rivers from manured
soils ; and in marshy districts the running waters are
frequently dark from the peaty matters dissolved from
the ground. In the case of large rivers with towns
and cities upon their banks, vast quantities of sew-
age are discharged into the streams, rendering
the water entirely unfit for drinking or culinary pur-
poses.
It is true, certain processes of natural purification
are in continual operation, and these greatly mitigate
the contaminating effects above referred to. The at-
mospheric oxygen, which freely dissolves in water,
unites with the products of organic decay there present,
and thus renders them in time comparatively inert.
Running water tends, therefore, to purify itself, but
the completeness with which this will be accomplished
depends upon the amount and the nature of the dis-
solved matters, and the proportion of free oxygen
present. The extent of this self -purification process
is a matter of considerable uncertainty. Some chem-
ists have asserted that a sewage -laden stream will free
itself from all impurity in flowing but a few miles, and
SOURCES OF WATER. 163
others have as strongly denied the possibility of such a
thing-.*
■ In country towns, running streams, which have al-
ready received attention, and wells, which are now to be
considered, are the only common sources of sup-
ply. Surface or shallow wells are usually made by dig -
ing or boring into the earth till an impermeable layer is
reached. Upon this the subterranean water rests, and
the well merely taps the supply. At such slight depths
the pressure .is insufficient to cause the water to rise of
itself as from a deep artesian pipe. The most of such
wells, when new, yield fairly good water, hard or soft
according to the depth of the shaft and the nature of
the surrounding soil, but after a short time the wells
become contaminated through surface drainage. Upon
the nature of this contamination we shall yet have oc-
casion to speak farther. It is evident that the dangers
of pollution are greatly diminished in the case of deep
wells ; the streams that supply these being purified by
their percolation through the soil. All surface wells
should be frequently cleansed. The openings should be
properly protected by curbs and covers, against the
accidental entrance of foreign bodies. The best of
wells may be fouled through negligence.
* In one of the reports of the English Commissioners on River Pol-
lution, it is declared that "the oxidation of the organic matter in sew-
age proceeds with extreme slowness, even when the sewage is mixed
with a large volume of unpolluted water ; and that it is impossible to
say how far such water must flow before the sewage matter becomes
thoroughly oxidized. It will be safe to infer, however, * * * that
there is no river in the United Kingdom long enough to effect the de-
struction of sewage by oxidation."
164 DOMESTIC SCIENCE.
CHAPTER 18.
WATER, A SOLVENT FOR SOLIDS ; HARDNESS OF WATER.
WATER has been called "Nature's universal sol-
vent," and this appelation is justified by the fact
that there are few if any substances that can be kept
in contact with water without yielding something to its
dissolving action. In undergoing solution in water,
the particles of a solid body become so separated that
the water is uniformly diffused among them. In a
solution, the solid particles are so finely divided and so
thoroughly incorporated with the liquid that the highest
powers of the microscope fail to reveal them. The
liquid may be filtered, but the dissolved solid passes
through with the menstruum; and in all physical re-
spects the liquid and solid appear as a single sub-
stance.
The solvent power of water toward different solids
is of varying intensity. Thus, a given quantity of
water will at ordinary temperatures dissolve five times
as much sugar as it will alum. When water has dis-
solved of any solid the full amount that it is capable
of dissolving, the liquid is said to be saturated, and
the energy of the dissolving action decreases as the
saturation point is approached. In domestic opera-
tions the solvent power of water is of very great ser-
vice. Through it we make our pickling brines, and
prepare sweetened and flavored dishes in great variety ;
WATER, A SOLVENT FOR SOLIDS. 165
but for it we could not successfully scrub a floor, or
even wash our hands.
The power of water to dissolve solids is greatly in-
fluenced by changes of temperature ; as a rule heat in-
creases the energy of solution, though to this there are
exceptions ; thus, hot water will dissolve many times
more sugar than will cold water ; yet ice water will
dissolve twice as much lime as will water at a boiling
temperature. In attempting the solution of any solid,
the substance should be pulverized as finely as pos-
sible, as by such means much greater surface is exposed
to the action of the liquid. This may be illustrated by
simple means. In an experiment, the writer took a
lump of rock salt, an equal weight of ordinary table
salt, and the same amount of fine sifted salt. Each of
these was placed in a vessel by itself ; then an equal
quantity of water was added to each ; at intervals the
vessels were shaken, all being subjected as nearly as
possible to the same degree of agitation. The sifted
salt was completely dissolved in twenty minutes ; the
table salt had disappeared in forty -three minutes, by
which time the size of the lump had scarcely dimin-
ished ; and after five hours part of the rock salt was
still undissolved.
The solution of a solid may be much hastened by
frequently agitating the mixture, either by shaking or
stirring. If the liquid be kept at rest, those portions
that immediately surround the solid substance become
saturated, and being thus increased in density they
tend to remain at the bottom, so that mixture can take
place only by the slow process of diffusion ; and the
unsaturated liquid above is kept away from the solid
166 DOMESTIC SCIENCE.
body. In an experiment to illustrate this, the author
took two equal quantities of alum. These were placed
in separate flasks, and to each the same quantity of
water was added. The contents of one flask were
shaken at intervals ; the other was allowed to remain
still. In the first vessel the solid was entirely dissolved
in three-quarters of an hour, while in the second, part
of the alum still remained "solid after twenty -two days.
In preparing any aqueous solution in large quantity
it is well to place the finely divided solid in a basket or
a bag of coarse material, and suspend this in the upper
part of the liquid. As the water in contact with the
solid becomes saturated, its specific gravity is increased,
and in consequence it sinks, thus giving place to other
liquid particles. As an illustration of the efficiency of
this method the following results of experiment are in-
structive. A weighed quantity of salt was placed in
an open vessel, and a measured amount of water was
poured upon it. An equal quantity of salt was sus-
pended in a cage of wire gauze, just beneath the sur-
face of a like measure of water in another vessel. In
the first, a quantity of solid remained undissolved after
three weeks ; in the second, all the solid had disap-
peared from view in forty -seven minutes.
In consequence of the great solvent energy of water,
it is impossible to find as a natural occurrence a speci-
men of pure water.
It will be profitable to consider briefly the amount
and kind of the solid matters in natural waters. The
following table shows the amount Ox total solid matter
in certain specimens of water, expressed in grains of
solids per gallon of water :
WATER, A SOLVENT FOR SOLIDS.
1G7
Source,
Total solids
expressed in
grains per gallon.
Authority.
• Wells.
Johnston.
Wanklyn.
Johnston.
Johnston.
River Loka, Sweden - - 0.05
Boston, U. S., water works - 1.22
Loch Katrine, Scotland - 2.3
Schuylkill River at Philadelphia 4.26
Detroit River, Michigan - 5.72
Ohio River at Cincinnati - 6.74 "
Loire at Orleans - - - 9.38 "
Danube, near Vienna - - 9.87 "
Lake of Geneva - - - - 10.64
River Rhine at Basel - - 11.8 Wanklyn.
Thames at London - - 18.5 "
Average of 12 artesian wells,
Provo, Utah - - '- 18.6 The Author.
Salt Lake City supply - - 16.92
Spring water, Provo, Utah - 23.3 "
Formation Springs, Idaho - 27.8 "
Octagon Spring, at Soda
Springs, Idaho - - 126.66 "
Well water, Gunnison, Utah - 148.01 "
" Ninety per cent. Spring," at Soda
Springs, Idaho - - 198.41 "
Warm Springs, Spanish Fork
Canyon, Utah - - 413.72
Atlantic Ocean - - 2,688.00 Wanklyn.
*Salt Lake - - 11,777.64 The Author.
fDeadSea - - - 17,064.42
The amounts of solid material as expressed above
may seem very great, but the actual percentage is
* The water of the Great Salt Lake is subject to great fluctuations as
regards its contents of solid matter, owing to the variations in amount
of supply and in the rate of evaporation. In 1849 the lake water, ac-
cording to Dr. Gale, contained 22.282 per cent, of solids ; that time,
however, was one of phenomenally low water, and consequently of
great concentration. In December, 1885, the author found the water
to contain 16.7162 per cent, solids, and in August, 1889, it held 19.5576
per cent. The mean of these two analyses shows 18.1369 per cent., or
11,777.64 grains of solid matter per gallon.
t Great discrepancy exists among published accounts of the solid
contents of Dead Sea water. Bernan gives 14,025.48 grains per gallon ;
Captain Lynch collected a sample at a depth of lllO feet, and found it
to contain 18,902 grains per gallon. The amount given above (17,064
grains per gallon) was determined by the author in a sample taken
from the Dead Sea in April, 1886, by Dr. J. M. Tanner, of Logan, Utah.
11)8 DOMESTIC SCIENCE.
small ; 10 grains of solids to the gallon represents only
.0145 of 1 per cent, by weight.
The presence of mineral matter in water may impart
to the liquid the property of hardness, which may be
concisely defined as the power of curdling soap with-
out the formation of a lather. The minerals most ef-
fectual in causing hardness are compounds of calcium
and magnesium. Salts of these unite with the fatty
acids* of the soap, forming insoluble curdy compounds,
and all the lime and magnesium in the water must be
so combined before a lather can be produced. A large
amount of soap is therefore lost so far as any cleansing
effect is concerned.
The hardness of water is usually reckoned in terms
of this soap destroying power. It has been adopted as
a rule among chemists, to consider the soap destroying
effect produced by 1 grain of calcium carbonate in a
gallon of water as one degree (1°). A water of 10°
hardness would contain therefore 10 grains calcium
carbonate per gallon, or the equivalent of this in other
soap destroying compounds.
Lime carbonate is but slightly soluble in pure water,
but dissolves readily in water containing carbon di-
oxide ; this gas is present in most natural waters. By
boiling water so charged, the carbon dioxide is expelled,
and the lime carbonate being so slightly soluble in the
* In a chemical sense, soap is to be regarded as a compound of cer-
tain alkalies with the acids of fats. The fatty acid in common soap is
oleic acid ; and ordinary hard soap is chiefly sodium oleate ; soft soap
is potassium oleate. In contact with hard waters the soap loses its
sodium or potassium, these substances being replaced by calcium and
magnesium ; thus, oleates of calcium and magnesium are produced,
which are still soaps, though they are nisoluble in water, and therefore
valueless for hithering purposes. (See chapter 36, Part IV.)
WATER, A SOLVENT FOR SOLIDS.
169
water after boiling, falls as a solid precipitate. Look
inside a much -used tea kettle; there will be found a
heavy deposit of lime salts, as thick scale or incrusta-
tion. It is plain from this that by boiling water con-
taining calcium carbonate in solution, the hardness of
the liquid may be materially diminished. Hardness
that is removable by boiling is called temporary hard-
ness. Other compounds of calcium, such as the sul-
phate (gypsum) and the chloride, as also the com-
pounds of magnesium, impart to the water permanent
hardness, which is not removed by simply boiling the
liquid, because the hardening solids are not thereby
precipitated from solution.
For general household purposes, soft waters are the
best, though for many operations a considerable de-
gree of hardness may be tolerated. The following
table expresses the hardness of several natural waters :
Degrees of hardness.
Source. Total.
Perman
- Tem-
Authority.
ent.
porary.
London Thames - 10.5
—
—
Wanklyu.
Klrby Shore, Westmoreland 25.
—
—
"
Hillside Spring, Provo.Utah 17.
5
12
The Authoi
Well water, Gunnison, Utah 6.5
1.7
4.8
"
Average, 9 artesian wells.
Provo, Utah - - 15.2
5.4
9.8
"
Average, 11 artesian wells,
Salt Lake City - i^.l
lU.T
7.4
li
Salt Lake City supply - 13.4
6.9
6.5
"
It is to be remembered that the hardness of water de-
pends largely upon the kind as well as upon the amount
of solid matter present. The water from Gunnison,
Utah, is named in the table on page 167 as containing
148.01 grains of solid matter to the gallon ; yet this is
a relatively soft water, as is seen from the table on
7
170 DOMESTIC SCIENCE.
page 169^ which shows for it a total hardness of but
6.5°, and of this 4.8° may be removed by boiling,
leaving a permanent hardness of but 1.7°. The
solid contents of this water, however, are mostly
compounds of the alkalies. The water here referred to
is remarkable in many w^ays ; its specific gravity is
high, and though it is constantly used as a potable water,
its taste is tolerable only to those who have become ac-
customed to it.
The continued use of water that is highly impreg-
nated with salts of lime and magnesia is supposed to
be a cause of goitre or hig neck. This disorder is an
enlargement of the thyroid gland in the neck.* From
its prevalence in the limestone regions of Derbyshire,
England, it is popularly called "Derbyshire neck."
Most recent investigations lead to the belief that the
potency of hard waters in producing this disorder has
been over estimated. Contaminated water may favor
the disease, but that the use of such water is the sole
cause can scarcely be credited in the light of demon-
strated facts.
* Johnston reported that in a jail at Durham, England, all the pris-
oners suffered from neck swelling. An examination of the water there
used showed that it contained 77 grains of solids per gallon, mostly
compounds of magnesia and lime. The use of the water was then dis-
continued, a purer kind being substituted, containing but 18 grains of
solid matter per gallon. The goitrous disorder immediately sub-
sided.
WATER, A SOLVENT FOR GASES. 171
CHAPTER 19.
WATER, A SOLVENT FOR GASES.
''PHE solvent power of water is not confined to its
1 action on solids ; gases also may be dissolved in
large quantities. The commonest gaseous admixtures
in ordinary waters are the constituents of air. Much
good results from such solution of air in water ; upon
the atmospheric gases so held, fishes and other aquatic
animals depend for respiration. It is a popular mis-
take that only land -animals breathe air: without this
medium of respiration the tiniest creature of the sea
would die. A living fish placed in non- aerated water
quickly expires ; and the same result follows * if the
fish be kept in an inadequate amount of water, with-
out renewal ; the fish then dies from suffocation caused
by its own respiratory products, just as a man shut in
a closed room from which the gaseous emanations of
his body cannot escape will be poisoned by his own
breath. A strong example of our subject is found in
the growth of the tiny coral animals. These belong
to the polyp family, and are very small and simple in
bodily structure. They possess the power of extract-
ing the calcareous matter from the sea water, and of
forming from the same a hard, external skeleton,
analogous in composition and use to the shells of
mollusks, such as oysters and snails. Corals usually
congregate in great numbers, the accumulations of
their external skeletons forming coral reefs. Such reefs
172 DOMESTIC SCIENCE.
are found only in places that are freely exposed to the
action of the waves : the little polyps seem to delight
in the breaking of the surf, and the whirl of agitated
waters. Farther, — they are never found living at a
great depth ; a hundred feet seems to be their limit.
These peculiarities seem to be due to the animals'
need for air. In still water or at a great depth the
coral polyps would be deprived of air, in consequence
of which they could not survive ; but the agitation of
the surface water entangles air sufficient for their use.
It is remarkable that the atmospheric gases do not
dissolve in the proportion in which they exist in the
air. In pure air there will be found about 20.9 per
cent, of oxygen and 79.1 per cent, of nitrogen; the
other constituents need not be considered in this con -
uection (see Chapter 3). Water that has been fully
aerated, however, contains the atmospheric gases in
the proportion of 32 per cent, oxygen and 68 per cent,
nitrogen. This increased amount of oxygen is of
great benefit to aquatic animals, the nitrogen, in res-
piration serving merely as a dilutent. *
To drinking water, the dissolved air imparts a pleas-
ing and somewhat pungent taste. This fact may be
realized by anyone who, for contrast, will drink for a
time water from which the air has been expelled b}'
boiling.
Inasmuch as heating water serves to expel its dis-
* It has been discovered by Dr. Hayes, "that the water of the ocean
contains more oxygen near its surface than at a depth of one or two
hundred feet. This fact has probably some connection with the com-
parative scarcity of animal life at great depths. When water is in
contact with an atmosphere of mixed gases, it dissolves of each a
(luantity precisely equal to that which it would have dissolved if in
contact with an atmosphere of this gas alone." Wells.
WATER, A SOLVENT FOR GASES. 173
solved gases, it is plain that a rise of temperature will
diminish the solvent power of the liquid for gases ;
this view is substantiated by following facts : Experi-
ment has shown that water at 78° C is able to hold
in solution 586 times its own volume of dried ammonia
gas; at 59° C. the water can hold 727 volumes; and
at 32° C. it may contain 1050 volumes of the gas. A
solution of ammonia gas in water is sold as aqua
ammonia, or tvater ammonia (the common hartshorn
of the shops). By warming such, large volumes of
the gas will be given off.
The ill -smelling gas, hydrogen -sulphide, is soluble
in water; indeed the waters of so-called sulphur
springs are usually natural solutions of hydrogen
sulphide. The influence of temperature upon the
solvent power of water for this gas, is illustrated by the
followingfacts : At 78°C. one volume of water dissolves
2.66 v^olumes of hydrogen sulphide ; at 59° C. water
dissolves 3.23 times its own volume of the gas : at 32°
C. it may hold 4.37 volumes.
Another gaseous substance commonly found in
natural waters is carbon dioxide. At 14° C. water
can hold in solution its own volume of this gas :
at 0° C. it may contain 1.8 volumes.
The pressure to which liquids are subjected greatly
affects their power of solution for gases. Thus in the
case of carbon dioxide, under a pressure of one atmos-
phere (15 lbs. to the square inch), at 14° C. water
dissolves its own volume of the gas ; under a pressure
of two atmospheres, (30 lbs. to the square inch) the
temperature being unchanged, two volumes may be
absorbed, and so on ; within certain limits the solvent
174 DOMESTIC SCIENCE.
power is directly proportional to the pressure. An
aqueous solution of carbon dioxide constitutes the
common soda water. By the action of some mineral
acid (usually sulphuric acid) on sodium bicarbonate,
chalk or marble dust, carbon dioxide is generated in
great quantity ; the gas is conducted into a stout closed
vessel containing water ; as the gas accumulates, the
pressure increases ; and at the same time the water
being kept violently agitated, the gas passes into
solution. It will be held captive by the water, how-
ever, only as long as the pressure continues ; as soon
as the liquid is drawn from the holder the gas escapes
giving the effervescent and pungent qualities which are
sought. *
The fact of the readiness with which gases dissolve
in water, should restrain us from using for drink-
ing purposes, water that has stood long in open vessels.
Water that has been exposed, even for an hour or
two, to the air of a closed room, will be found to be
charged with the gases of the apartment ; and these
may be of the most deleterious kind. In the treatment
* The question of the wholesomeness of soda water has excited some
general interest. The presence of small quantities of carbonated
water in the stomach seems to produce pleasing and exhilarating
effects ; and if the preparation be pure, it is difficult to see what harm
is likely to result from its moderate use. Some soda-water makers, are
not careful to use pure water; and are indifferent to the cleanliness of
their apparatus. It is possible too, that metallic compounds may re-
sult from combinations with the material of the holders and pipes.
The admixture of flavoring syrups is objectionable, for the reason that
the purity of such preparations cannot be relied on, and the coloring
matters used to impart the deceptive tints to strawberry, raspberry,
blackberry and other syrups are frequently of a deleterious kind; and
farther, the habitual taking into the system of large quantities of sac-
charine material is certainly injurious to health.
WATER, A SOLVENT FOR GASES. 175
of the sick, precautions are necessary that the patients
drink not of any liquid that has been long exposed to
the air of the room.
176 DOMESTIC SCIENCE.
CHAPTER 20.
ORGANIC IMPURITIES IN WATER.
THE impurities most to be feared in water that is
used for domestic purposes are of an organic nature,
— that is, they are products of vegetable and animal
decay.. An average amount of mineral impurities need
not render water at all unlit for use. A water contain-
ing less than 15 grains of calcium salts to the gallon is
usually considered good ; and 20 grains of such solids
to the gallon is not an unusual amount; indeed,
waters containing even three times the last named
quantity of calcium carbonate have been drunk for long
periods without producing any marked deleterious
effect, though such waters are apt to be hard ; and hard
waters are poorly adapted for laundry and cooking
purposes. But a very small amount of organic impurity
may render the water unsafe for drinking purposes.
Organic matters containing nitrogen are most
deleterious. It is common with chemists to determine
this organic impurity in the form of ammonia, it being
possible to convert all such nitrogenous matters into
ammonia, and to determine the amount present with
accuracy. The ammonia present in waters as a result
of decay that has already taken place is determined as
free ammonia ; the rest of the nitrogenous organic
matter may be decomposed, and converted into
ammonia by the analytical process ; this is called
albuminoid ammonia. Regarding the amounts of these
ORGANIC IMPURITIES IN WATER. 177
matters allowable in drinking water according to the
established standard of safety, Mr. Wanklyn of Eng-
land, agenerally recognized authority upon this subject,
has said: "I should be inclined to regard with some
suspicion a water yielding a considerable quantity of
free ammonia, along with 0.05 parts of albuminoid
ammonia per million.* * * Albuminoid ammonia above
0.10 per million begins to be a very suspicious sign,
and over 0.15 oughtto condemn a water absolutely."
Below are exhibited the results of some analyses of
natural waters.
Parts per million.
S^^i'^e- anfmonia
Ahluminoid ... .^
. ammonia, ^"thority.
Town water, Manchester,
England . . ' .
.01
.06
J. A. Wanklyn.
Glasgow, Scotland, Loch
Katrine
.00
.08
<(
London Thames, at high
tide
1.02
.59
((
Average 10 artesian wells,
Provo City, Utah
•2.n
.18
The Author.
Average IG surface wells,
Provo City, Utah
.125
.284
"
In-doors pump, Provo
City, Utah
0.73
5.40
<(
Artesian well, Spanish
Fork, Utah
.72
5.18
<(
Average 13 artesian wells.
Salt Lake City, Utah .
.669
.22
<'
Surface well,Salt Lake City
3.28
.34
«
City water mains, Salt
Lake City
.13
.052
<<
Emigration canyon stream.
Salt Lake valley
.046
.045
J. T. Kingsbury.
Red Butte canyon stream
.023
.120
"
Parley's canyon stream .
.010
.060
"
Associated with organic impurity of the kind describ-
ed, water may contain large quantities of chlorine,
usually combined with sodium as common salt, or with
178 DOMESTIC SCIENCE.
calcium as calcium chloride. This may result from the
presence of sewage filth or drainage from cess pools ;
though the discovery of chlorine in water, unaccom-
panied by organic impurity, is not of such serious
import.
The following table will convey an idea of the vary-
ing amounts of chlorine in different waters.
Source.
Chlorine.
Grains per gallon.
Authority.
Bala Lake, Wales .
0.7
Wanklyn.
Thames at London
1.2
"
Average 22 surface wells,
Provo City, Utah
1.22
The
Author
Average 8 artesian wells,
Provo City, Utah
2.029
"
Average 8 artesian wells,
Salt Lake City, Utah ,
3.688
(<
Surface spring, Provo City
.977
<<
Artesian well, Spanish
Fork, Utah
.992
"
Salt Lake City supply
TIT . „£
.87
11 J._ _!!
fC
The pres.ence of small amounts of organic matter
would not of itself prove a source of injury to health.
The danger lies in the fact that living organisms flourish
in water so contaminated, and these may be of an
injurious type since man)^ forms of contagious disease
have been proved to be always associated with the ex-
istence of such organisms within the system. The
germs of cholera, small pox, and many forms of fevers,
thrive in water that is organically impure. Dr. Cyrus
Edson, the well known sanitary chemist of New York,
has declared his belief that ninety -nine per cent, of
cholera cases are propagated through the medium of
drinking water. The reports of the sanitary officials
in India show a close relationship between the epidemic
outburst of cholera, to which that country has been
ORGANIC IMPURITIES IN WATER. 179
frequently subject, and the use of polluted drinking-
water. Enteric or typhoid fever is more frequently
spread by the use of contaminated water than in any
other way. *
Dysenteric and diarrhceal affections are in many cases
directly traceable to polluted water. The sample
named "In -doors pump, Provo City, Utah," in table on
page 177, was taken from a well, provided with a curb
and a drainage pipe. The water was used in a large
boarding house, and the fact was reported that severe
dysentery was common among the inmates. An ex-
amination of the well was made, and the drain pipe
was found to be completely choked, so that the foul
wastes made their way back to the well, and this repuls-
ive mixture was drunk. The pipe was cleared, the well
thoroughly cleansed, and the derangements in the health
of the inmates straightway disappeared.
Mr. Wanklyn, the English analyst, examined water
from a well at the Leek Workhouse ; and found it to
contain .02 parts of free ammonia, and .34 parts of
albuminoid ammonia per million of water. Of this
occurrence he says, ''In the Leek Workhouse there hajS
been for years past a general tendency to diarrhoea,
which could not be accounted for until the water was
examined and shown to be loaded with vegetable
* In referring to typhoid fever as a result of the use of water con-
taminated with filth, Drs, Huxley and Youmans say: "The instances,
of its originating in this way are too numerous, and have been too
clearly traced to admit of a doubt of the fact ; nor does mere dilution
of the poison remove the danger as the following will show: A recent
outbreak in an English town was traced to the milk with which
numerous families were served, and it was conclusivly proved that the
milk was poisoned by being stored in cans that had been washed with
water contaminated with sewage from an imperfect drain."
180
DOMESTIC SCIENCE,
matter." He adds, "A well on Biddulph Moor, a
few miles from Leek, yielded .05 grain chlorine per
gallon, and .03 free, and .14 albuminoid ammonia per
million. The persons who were in the habit of drink-
ing this water suffered from diarrhoea."*
Fig. 77.
Suspended matters in well-waters.
Well waters are often contaminated by the entrance
of foreign matters because the openings are not suffi-
ciently protected. The author has examined many
* "Dissolved or suspended organic matter, whether of vegetable or
animal origin, will cause diarrhoea. In the recent war great numbers
of cases occurred from the use of marsh or ditch water; the sickness
ceased when wells were sunk."
"Mineral matters, either dissolved or suspended, will give rise to it if
present in considerable quantity."
"WaterMmpregnated with nitrate of lime will produce diarrhoea.
]}rackish water acts in the same way."
Hl'XLEY & YOUMANS.
ORGANIC IMPURITIES IN WATER.
181
specimens of water from wells so exposed, and is con-
vinced that reckless carelessness exists as to protecting
the wells from dust, and the like. Nearly one -third
of the waters so examined have been found to contain
suspended particles, which, under the microscope, reveal
themselves (figure 77) as partly -decayed fibres of
straw ; cotton ; wool (c) ; hair (e) ; pollen grains
Fig. 78.
Living organisms iu potable waters.
from plants (6) ; spores of fungi ; scales of butterflies
and moths (a). Dr. Parkes, of London, referring to
the results of his examinations of water in that great
city says, "Fibres of cotton, wool or linen, starch
cells, (figure 77,/) macerated paper, human hairs, yel-
low globular masses, and striped muscular fibre (un-
digested meat) (d), with squamous epithelium cells,
are all indicative of contamination of the water with
182 DOMESTIC SCIENCE.
human refuse, and most probably with sewage.
Amongst these matters and feeding on them will
probably be found living organisms of low types, such
as bacteria (micrococci, bacilli, and vibriones) amoebae
and infusoria. These organisms are not in themselves
dangerous, but they indicate the presence of matters,
chiefly organic, upon which they feed, and amongst
them may be those germ-producing organisms which
so often find their way into sewage."
The accompaning sketch (figure 78) shows a few of
the living organisms reported as having been found in
potable waters ; a, represents a species of green mold
(penecillium) ; 6, another form of mold (mucor) ; d,
a fungus (aspergillus) ; e, forms of bacteria (micro-
coccus, bacillus, and vibrio) ; c, a simple form of
animal belonging to the protozoans (vorticella) ; 7,
another protozoan, (paramecium).
SIMPLE TESTS FOR WATER. 183
CHAPTER 21.
SIMPLE TESTS FOR PURITY IN POTABLE WATER.
IN CASES of suspected water contamination, a sam-
ple should be submitted to a competent chemist for
analysis. He will certify to the state of purity in the
sample, and as to the possibility for bettering the water
by any simple means. From him the following items
of information should be asked :
1. The total amount of solid matters present.
2. The nature of the dissolved solids. If possible a
full analysis of the solids should be made, and in all
cases the predominating metals should be determined,
and the nature of the prevailing salts, whether carbon -
ates, sulphates, or chlorides.
3. The degrees of hardness, expressed as total hard-
ness, temporary hardness and permanent hardness.
4. The amount of chlorine present.
5. The amount of nitrogenous organic matter de-
termined as free ammonia and albuminoid ammonia.
6. The presence or absence of deleterious gases.
7. The presence or absence of poisonous metals.
8. The nature of the mechanically suspended
matters.
From such facts, the general condition of the water
can be inferred. However, it is not always possible to
secure the aid of chemical skill in examining drinking
water ; it is proper therefore that we become acquainted
with at least a few of the t^eterminative tests to which
184 DOMESTIC SCIENCE.
water can be subjected. The following observations may
be made by any one with practice and scrupulous care,
and by such assistance much reliable information as to
the purity of any water may be gained.
1 . Color. It is a common statement that pure water
is colorless ; this, however, is strictly true of small
bodies of water only ; for when viewed through great
depths, the purest of waters possesses a distinctly bluish
tint. To determine the color of a potable water, fill
with the sample a tall cylinder or bottle of clear white
glass ; cylinders made for the purpose, about two feet
in length are best adapted. Place the vessel on a white
dish, or a sheet of white paper, and carefully examine,
looking from the surface downward. Good waters will
show the bluish tint above referred to ; any large amount
of vegetable impurity will give a greenish color ; and
sewage filth will tint the water yellow or light brown.
If salts of iron are present in the water, the last
named indication will be unreliable, as such salts
themselves would give to the water a brownish hue.
2. Clearness. Examine as for color ; also hold the
vessel containing the sample toward the light ; then
view it when held before some black object. Any tur-
bidity is an indication of the presence of organic im-
purities in solution, or of suspended solid matters. All
turbidity is a sign of contamination, though the op-
posite must not be inferred — that clear water is neces-
sarily pure. There is a wide -spread popular error
on this point, and it has led to the use of very foul
waters because of their sparkling appearance. One of
the clearest waters ever examined by the author, was
taken from a pump in Greenwood Cemetery, Brooklyn.
SIMPLE TESTS FOR WATER. 185
N. Y. ,* yet it wasfound to be heavily laden with nitrates,
which, doubtlessly, were.derived from the bodies there
entombed, t
3. The odor of drinking water is an important char-
acteristic. To determine it, procure a quart bottle ;
see that it is clean and provided with a well -fitting
cork. Half fill the bottle with the water under ex-
amination ; cork the vessel and set it aside in a warm
place for a few hours ; then shake it well, open and
smell. Any perceptible odor should condemn the
water for domestic use until a determinative analysis
has been made. If no odor is perceptible after gentle
warming, the water should be heated nearly to boiling,
* A number of pumps are to be found in that wonderful and beauti-
ful city of the dead, and I have looked with horror upon visitors drink-
ing from these grave-fed wells. Such water is highly charged with
the nitrates and nitrites of decomposing flesh, and water so impreg-
nated has a cooling, saline taste, very pleasant to the palate of the
blissfully ignorant drinker, and sure to excite subsequent thirst,
which will lead to continued draughts. During another visit to Green-
wood in the summer of 1889, I was glad to see that a notice had been
placed over each of the pumps, stating that the water was to be used
for irrigating the flower beds only: but the pumps are still there, with
the levers free, and visitors continue to drink at them. Should we
marvel that the silent metropolis is so well tenanted ?
t The London Lancet in referring to water so contaminated, says :
" It is a well ascertained fact, that the surest carrier and the most
deadly fruitful nidus of zymotic contagion, is this brilliant, enticing-
looking water, charged with the nitrates which result from decompo-
sition."
Johnston says of such waters: " The water of a well close to the old
churchyard on the top of Highgate Hill was examined by the late Mr.
Noad, and found to contain as much as 100 grains of solid matter to
the gallon, 57 grains of which consisted of the nitrates of lime and
magnesia. This large amount of nitrates is traced to the neighboring
graveyard, as such compounds are generally produced where animal
matters decay in porous soils. . . . While the buried bodies were
more recent, animal matters of a more disagreeable kind would proba-
bly have been found in the well, as I have myself found them in tlie
water of wells situated in the neighborhood of farm-yards."
186 DOMESTIC SCIENCE.
the odor being tested at frequent intervals as the heat-
ing proceeds. Remember that pure water is odorless.
4. Taste. Water intended for household use should
be entirely devoid of taste. Any perceptible flavor
should be considered as strong evidence that the
liquid is contaminated, and chemical tests should be
employed. As many mineral ingredients impart but a
feeble taste to water, these tests must be made with
critical care. Many waters that seem tasteless while
cold develop a positive taste if gently warmed. Do not
consider the flat insipid nature which all ordinary water
acquires by boiling, as a proof of contamination.
5. The presence or absence of chloriiie should be next
determined. This can be satisfactorily done by a com-
petent chemist only, though the method of proceeding
is simple. A drop of pure nitric acid and a few drops
of clear silver nitrate solution are to be added to the
water under test. A milkness or turbidity is due to
the formation of silver chloride, and is a proof of the
presence of chlorine in the sample. As was stated on
page 178, the presence of chlorine in moderate quantity
is a sign of danger only when associated with organic
matter.
6. The presence of organic matter in water is difli-
cult to determine, except by complicated chemical tests.
Yet such determination is of utmost importance in de-
ciding uponthe wholesomeness of water. Much infor-
mation upon this point, however, may be gained from
the tests on color, odor and taste as before described.
Heisch's test for organic impurity in water may be
made as follows : "Fill a clean pint bottle three -fourths
full of water; dissolve a teaspoonful of loaf or granu-
SIMPLE TESTS FOR WATER. 187
lated sugar ; cork the bottle and set it in a warm place
for two days. If the water becomes cloudy or muddy
it is unfit for domestic use. If it remain perfectly
clear it is pro6a5/// safe to use." Some waters con-
tain so much organic filth that when boiled the pollut-
ing substances coagulate, as does the white of an egg
when heated ; when the water cools the impurities
separate in flocks.
188 DOMESTIC SCIENCE.
CHAPTER 22.
PURIFICATION OF WATER.
THE fact that water becomes so readily contaminat-
ed with both organic and inorganic impurities,
gives great importance to the subject of water purifi-
cation. Many methods of improving the qualities by
simple treatment have been proposed and practiced.
For operating on a small scale as for domestic
purposes, boiling has long been in favor. This treat-
ment may produce important changes in potable water.
For example, consider a specimen of water possessing
great temporary hardness, and moderately contaminat-
ed with organic refuse. As the boiling proceeds, the
dissolved gases of the water, among them the carbon
dioxide, which is sure to be present in such a sample,
will be expelled ; the lime carbonate, from which the
water derived its quality of temporary hardress will
separate from solution, and fall as a sediment, leaving
the water comparatively soft. This is the easiest and
the cheapest known method of softening on a small
scale such lime -carbonate waters.
Another probable result of the boiling will be the
coagulation and consequent separation of certain forms
of organic matter. Farther than this, the boiling
temperature will kill many if not all of the living germs
present in water, thus insuring the liquid against
the power of communicating specific diseases. Mudai
discussion has arisen among scientists as to the minimuio
temperature that is fatal to the common forms, of
PURIFICATION OF WATER. 189
bacterial life, and from the facts adduced by the con-
troversy we may conclude that the temperature of 212°
F. will effectually destroy all living organisms found
in water, except possibly the spores of certain bacteria,
and these may be surely killed by boiling the water
several times at intervals, allowing time between the
boilings for the spores to develop. Parkes declares
his belief that there is scarcely any doubt that the
specific poisons of cholera, enteric fever, and other
forms of contagion such as are commonly propagated
through the medium of impure drinking ^ater, are
destroyed with certainty by even afew minutes' boiling.
It must be remembered however, that at great altitudes
water boils at a temperature considerably below 212°
F. Under such conditions of diminished heat, the
certainty of destroying microscopic organisms by boil-
ing the water is considerably lessened.
Boiled water possesses an insipidity which, to many
people, is almost nauseating ; this taste is due to the
non- aerated condition of the water, the atmospheric
gases having been expelled by the heat. Such water
may be again aerated by allowing it to flow slowly from
a perforated cask, or through a collander, in many
fine streams.
Distillation is the means by which the purest water
may be obtained. The process consists in boiling the
water, and in collecting and condensing the steam.
In this way the solid ingredients are left in the
boiler. The greater part of the dissolved gases will be
carried off in the first part of the distillate ; if this
portion be rejected, the water that subsequently distills,
may be regarded as approximately pure.
190
DOMESTIC SCIENCE.
The apparatus for distillation (figure 79) consists of
a boiler a, with a delivery pipe b through which the
steam is conducted to a spiral tube or worm set in a
vessel of cold water c ; within the spiral tube, the steam
condenses to the liquid state, and this water is caught,
in a suitable vessel d. A stream of cold water is
supplied to the condenser through the tube e, the surplus
being carried off through the exit pipe/.
Fig. 79.
Apparatus for distillation of water.
For the distillation of water or other liquids on a
small scale, the apparatus represented in figure 80 may
be employed. In addition to its portability this has
the advantage of being constructed in all its essential
parts of glass. In the sketch a is a glass flask, con-
taining water, and heated by a spirit lamp placed below ;
6 is a delivery tube connected with the condenser c.
PURIFICATION OP WATER.
191
This form of condenser is called from its inventor the
Liebig condenser ; it consists of a central tube continuous
with b, and surrounded by a large outer tube, through
which cold water is flowing. The central tube is
thus incased in a water jacket, a continuous supply
being made through d, an escape is provided through
e. The distillate is caught in /.
Fig. 80.
Portable distillation apparatus of glass.
Great care should be exercised that the distilling
apparatus be clean, and of such material that the water
will not dissolve appreciable amounts of its substance.
Houses that are furnished with steam heating appliances
may be easily supplied with a sufficiency of distilled
water. Water that has been distilled with all proper
precautions may be considered free from all disease
germs, . and therefore comparatively safe for domestic
use. Before such water can be relished for drinking
purposes it must be aerated, and this may be accomplish-
192 DOMESTIC SCIENCE.
ed by the same means as employed to aerate the boiled
water.
Filtration is often resorted to as a purifying process.
Many forms of domestic filters are now in the market.
The manufacturers of these devices usually guarantee
them to free the water from all suspended and dissolved
matters ; but such extravagant claims are seldom realiz-
ed in practice. The commonest form of water filter
consists of a vessel of wood, stone, or metal, containing
a slab of porous earthenware, and layers of charcoal,
magnetic iron oxide, and gravel ; in some filters pound-
ed glass and sponge are used. Through this the water
is allowed to percolate, thus imitating in a feeble way
the grand processes of natural filtration by which foul
waters become sweet by percolating through the porous
strata of the earth. A filter, which in service will
prove fully as efiicient as the high-priced articles offer-
ed in the market, may be made as follows : Provide
some water-tight box, cask, or jar of convenient size;
bore a number of holes in the bottom of the receptacle,
and place within it alternate layers of recently heated
charcoal, fine gravel, and sand, till it is half or two -
thirds full. Pour in at the top the water to be filter-
ed ; that which first passes through may be somewhat
turbid, from loose particles derived from the filter ;
return such to the top. In a short time the filtered
water will appear perfectly clear, though it may have
been originally of the foulest kind. Such a filter is of
service as long as it is clean. The great objection to
the use of domestic filters is based upon the exceedingly
small amount of filtering material, and the consequent
rapidity with which the filters become choked. A
PURIFICATION OF WATER. 193
dirty filter — one that has taken from the water all the
foul matter that it is capable of removing — is a source
of pollution to the water that subsequently passes
through.
The process of filtration is a serviceable one, and
could it be successfully performed with an apparatus
of adequate size, it would he regarded as a very
efficient aid in the purification of water. The writer
has examined many forms of household filters, and has
analyzed samples of water both before and after filtra-
tion through such ; and he has not yet found an
apparatus of the kind that retains its eflBciency for any
great length of time ; and most of the filtering devices
require far more care and attention than the ordinary
house -keeper is inclined to bestow upon them. And if
not cared for, they become sources of positive danger.
A filter, even when working in the best manner
possible, cannot separate from water its dissolved
matters ; charcoal, it is true, will take out some portion
of the ammonia and other gases, but the removal of
theseisin no case complete, and the amount of dissolved
solids is in no way diminished by filtration. For the
removal of mechanically suspended matters, such as
clay, mud, and sand, the filtration process proves of
great service ; and in the purification of water on a
large scale, as for a city supply, filtration is an in-
dispensable part of the treatment. The water of
London is filtered by being passed through beds of
sand and gravel. The average thickness of the sand
layers is three feet; beneath this are strata of gravel,
the coarseness increasing with the depth. The water
upon the filter beds is never allowed to exceed two feet
194 DOMESTIC SCIENCE.
in depth. In practice it is found necessary to frequent-
ly remove the upper layers and to replace such with
fresh material ; the rapidity with which the filters be-
come choked is surprising.
A domestic filter of recent invention is the Pasteur-
Chamberland device. In this the water is forced through
at least five partitions of porous earthenware, by which
treatment it is entirely freed from bacterial organisms.
Water filtered in this apparatus is completely steriliz-
ed, though its dissolved solids are not diminished.
Difficulty is experienced in cleaning this filter.
For softening waters possessing a high degree of
temporary hardness, the value of the boiling process
has been already pointed out. This mode of treat-
ment, however, is inapplicable on a large scale ; and a
much cheaper method has been de^'ised. This is
known as Clark' s process ] and consists in adding lime
water to the water that is to be softened. It may
appear to be a strange proceeding, to add lime for the
purpose of removing a compound of lime, yet the ex-
planation of the operation is simple. As already ex-
plained, it is lime carbonate that gives to water the
property of temporary hardness ; and this substance
is scarcely soluble at all in pure water ; but it dissolves
with ease in water containing carbon dioxide. Now
the lime that is added to such a carbonated water will
unite with the free carbon dioxide there present, form-
ing with it insoluble lime carbonate ; at the same time
the carbonate originally in solution will fall as a sedi-
ment because the removal of the free carbon dioxide
robs it of its solvent. In this way it is possible to re-
duce the hardness of water 70 or 80 per cent. The
PURIFICATION OF WATER. 195
addition of the lime water causes a great turbidity
throughout the liquid, and time must be allowed for
the sediment to subside before the water can be used.
In Porter's modification of Clark's process, the water
is filtered under pressure, the solid particles being thus
more speedily removed.
It is claimed that certain chemical substances when
added to water exert a purifying effect upon it. Of
these alum is perhaps in commonest use. When mixed
with certain waters, alum forms a bulky, gelatinous
precipitate of aluminium hydrate, which in settling
carries with it much of the matter held in mechanical
suspension. Good authorities recommend 6 grains of
alum to the gallon of water as the best proportion . The
waters of the Seine are used in Paris after clarification
by this simple process. Tannin exerts a coagulating
effect upon certain forms of organic matter. The com-
mon way of adding the tannin is to place oak chips in
the water, this kind of wood being very rich in the
astringent named. This treatment is of use only if the
polluting ingredients are of an albuminoid character ;
but in waters so contaminated the method is a very
serviceable one, as the coagulum in forming entangles
most of the other impurities. Prof. Johnston states
that the marshy waters of India are rendered potable
by the use of a nut — strychnos potatorum. The powder
produced by crushing the nut is rubbed on the inside
of the water vessel, and the impurities of the liquid
soon subside. The same authority reports that in
Egypt the muddy water of the Nile is clarified by the
addition of bitter almonds.*
*It is well to read here, the experience of the Israelites, Exodus XVII,
23—25.
190 DOMESTIC SCIENCE.
"And when they came to Marah, they could not drink of the waters
of Marah, for they were bitter: therefore the name of it was called
Marah.
"And the people murmured against Moses, saying, What shall we
drink?
"And he cried unto the Lord; and the Lord shewed him a tree, which
when he had cast into the waters, the waters were made sweet : there
he made for them a statute and an ordinance, and there he proved
them."
MINERAL WATERS. 197
CHAPTER 23.
MINERAL WATERS.
THE term mineral water is applied to any natural
water that contains so large a proportion of min-
eral ingredients as to derive therefrom a characteristic
taste. No clear distinction, other than this, exists
between potable and mineral waters.
According to their prevailing ingredients, mineral
waters are usually classified as sulphur waters, car-
bonate waters, chalybeate waters, alum waters, and
saline waters. We will briefly consider each of these
kinds.
Sulphur Waters contain a considerable quantity of
hydrogen sulphide, and this gas posesses such an
unmistakable odor that no chemical skill is needed to
determine its presence. Utah furnishes many re-
markable examples of sulphur springs. The waters of
the Warm Springs and of the Hot Springs at Salt Lake
City are rare and wonderful mixtures.
Carbonated Waters are such as contain an abundance
of carbon dioxide gas, by virtue of which they dissolve
large amounts of calcium carbonate and of other car-
bonates. It has been already shown that the solvent
power of water for gases is increased by pressure, and
we may conclude from this, that, within the crust of
the earth, waters coming in contact with carbon dioxide
would take into solutions very great proportions of the
gas. This addition gives the water power to dissolve
198 DOMESTIC SCIENCE.
many mineral carbonates of which limestone or cal-
cium carbonate may be taken as a type. As such
highly charged water reaches the surface as springs,
the undue pressure being relieved, most of the carbon
dioxide escapes, in consequence of which the lime
carbonates falls from solution in the solid state. This
may be deposited in such quantities as to form a curb of
stone around the spring, and to incrust articles immersed
in the water. Very remarkable carbonated springs
exist at Soda Springs, Idaho, and at Midway, Utah.
At the former place the waters are so highly charged
with carbon dioxide that the escaping gas keeps the
springs in constant and violent agitation. Any article
immersed in the water soon becomes coated with a
deposit of lime carbonate. Such process is sometimes
incorrectly spoken of as petrifaction ; it is simply an
incrusting or covering, not a replacing by stone. A
bunch of grapes or a bouquet of flowers may be com-
pletely covered in this way, and long after the soft
fruit and the delicate petals have decayed, the stony
casing remains, preserving the full form of the original.
Carbonated waters are of two kinds ; those contain-
ing much lime in combination are known as Calcium
Waters ; to this class belong the examples already cited ;
and waters containing iron compounds as predominat-
ing ingredients are known as Chalybeate Waters. The
iron in such waters is present in the form of ferrous
carbonate, which compound is soluble in water con-
taining free carbon dioxide, but not in pure water.
In this respect it resembles the lime carbonate already
referred to. When the carbon dioxide escapes from
such water, the iron carbonate is deposited from
MINERAL WATERS. 199
solution, under the influence of atmospheric oxygen,
however, it soon changes to ferric oxide, and appears
about the springs, and upon objects placed in the
water as a red or yellow incrustation. Typical illus-
trations of this class of waters are found in Sevier Co.,
and in Millard Co., Utah. At the former place the
deposits of ferric oxide are so pure and plentiful, as to
be used with very little preparation for making paints.
Alum Waters are rich in iron and aluminium sul-
phates, and frequently contain small quantities of free
sulphuric acid. The strong styptic taste of alum is
characteristic of such waters. Alum springs are not
of common occurrence in the West.
Saline Waters contain many earthy salts, among
which the chlorides of sodium and of calcium predom-
inate. The celebrated Kissengen and Seltzer Springs
in Germany, belong to this class, as do also the famous
Saratoga Springs in the United States.
To this division of mineral waters belongs also the
waters of the ocean, and of salt and alkaline lakes.
The composition of saline waters is very complicated ;
indeed sea water contains all soluble compounds that
are found in the earth, and that are capable of existing
together in the same solution. The prevailing ingre-
dient is sodium chloride.
A very concentrated saline water is that of the
Great Salt Lake, which contains on an average from
16 to 19 per cent, by weight of solid ingredients, or
say from 10,000 to 12,000 grains per gallon of water.
The author collected and analyzed a sample of Salt
Lake water in December, 1885, and found in it the
following ingredients :
200 DOMESTIC SCIENCE.
Grams
Per cent.
per litre.
by weight
Sodium chloride
152.4983
13.5856
Sodium sulphate
15.9540
1.4213
Magnesium chloride .
12.6776
1.1295
Calcium sulphate
1.6679
0.1477
Potassium sulphate .
4.8503
0.4321
Total solid matter . 187.6481 16.7162
The proportion of solid matters in an enclosed body
of water like the Great Salt Lake is variable according
to the prevailing climatic conditions. Thus, during
the dry and warm season, evaporation proceeds much
more rapidly than water is supplied by the inflowing
streams, consequently at such times lake water becomes
more concentrated. During the wet months, however,
the supply far exceeds the loss by evaporation, and the
water becomes correspondingly diluted. As a basis
for comparison with the above figures, there are given
below the results of an analysis of lake water collected
in August, 1889. This contained:
Grams
Per cent.
per litre.
by weight.
Sodium chloride
182.131
15.7430
Sodium sulphate
12.150
1.0502
Magnesium chloride
23.270
2.0114
Calcium sulphate
3.225
.2788
Potassium sulphate
5.487
.4742
Total solids
226.263
19.5576
The water of the Dead Sea, in Palestine, is still
more concentrated. An analysis of a sample of Dead
Sea water collected at a depth of 1110 feet, by Capt.
Lynch, showed the following composition :
Per cent, by weight
Sodium chloride
7.555
Potassium chloride
0.658
Magnesium chloride
14.889
lAme sulphate
0.070
Calcium chloride . ■<»
3.107
Potassium bromide
0.137
Total solids
26.416
MINERAL WATERS. 201
The average temperature of spring water is from 60°
to 66° F., but mineral springs often far exceed this.
Indeed some mineral waters are discharged from the
spring at a boiling temperature. The Hot Springs,
near Salt Lake City, have a temperature of 128° F.
The Munroe Springs, in Sevier Co., Utah, discharge
water at 137.5° F., and certain hot springs, near
Draper, Salt Lake Co., Utah, emit water at' a tempera-
ture of 158° F. The constancy of temperature in most
of these springs is remarkable. Wells says: "There is
evidence to show that the temperature of some hot
springs has not diminished for upward of a thousand
years."
Before leaving the subject of mineral waters, refer-
ence should be made to the common belief that all such
waters are of necessity valuable remedial agents in dis-
ease. Indeed, there seems to be a popular belief that
any natural water possessing a particularly disagreeable
taste or odor is surely good for the body. It is an undeni-
able fact that many mineral waters possess great thera-
peutic properties, especially are they valuable for wash-
ing and bathing in cases of skin diseas.e, gout and
rheumatism ; and in rare cases it may be wise to ad-
minister the waters internally ; but there is a reckless
carelessness now existing as to the use of such waters.
They should be used in moderation and under skilled
direction. Mineral water is to be regarded as a medi-
cine, not as a panacea, and if administered unwisely the
water may prove positively harmful.
202 DOMESTIC SCIENCE.
CHAPTER 24.
COMPOSITION OF PURE WATER.
KNOWIMj now that natural waters are never pure,
and having considered the process of distillation,
by which chemically pure water may be prepared, it
would be well now to consider the nature and com-
position of this purest kind of water. From the earliest
times of which we have general record till near the end
of the eighteenth century, water was thought to be an
element; now it is known to be a compound. Ele-
ments are simple substances, such as man has never
yet decomposed into other constituents ; a compound,
however, is composed of at least two elementary sub-
stances. As illustrations: gold, silver, iron, nitro-
gen, carbon, oxygen, sulphur, are elements ; for not one
of them has ever been decomposed by man. Thus far
no chemist has been able to produce from pure gold
anything but gold ; and so with each of the elements,
of which now between 60 and 70 are known. On the
other hand, common salt is an example of a compound ;
it may be separated by chemical means into the two
elements sodium and chlorine ; carbon dioxide is also
a compound, it consists of carbon and oxygen. So,
too, water is a compound, for it may be decomposed
into the two ingredients, hydrogen and oxygen.
The decomposition of water may be very beauti-
fully and instructively illustrated by passing an electric
COMPOSITION OF PURE WATER. 20B
current through a quantity of water, and collecting the
gases that result. If an apparatus similar to that shown
in figure 81 be employed, the collecting tubes being
filled with water and inverted over the terminations of
Fig. 81.
Electrolysis of water.
the conducting wires from the battery on the right,
bubbles will be seen rising in the tubes as soon as the
current is started. One tube is seen to fill as fast again
as does the other. The double quantity of gas will be
proved by investigation to be hydrogen, and the gas
in the other tube to be oxygen.
If steam be passed through an iron tube containing
scraps of iron heated to bright redness, the vapor will
be decomposed, its oxygen combining with the metal
in the tube to produce an oxide of iron, and the hy-
drogen escaping at the open end of the tube, where it
may be collected. By either of these methods we may
prove that water consists of the elements hydrogen and
oxygen.
The general mode of preparation and the general
properties of oxygen have been briefly considered in a;
204 DOMESTIC SCIENCE.
preceding chapter (see pages 37 and 38). It will be
well at this stage to review the subject and re-read the
pages referred to .
Hydrogen, however, is to us a new element. To in-
vestigate its properties we should prepare it in larger
quantity than will be yielded by a weak battery current
in water. The simplest and for our present purpose
the best mode of preparing the gas is as follows : Ar-
range a generating bottle, with funnel, delivery tube,
pneumatic trough, and collecting bottle. Place within
the bottle some scraps of zinc ; then adjust the cork
and pour into the bottle through the funnel tube enough
dilute sulphuric acid* or muriatic acid to cover the bits
of zinc to a depth of an inch. Gas will soon collect
in the inverted bottle ; discard the first bottleful ; it is
mixed with air ; then collect several bottles of the gas.
By collecting and examining the hydrogen we shall find
it to be a colorless gas, and if pure it will be devoid of
odor, though the impurities of the materials used in its
manufacture usually impart to the gas a very disagree-
able smell. It is also very light, exerting a buoyant
effect on the vessels within which it is confined ; in
fact, hydrogen is the lightest known substance. Its
buoyancy may be prettily tested by filling with the dried
gas a child's toy balloon ; when released this will rise
swiftly through the atmosphere.
* Care is called for in diluting sulphuric acid, as great heat Is devel-
oped in the process. The acid and the water should be measured
separately— one volume of the former to three of the latter ; the acid
should then be poured in a small stream into the water, which in the
meanwhile should be vigorously stirred. The mixture must be made
in a vessel of glass or earthenware, as the acid will attack wood and
metal. Remember that sulphuric acid is intensely corrosive and poi-
sonous.
COMPOSITION OF PURE WATER.
205
Fig. 82.
Hydrogen burning.
Hydrogen is also inflammable ; it may be bnrned at
the mouth of the bottle, as shown in figure 82. A
better exhibition of the com-
bustible nature of hydrogen
may be made by passing the
gas into a tube that has been
drawn at one end to a jet.
The gas as it issues may be
burned in a continuous flame.
While the hydrogen jet is
burning, invert over it a cold
dry bottle containing air or
oxygen. A mist appears on
the inside and drops of liquid
may collect there. The com-
bustion of hydrogen then
marks a combination between this gas and the oxygen
of the atmosphere, the result of the union is water.
AVe thus prove the composition of water by analysis
and by synthesis. By analysis we separate the water
into its elements, hydrogen and oxygen ; by synthesis
Ave combine the elements and produce the compound
water.
It is remarkable that hydrogen, which burns with
a very intense heat, and oxygen which is so vigorous
a supporter of combustion, by their union should form
a compound possessing the property of extinguishing
fire. If a stream of oxygen be forcibly driven into the
midst of a flame of burning hydrogen, the oxyhydro-
gen flame is produced ; this is attended by the most
intense chemical heat known. In such a flame, steel wire
will burn like wood in an ordinary fire ; zinc.
206 DOMESTIC SCIENCE.
copper, and all known metals may be deflagrated with
characteristic flame tints ; even platinum, the most in-
fusible of metals, may be readily melted by this means.
Yet the flame is practically non-luminous; its great
heat may be utilized, however, in raising some incom-
bustible solid to a state of incandescence. A piece of
lime or of magnesia introduced into the flame is at once
raised to a state of dazzling brilliancy. This is known
as the calcium or Drummond light ^ and is of great ser-
vice in the operation of optical lanterns, and in other
cases wherein a particularly brilliant illumination is de-
sired.
When oxygen and hydrogen are brought together in
quantity, and a flame or an electric spark is applied to
the mixture, a very violent explosion occurs, and water
is produced by the union of the gases.
As a result of very accurate experiments we know
that pure water consists of :
By volume. By weight.
Oxygen . . . . l part 8 parts
Hydi'ogen . . . 2 parts l part
These proportions are invariable, as indeed are the
proportions of the constituent parts in any compound.
In accordance with some great principle, which the
mind of man has not yet comprehended, the elements
of matter unite in fixed and unchangeable propor-
tions. The discovery and proof of this fact is one of
the greatest achievements of modern science. Not
only is there order and system in the world of living
things ; even the dead minerals of earth, and the water
of ocean and air, each is compounded according to
governing laws.
FOOD ITS NATURE AND USES. 207
I=^jPlK.T III.
FOOD AND. ITS COOKERY.
CHAPTER 25.
FOOD ITS NATURE AND USES.
CHEMICAL analysis has demonstrated that the
human body consists of at least fourteen separate
elements. These are nitrogen, carbon, oxygen, hy-
drogen, phosphorus, sulphur, sodium, potassium,
calcium, magnesium, iron, silicon, chlorine, and
fluorine. Of these the first four are by far the most
plentiful within the body. It is known that the organs
of the living body are in ceaseless action, whereby
great expenditure of force occurs, with consequent loss
of material." It is therefore necessary that the' system
be supplied with material from which to repair its vari-
ous parts ; such supplies we call Food.
The term food may then be applied to substances,
that, when taken into the body, serve to nourish its
tissues, and sustain its vital energy. A perfect food
would be one that contained all of the fourteen ele-
ments of the body in a digestible condition, and in the
proper proportion to supply the various tissues of the
body. Such a food stuff is not known. Milk ap-
proaches this ideal standard, yet the proportions in
which the elements are present in milk fit it to be a
208 DOMESTIC SCIENCE.
complete food only for infants ; it is deficient in many
of the substances required by adults.
From these statements we will perceive at once the
necessity of employing a mixed diet, in which we may
supply with one article, the elements lacking in
another. According to their composition Foods com-
prise : —
I. — Inorganic or mineral substances ; of which the
principal ones are, (1) Avater, (2) common salt, (3)
lime, (4) iron, (5) sulphur, (6) phosphorous, (7)
potassium, (8) silicon, and (9) magnesia.
II. — Organic substances ; such as are derived from
plants and animals. These are : 1. Carhonaceous : —
comprising, (1) amyloids; (2) vegetable acids; (3)
fats. 2. Nitrogenous substances, sometimes called
albuminoids, or proteids. Of these we shall con-
sider: (1) albumen; (2) fibrin; (3) gelatin; (4)
casein; (5) gluten.
III. — Auxilliary foods, and condiments.
A well-regulated dietary should include a proper
amount of each of these classes of food ; and by an
instinctive tendency we select and combine foods, to
accomplish this purpose. As an example, bread is
rich in starch, a compound of the amyloid group ; it
contains a small proportion of gluten, which is a
nitrogenous compound ; but it is very deficient in fat ;
however, we are prone to add butter to our bread,
thereby supplying the chief lack. But bread and but-
ter is an incomplete food ; it is still poor in nitrogen,
and we usually endeavor to add a nitrogenous element,
such as meat or eggs at our meals. Potatoes are rich
in carbon and hydrogen, and in many of the mineral
FOOD ITS NATURE AND USES. 209
salts of food ; yet they are very deficient in nitrogen-
ous substances, and we relish them best with meat.
It is beyond doubt that many people indulge too
freely in animal foods ; and others have adopted an
intemperance of an opposite kind, by abstaining from
animal matters entirely. Nitrogenous foods we must
have, and these are advantageously supplied through
the medium of animal products. It is not necessary
that flesh be frequently eaten ; milk, butter, cheese and
eggs are rich in albuminoids. The indications of
chemical and physiological science and above these,
the words of the Omniscient* declare that though ex-
cessive indulgence in animal food is highly injurious,
yet strict vegetarianism is not a proper course.
The quantity of food needed for proper bodily sup-
port varies widely in different persons. The state of
the person's health, the amount of exercise taken, the
climate, and many other circumstances unite to regulate
the demand for food. The natural appetite, un vitiated
by improper habits, weakening deprivation or unwar-
ranted excesses, is one's best guide. From numerous
observations, in many climes and on persons of dif-
ferent temperaments, it is believed that the average in-
dividual requirements call for 23 ounces dry solid
* "Yea, flesh also of beasts and of the fowls of the air, I the Lord
have ordained for the use of man with thanks-giving: nevertheless
they are to be used sparingly. And it is pleasing unto me that they
should not he used only in times of winter, or of cold, or famine."
Doctrine and Covenants, 89: 12, 13.
"And whoso forhiddeth to abstain from meats, that man should not
eat the same, Is not ordaihed of God; for behold, the beasts of the
field, and the fowls of the air, and that which cometh of the earth, is
ordained for the use of man for food and for raiment, and that he
might have an abundance.
Doctrine and Covenants, 99: 18, 19.
210 DOMESTIC SCIENCE.
matter, and 70 to 80 ounces of liquid per day. Dr.
Hutchinson places the average daily quantity of food
and drink for a healthy man at 6 pounds ; and divides
this amount as follows : three and one -half pounds
from the mineral kingdom, including water and salt ;
one and one -half pounds from the vegetable kingdom,
including bread, vegetables and fruits ; one pound
from the animal kingdom, comprising meat, eggs,
butter, and such.
Not all substances containing the elements of the
human body are fitted for use as food -stuffs. A food
must contain the essential elements already named,
in digestible condition. As an example of this necessity,
consider the case of carbon, which forms so large a
proportion of most of our ordinary food materials ;
and is so indispensable to the well-being of the body.
Carbon in its purest and uncombined state* is entirely
indigestible, and eoB^equently valueless as food. A
lump of charcoal contains far more carbon than does
the same weight of bread ; yet the carbon of the bread
may be assimilated within the body and become part of
the tissues ; whereas charcoal, if introduced into the
stomach, would serve mainly to derange the digestive
functions. Another example, — nitrogen constitutes
the larger portion of the muscular tissues, and in
some proportion it is present in all the bodily parts ;
there is consequently a great demand for this element.
The air about us contains nitrogen to the extent of
*TIie purest carbon exists in a crystalized form as the diamond.
Other forms of uncombined carbon are graphite or plumbago (the
"black lead" of pencils^ charcoal, coke, gas-carbon, and lamp black.
Though these consist almost entirely of this essential element of food,
yet they are indigestible and consequently unfitted or diet.
FOOD ITS NATURE AND USES. 211
four -fifths of its entire weight; yet this atmospheric
nitrogen is valueless as a food ; it enters the body at
every respiratory inhalation, and escapes unchanged
when the breath is expelled. Free nitrogen is not
assimilated by the tissues : indeed the body seems un-
able to use the chemical elements as food, until they
have been brought together as compounds through the
agency of plaut or animal life. This is true of all
animal bodies ; they cannot live on unorganized mat-
ter ; plants may absorb and assimilate mineral sub-
stances, but animals do not possess this power. In our
own bodies we can use comparatively complicated
materials only, — substances that have, been already
organized under the influences of life. It is a natural
law that men and animals shall be supported by the
plant kingdom;* if they feed upon animal bodies,
these have been nourished by plants, so that their sub-
sistence comes directly or indirectly from the vegeta-
ble kingdom.
Now we may very properly ask, what are the
essentials of this condition of digestibility in food
materials? In the first place, to be available as food,
substances must be readily soluble in the digestive
fluids. This dissolving action may be in some degree
imitated outside the body. Chemical mixtures have
been prepared, analagous in composition to the diges-
tive juices ; and in these, food materials have been dis-
solved. Thus one part of the digestive process may
be carried on in glass flasks before our eyes. Any
soluble substance may be thus dissolved ; the artifi-
* "Plants may be considered as the laboratory in which Nature pre-
pares aliment for animals." Richerand.
212 DOMESTIC SCIENCE.
daily prepared mixture acts alike on all soluble
matters. Not so, however, with the body ; its diges-
tive apparatus is more complicated than a mere col-
lection of vessels and tubes ; it is a sensitive, living
organism, and rejects food that is not pleasing to the
senses. A food preparation that excites disgust in the
mind* will be digested only with difficulty, and in
some cases not at all ; though it may be from a
chemical point of view very nutritious.
Several years ago M. M. Edwards and Balzac, two
French academicians, performed some noted experi-
ments by feeding dogs on prepared food and carefully
noting results. The animals were kept for days on a
preparation of gelatine soup mixed with bread, —
chemically speaking a very nutritious diet though almost
devoid of flavor. After a few meals of this stuff, the
dogs evinced decided dislike, and finally refused to eat
more of the insipid mess though they were suffering the
pangs of starvation. The experimenters then mixed with
the daily allowance of gelatine about two tablespoon -
fuls of meat broth ; this gave to the soup a pleasing
flavor ; the dogs ate ravenously of it. One animal
that had already lost a fifth of its weight under the
pure gelatine regimen, began immediately to improve,
and in twenty -three days from the time of the change
in diet the creature was heavier than before the ex-
periments were begun. Tests of a similar kind have
been commenced on human beings. Men have been
* The digestive organs, as indeed is the case with all other bodily
parts, are readily affected by the varying conditions of the mind.
Many a person while eating with relish, has suddenly "lost his
appetite" under the influence of some strong emotion, either joyous or
distressing.
FOOD Its NATURE AND USES. 2l3
kept on pure chemical preparations, containing all the
needed elements, but devoid of attractive flavors ; and
it is beyond doubt that, had the trials been sufiiciently
prolonged, fatal results would have followed.
Much of our food has therefore to be prepared for
the table by a process of cooking. The aim of this
art is to render food materials more easily digestible
than they are in a raw and purely natural state, and to
develop pleasing savors.* Any operation in cookery
which fails to accomplish both of these ends, but in-
completel)^ serves its purpose. In its effects upon
human kind the art of cookery exceeds the influence
of the fine arts. The use of poorly cooked and insipid
food has led many people to indulgence in spirituous
liquors, whereby they hoped to stop the unsatisfied
craving for a stimulating diet.
* In their efforts to teach people that mastication and insalivation
of food are important steps in the digestive process, physiologists have
long declared that "digestion begins in the mouth;" now, however, this
saying has with propriety been changed, and may be more properly
rendered as "digestion should begin in the cook room."
214 DOMESTIC SClENCfc.
CHAt'TER 26.
MINfeRAL INGREDIENTS OF FOOD.
MINERAL compounds may exist in nature uncoin^
bined with any product of animal or plant life ;
of these common salt and lime are good examples.
Such substances are found also in the bodies of living
things, though they there exist largely in an unorganized
condition. On the other hand, starch, sugar, and al-
bumen are produced in nature only by processes of
vital growth as exhibited in the life of animals and
plants.
Certain mineral matters are indispensable to the
growth of the body ; the chief of these are water, com-
mon salt, and certain compounds of calcium, magne-
sium, iron, sodium, and potassium. Chlorine is
present in common salt, and sulphur, phosphorous,
and silicon are combined with the metals named above.
Except water and salt, however, these mineral sub-
stances are absorbed within the body only when in
combination with organic matters.
The phosphates of calcium, magnesium, and potas-
sium are needed for the formation of bone, muscle,
brain and nervous tissue ; iron is an essential ingredi-
dient of the red corpuscles of the blood ; the alkalies,
potash and soda, are required for the blood and for
many of the solid tissues ; salt is needed, throughout
the system, and water composes from two -thirds to
three -fourths of the whole bodily weight. The im-
MINERAL INGREDIENTS OF FOOD. 215
portance of the mineral ingredients of food is therefore
clear.
Water has already received a somewhat extensive
treatment, an entire section of this little book having
been devoted to its consideration. A mere mention at
this point must therefore suffice. The table on page 150
shows the proportions of the liquid present in different
tissues of the body. Water is a universal carrier. No
solid matter is absorbed in bodies of men, animals, or
plants, except in solution.
Common salt is second only to water among the
mineral elements of food. It exists as an essential
constituent of all solids and fluids of the human body.
In the blood, salt is present in greater quantity than any
other ingredient except water. Dalton gives the fol-
lowing proportions of salt present in certain parts and
products of the human body ; the figures state the parts
of the solid present in a thousand parts of the sub-
stances named :
Common salt present
in
1000 parts.
Muscles
-
2.
Bones
-
2.5
Cartilages
-
2.8
Milk
-
1.
Saliva
-
1.5
Bile
-
3.5
Blood
-
4.5
Mucus
-
6.
Salt is present as a natural constituent in many ar-
ticles of diet ; but to supply the requisite quantity it is
added to food as a condiment. Moderation in its use,
however, is essential to health.
It is possible to acquire a disordered appetite through
he lavish use of salt ; the craving of condiments once
216 DOMESTIC SCIENCE.
started within the body is liable to grow till it becomes
a serious habit. Salt excites the nerves of taste, and
renders pleasing, food that otherwise would be insipid
and tasteless. In the absence of salt, food could be
but imperfectly digested, and a long continued depri-
vation of this substance would seriously affect the
bodily powers, and would lay the system open to the
inroads of disease. In Holland there was once a law,
that for certain grave offenses, prisoners should be fed
on food entirely free from salt ; this was regarded as
the severest punishment that could be inflicted. Few
sufferers long survived treatment of this kind ; their
craving for salt grew so intense as to induce insanity ;
and their bodies became fatally disordered. Salt is no less
essential to animals than to the human being. Without
salt our domestic animals become dull and diseased ;
their skins grow rough, and much of the hair falls.
Stock -keepers know from experience the value of pro-
viding their animals with a free supply of salt. Wild
beasts whose wariness secures them against being en-
trapped by tempting baits of food, are readily captured
at natural or artificially prepared "salt licks." In
some parts of the world, where salt is scarce, the
article commands a very high price.*
* "In man, the desire for salt is so great that in regions where it is
scarce, it is used as money. In some parts of Africa a small quantity
of salt will buy a slave, and to say that a man commonly uses salt at
his meals is equivalent to stating that he is a luxurious millionaire.
In British India, where the poorer natives regard so few things as
necessaries of life that it is hard to levy any excise tax, a large part of
the revenue is derived from a salt tax, salt being something which
even the poorest will buy. As regards Europe, it has been found that
youths in the Austrian Empire who have fled to the mountains, and
there led a wild life to avoid the hated military conscription, will, after
MINERAL INGREDIENTS OF FOOD. 217
Yet the natural sources of salt are apparently inex-
haustible. Vast deposits of it occur in the earth, and
streams of water flowing to the sea carry the sub-
stance in solution to their ocean bed.
Sea water contains on an average three per cent, of
salt ; the waters of the Great Salt Lake contain over
eighteen per cent, of their weight of salt. Some varie-
ties of commercial salt are very impure, containing
considerable quantities of magnesium and lime in
combination.
Utah possesses natural salt in apparently unlimited
quantities ; vast deposits of rock salt occur throughout
a time, though able abundantly to supply themselves with other food
by hunting, come down to the villages to purchase salt, at the risk of
liberty, and even of life."— Dr. Newell Martin.
"Animals will travel long distances to obtain salt. Men will barter
gold for it: indeed, among the Gallas and on the coast of Sierra Leone,
brothers will sell their sisters, husbands their wives, and parents their
children for salt. In the district of Accra, on the gold coast of Africa,
a handful of salt is the most valuable thing on earth after gold, and
will purchase a slave or two. Mungo Park tells us that with the
Mandingoes and Bambaras the use of salt is such a luxury that to say
of a man 'he flavors his food with salt,' it is to imply that he is rich ;
and children will suck a piece of rock salt as if it were sugar. No
stronger mark of respect or afEectiou can be shown in Muscovy, than
the sending of salt from the tables of the rich to their poorer friends.
In the book of Leviticus it is expressly commanded as one of the ordi-
nances of Moses, that every oblation of meat upon the altar shall be
seasoned with salt, without lacking ; and hence it is called the Salt of
the Covenant of God. The Greeks and Eomans also used salt in their
sacrificial cakes ; and it is still used in the services of the Latin church
— the 'parva mica,' or pinch of salt, being, in the ceremony of baptism,
put into the child's mouth, while the priest says, 'Receive the salt of
wisdom, and may it be a propitiation to thee for eternal life.' Every-
where, and almost always, indeed, it has been regarded as emblemat-
ical of wisdom, wit, and immortality. To taste a man's salt, was to be
bound by the rites of hospitality ; and no oath was more solemn than
that which was sworn upon bread and salt. To sprinkle the meat with
salt was to drive away the devil, and to this day, nothing is more uu-
Jucky than to spill the salt."— Letheby.
218 DOMESTIC SCIENCE.
Sanpete and Sevier Counties, and so in other parts ;
and the waters of the Salt Lake could supply the world
with salt for a long period.
Lime is the most abundant of the solid inorganic
ingredients of the human body. It is present in all
solids and fluids of the system though in widely vary-
ing quantities. It occurs mostly as calcium phos-
phate, and less abundantly calcium carbonate.
According to Dalton, the following figures show the
quantity of calcium phosphate in 1000 parts of the
tissues and fluids named :
Lime phosphate
in 1000 parts.
Teeth
650
Bones
550
Cartilages .
40
Muscles
2.5
Blood
0.3
Gastric juice
0.4
Lime imparts strength and rigidity to the bony skel-
eton ; a deficiency of it causes pliancy and disease of
the bones. In early life, the bones are naturally soft,
because, ossification being then incomplete, the ani-
mal matters of the bones exceed in quantity the min-
eral substances ; children, therefore, require a com-
paratively large amount of lime salts ; and this is best
supplied through means of a generous diet of milk and
grain preparations, with a very moderate allowance of
other animal food.
The hardest substance of the body is the enamel of
the teeth; this consists mostly of lime salts, the phos-
phate, being in excess. A common and an instruc-
tive demonstration of the importance of lime com-
pounds in the bones, may be made hj soaking a bone
Mineral ingredients of FOOt>.
219
in dilute acid, thereby removing the mineral substances.
Procure a rib for the purpose ; it being in shape long
and slender will be well adapted. Place the bone in
a mixture of one part muriatic acid and fifteen parts
water ; allow it to remain in the acid during a few
days, then remove and wash it. The bone will be
found soft and pliable, so that it may be easily bent
in any desired form, or even tied in a knot. The ani-
mal tissue that remains after the treatment with acid
will dry and become hard and transparent.
Fig. 83.
Bone of human arm. Same bone after treatment with acid.
Figure 83 represents the large bone of the human
arm ; and the same bone after the removal of its
mineral matter by treatment with acid. It has been
bent and tied.
Iron constitutes about one -thousandth part of the
weight of the blood ; it is essential to the red color of
the blood corpuscles. In the entire body there is about
five drachms of iron. When the blood is deficient in
this element, it becomes pale in color, the skin as-
sumes an unnatural pallor, and the bodily strength
very rapidly diminishes. It is then a common practice
in medicine to administer iron in a soluble form, usu-
220 DOMESTIC SCIENCE.
ally as the tincture of iron per -chloride, or as iron
citrate.
Iron is supplied in the food through the medium of
milk and eggs, and many vegetable articles of diet.
Sulphur and Pliospliorus, though present in very
small quantities, are still essential within the body.
These substances occur mostly in combination, as
phosphates and sulphates of calcium, magnesium,
potassium, and sodium. Dr. Foster says: "The ele-
ment phosphorus seems no less important from a bio-
logical point of view than carbon or nitrogen. It is as
absolutely essential for the growth of a lowly being
like penicillium* as for man himself. We find it
peculiarly associated with the proteids, apparently in
the form of phosphates, but we cannot explain its
role. The element sulphur, again, is only second to
phosphorus, and we find it as a constituent of nearly
all proteids, but we cannot tell exactly what would
happen to the economy if all the sulphur of the food
were withdrawn."
The compounds of magnesium^ potassium, sodium,
and silicon, which are called for in much smaller quan-
tity than are the substances already named, are pres-
ent in ordinary food stuffs, and are seldom found in
insufiicient quantity within the body.
The mineral elements of food as a rule do not un-
dergo chemical change by decomposition or combina-
tion within the body. They are absorbed with the
food and enter the tissues, forming an indispensable
* Penicillium— the common green mold or mildew, so common in damp
situations, as upon old shoes, bread, vegetables, fruits, and jams. It is
a living thing; a plant belonging to the order otfunffi.
MINERAL INGREDIENTS OF FOOD. 221
part of the body substance ; then they are removed by
the processes of secretion, and their place supplied by
more particles of the same kind. The changes pro-
duced upon mineral matters by the processes of cook-
ing are so slight as to be inconsiderable for our present
purpose.
222 DOMESTIC SCIENCE.
CHAPTER 27.
ORGANIC INGREDIENTS OF FOOD ; CARBONACEOUS FOODS !
STARCH, SUGAR, GUM.
CERTAIN food materials occur in nature as products
of animal or vegetable life only ; such are called
organic foods, to distinguish them from mineral matters.
The organic ingredients of food may be classified as
shown on page 208.
Carbonaceous food substances claim our attention
first. These are so named because of the predomin-
ance of carbon as an element of their composition. The
amyloids, such as starch and sugars, consist entirely of
carbon, hydrogen, and oxygen ; they are therefore
known chemically as carbohydrates. The fats contain
the same elements, though in different proportions, the
oxygen being present in them in very small quantity.
The AMYLOID GROUP of food substances include
starch, sugar and gum, of each of which there are many
varieties. Starch in its prepared form appears as a
white powder, possessing a gritty feel if rubbed be-
tween the fingers. When viewed through the micro-
scope the powder will be seen to consist of minute
rounded grains, the exact form varying in starches from
different sources. Figure 84 represents starch granules
from many plants; a from the potato; these parti-
cles are somewhat like clam shells, the surface of each
being marked by waving lines, concentric about a point
known as the hilum; this point marks the place at
which the grain was originally attached to the cell wall.
ORGANIC INGREDIENTS OF FOOD.
223
Grains of potato starch vary in size from ^ to ^
of an inch in diameter. The grains of wheat starch are
/
m
^ e
6>
c/
d®,
(^
(2f
6
■% a>
/
>'^.fii,'#^,^^
<^
^1
/^
C^ri, (3
-# (fs ^^ C'"*'
Fig. 84.
Starcli granules.
224 DOMESTIC SCIENCE.
smaller than the preceding ; they rarely exceed -^
inch in diameter, and from that thev vary to -^. Starch
granules from wheat present a more perfectly cylindri-
cal outline (7^) ; many of the grains are flattened, so
that in a side view they present a narrow edge.
Starch from oats consists of large, compound gran-
ules, which under pressure may be readily broken into
sections. Starch grains from maize, or Indian corn,
are shown at c, and d grains from rice. In both corn
and rice starch the grains are irregular in form, many
of them presenting an angular outline. At /is shown
the appearance of starch grains from peas, and g from
beans. Starch is of common occurrence in plants ; in-
deed, no plant entirely devoid of it has yet been found.
At certain seasons the substance accumulates within
the body of the plant in great quantity ; starch is the
form in which the plant stores its food material for
future growth. Its wide occurrence is shown by the
following table :
Average percentage
of starch. ,
Potatoes -
-
15.70
Peas
-
32.45
White beans
-
33.00
Kidney beans
-
35.94
Buclcwtieat
-
52.00
Kye flour -
-
56.00
Oatmeal -
-
59.00
Wheat kernel
-
59.5
Rye meal -
-
61.07
Barley meal
-
67.18
Wheat flour
-
72.00
Maize
-
80.92
Rice
-
85.07
Certain articles of diet consist almost entirely of
starch, such are corn starch, arrowroot, sago, tapioca
and rice ; these will receive our future attention. For
ORGANIC INGREDIENTS OF FOOD.
225
the present let us examine the living plart and inform
ourselves of the way in which starch is stored within
it. The microscope has revealed the important fact
that all plant tissue consists of thin -walled enclosures
known as cells, and within these the secretions peculiar
to the plant are formed. Figure 85 shows three sec-
tions of plant tissue containing starch granules ; the
upper left hand sketch illustrates a potato cell ; the
Fig. 85.
Plant cells filled with starch.
next section is that of an oat seed, and the lower one
represents a wheat kernel.
Starch is scarcely soluble at all in cold water ; but,
when heated in water near the boiling point, the grains
absorb liquid, and burst, forming a jelly or paste. In
this form starch is of use for laundry purposes ; this
"boiled starch" is not a true solution, however; the
starch and water may be almost entirely separated by
freezing. The fact that cold water has so little sol-
vent effect on starch, suggests a method for its prepar-
ation.
226 DOMESTIC SCIENCE.
Grate some potatoes to the condition of a fine pulp ;
place this within a bag of coarse muslin ; immerse in
water and knead well under the liquid. The water
soon becomes milky, and after a time a white powder
settles to the bottom. This is starch; it may be re-
moved from the water and dried. Wheat flour may be
treated in the same way and starch procured from it.
Siigar is a sweet vegetable product, found in the
juice of cane, the roots of beets, the' sap of certain
trees, and in many fruits. In a chemical sense there
are many kinds of sugar, the chief of which are sac-
charose or cane sugar, glucose or grape sugar, levulose
or the sugar of fruit, and lactose or su^ar of milk.
Saccharose is found in a fairly pure form, as loaf and
granulated sugar of commerce, though a still purer
kind is met with in the uncolored and crystallized rock
candy. This is the most sweetening of all common
sugars. It is prepared chiefly from the sugar cane,
sugar beet and sugar maple. It may also be produced
from sorghum, and in smaller quantity from the juices
of mauy other plants, as maize, parsnijDS, carrots. The
following table shows the proportions of sugar present
in different products :
Per cent,
of sugar.
Indian corn - - - - 1.5
Peas ----- 2.
Eyemeal - - - - 3.2
Oatmeal - - - - 4.8
Barley-meal - - - - 5.2
Wheat flour - - - - 5.4
Beets - - - - 9.0
Ripe pears - - - - 11.5
Ripe peaches - _ . i6.5
Ripe cherries _ _ _ is.i
Figs - - - - 62.
ORGANIC INGREDIENTS OF FOOD. 227
Saccharose melts at about 356° F., and if cooled
rapidly from that temperature it forms a granular mass
known as barley sugar ; of this the prepared candies
largely consist. If a higher heat be applied to sugar
it becomes burnt or caramelized. Caramel is used as
a coloring agent in cooking.
Glucose or grape sugar occurs in many fruits, being
specially plentiful in grapes. This sugar does not
readily crystallize, and its sweetening power is not more
than three -fifths that of cane sugar. It may be pre-
pared from starch by simple processes. Several large
establishments in the United States are devoted entirely
to the manufacture of glucose. The material used for
the purpose is Indian corn. As a result of extended
tests it is believed that glucose is no more unwhole-
some as an article of food than is true cane sugar,
though doubtlessly extensive frauds are in operation by
which saccharose is largely adulterated with the cheaper
glucose. The transformation of starch into glucose
takes place in the sprouting of seeds ; plants store their
food supplies within the seeds as insoluble starch ;
when germination begins the starch becomes glucose,
and is easily absorbed and assimilated by the growing
plant. It is an easy matter also by chemical means to
transform saccharose into a mixture of glucose and
levulose ; but thus far no satisfactory method of making
the reverse transformation, namely, from glucose to the
sweeter saccharose, has been devised.
The preparation of saccharose from vegetable liquids
is an instructive process. The juice is obtained by
pressure ; it is then mixed with a quantity of lime to
neutralize any free acid present and to assist in settling
228 DOMESTIC SCIENCE.
the impurities ; the clarified juice is then evaporated,
and the product is crude, brown sugar, commonly
known as Muscovado sugar. This is to be purified. It
is dissolved in water and the solution is decolorized by
being heated with bone black or animal charcoal. It is
then clarified by an addition of albumen, usually in the
form of blood, this by its coagulation and settling car-
ries most of the impurities to the bottom. The liquid
is then evaporated, and the crystallizing sugar is separ-
ated by centrifugal power. To prevent burning of
the sugar, the evaporation is conducted in vacuum
pans, which are vessels so constructed as to cause the
removal of the vapor as fast as formed ; by these
means the pressure upon the liquid is reduced and the
boiling proceeds at a much lower temperature. The
purified article appears as loaf or granulated sugar.
The syrup remaining after the crystallization is
known as molasses, though much molasses is made
from sorghum juices without any separation of sugar.
The diflSculties thus far experienced in the preparation
of sugar from sorghum have been largely due to the
ready inversion of the contained saccharose, by which
it becomes changed into glucose and levulose. These
obstacles have been mostly overcome during recent
years, and a very good article of sugar is now obtain-
able from sorghum cane.
Vegetable gums are by no means inconsiderable as
elements of food, though in this country they are
seldom used in special food preparations. The prin-
cipal gums that enter into the composition of food
stuffs are arabin or gum-arabic, cerasin, the gum from
cherries and plums, and vegetable mucilage which oc-
ORGANIC INGREDIENTS OP FOOD.
229
curs in almost all kinds of plants. Gum is present in
considerable quantity in grains and in preparations
from them. The following table, according to Von
Bibra, shows the proportions of gum in several dry
plant products :
Per cent, of
gum.
Wheat kernel .
4.50
Wheat flour .
6.25
Wheat, bran .
8.25
Rye kernel
4.10
Rye fiour
7.25
Rye bran
10.40
Barley flour .
6.33
Barley bran .
6.88
Oatmeal
3.50
Rice flour
2.00
Millet flour .
10.60
Maize meal
3.05
Buckwheat flour
2.85
By heating starch to a temperature of 300° F. it un-
dergoes a remarkable change, assuming a yellow color
and becoming readily soluble in water. This substance
is a kind of gum, and has been named dextrin. It is
largely used as a dilutent for other gums, and in a pre-
pared state as a mucilage is sold as British gum, Alsace
gum, and starch gum. It has strong adhesive prop-
erties.
230 DOMESTIC SCIENCE.
CHAPTER 28.
CARBONACEOUS INGREDIENTS OF POOD, CONTINUED.
VEGETABLE ACIDS AND FATS.
IN composition, the vegetable acids are closely allied
to the sugars and starches already considered. The
name vegetable acids expresses at once the nature and
occurrence of the substances ; they give sourness to
fruits and many vegetable products, though they are
present in plants in very small proportion only. In
food they serve to impart a pleasant pungent taste, and
within the body, they undergo ultimate digestion as
do the starches and the sugars. The chief of the veget-
able acids are citric acid, tartaric acid, malic acid, and
oxalic acid.
Citric acid is the sour principle of lemons ; it occurs
also in oranges, citrons, cranberries, and unripe tomatoes ;
associated with other acids it is found in strawberries,
raspberries, currants, gooseberries, and cherries ; and
in smaller quantity, combined with lime as calcium
citrate, it is found in artichokes, onions, and beets.
Citric acid is an ingredient of many common sour and
effervescent beverages.
Tartaric acid^ is the prevailing acid of grapes ; it is
found, too, in many other fruits ; and in the combined
state as tartrates of potassium and calcium, it is also
found in potatoes, pine apples, cucumbers, and in
sumach berries. The chief source of the acid is argol
or crude potossium tartrate, which collects as sediment
VEGETABLE ACIDS AND FATS. 231
in vats of fermenting grape juice. Purified potassium
tartrate is known as cream of tartar. In a pure state
tartaric acid crystallizes in clear large plates ; it is in-
tensely sour to the taste, and is used in preparing
effervescing drinks. For such purposes, however, it is
but an inferior substitute for citric acid.
Malic acid is the chief cause of sourness in apples,
small fruits, plums, and cherries. It is widely distribut-
ed throughout the vegetable kingdom, especially in
immature fruits. In combination with potassium as
potassium malate it is abundant in the juices of rhubarb.
The acid is seldom prepared in a pure state, as but
little practical use has been found for it ; it may how-
ever be purified as a white crystalline solid very readi-
ly soluble in water, the solution possessing an intense-
ly sour taste.
Oxalic acid exists in sorrel, rhubarb, and many other
plants. It is usually found in combination with
calcium and potassium as oxalates of those metals.
Potassium oxalate has long been sold as "salts of
sorrel," and has found domestic application as a means
of removing ink stains and iron -mold spots from
clothes. Purified oxalic acid appears as transparent
crystals ; it is intensely poisonous, and many fatalities
have resulted from its use. It has many times been
mistaken for Epsom salts, which indeed it greatly
resembles.
Another substance very closely akin to the vegetable
acid just considered is Pectin or vegetable jelly. This
is largely prepared from fruits by heating them with
water, sweetening and straining. The solution be-
come a jelly in cooling. The acids present in jelly so
232 DOMESTIC SCIENCE.
prepared arc known as pectic and pectosic acids. These
by long continued heating become transformed into
metapectic acid which is so readily soluble that a solu-
tion containing it no longer solidifies on cooling. This
is Avell known to housewives, who have tried to con-
centrate a fruit jelly by long continued heating ; usually
a syrupy liquid only is obtained. It is a general
belief that sugar is essential to the production of a
jelly from vegetable juices ; the sugar, beside its
sweetening effect, absorbs the excess of water present,
and leaves the pectic and pectosic acids free to solidify
by cooling.
An acid of vegetable origin, though not occurring
free in nature is acetic acid, the sour substance in
vinegar. This will receive brief attention in the
chapter on "auxilliary foods.''
It has already been stated that the vegetable acids
are allied in chemical nature to the amyloids already
described. Examples of the transformation of acids
into starch and sugar are common in nature. Thus,
in the green state, apples are intensely sour ; as the
ripening process proceeds however, the sourness is less
marked, and a chemical examination shows an increase
in sugar, and a corresponding diminution of malic
acid and starch.
The next group of carbonaceous food elements, com-
prises Fats and Oils. These substances consist of
carbon, hydrogen, and oxygen, the last named element
however, being present in very small proportion only.
The fats are therefore mostly composed of carbon and
hydrogen, and are spoken of as hydro -carbons. Some
fats both of animal and of vegetable origin, are
VEGETABLE ACIDS AND FATS. 233
characterized by containing a small amount of phos-
phorus ; these are known as phosphorized fats. The
oil from peas contains 1.17 per cent, phosphorus ; bean
oil .72 per cent. ; vetch oil .5 per cent. ; barley oil .28 ;
rye oil .31 ; oat oil .44. These figures are given on
the strength of Toepler's experiments.
There appears no essential difference of composition
between the solid fats, and the liquid oils, the con-
sistency depending greatly upon the temperature.
Tallow may be reduced by warming to a mobile liquid ;
and olive oil may be solidified by cold. In Africa, the
fat of the palm tree is in the state of liquid palm-oil ;
with us the same substance is semi -solid and is known
as palm -butter.
Both the animal and vegetable kingdoms supply us
with requisite food fats. Of common oils there
are two main groups, the fixed oils, and the volatile or
essential oils. The former are the more important as
food elements ; they may be recognized by their power
of producing permanent grease stains when placed upon
paper ; even gentle warming fails to remove such spots.
The volatile oil if smeared on paper, produce but
temporary stains : these entirely disappear by heating.
Some volatile oils do slight service as auxilliary foods ;
for the present we confine ourselves to a consideration
of fixed oils and fats only.
Vegetable fats are largely obtained from seeds ; good
examples are furnished by the oily seeds of flax, colza,
cotton, peanut, butternut, and sunflower. The
following specifications show the amount of oil present
in certain vegetable products :
234
DOMESTIC SCIENCE.
Meadow grass
Meadow hay
Clover hay
Wheat bran .
Wheat kernel
Wheat flour
Maize kernel
Pea
Rice
Buckwheat
Olives
Cotton seed
Flax seed
Colza seed
Cocoanuts
Filberts
Fat is also present
Per cent, of oil.
0.8
3.0
3.2
1.5
1.6
1.5
8.0
3.0
0.8
0.4
32.0
34.0
34.0
45.0
47.0
60.0
in common articles of animal
food, as these figures will show :
Cows' milk
Goats "
Human milk
Ordinary meat
Liver of ox
Yolk of eggs
Per cent, of fat.
3.13
3.32
3.55
14.03
3.89
28.75
There is a strong prejudice, none the better because
popular, against the use of vegetable oils in food. As
a rule we prefer the poorest of lard, to the purest oils
of olive and palm ; yet as cooking media the plant oils
are in all respects superior. Cotton -seed oil has been
proved to be nutritious and wholesome ; it has lately
found extensive use in the preserving of fish, and cot-
ton planters now find the seed of their crop almost as
valuable as the fibre. True, the price of refined
vegetable oil is at present high when compared with
the cost of animal fats ; the crude oil, however, is far
cheaper than the unrefined animal product, and as
soon as a demand arises for pure vegetable oils, there
will be no lack of supply at a cheap rate.
Vegetable acids and fats. 235
The chief of common fats are enumerated and briefly
described below :
Olein is abundant in ordinary oils ; being the most
fluid of common fats, it may be prepared in quantity
from oils and the softer fats.
Palmitin is plentiful in African palm oil ; it occurs
also in beeswax and tallow. It is fluid only during
warm weather, or under the influence of artificial
heat.
Stearine may be prepared from tallow. It is
present in all common fats, and being-solid at ordinary
temperatures imparts solidity to other fats.
Fatty substances are generally insoluble in water ;
yet under certain conditions, oils may be suspended in
water in a very finely divided state ; such a mixture is
known as an emulsion. A little oil shaken up in water
to which a minute quantity of soda had been added,
will exemplify an emulsion. The microscope shows in
such a mixture the oil drops still separate and perfect.
Milk is an example of a natural emulsion.
A farther characteristic of all fats is their property
of forming soaps with the alkalies. Fats constitute a
very important part of food material. When eaten,
fatty matters develop great bodily warmth, they are
therefore well adapted as a diet for cold climes.
Under the influence of severe cold, a strong, natural
craving for fat is developed. Seamen, wintering in
arctic regions eat fats with relish. The Esquimaux in
their wintry home devour immense quantities of
oleaginous matter.*
*Dr. Hutchinson says, "The Esquimau consumes daily from ten to
fifteen pounds of meat or blubber, a large proportion of which is fat.
236 DOMESTIC SCIENCE.
The Laplander will drink train oil, and regards tallow candles as a
great luxury."
The need of fat in the food of children is very great. Dr. Edward
Smith says on this subject, "Children who dislike fat cause much
anxiety to parents, for they are almost always thin, and if not
diseased, are not healthy. If care be not taken they fall into a
scrofulous condition, in which diseased joints, enlarged glands, sore
eyes, and even consumption occur; and every etfort should be made to
overcome this dislike. If attention be given to this matter of diet,
there need be no anxiety about the possi]5ility of increasing the
(luantity of food consumed; whilst by neglect, the dislike will probably
increase until disease is produced. The chief period of growth, viz.—
from seven to sixteen years of age— is the most important in this re-
spect, for a store of fat in the body is then essential. Those who are
inclined to be fat, usually like fat in food, and then it may be desirable
to limit its use. Some who cannot eat it when hot like it when cold,
and all should select that kind wliich they prefer."
NITROGENOUS INGREDIENTS OF FOOD. 237
CHAPTER 29.
nitrogp:nous ingredients of food.
NITROGEN is an essential constituent of most tis-
sues of the human body ; there is need therefore
of nitrogenous food to nourish tlie parts. The im-
portance of foods of this nature is so great that they
have been called flesh formers. We must not be led
by this appellation to the extreme belief that no food
material devoid of nitrogen is of value ; starches and
sugars, gums and fats, are of indispensable service in
sustaining bodily heat, and they serve also as sources
of actual energy, which manifests itself as muscular
force. It is a plain fact nevertheless, that non-nitro-
genous matter can but imperfectly build up tissues of
which nitrogen forms an important constituent. From
the general resemblance of all nitrogenous food com-
pounds to the first and commonest of the group they
are often called Albuminoids, sometimes also Proteids;
this last name is derived from the Greek and signi-
ties "first" or "most important," having reference
here to the imperative need of nitrogenous substances
within the body. The albuminoids are composed of
nitrogen, carbon, hydrogen and oxygen ; many of
them contain also a small proportion of sulphur.
Albumen may properly be studied as the first of the
group; it is found in an aknost pure condition, ex-
cept for its admixture with water, in the white of Qgg.
The word "albumen" is of Latin derivation, — albus,
238 DOMESTIC SCIENCE.
meauiiig white, and is so applied because of the white
color assumed by the substance when heated. A care-
ful study of the properties of albumen is essential to
an understanding of many operations in cooking.
Procure a fresh egg, separate the yolk from the white,
and place the latter in a glass test tube, insert a ther-
mometer, and immerse the lower part of the tube in
water which is being gradually heated. As the tem-
perature within the tube ranges from 130° to 140° F.,
white, opaque fibres appear in the substance ; these
increase till the whole mass of albumen has been con-
verted into a white, semi -solid coagulum. This change
will be complete when the temperature has risen to
170° F., and any greater heat will harden the egg
substance, and if long continued will convert it into
a tough, apparently indigestible mass. It is plain
then that a temperature of 170° F. is sufficient to prop -
erly coagulate the albumen.
In the liquid condition, albumen is soluble in water ;
after coagulation, however, it is almost entirely insol-
uble. As an illustration of this, the white of egg may
be shaken or stirred in cold water, and completely
dissolved therein ; on heating the liquid to the proper
temperature the albumen will appear in the solid
form as flakes. Albumen as a food is mainly de-
rived from the animal kingdom, though the substance
exists in the juices of plants, and in many seeds and
grains.
Fibrin, another albuminoid, is present in considera-
ble quantity in many animal fluids. The clotting of
blood is due to the spontaneous coagulation of the
contained fibrin. To procure fibrin for examination.
NITROGENOUS INGREDIENTS OP FOOD.
239
place a quantity of fresh blood in an open vessel, agi-
tate or whip the liquid with a wisp of fine twigs or
wires ; the fibrin will gather upon the bundle in the
form of stringy, semi-liquid masses. Blood so de-
fibrinated has lost its power of clotting.*
The separated fibrin may be washed and purified ;
then it appears of a yellowish color, and is soluble in
hot water. Take now a bit of raw lean meat; thor-
oughly wash it in water ; the liquid becomes colored
from the red juices taken from the meat, and that
which remains is of a purplish tint and a fibrous struc-
ture. These fibres consist mainly of animal fibrin,
though the
distinguish i n g
name of myos-
in has been ap-
plied to such.
Fig. 86 is a
sketch of the
magnified fibres
of lean meat.
Fibrin is also present in certain plants, especially in
juices. If turnip juice be exposed to the air, after a
short time it deposits solid flakes of coagulated fibrin.
Fig. 86.
Fibres of lean meat.
* Exposure to the air induces the clotting of Wood. This change is
caused hy the hardening of the fibrin— a constituent of the plasma—
by which the blood corpuscles are entangled so as to form a plug or
clot. A yellowish liquid separates as the clot forms ; this is known as
blood-serum. The benefits resulting from this property of blood can
scarcely be over-estimated. In the case of a severed vein or artery, the
flow is checked by clotting, while the healing of the vessel is in pro-
gress. Did this nroperty not exist In the blood, bleeding could be
stopped only by artificial means. Among birds the clotting of blood is
especially rapid. This feature is a great benefit to these winged creat
240 DOMESTIC SCIENCE.
For purposes of distinction this has been named vege-
table fibrin.
Gelatin is a very important member of the albumi-
noid family of foods. It is present in most of the tis-
sues of the animal body, including bones and cartilage.
In a purified form gelatin is insoluble in cold water,
though it dissolves readily in hot water, and the solu-
tion on cooling assumes the condition of a jelly. Gel-
atin is the chief ingredient of all animal jellies, one
ounce of pure gelatin is capable of combining with
one and a half pounds of water to form jelly. The
purest commercial form of gelatin is isinglass, which is
a preparation from the swimming bladders of fishes.
Specimens of gelatin from different sources possess
widely varying degrees of solubility. Calves' foot
jelly is a delicious food ; jelly made from the feet of
^ <«.> to prevent these destructive changes.
^ -s»o t . 299
CHAPTER 37.
BLEACHING.
IT is often found desirable to modify or to remove
the natural colors of textile goods ; the process of
whitening such fabrics is known as bleaching.* It
has long been an art among men, they having learned
its fundamental principles from observing certain
operations in nature. Light and air are universal
bleaching agents.
The earliest processes of artificial bleaching consisted
of exposing the colored fabrics to light and air. This
was accomplished by spreading the goods on grass
plats in the open sunshine, and by occasionally wetting
them if dews or rain did not afford sufficient moisture.
The explanation of the whitening process so con-
ducted is simple as far as we understand it ; the
oxygen of the air unites with the organic compounds
constituting the coloring matters, thus changing their
composition with consequent loss of their property of
color. This operation is most applicable to cottons and
linens. Under the best conditions sun -bleaching is a
slow process ; in Holland where the art was most
highly developed, the bleaching required for its com-
pletion eight or nine months ; and oftentimes if the
season were cold and wet the fabrics were injured by
the continual exposure. The Dutch mode of pro-
* The old English name for bleachers is "whitesters," or whitsters;
it fully expresses the nature of their occupation.
300 DOMESTIC SCIENCE.
cedure in bleaching, consisted of treating the cloth for
a week with caustic alkali or lye ; then came an im-
mersion in buttermilk, and then the many months'
exposure to sunlight and dew. The large space needed
for the process gave to bleaching establishments the
common name of "bleach- fields."
Chemists have discovered several substances that
possess strong bleaching powers. Of these, chlorine
and sulphur dioxide are among the chief; and they are
the ones that are best adapted for domestic applica-
tion.
Chlorine is a gas, yellowish green in color, and of
penetrating, strongly suffocating odor. It is pos-
sessed of remarkably strong chemical affinity for
other elements, and will often decompose other com-
pounds to form with the elements combinations of its
own. Upon this property depends the value of chlor-
ine as a bleaching agent, and, as will subsequently be
seen, its efficacy as a disinfectant also. The tinted
petal of a flower, a green leaf, or a piece of cloth dyed
with vegetable colors may be readily whitened by exposure
to the gas. To illustrate, placein a wide -mouth bottle a
little chloride of lime; — this substance is a con-
venient source of chlorine, and is commonly known
as "bleaching powder ;" pour upon it a little dilute
acid, — muriatic acid is best ; — then quickly cover the
mouth of the jar with a plate of glass. The vessel
will soon become filled with the green gas, — chlorine ;
if you desire to test its odor, do so cautiously ; if in-
haled in quantity it produces painful and injurious
spasms ; suspend in the upper part of the vessel
some bits of colored calico, and a colored flower, — all
BLEACHING. 301
of which must be moistened ; the colors disappear with
magical quickness.
Another pretty demonstration of the decolorizing
action of chlorine consists in conducting the gas or
pouring chlorine water into red ink, colored wine, in-
fusion of red cabbage, or of indigo ; the tints almost
instantly disappear. Printers' black ink is not so
affected ; as its color is due to finely divided carbon
(lampblack) which is not eager to form combinations
with other elements. Dry substances are not whitened
by chlorine and this fact is a key to an understanding
of the bleaching process. Chlorine possesses a strong
affinity for hydrogen, so strong indeed as to readily
take the hydrogen from water, thus leaving the oxygen
free ; this oxygen in its nascent or freshly liberated
state eagerly unites with the organic coloring com-
pounds, and, as was explained in the case of sun-
bleaching, robs them of color. So that chlorine is not
the true bleacher after all. Oxygen is the eflflcient
color destroyer, the chlorine simply liberates the oxygen
from its combination in water ; and thus there is great
similarity between the processes of sun -bleaching and
' 'chlorine -bleaching ;'' each is a result of oxidation.
The bleaching operation may be carried too far ; for
if after the coloring matters have been decomposed,
chlorine be still allowed to decompose the water con-
tained within the pores of the cloth, the energetic
oxygen will attack the textile fibres themselves, and
this will rot the fabrics.
Exposure to gaseous chlorine is very apt to partially
destroy the fabrics ; a more practical method, and the
one most commonly adopted, consists in immersing
302 DOMESTIC SCIENCE.
the goods to be bleached in a sohition of chloride of
lime ; they should be kept in the bath several hours, —
sometimes days are required ; they are then to be re-
moved, and if the whitening be not satisfactory they
should be placed in a tub of acidified water ; the acid
will liberate chlorine in quantity from the bleaching
powder within the pores ; the acid treatment must be
carefully watched, lest it result injuriously to the
goods.*
Colors bleached through the agency of chlorine can-
not be restored, the pigment having been destroyed.
Chlorine -bleaching is not applicable to straw, wool, or
silk. For these, sulphur dioxide is employed as a
whiteuer. This gas may be produced by burning
sulphur in air; it is colorless, and produces an in-
tensely irritating effect within the respiratory passages.
Like chlorine it is soluble in water, and its solution
possesses the essential properties of the gas. Sulphur
dioxide is valuable both as a bleaching agent and as a
disinfectant. Its bleaching powers may be prettily
illustrated by holding a moist red rose over a bit of
burning sulphur ; a burning match held beneath the
flower is often effective in banishing the color. The
* "A very elegant application of chlorine to bleaching purposes is
made in the printing of bandanna handkerchiefs. The white spots
which constitute their peculiarity are thus produced: First of all,
the whole fabric is dyed of one uniform tint, and dried. Afterward,
many layers of these handkerchiefs are pressed together between lead
plates, perforated with holes conformable to the pattern which is de-
sired to appear. Chlorine solution is now poured upon the upper
plate, and finds access to the interior through the perforations. By
reason of the great pressure upon the mass, the solution cannot, how -
ever, extend laterally, further than the limit of the apertures, wljence it
follows that the bleaching agent is localized to'the desired extent, and
figures corresponding in shape and size to the perforations arebleached
white upon a dark ground." Faraday.
BLEACHING. 303
process of sulphur -bleaching is conducted by moisten-
ing the articles and suspending them in closed cham-
bers in which sulphur is being burned. A large box
or an inverted tub may be used as a bleaching chamber.
The moistening of the goods is to aid the absorption
of the gas. The coloring matters so bleached are not
in reality destroyed ; the union between them and
sulphur dioxide is an unstable one, and the colors are
after a time restored in part. Flannels that have been
bleached with sulphur dioxide often regain their color
when washed with alkaline soaps. Certain chemicals
— e.g. sulphuric acid, may promptly restore the color
to articles so bleached. To illustrate this, prepare an
infusion of logwood ; conduct into it gaseous sulphur
dioxide, or pour into it an aqueous solution of the
gas ; the color immediately disappears ; now add a
little sulphuric acid ; the color is as promptly restored.
Sulphur -bleaching is therefore only practiced in cases
to which chlorine is not applicable, as in whitening
silk, wool, and straw.
304 DOMESTIC SCIENCE.
CHAPTER 38.
DISINFECTANTS.
CERTAIN kinds of impurity cannot be removed from
our dwellings by the ordinary methods of cleans-
ing. The presence of dust in the house has been shown
to be universal; the complex nature of the dust, con-
sisting as it does of inorganic and organic matters, and
even of living organisms, has been dwelt upon ; the
close relationship between the progress of contagious
diseases within the body and putrefaction without
is now well understood. Following a consideration of
these facts, the operation of disinfectants will be clear.
A ''disinfectant" is a substance that destroys the
eflu via of putrefaction, and the poison of contagion;
yet the term, by a popular inaccuracy, is applied also
to absorbents and deodorizers. Foul smells are usu-
ally associated with poisonous properties ; the disagree-
able odor seems to be a danger signal, affixed in wis-
dom to many noxious matters. Fatalities from
inhalation of the toxic coal gas, the nauseating hy-
drogen sulphide, and the deadly prussic acid would be
more frequent than they are but for the disgusting odor
possessed by each of them. Substances that absorb
ill -smelling matters, therefore, may be of value, yet
they hold the offensive gases much as a sponge retains
water, and they may again allow the escape of the foul
matter.
Charcoal and Lime are efficient absorbents of many
DISINFECTANTS. 305
foul gases. A solution of hydrogen sulphide shaken
with fresh charcoal loses almost immediately its foul
odor. Lime is less efficacious, yet it is valuable. The
practice of whitewashing the walls of rooms, and es-
pecially of cellars and such places, is very beneficial in
sweetening the enclosed atmosphere ; though, as the
lime soon loses this power, frequent renewal of the
wall-wash is necessary.
The merits of charcoal as an absorbent of gases are
not generally recognized. It is used in water filters
to arrest gaseous impurities ; organic filth of many
kinds, even the bodies of dead animals if covered with
a layer of freshly heated charcoal may undergo decom-
position with no escape of foul effluvia ; tainted meat
packed in charcoal loses its disagreeable smell ; the aii-
of sick rooms may be greatly improved by placing
therein charcoal in shallow pans. Finely divided char-
coal is one of the most efficient and least harmful of
powders for the teeth ; being soft it produces no in-
jurious abrasions of the enamel, while its deodorizing
action does much to sweeten the breath.* A small
amount of pure charcoal swallowed immediately after
onions will keep the breath free from disagreeable
effluvia. A lump of clean charcoal in a cooking vessel
with cabbage, onions, or other strong-smelling vege-
tables, will prevent the escape of disagreeable odors.
Roasted coffee is partially charred vegetable matter ; a
few coffee seeds may be substituted for the lump of
* Charcoal from wood is apt to be "gritty," such may be of injury
if rubbed on the teeth. The best Ivind for the purpose named may
be made by charring the crust of bread. Let the bottom crust of a loaf
be removed in one piece, and this be completely charred before or over
a glowing Are. It is then to be finely pulverized.
306 DOMESTIC SCIENCE.
charcoal in the cooking process just named. Bone
black or animal charcoal has great affinity for the elements
of vegetable colors, and is of great use as a decolorizer
of syrups, etc., which are filtered through it.
Certain substances are used as deodorizers, such as
cascarilla, cologne, and other extracted perfumes, musk,
fragrant spices, aromatic mixtures, burning coffee, and
even smoldering paper and rags ; these, however,
merely hide the bad odor by substituting a stronger
one. Such substances are almost valueless as disinfect-
ants.* Among common disinfectants the following
are efficient ones :
ChloriJie, in its pure state is a pale yellowish -green
gas; intensely irritating if inhaled. Its chief proper-
ties have been considered in connection with its use as
a bleaching agent. Hydrogen sulphide, ammonia, and
most other compounds formed by the putrefaction of
organic matter are decomposed by the gas. If allowed
to escape in closed rooms it will destroy or render inert
most foul matters ; but it is likely to bleach the colors
of furniture and drapery in the presence of moisture,
and to corrode metals. Its most accessible source is
Chloride of lime, or bleaching powder, which is pre-
pared by saturating slaked lime with the gas. The
powder contains about 30 per cent, available chlorine,
which is set free very slowly by mere exposure ; but
* "They are the only resources in rude and dirty times, against the
offensive emanations from decaying animal and vegetable substances^
from undrained and untidy dwellings, from unclean clothes, from ill-
washed skins, and ill-used stomachs. The scented handkerchief in
these cases takes the place of the sponge and the shower bath ; the
pastile hides the want of ventilation, the attar of roses seems to render
the scavenger unnecessary, and a sprinkling of musk sets all other
stenches and smells at defiance."— (Quoted).
DISINFECTANTS. 307
may be liberated very rapidly by the addition of an
acid. The common attempt at disinfection by simply
scattering lime chloride about the premises is a very
ineffectual one ; the substance should be mixed with
acid — hydrochloric acid, sulphuric acid, or even strong
vinegar may be used. For disinfecting rooms, chlorine
may be liberated by mixing 4 ounces of hydrochloric
(muriatic) acid, previously diluted with three times its
volume of water, and 1 pound of chloride of lime.
Let the mixture be made in an earthen vessel ; the
room should be immediately closed, and be kept un-
opened for 24 hours. Another method of chlorine
preparation consists in treating manganese dioxide
(two parts by weight) with strong hydrochloric acid
(three parts by weight).
Sulphur dioxide is a colorless gas, entirely irrespir-
able. It may be easily prepared by burning sulphur,
and is an efficient disinfectant. It is in most respects
best adapted among disinfectants for general use. Wet
fabrics containing vegetable dyes are bleached, how-
ever. To prepare and use the gas : set an iron pan on
bricks in the middle of the floor ; as an additional pre-
caution the bricks may be placed In a shallow tub con-
taining water ; put the sulphur (roll brimstone is best
adapted) in the pans, allowing at least two pounds for
a room 10 feet square ; light by adding a small shovel-
ful of glowing coals, or by pouring a table -spoonful of
alcohol over the brimstone and applying a match. Let
the room be closed, and remain so for 24 hours. Do
not use chlorine and sulphur dioxide together ; they
partially neutralize each other.
Carbolic acid is prepared from coal tar ; it is a color-
308 DOMESTIC SCIENCE.
less crystalline solid, though by exposure to light and air
it soon darkens. In an unmixed state it is very cor-
rosive to organic substances, but being soluble in
water it may be diluted to any degree. It is a sure de-
stroyer of bacterial life if brought in contact with the
organisms, and is also an antiseptic, acting in this re-
spect much like creosote. A two per cent, solution of
carbolic acid ; i. e. 2 parts acid diluted with 98 parts
water, is suitable for most purposes. of disinfection.
The odor of the acid is objectionable to many per-
sons ; this may be somewhat modified by dissolving
camphor in the acid before dilution. Many prepared
disinfectants now offered for sale are mixtures of car-
bolic acid and dilutents. Carbolic powders consist of
the acid mixed with sawdust, lime, or clay.
Thymol is another product of coal tar distillation.
Its odor is agreeable, and as its disinfecting action is
similar to that of carbolic acid, it is largely used as a
substitute for the latter. It may be purchased in the
solid state, or as spirits of thymol, consisting of 1 part
thymol dissolved in 3 parts alcohol of 85 per cent,
strength. To prepare for use, add one table-spoonful
spirits of thymol to a half gallon of water. This solu-
tion may be sprinkled about the apartment, even on
carpets and draperies without serious detriment ; still
further diluted, it may also be applied to the flesh as a
wash, after exposure to contagion. Do not allow it to
enter the^eyes.
Copperas, iron sulphate, or green vitriol, may be
purchased ; it is cheap. It exists as pale green crystals,
and is very poisonous. Copperas is a good disinfect-
ant; for use it should be dissolved in water, — 2 pounds
DISINFECTANTS. ^OJ
Of the crystals to a gallon of water. This solution
may be improved by the addition of 2 ounces carbolic
acid per gallon of fluid. AYhen required in large quan-
tity, a basket containing fifty or sixty pounds of cop-
peras may be suspended in a barrel of water ; the solu-
tion soon becomes saturated.
Lime and charcoal, though absorbents rather than
disinfectants, occur as ingredients of many patented
disinfectant preparations. Gypsum (lime sulphate) is
mixed with carbolic acid, and used for disinfecting
stables, etc.
Corrosive sublimate or mercuric chloride, is a power-
ful disinfectant, and acts by destroying the germs of
decay. It readily coagulates albuminous matters.
One part of the substance in 1000 parts of water forms
a solution of suflacient strength to kill most bacteria.
It is a deadly poison, and does not admit of general
It should be employed only under skilled direc-
use.
tion.
Certain Salts of zinc, especially the sulphate (white
vitriol), and the chloride (butter of zinc), are good
disinfectants. With albuminous matters they form in-
soluble compounds, and act as absorbents for certain
gases. The substances are poisons and must be used
with care. A very good zinc disinfectant consists of
zinc sulphate, 1 pound ; common salt, % pound ; and
water, 4 gallons. Infected clothing, bedding, and the
like may be immersed and boiled in the solution.
Lead chloride is of service as a disinfectant, but
must be used with care because of its poisonous nature.
To prepare : Dissolve 1 drachm of lead nitrate m a
quart of boiling water; dissolve also 4 drachms of
310 DOMESTIC SCIENCE.
common salt in a bucket of water, and mix the solu -
tion. A copious precipitate of lead chloride will form,
much of which will settle ; the superuataut fluid is ready
for use. It may be sprinkled about the floor, or in
drains and gutters.
Heat is an important agent of disinfection. Cloth-
ing, carpets, and such articles as admit of this treatment,
should be boDed in water, or subjected to a dry heat
in an oven at 250° to 300° F., for several hours.
Woolen fabrics are injured by this.
For house disinfection, abundance of fresh air. free
access of light, and strict cleanliness are among the
most valuable of disinfectants. Xo chemical preparation
can take the place of the natural purifiers, air and light,
and no cure of uncleanliness is equal to the prevention
of such a state.
Below is given a brief code of instructions for the
management of contagious diseases, as authorized by
the National Board of Health :*
INSTRUCTIONS FOE DISINFECTION.
Disinfection is the destruction of the poisons of in-
fectious and contagious diseases.
Deodorizers, or substances which destroy smells, are
not necessarily disinfectants, and disinfectants do not
necessarily have an odor.
Disinfection cannot compensate for want of cleanli-
ness nor of ventilation.
I. Disinfectants to he employed.
1. Roll sulphur (brimstone) for fumigation.
* These instructions were prepared by a special committee of eminent
scientific men. They are here quoted from Dr. Tracy's admirable
little "Hand Book of Sanitary Information."
DISINFECTANTS. 311
2. Sulphate of iron (copperas) dissolved in water,
in the proportion of one and a half pounds to the gal -
Ion, for soil, sewers, etc.
3. Sulphate of zinc and common salt dissolved to-
gether in water, in the proportion of four ounces sul-
phate and two ounces salt to the gallon, for clothing,
bed linen, etc.
II. — Hoiv to use disinfectants,
1. In the sick room: The most available agents are
fresh air, and cleanliness. The clothing, towels, bed-
linen, etc., should, on removal from the patient, and
before they are taken from the room, be placed in a pail
or tub of the zinc solution, boiling if possible. All
discharges should either be received in vessels contain-
ing copperas solution, or when this is impracticable,
should be immediately covered with copperas solution.
All vessels used about the patient should be cleansed
with the same solution. Unnecessary furniture, espec-
ially that which is stuffed, carpets and hangings, should
when possible be removed from the room at the onset,
otherwise they should remain for subsequent fumigation
and treatment.
2. Fumigation with sulphur is the only practicable
method for disinfecting the house. For this purpose
the rooms to be disinfected must be vacated. Heavy
clothing, blankets, bedding, and other articles which
cannot be treated with zinc solution, should be opened
and exposed during fumigation as directed below.
4. Premises: Cellars, yards, stables, gutters,
privies, cess-pools, water-closets, drains, sewers, etc.,
312 DOMESTIC SCIENCE.
should be frequently and liberally treated with copperas
solution.
4. Body and bed-clothing, etc. It is best to burn all
articles which have been in contact with persons sick
with contagious or infectious diseases. Articles too
valuable to be destroyed should be treated as follows :
(a) Cotton, linen, flannels, blankets, etc., should be
treated with the boiling -hot zinc solution, introduced
piece by piece : secure thorough wetting, and boil for a
least half an hour, (b) Heavy woolen clothing, silks,
furs, stuffed bed-covers, beds, and other articles which
cannot be treated with the zinc solution, should be
hung in the room during fumigation, their surfaces
thoroughly exposed, and pockets turned inside out.
Afterward they should be hung in the open air, beaten
and shaken. Pillows, beds, stuffed mattresses, uphol-
stered furniture, etc., should be cut open, the contents
spread out and thoroughly fumigated. Carpets are
best fumigated on the floor, but should afterwards be
removed to the open air and thoroughly beaten.
Corpses, especially of persons that have died of any
infectious or malignant disease, should be thoroughly
washed with a zinc solution of double strength ; should
then be wrapped in a sheet wet with the zinc solution,
and buried at once.
POISONS AND THEIR ANTIDOTES. 313
CHAPTER 39.
POISONS AND THEIR ANTIDOTES.
/\ POISON may be defined as any substance capable
i\ of producing within the animal or human body a
noxious or deadly effect. This definition includes, of
course, injurious chemical compounds of an inorganic
nature, also certain vegetable products, and the venom
of animals. Many poisonous matters produce local
effects of irritation and pain, such as the strong acids
and alkalies and corrosive mineral compounds ; others
act remotely upon the body, that is, through absorption
by the blood and consequent derangements of the nerv-
ous system ; such are called narcotic or neurotic poisons,
and include opium, aconite, alcohol, etc. All poisons
in large quantities operate speedily when taken into
the body ; though some are cumulative in their nature,
that is, they may be taken in repeated doses each too
small to produce alone serious effects, but by accumu-
lating within the body they give rise to chronic de-
rangements of increasing severity : of such poisons
lead and arsenic are examples.
In most severe cases of poisoning, the symptoms will
be clearly marked and the attendant circumstances will
likely indicate the nature of the poisonous substance
used. Prompt measures for relief should be taken.
As a rule, when it is found that a poison has been
swallowed, the first thing to be done is to remove the
contents of the stomach, thus preventing farther
absorption of the poison. If vomiting has not
Sl4 DOMESTIC SCIENCE.
occurred, simple" emetics should be administered.
Among common emetics, the wine of ipecacuanha is
good ; give at least a tablespoonful in the case of an
adult, less for children. In the absence of this, mix
powdered mustard and salt in water — a teaspoonful of
mustard and an equal amount of salt, the latter dis-
solved and the former well mixed in a pint of warm
water. A tablespoonful of powdered alum, with an
equal quantity of molasses, honey, or sugar, well
stirred in water, is a good emetic dose. Mechanical
irritation in the throat, as by tickling with a feather or
the finger, will often induce vomiting. As quickness
of action is of great import, repeat the emetic doses
at frequent intervals (every ten or fifteen minutes) till
copious vomiting occurs ; then aid the operation by
plentiful draughts of dilutent liquids, such as warm
water, alone or with sugar ; mucilage of gum arable
(do not use the prepared gum mucilage, it contains
poisonous ingredients), watery infusions of slippery
elm, or fiax-seed tea. A stomach pump, if at hand,
may be used to good effect in cleansing the stomach.
Another important step is to neutralize and thus
render inert, as far as possible, the poison within the
body, for this purpose certain antidotes should be
given. ■ The object of the antidote is to produce
insoluble compounds which will be secure against
absorption till they can be removed from the body.
Below are named some of the commonest poisons and
the antidotes well suited to each case.
Strong Mineral Acids, such as nitric acid (aqua-
fortis), hydrochloric acid (muriatic), sulphuric acid
(oil of vitriol). Administer alkalies, such as soda,
POISONS AND THEIR ANTIDOTES. 315
lime, whiting, magnesia, stirred in water. In the
absence of these, take some plaster from the wall,
crush fine, stir in milk, and administer ; soap dissolved
in water is good. In any case, follow with dilutents.
Organic Adds : — Oxalic acid is frequently taken by
mistake, because of its resemblance to another house-
hold chemical — Epsom salts. Antidotes for oxalic
acid — magnesia, chalk, or even wall plaster mixed with
water. Prussic acid may be taken as oil of bitter
almonds, or potassium cyanide ; the effect is usually
too rapid to admit of effectual antidotes, when possi-
ble, however, give very dilute ammonia, or chlorine
water, or let the dilute gases from such be inhaled.
Cold water applied to the spine is beneficial.
Strong Alkalies, such as ammonia, potash — as caus-
tic potash, potash lye, pearlash, .potassium nitrate
(saltpeter) ; soda, as soda lye, etc. Give freely dilute
acids, such as vinegar, citric acid, or tartaric acid, in
water ; these tend to neutralize the alkali. Give also
large doses of oil, as olive oil, linseed oil, or castor
oil ; the oils form soap vnth strong alkalies, and so
delay their ill effects.
Antimony compounds, as tartar emetic, wine of
antimony, etc. Vomiting is of great importance.
Give astringent infusions, as strong green tea ; let tea
leaves be chewed and swallowed; infusion of oak-
bark, nut galls, or tannin.
Arseiiic: — Usually taken as white arsenic, Paris
green, Scheele's green, cobalt powders ; and among
patented preparations: Fowler's solution, and various
mouse and rat poisons. Give abundance of milk and
lyhite of eggs. The best antidote is the hydrated per-
316 DOMESTIC SCIENCE.
oxide of iron; to prepare: pour together solutions of
perchloride of iron and dilute ammonia, both of which
may be obtained at drug stores ; a brown precipitate
forms in the mixture ; strain through linen ; mix the
brown mass with water and administer freely.
Copper salts ; as copper acetate (verdigris) often
imbibed from unclean copper vessels used in cooking
or pickling; copper sulphate (blue vitriol). Give
freely of milk, white of eggs, and carbonate of soda.
Iron ; as iron sulphate (green vitriol). Give carbon-
ate of soda and plenty of mucilaginous drinks.
Lead', as lead acetate (sugar of lead), lead carbon-
ate (white lead), red lead, also from water that has
been kept in leaden pipes or vessels. Give very dilute
sulphuric acid, or Epsom salts, in water. Administer
oil and mucilaginous drinks with emetics. In chronic
cases of lead poisoning, as in " leading" from exposure
to fumes of the metal, repeated doses of diluted sul-
phuric acid, or of potassium iodide, may be recom-
mended.
Mercury : as mercuric chloride (corrosive sublimate),
ammoniated mercury (white precipitate), mercuric
oxide (red precipitate), murcuric sulphide (vermillion).
Give white of Qgg in abundance, or flour mixed with
water or milk, or soap and water. Avoid strong emetics
or irritating substances. Use the stomach pump if
possible.
Silver:, as silver nitrate (lunar caustic). Give salt
and water, then oil.
Zinc: as zinc chloride (butter of zinc,) zinc sulphate
(white vitriol). Zinc salts are themselves emetics;
POISONS AND THEIR ANTIDOTES. * 317
relieve the vomiting by dilutent drinks, and give
sodium carbonate in water.
PJwsj^horics, from matches and vermin poisons.
Give magnesia, or chalk, in water; flour in water;
follow with mucilaginous liquids in abundance.
Certain Gases are sometimes breathed with toxic effect.
For chlorine inhalation, let the sufferer cautiously
breathe ammonia. In cases of poisoning from carbon
dioxide, carbon monoxide (from fumes of coke or of
burning charcoal), hydrogen sulphide, illuminating
gas ; relieve the stupor by applying cold water to the
head, — give stimulants, and establish artificial respira-
tion. To effect this, take the patient in the fresh air,
and, except in the severest weather, expose the face,
neck, and chest; clear the throat of mucus by turning
the patient face down wand with mouth open ; hold
dilute ammonia to the nostrils. If respiration does
not take place, put the patient face downward, then
roll the body almost over and back again, regularly
(about fifteen times a minute) : this causes alternate
compression and expansion of the chest and favors the
influx and escape of air. Rub the limbs upward,
using considerable energy.
Narcotic poisons : — as opium (gum opium, laudanum,
paregoric, infusion of poppies, soothing syrup ; cholera
mixtures; most patented "cordials"), digitalis,
aconite, hemlock, belladonna ; stramonium. GivS
emetics, or use stomach pump promptly. Keep the
patient awake, in motion if possible ; dash cold water
On head and shoulders, administer strong coffee or tea ;
also vinegar, or lemon juice. Keep the limbs warm ;
if necessary resort to artificial respiration. As con-
318 DOMESTIC SCIENCE.
sciousness returns, continue the use of coffee and give
weak stimulants, such as wine or brandy in water.
Strychnine and brucine (nux vomica) are somewhat
allied to the foregoing, though these usually produce
violent spasms. Cautiously administer chloroform or
ether to quiet the spasms ; then give powdered charcoal
in water (Walker).
Irritant vegetable poisonf^, such as croton oil, and
many essential oils and essences, are often swallowed
with poisonous effect. Vomiting is likely to occur
spontaneously ; if not, however, administer emetics
without delay, aid vomiting by warm draughts, and
follow with an efficient purgative. Give vinegar,
lemon juice, or strong coffee.
Poisonous meats, jish^ or cheese are sometimes eaten.
Evacuate the stomach without delay by emetics and
purgatives, and give good doses of vinegar and water.
Hutchinson recommends that this treatment be followed
by small doses of ether with a few drops of laudanum
in sweetened water.
Animal venom may be received from bites of mad
dogs, and of snakes, and spiders, and the stings of
insects. Wash the wound with dilute ammonia ; if on
a limb, tie a bandage above the place of injury ; if pos-
sible let the wound be freely sucked, the mouth being
afterwards well rinsed with water. Moderate amounts
of alcoholic stimulants may be given. In severe cases
ammonia may be injected into the veins, — only a com-
petent physician or surgeon should attempt this
operation. As an extreme measure, the wound may
be cauterized by the application of nitrate of silver, or
by pressing the heated point of a small poker, or a
POISONS AND THEIR ANTIDOTES. 319
knitting needle, into the wound. In the case of
insect stings, extract the sting if still in the wound : a
pair of forceps will aid in this, or the barrel of a small
key may be pressed around the sting. Apply to the
wound a little dilute ammonia, or spirits of camphor,
or moistened soda ; or in lack of these, earth, mixed
into a mud with saliva. A cloth dipped into a weak
aqueous solution of carbolic acid may be applied to the
affected part. If symptoms of internal distress make
their appearance, give cautiously four or five drops of
carbolic acid in a wine glass of water.
These are but a few of the commonest poisons ; the
antidotes recommended are such as are likely to be of
ready access.
Page 23, twelfth and thirteenth lines, should read
25,600 pounds or 12.8 tons.
Same page, sixteenth and seventeenth lines, should
read 30,000 pounds, or fully 15 tons.
Page 43, table should read as follows : —
BY WEIGHT. BY VOLUME.
Oxygen 23.1 per cent, 20.9
Nitrogen 76.9 " •• 79.1
100. 100.
INDEX.
Air, Physical properties of - - 9
Air, Impenetrability of - - 10
Air, Weight of - - 12
Air, Pressure of - - 14, 20
Air-pump - - - 16
Aneroid barometer - - 26
Air, Composition of - - 33
Air, Humidity of _ , _ 42
Air, Permanency of - - 44
Air of rooms - - 51
Air, Contamination of - - 51-57
Air supply for dwellings - . - 57
Air of cellars - - - 58
Aeration of blood - - 63
Arsenical wall papers - - 78
Anthracite - - 115
Argand lamp _ . _ 133
Animals, Water in - - 149
Ammonia in water - - 176
Albuminoid ammonia in water - 176
Alum, for purifying water - - 195
Alum waters - - 199
Amyloid foods - - - 222
Acids, Vegetable - - - 230
Acid, Tartaric - - 230^
Acid, Citric - - - 230
Acid, Malic - - 231
Acid, Oxalic - - - 231
Acid, Acetic - - 232
Acid, Salicylic, as preservative - - 292
Albuminoids in foods - - 237
Albumen - - 237
Antiseptics, as preservatives of food - 289
Alcohol as an antiseptic - - 290
322 INDEX .
Ammonia as a detergent - - 298
Antidotes to poisons • - - 313
Barometer - - 24
Barometer, Siphon - - 24
Barometer, Wheel - . - 25
Barometer, Aneroid - - 26
Blood, Aeration of - - 63
Bituminous coal - - 115
Blowpipe - - 131
Burners, (gas) - - 139
Burners, (ventilator) - - 140
Boiling of water - - 188
Blood, Clotting of - - 289
Bulbs — onions - - 248
Beets - - 249
Bran — of grains - - 255
Bread - - 259
Bread — new and stale - - 260
Baking powders - - 260
Barley as food - - 262
Buckwheat as food - - 264
Beef- tea - - 267
"Boiling" of meat - - 266
Broiling of meat - - 269
Butter - - 275
Butter, .Artificial - - 275
Bacteria - - 286
Boric acid, as preservative - 291
Bleaching - - 299
Bleaching by chlorine - - 300
Bleaching by sulphur-dioxide - - 302
Bleaching powder - 306
Carbon-dioxide in air - - 38
Chlorophyle - - 47
Carboniferous age, Atmosphere during - 48
Cellars, 111 effects of - - 58
Consumption induced by impure air - 64
Coal-miners, Mortality among - 71
Currents, Ventilating - - 83
Compensation pendulum, (gridiron) - 95
Coigjpensation pendulum (mercurial bob) - 95
Celsius thermometer - - 98
INDEX. 32S
Communication of heat - - 101
Conduction of heat - - 101
Convection of heat - - 103
Coal, Varieties of - - 114
Cannel coal - - 114
Charcoal, as fuel - - 116
Coke - - - 116
Candle ilame - - 130
Coal-gas as fuel - - 116
Coal-gas as illuminant - - 138
Crystals of ice - - 154
Chlorine in water - - 178
Condenser, Liebig's - - 191
Carbonated waters - - 197
Calcium waters - - 198
Chalybeate waters - - 198
Composition of water - - 202
Cookery, Purposes of - - 213
Carbonaceous foods - - 222
Citric acid - - 230
Casein - - - 242
Carrots - - 249
Cabbage - - - 250
Cheese - - 277
Condiments - - - 278
Coffee - - 283
Cocoa and chocolate - - 283
Creosote as an antiseptic - - 291
Cleansing agents - - 293
Chlorine as bleaching agent - 300
Chlorine as disinfectant - - 306
Charcoal — its absorbing power - 304
Chloride of lime - - 306
Carbolic acid, (disinfectant) - 307
Copperas, (disinfectant) - - 308
Corrosive sublimate, (disinfectant) - 309
Dropping tube - - 31
Diffusion of gases - - 34
Drying power of air - - 42
Dysentery — induced by impure air - 65
Dysentery — induced by impure water - 179
Dust in the air - - 70
Dust, Poisonous - - 73
324 INDEX.
Dust, Household - - 75
Double case stove - - 123
Dead sea, Water of - - 167, 200
Distillation of water - - 189
Drying, as preservative - - 289
Detergents - - - 293
Disinfectants - - 304
Deodorizers - - - 306
Disinfection, Directions for - 310
Esquimaux, Ventilation among the - 66
Exhaust fan in ventilating - 89
Effects of heat - - - 92
Expansion of solids by heat - 93
Expansion of liquids and gases by heat - 96
Electric lamps, (arc) - - 140
Electric lamps, (incandescent) - - 141
Efflorescence - - 145
Electrolysis of water - - 203
Eggs as food - - 271
Emetics, in poisioning cases - - 313
Force-pump - - 29
Fungi, Exhalations of - - 47
Fan in ventilating - - 89
Fahrenheit thermometer - - 97
Fuels - - - 109
Flame - - - 111
Fireplace, Open - - 119
Flashing point of oils - - 137
Fire-test point of oils - - 137
Freezing of water - - 153
Free ammonia in water - - 176
Filtration of water - - 192
Filter, Domestic - - 192
Filter, Pasteur- Chamberland - - 194
Foods, Nature of - - 207
Foods, Classification of - - 208
Foods, Necessity for several kinds - 208
Foods, Flesh - - 209
Foods, Mineral Ingredients of - 215
Foods, Organic ingredients of - - 222
Foods, Carbonaceous - - 222
INDEX. 325
Foods, Nitrogenous - - 237
Foods, Auxilliary,' - - 278
Food-stuffs, Preservation of - - 286
Fats in food - - 232
Fats, Phosphorized - - 233
Fats in plants - - 234
Fats in animal matters - - 234
Fibrin - - - 238
Fibres of meat _ - _ 239
Fruits, as food - - 252
Flour as food - . _ 255
Flesh as food - - 265
Fish as food - - - 266
Frying of meat - - 269
Frying kettle - - - 270
Freezing as preservative - - 287
Gillis system of ventilating - - 88
Gas coal, as fuel - - 116
Gas coal, as illuminant - - 136
Gasoline - - 116
Gas, Water - - 139
Goitre - - 170
Gasses in water - - 171
Glucose - - 227
Gums in food - - 228
Gelatin - - 240
Gluten - - - 243
Grains, as food - - 254
Grilling of meat - - 269
Green vitriol (disinfectant) - - 308
Humidity of air - - 42
Human respiration, effects on air - 55
Household dust - - 75
Heat, Some effects of - - 92
Heat, Communication of - - 101
Heat, Conduction of - - 101
Heat, Convection of - - 103
Heat, Radiation of - - 104
Heat, Latent _ _ _ io5
Heat, Specific - - 106
House warming - - 119
Hollow-wick lamp - - 13
S26
INDEX.
Hardness of water - - i68
Hydrogen - - 204
Hermetic sealing as preservative - - 287
Heat, (agent in disinfecting) - 310
Impenetrability of air - - - lo
111 effects of impure air - - 61
Inlets for air to room - - 90
Illuminants - - 137
Ice crystals - - - 154
Iron in food - - 219
Indian corn as food - - 262
Impure soaps - - 297
Iron sulphate (disinfectant) - - 308
Kerosene _ _ _ 137
Lifting pump - - - 28
Lyman's ventilator - - 84
Latent heat - - - 105
Lignite - - - 114
Lighting - - - 129
Lamp, Simple _ _ . 132
" Argand - - - 133
" Student's . - - - 134
" Hollow wick - - - 135
Living organisms in water - - 181
Liebig condenser _ _ _ 191
Lime in food - - 218
Leaves as food _ _ _ 250
Lemon juice - - 279
Lime (absorbent) - - - 304
Lime (in disinfectants) - - 309
Lead chloride (disinfectant) - - 309
Magdeburg hemispheres - - 18
Morbid effects of impure air - 63
Mental powers affected by impure air - 67
Mines, Ventilation of - 84
Mechanical aids to ventilation - - 89
Matches - - 117
Mineral, Water in - - 144
Marah, Waters of - - 196
Mineral waters - - 197
Mineral ingredients of food - 214
INDEX, 327
Malic acid - - 231
Maize as food - - 262
Milk - - 273
Margarine - - - 275
Marine soap ' t - 296
Mercuric chloride (disinfectant) - - 309
Nitrogen in air - - 35
Nitrogenous ingredients of food - 237
Neurotic poisons - - 313
Narcotic poisons - - 313
Oxygen in the air - - 37
Organs of respiration - - 61
Open fire place - - 119
Organic impurities in water - 176
Oxy- hydrogen flame - - 205
Organic ingredients of foods - 222
Oxalic acid - - 231
Oils in food - . - 232
Oils, fixed and essential - - 233
Oils, Essential - 279
Oils in plants - - 234
Olein - - 235
Onions as food - - 248
Oats as food - - 263
Oleomargarine - - 275
Oil, as a preservative - - 291
Physical properties of air - - 9
Pressure of the air - - 14-20
Pump, Air - ^ - - 16
Pump, Lifting - - 58
Puimp, Force - - - 29
Pipette - - 31
Permanency of the atmosphere - - 44
Poisonous dust - - 73
Poisonous wall papers - - 78
Pendulum, compensation - - 95
Production of heat - - 109
Plants, Water in - - 146
Properties of water - - 151
Pasteur — Chamberlain filters " 194
Phosphorus in foods - - 220
328 INDEX.
Penicillium, a mold - - 220
Pectin - - 231
Phosphorized fats - - 233
Palmitin - - - 235
Proteids in food - - 237
Potatoes - - - 245
Potatoes, Cooking of - - 246
Parsnips - - - 249
Pickles _ _ _ 279
Preservation of food - - 286
Poisions and their antidotes - - 313
Poisons, (narcotic) - - 313, 317
Poisoning, Symptoms of - - 313
Poison, (mineral acids) - - 314
Poison, (organic acids) - - 315
Poison, (alkalies) - - 315
Poison, (antimony) - - 315
Poison, (arsenic) - - - 315
Poison, (copper) - - 316
Poison, (iron) - - - 316
Poison, (lead) - - 316
Poison, (mercury) - - - 316
Poison, (silver) : : 316
Poison, (zinc) - - 316
Poison, (phosphorus) - - 316
Poison, (gases) - - 317
Poison, (strychnine, etc.) - - 317
Poison, (irritant vegetable) - - 318
Poison, (meats, fish etc) - - 318
Poison, (animal) - - - 318
Respiration, Effects of, on air • - - 55
Respiration, Organs of - - 61
Respiratory organs. Ciliated passages of - 74
Registers, Ventilating - - 88
Radiation of heat - - 104
Rain water - - 156
River water - - - 162
Radishes - - 250
Rye as food - - - 262
Rice as food - - 264
Roasting of meat _ . - 268
Siphon barometer - - *" 24
INDEX.
329
Storm -glass
Siphon
Scrofula, induced by impure air
Scheele's green on wall paper
Schweinfurth green
Specific heat
Semi-bituminous coal
Stoves
Steam warming
Student's Lamp
Sources of water
Springs
Springs, Intermittent
Springs, Thermal
Solids dissolved in water
Solutions
Salt Lake, Water of
Soap, Effects of hard water upon
Soda water
Solid impurities in water
Sulphur waters
Saline waters
Salt in food
Salt in the human body
Salt, Necessity for
Stearine
Sulphur in foods
Starch in foods
Starch in plants
Sugar in food
Sugar — Saccharose
Sugar— Glucose
Salads
Seeds for food
Seething of meat
Spices, as condiments
Salt, as an antiseptic
Soap,
Soaps, Hard and soft
Soap, Marine
Soap, Impure
Saponification
12
27
31
63
79
79
106
115
122
126
133
156
157
160
201
166
164
167,199
168
174
180
197
199
215
215
216
235
220
222
224
226
226
227
251
252
266
280
290
294
295
296
297
295
330 • INDEX.
Sulphur dioxide in bleaching - 302
Sulphur dioxide in disinf ectinj^ - - 307
Tabernacle, Salt Lake City, Weight of air in - 13
Tabernacle, Air pressure on roof - 23
Tuberculosis — Induce by impured air - 64
Tonsilitis — Induced by impure air - 63
Tin miners. Mortality among - - 72
Thermometer - - 97
Thermometer, Fahrenheit - - 97
Thermometer, Celsius - - 98
Tests for potable water - - 183
Tannin, for purifying water - 195
Thermal springs - - 201
Tartaric acid - - 230
Tubers — Potatoes - - 245
Turnips - - 249
Tea - - - 281
Thymol (disinfectant) - - 308
Uses of water - - - 151
Vapor in air - - 41
Ventilation - - - 81
Ventilating currents - - 83
Ventilator, (Lyman's) - - 84
Ventilation by Gillis system - 88
Ventilation by mechanical means - - 89
Vapor gas' - - 139
Ventilator-burners - - 140
Vegetable gums - - 228
Vegetable acids - - 230
Vegetable jelly - - 231
Vegetable food stuffs - - - 245
Vinegar - - 278
Vitriol, Green, (disinfectant) - - 308
Weight of air . . 12
Wheel barometer - - 25
Watery vapor in air - - 41
Woods, as fuels - - 113
Warm air, (for house warming) - 125
Warm water, (for house warming - - 127
Water gas - - 139
INDEX. 331
Water — its occurrence - - 144
Water in minerals - - 144
Water in plants - - 146
Water in animals - - 149
Water, Rain - - 156
Water of rivers - - 162
Water of wells - - 163
Water, a solvent - - 164
Water, a solvent for gases - - 171
Water, Organic impurities of - 176
Water, Solid impurities in - - iso
Water, Living organisms in - 181
Water, Tests for purity of - - 134
Water, Color of - - 184
Water, Clearness of - - i84
Water, Odor of - - 185
Water, Taste of - - I86
Water, Purification of - - 188
Water, Boiling of - - 188
Water, Distillation of - - 189
Water, Mineral - - 197
Water, Composition of - - 202
Waters of Marah - ^ - 196
Waters, Carbonated - - 197
Waters, Sulphur - - 197
Waters, Calcium - - 198
Waters, Chalybeate - - 198
Waters, Alum - - I99
Waters, Saline - - 199
Water of Great Salt Lake - 167, 199
Water of Dead Sea - - 167, 200
Wheat as food - - 254
Water bath - - - 267
Washing compounds - - 297
Yeast, in bread making - - 257
Yeast, Structure of - - 257
Yeast, Compressed - - 258
Zinc Salts, (dssinfectants) - - 309
Zinc sulphate, (disinfectant) - - 309
Zinc chloride (disinfectant) - - 309
PUBLISHERS' NOTE.
We respectfully offer a brief explanation regarding the
illustrative cuts that appear in this little work. Photo-
types were made for the book, but when all else was
in readiness for the compositors, these were found to
be of wrong size ; they were therefore discarded, and,
under press of time, a substitute was sought in the
free-hand platae appearing in the text. We are well
aware of their many imperfections ; but we venture to
present theni as they are rather than delay the issuance
of the book during the time requisite for the prepara-
tion of other engravings.
i vikk