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PREFACE.
Ik an Ekimeiitary Chemistry, written in 1872,

piupose to give a short

was

it

my

for l)eginners, in ivhit'h the

c<.)iirfie,

experi menial evidence, on whieli

most fimdaniental parts

LJie

of the science rested, should take the place of minnle details

advanced theoretical discussions, hoping

aild

encourage the study of clicmistry
MENRV

H,

CLAPK & CO., BOSTOK.

books alone,

a,s

was

s
much

my

way

to

experimcTit instead of by

Viy

the custom at

Guide, printed for the use of

this

in

tliat

day.

A

Student's

classes in 1878, contained a

course introductory to qualitative analysis, giving the student

nothing but an outline of experiments.

make

to

the experiments,

to

He

was expected

observe and describe

iiis

own

results, and from these to construct for himself a plan for the

detection of the metals.

now combine

I

those two books, and offer to

which they are more

in

the

fully

unbroken experience

the leading ideas of

my fellow-teachei-s

a

new volume,

developed in ways suggested by

of the intervening years.

Chemistry as a bravich of study in the schools has two great
merits happily combined.

knowledge

it

training

affords.

least

much

it

oifera,

important,

is

to

Of these the

bo found in the kind of
in the

peculiar

mental

latter ia certainly not the

because a person

in proportion

what he can do with

fS

One

and the other

is

well educated, not so

to

what he knows,

his

knowledge.

as

in proportion to

Hence a

chief purpose


PEEFACE.

IV
of

stndy of elementary chemistry in schools

tlie

the

mind by

giving

it

is

to educate

All that

the right kind of exercise in

tlie

use of

powers,

its

make

I have therefore tried to

most fundamental

and

facts

present these in such a

way

use his senses to discover

and

principles of chemistry,
the student

tliat

facts, his

he

inferences from the data

judicious selection of the

a,

to

must constantly

reason in drawing correct

and good English

collects,

V

PREFAOE.

in ex-

pressing accurately what he sees and thinks.

can be done to

make

it less

work.
plex and diificnlt
mechanical
to make one or the other, the
is
lo for heghiners
processes, predominate in our elementary course
or the mental

Then which

of instruction.

course stands

first,

one

in

shall it

be?

The mechanical of
no phenomena

sense, for there will be

apparatus is selected and arranged to exhibit
to study until
hand, a wise selection of apparatus
them But, on the other

by one who has not already
and conditions cannot be made
some skill in tracing the relations of cause and effect,
acquired

I

know

of hut one

way

to teach

how

a student

a real knowledge of nature, and that

is,

mind habitown eye, and

to fix his

on things and events brought under hia
direct him to the discovery of facts and principles
ually

The use
student
of

of apparatus

is

is,

thus to study

of

phenomena, and the use

many

in

the

way

is

schools
of this

the

if

instead of descriptions

most certain to stimulate

is

his

Laboratory stndy for students

to tlie gieafest activity.

in high schouls

for himself.

indispensable

of apparatus, by himself, is with-

out doubt the method which

mind

course,

phenomena

to acq^uire

rapidly growing in favor, but unfortunately,

where chemistry

method are

still

taught, the difflculties in

is

thought

to

be truly useful shoold

these, chemistry to

bo

lie

Even

real.

in

presented as a

study of phenomena, hy esperiments, instead of what someliody has said about
I

phenomena

have therefore tried

in books.

to construct

of the teacher

facilities for stuilents to

for his

work

for

of exercise;

On

of

class

of beginners, where

themselves seem

to

he out

any subject by experiment combines two kinds

mechanical and menial operations go hand

this

first

the

cultivate

power

to

—

elementary study of chemistry. Accordingly:
In this courae of experiments the mechanical operations
Exactly what is to he
and
the meaning of it, is
happen,

are described in quite minute details.

done
for

is told,

but what

a time withheld.

in the description

is

to

Exceptions to this plan will be found

of processes

which are simply means

to

secure conditions, and in the statement of facts which may be
But in general the phenomena
needed for immediate use.
whioli hold the chemistry of substances or pi-ocesses are left
for the student to discover.

See, for example,

page

35, or

85, 86.

I

know

seems

account experimental investigation

is

a

com-

much

stress

to

me

is,

i>y

many,

laid

that the study of chemistry

upon the

industrial

is

But

it

not primarily to

mechanics, and that the use of tools and the po.ssession

of mechanical ingenuity
trial

in

that

value of an instrument-making course in chemistry.

teacli

The study

think we should

I

of experimental

application

the

that we should
observe exhaustively and to detect relations,
mechanical
in the
than
the
prominent
more
mental
make the

pages

of reach.

hand.

methods.

in

experience

a course of experiments

suited to the use of the beginner, at his laboratory desk, and
to the use

and some

am

be better acquired in the indus-

school or workshop, where these are the specific aims,

than in the laboratory of the high school or academy, where
the acquisition of knowledge for the sake of mental training

is


:

Home-itiade apparatus

the chief purpose.

,i,t

he greatly respected, where nothing better can be

spised, but lo

common

had, for miicli can be done with the most

such as

lea-saiiccrs,

bottles, fruit-jai's,

do

certainly heginncrs can

And

with poor ones.

whieh

not to be de-

is

and oyster-cans.

work with good

Vietter

utensils,

wliile there'is so

much

But

facililies

in the

than

market

at once scientific and inexpensive, the student sliould

is

Si

jud.cous seleohon,
hut have .vied to make a
of experiments,
ones well made and thoroughly
in^hat a few typical
would be
useful than a larger number
far

studied^are

more

study of a
I mean by the thorough
subject may be seen by
of
a
treatment
In the
f.w experiments
" Decomposition of mtnc
" Substitution;' pp. 10-31

What

stu,lied in haste.

:

Teferrin" to

" ailorides," pp,

02-95; or
acid," PP-

be tanght to reach more accurate resulls tlian are otherwise
possible

liy

use of

tlie

Productive ingenuity and

it.

must be founded on exact knowledge and
Tlie apparatus called for in
tliat

which

is

clear thinking; they

Therefore

cannot precede these.

from

skill

made

this

for, aiid

course has been selected

appioved

The

by, cheniists.

pieces are neat, simple, easily put together, always in market,

and as cheap

good

as possible for

scientific ^vork.

(See Appen-

Additional work
T,upils or

classes as

follows the e :« pel-

i

of the

most important

and

facts

1

mental work, by which the student can chock

his results.

have

In this sunmiary

tried to include in

of most value to

will

be found the

tlie

many who

it

only such things as will be

will finish the

study of chem-

who are tiiero to
lay a foundation for college work. "Not liow much we know
is the best question, but how we have got what we know, and
what we can do with it, and, above all, wliat it lias made of
istry in the

us."

—

It is

J. P.

high school, and to the few also

Lesue,

much

have time or talent

to

such

teacliers for

undertake

I

it.

A

as possible.

student

may

as

some question lo
two substances wh(^e

be given

own experiments, or
be answered by his
results he is directed to investigate, or
mutual reactions and
properties he is asked to study and report.
a single body wliose
the head of "Exwork of tliis kind I have given under

the student's text-book
to master.

extending the search

It is

not best to have

burdened with matter which he

There
for

is

more education

facts

is

to be gained

into other volumes than

skipping parts of the book in use.

I

(See, for

examples, pp. 39, 82, 100.)

laboratory stands research
JText in value to research in the
how to make
all means teach the student

not

by
by

have not given a long

By

in the library.

apparatus authe results of his study, wilh
to group other facts, a center from
nucleus around

which

to

which

extend his knowledge.

the teacher can select

From

the following works

abundant materials

for this exercise, in

of different
quantity suited to the varying wants

kind and

Individuals or of successive classes,

Buckley's

"

Short History

"History of Chemical Theory."
of Natural Science." Wnrtz'
Cooky's " Xew Text-Book of
Tlicory."
Wurt7.'

not well to undertake too much.

expected

when provided by

principles

information which should be acquired by beginnei's in cheniistry.

better

partake of the nature of research
would make such work

ercises."

summary

and correct

is

141-145,

Some

dix, Fig. 69.)

A brief

vn

PREFACE.

,!

PREFACE.

VI

"Atomic

Chemistry,"

Cooke's

ganic Chemistry."

"New

Remsen's

Chemistry."
" Theoretical

Remsen's

"Or-

Chemistry."

Eos-

Chemistry."
coe and Schorlemmer's "Treatise on
"Qualitative Analysis."
Analysis-"

Frcsenius'

Douglas Mid Prescott's "Qualitative


;

vm
I

PREFACE.
have in

al) case, rejected
cbngorou. experiment,
hat I
n,any ca.es devi.e,J simple,
safe, and oifioiem
w.vs to
.^iidy expIo.,ve and
noxio.s .obsta.ce.. Sec, for
e.aniple.
Hydrogen, pp. 29, 30, and Chlorine,
pp. 138 1S9
The wood-ents whioh represent
the experiment, are,
with
a single exception. Fig.
23, made fi-onr the

photographs or
.l™g. oi the apparatus in actual use.
For the .elected eut.
wh.ch :„ustrate the

Im-e

n,

'

description, of

work,

r

am

unknown

hi.ioncal

unable to give the credit
which

i.

or

CONTENTS.
OBSBEVATION AND EXPERIMENT.

indn^t^i

due

to their

Ch«niistrj'

OhBcrvation

!

;

experiment; way

to stii
rAOR
9

.

authors.

CHEMICAL CHANGES.
FOUOHKEEPSIE, Jime,

1886.

''

'^-

'^

Decomposition combinatiaii substitution; double decomposition
heat and cheniical action
electricity and
chemical action liglit and chemical action
;

i

;

;

....

;

Hydrogen:

13

Preparation of; properties of; cause of the

its combustion; heat a

explosion of; water a jnoduct of

product of

Oxygen:
of;

its

combustion

Preparation of; properties of; chemical actions

occurrence

Exercises

28

:

.....

ozone

of; allotropisni of;

Experimental study of chemical changes

-

-

33
3!)

CHEMISTRY OF COMBUSTION.
Bnrning of a candle; burning of other substances material
products; heat also a product; light also a product;
structure of flame queries
;

;

41

CHEMISTRY OF WATEB.
Analysis and synthesis

analysis of water composition of
water by weight; percentage com position composition
by volume; constant composition of water; constant
composition of otlier compounds the law of constant
composition wrter in nature solvent poiver of water
drinking watei's
mineral ^valers
elfect of cold on
water

;

;

;

;

;

;

;

Exercises

:

;

Experimental hivestigations

5U
03


XI

CONTENTS.

CONTENTS.

2

FACr.

CHEMISTRY OP THE ATMOSPHERE.
.

Liwoisier'a

t.'xj)eii]us;[it

phur and

\'\

Nitrog'eii:
of;

oxygen removed

;

I'lviwratioii

65
properties

of;

vontilalioii

'Exercises

:

:

Of unimals
of

;

produces

;

Am:

ol';

tliliiit^ioii

.

in

air

77

Invest isjiitious

oxaliu acid anil

Llie

— llm

action

ol'

action

of siilpliuvio on

on

pliosplioriis

air

...

;

^^^

82

md

table of

of the klements;

number
The
'"

pliiiits

hydrogen

and

carbon

of

ATOMS.
ELEMENTS, MOLECDLES, AND
66

-

-..ou,i

nietliano

imalysis

of gases

cliaiiges

«.. .lio-vUle:

*^^;rx'r

by sul-

£)hos{)lionis

composiiioiL of; a mixture;

RcHpiratioii

IVoiii iur

carbon
rrepju-alion of; properties of;

names symbols,
a.

focts

of matter;
aTomic weights; thro, fonns

,

Mole^

ch.tu.gvnshed.

bo carefully
„d
gases, the
about the ex pans, on ot
cuLES- some fael.'^
molecules;
changes
are
Seorv'; chemical changes
explamed; atom.c
"nniltiple proportions''
^oul
weights molecular
atomic
fonnula.s;
theory; symbols;
to

theories,

!

m

;

COMPOUNDS OP NITROGEN, HYDROOEN, AND OXYGEN.
Oliicc of nitrogen in the

uomjioiuids

chiiriictcr of the

iiir;

Acids; salts; hydroxides;
neutral compounds

ammonia; the nascent state;
amnionic in gas-works; jiroparalioii of ammonia; properties of ammonia
its action on the acids
composition

Aiiiiuoiiiii

i'roihiction of

:

;

84

At'id:

OccuiTeiuic

of,

Kodiuni nitrate; proporlicK

in

ilccompoi-ition of;

iii';

Discovery

tlio

90

nitr:Ucs

products;

several

oxides

;

the

law

nitrous

of multiple

oxide

;

five

proportions

;

Exercises :

preparation and
bleaching; the r,n.OH,.Ks;
chlorine;

;

ume
il-2

I'S

and hases;^^

.

135

-

propertip^

of

-

by

^'^

js

chlo, ides

ae.d
chlorides by bydrochlonc

?.eparation of; composition

of volume; composition of

combining

Investigation of tests

reaction of acid,

;

metal; ..yi.rogek
aqua regia; two chlorides of one

SZ>e:

nitrogen

weiKlLts

"""IZL;
by

;

the

of

chlorine water

Nitrog'on Oxides: .Stnacid by copper proof that air takes part in the action

SALTS.

CHLORINE AND THE CHLORIDES.

made from

iiiitim];

AND

acids; of salts; of bases.

Chemical names: or

;

by volunic
Witric

ACIDS. EASES.

M

of nitrogen

^^^

weights; reactions

"

law deduced

;

compounds

test for ehlori,.e

The Chlorine Gro«p

:

o^

-.-""

the

J''^«

and the chloride.

Bromine; iodine

138

.

fluorine
;

relation of atomic weight.,
their hydrogen e<,mpounds;
^^^

to properties

THE COMPOSITION OF PLANTS,
Decomposition of wood by heat; constituent.s of plants

Carbon: Source

Exercises
-

.

101

of carbon in plants; eharcoal-making

action of charcoal on gases; action of
charcoal on colors; action of charcoal on oxides; the

lamp-l>lack

;

diiunonii; graphite; allolrtipism of carbon

:

Study of

tet^ls

SULPHUR AND

ITS

COMPOUNDS.

preparation of sulphn,';
Native sulphur and snlpbides;
sulphides; inimo^E^
artil^clal
properties of snlphnr;
to4
properties of; use of
BUi.rHii.E: preparation and
.

103

.

-


;

;

;

Xlll

CONTENTS.

xu

CONTENTS.

The Sulphur Group:
coiiii)Ound'i

Soleiiiuni

hohaviur

guneral

;

THE METALS.
PAGE

tellurium; hydrogen
relation of atomie

;

;

wei^lits to projierties

Lleacliing

and

tlie

upcs of the

Sulphates;

aeiil;

iieiil;

.

Investigation of tests

:

of ])hos]>lioriis

;

properties

;

red
tlie

1(56

Aiuniouium:

.

.

182

effect of
iU occurrence in nature;
the carbonate
on
acids
of
effect
carbonate
heat on the
carbonate; the sulphate; to preeffect of water on the

to prepare the soluble
compounds;
pare the insoluble

go\'crned

valence

by valence; the valence

useful in study of reactions;

changes

tions of

defined

;

valence

study of

metal;

its

compounds; study of

reive-

magnesium compounds

characteristic reactions

valenee of an element
188

n

members; com-

uses of; compoiinds
Zinc: The metal; manufacture of;
and study of
compounds,
in^luble
of; preparation of

substitution

of horoii;

^^

METALS OF THE ZINC GROUP.
Magnesium: The

VALENCE.

of t],c

properties;
parison of atomic weights and
colors
flame
reactions;
characteristic

185

;

^^

Calcium: The metal;

element; borax; boric acid; no hydrogen

atnnis

of membei-s; compari-

THE CALCIUM GROUP.

The Calcium Group: Xames
183

in

of

compounds

AND THE CAEBON GROUP.

compound

difference

coniparison

;

5Ieml>ers; their hydrogen com-

silicates

A

about ammonia;

Facts

salts; the sulformulas; the hypothetical metal; its
JOl
compounds
ammonium
phides; study of reactions of

175

Silicon: Its oxide; the cakbon ghoup; members; their
hydrogen compounds; tlieir oxygen compounds; tlie

Boron: The

sodium eoniponnds

son of properties

phosphates;

relation of atomic weights to properties

SlIilCON,

reaction of

The Potassium Group: Names

phosphorus

;

;

_^^

liame test

-

Arsenicj: Arsenous oxide; arsenic oxide; arsenic and
hydroKon Jhirsh's test
J78

The Nitrogen tlroup:

;

nature; sodium
Description of; occurrence in
test; study of
Hame
hydroxide;
carbonate; sodium

173

matches; phosphorus oxides and acids;
manufacture of phosphorus

pounds

192

Sodium:

PHOSPHORUS. AND THE NITROGEN GROUP.
Discovery

j

of the metals

water;
Deseription of; chemical action on
potassnmi
carbonate;
occurrence in nature; potassium
preparation of some
hydroxide; experiments hi the
other salts

te^t for the acid;
:

Exercises

number and abundance

occurrence in nature

Properties of

manufacture of the acid; the sulphatejs
svilphatcs by action
of the iwid on metals; hy aetioii of the aeid on bases;

two sulphates of the same metal; other sulpbur acids
the

?

Potassium:
Ili3

Sulpliuric Acid

a metal

THE POTASSIUM GROUP.

Preparation of siilpliurous oxiilc; properties ot sulpliiiroiis oxick; sulphurous
;

is

li;]

Sulphurous Oxide and Acid:
acid

What

;

the nuic group

^


PAOE
^

THE IRON GROUP.
Mangaiifisc
ganate

:

Tlie metal

aniJ

its

;

oxides

;

Iron: Occurrence of
the Ores

;

east-iron

iron
;

its

;

ores; roasting

manufaeture of

process; cementation;

compounds of

chlorides;

distinctive

;

steel,

iron

;

Se-

S^und. of silver

220

....

;

:

comparison of properties

-V

of

Platinum: Occurrence

233

bismuth compared

AND LEAD.

reaction for tms :ind

iu

;

extraction

;

extension; the spiral
Newland's discovery MendelejeUs
^^^
JM
places
vaciint
elements; the
of

l^ilities

from the ore

239

part;

;

to

of notes

Ijcad:

Occiirrencii in nature; extraction from the ore;

two methods; lead oxides; lead carbonate; reactions of

the salts of lead

242

THE COPPER GKODP.
M.

Copppp; Occurrence

iji

nature; extraction from

ils'TJres;

copper compounds; the sulstudy of reactions of the salts of copper
347

properties of the metal;

phate

;

...

ClassHi cation founded

on

s,>la-

the preceding exanalytical table drawn from
out what metal a
this com^e; how to find

compound

reactions of

the salts of tin

:

periments in

distinctive

;

by atomic weights;

Cl.wsilication

V The Analytical System

compoimds of tin
compounds general

;

-'"^

;

235

Occurrence in nature

^^^^^
'

of the nonthey are made; the classes
classed
always
not
metals founded on valence; metals
metals;
the
group
to
one way
in tills way; more than
ways to classify the metals

The If atm-al System;

;

:

the

four principal

Antimony: 'I'lie metal; alloys of; bismuth; the antimony group the I'cactions of ai'sonie, antimony, and

properties of the metal

of

How

Classes:

THE ANTIMONY GROOP.

Tin

properties

nature;

in

metal; the platinum group

OLASSIPICATION.

salts

TIN

.

231

alum; aluminum oxide; study of reactions

aluminum

.

''washing";
in nature; obtained hy
.2-9
properties of gold
"amalgamation";
obtained by

Gold: Occurrence

ALUMINUM.
Tlie metal;

.

;

GOLD AND PLATINUM.

two

Clironiiuin; The metal; its ore; the potassium chromate;
the dichromate reactions of chromium salts
229

The Iron Oroup

its

tivo classes;

classes; general reactions of iron salts

sul-

from
in nature; extraction
Oliver- Occnrrence
properties of the metal,
galena;
from
extraction
254
reactions of the salt, of .Iver

manofacBessemer

reactions for the

ore;

reactions
pounds; study of

217

and reducing

the three forms of iron

its

compounds of n.ercury; the
mercurous compounds; mercur.c com-

Of the n.etal;

fj^rides;

with

;

extraction from
Occurrence in nature;

"^''Ses

the potassium maii-

ture of wrought-iron;

the two

.v

PAQE

Ktndy of reactions
manganese salts; cobalt; uickrl
jjerniaiigiiimte

XV

CONTENTS.

COI^TENTS.

XIV

contains;

name

notes to identify the acid
bint for further work; form

making

the salt;

;

268


ELEMFiXTARY CHHMISTRY.

AND EXPEEIMENT.

OISSEKVATION

In the stiuly of Chemistry we are to learn some things
There are two ways
:ibout tlie ditfereut kinds of matter.

have been found out, and in these
same ways we iran most easily lear:i wliat these things are.
Tliese two ways of studying nature are ealled ohservution
and eypi'vlmpnt.
"WIk'u I look a.t something which is
Observation.
going on, and watch carefully to sec wliat happens, mj act
To hiok at an olijei't so elojiely that we
id an observation.
can see its shape, its color, and wliatever else is visible
about it, is an act of observation.

in wliicli tliese things

If,

for example, I desire to

know

as nuich as possible

about a butterfly, the best way to learn
butterfly, look at

what

1

The

see.

it

is

to catch the

down and remember
would show mc that it has four

intently, note

it

butterfiy

wings, six legs, two long haii'-like bodies (antenuEe) reach-

upon their ends, two
and prominent eyes which do not close nor

ing forward from its head with knobs
large, dark,

turn,

and that the beautiful

a fine dust which
these facts

and looking

I

could

learir

at it thoughtfully.

Knowledge which
vation.

colors of its wings are due to

rubbed off by my fingers. All
by holding the insect in the hand

is easily

I

get in this

way

is

learned by obser-


:

10

OBSEEVAriON AND EXPERIMENT.

Experiment.
object

1 find

iia

-But
it,

I

if,

instead of only looking at an

do soiiietluug to

it

to see

how

it

will

behave or appeal' in ditferent conditions,
this operation

is

an experiment.
Will 5 ciibifi centimeters of water dissolve as much
as 10
grains of granulated sugar ?
I cannot iind out by simply
looking at

and water. In order to leai'n what the
faet IS, I may put the two
things together in the right
way, and if I do so I make an
experiment. Thus:
J'-x. 2.

siigai'

—I

take a tall glass cylinder,

gi-aduated to measure cubic centimeters,

a,

Pig.

1,

and pour

U

OBSERVATION AND EXPERIMENT.

which
in

is

water

and

to avoid this

danger I move

When

heat all sides evenly.

it

slowly in the flaine to

the liquid begins to boil

I lift

the tube into the hot air above the flame, where I can keep
I watch to see
it hot without boiling it too vigorously.
"Whether the sugar remains, or becomes less and less.

Whether

it all

finally disappears.

If the liquid at length

quite transparent,
dissolve 10

we

of sugar.

g.

and when

tube-rack,

Whether 5

cc,

Let us keep

The sap

shall

of

of

this

some

becomes, as

know

I will

it is

that 5

it

ec.

will,

almost or

of hot water can

then stand the tube in the

cold I will look again and sec

water can hold the 10 g. in solution.
syrup for use in another experiment.

'/nld

trees and the juices of

some plants

are

natural solutions of sugar in water, hut
the quantity of sugar in 5 cc. of these
juices is very small.

Nothing but an

experiment could have first shown that
5 cc. of water can dissolve so much
Ke.

up

sugar as

1.

to the 5 00, mark."

I transfer this water to one
of
rouiiddwttoined cylinders, b, called a
test-tube
I also weigh out 10 g. of grmiulated
sugar = and put it
into the water in the tube i.«
I now warm tlie tube in
the
flame of a Bunsen lamp, c. There is
danger of breaking
the tube if I heat it too suddenly, or too long
in one spot,

the thin

'

If

obtitii,

uiie

cc.

must

set along witlinut a graduated cylhuier
he
very nearly by filling liis test-tulie one
incii

maw

5
above tlie
rounded bottom. The tube is supposed to be §- i.ich in
diameter
= If one must got along
witbout a balance, he caii obtain
about
10 g. of dry sugar by filling a teaspoon twite,
= Pold a narrow strip of
paper into tl.e shape of a trough and
lav
this in the inbe, wliioli should be field in
a slantins position. The dry
sugar will slide safdy down this trough instead
of clinging to the wet

walls of the tube.

we have found

it

to do.

experiments we often put
together
in ways in which na^
things
Fie. 2.
For example, I wish
ture never does.
to know how sugar will behave in strong sulphuric acid.
Kature never puts these two things together, and the only
way I con find out how they will act in the presence of

But

in

each other

is

—I

to bring

them

together.

Thus

measure out 6 cc. of strong sulphuric acid
Ex.
^vitli the cylinder a. Fig. 1, pour it into an empty test-tube,
then rinse the cylinder and stand it on a small plate. Fig. 2.
I now [lour the sugar syrup miule in the other experiment
into this cylindei*.
1 am ready now to biing the two together,
I pour the acid in a slender stream into the syrup,
and watcli for evevy change that happens. I notice
A change in color.
2.


OBSERVATION ANh KXPERIMENT.

12

A change
A

A

in

volume

As soon

i\A

tlio

experiment

book, a sliort account of
1

'

CHKMICAT. ClIANGTCS.

(size).

chauge in temperature («"armer or colder).
new auliMtaiu'e unlike wugai' or Myrnp ur acid.

saw

tliem.

The

faet

is

that a

over

is

ivliat I did,

I write, in

bulky mass of

eo;il-l)laek,

my

note-

and the results just as

or cliarooal is the resnit of bringing tliesc

carbon

liot

two substances

together.

The

.iwlth

science of Chemistry is founded on facts which have

been discovered by experiment, and the most natural ii'ay
to .study Cliemistry is by tlie same means. The best «ay foi'
the student is to make the experiments iiimself. The sec-

ond best way

is

scribe
,,.,

How

these changes.

do they differ

!

How

them?

or nbbon

of magnesium w.re
s -^l take a piece

them Jiiade by a teacher. In either
remember that the object of makdiscover triitli. An ex|ierimeiit may

tu see

case the student should

ing experiments
ije

is

to

pretty and interesting, but

beauty.

Xo

exjieriment

of Chemistry unless

it

is

its

value does not

lie in its

good for anything in the study

Nothing

helps to reveal .'iome truth.

The student should remember,

al.'io,

that

it is

Jix. 4-

not what he

piece

going to give him the best and quickest insight into
Chemistry, but that whii'h he sees with his own eyes and
is

describes in his

own

And

Arrange the ajiparatus and use it PMKthj as directed.
2, Watch (^arei'nllj- tu see every change which takes place,
li.
Note accurately on paper every important eliange;.
4. Compare these results with the facts stated in the
book, and correct those which are found to be wrong.

may

iron wive iu

hot,

but

does not burn.

1.

made from the

c^f

The metal becomes red

—

Stirdy carefully to see ho\\' certain inferences

"'»w in

sen lam]i, and see that

To study Chemistry by experiment the student should

5.

i

solid.

the flame of the Bmi-

words.

obey the following rules;

—

.Int.
renndus but . .run.bbng

the same way hold a

reads about experiments, or hears a teacdier say about them,
that

finally

finally,

when

cold, is the

same substance as at first.
by
Hoth metals were changed
the

very different ^:5j:
The iron became hot m-

heat,

ways.

but

in

be
atk'k.

results.

i

The wire cau be

inserted

m the split and

rij. 3.

neia a^^


colorless gas

The shining

which brightens the burning of a

unusual brightness
is

is

bums with

oxt/gun.

a fine example of {'hymical change.

important thing to notice
stance

splinter.

droplets wliioh coat the cold walls of the tube

are m^i-'mrij, and the gas in which a splinter

This

But the most

that in this change one sub-

is,

broken into two which are entirely unlike itself

is

and unlike each

other.

Such a

cheuiical change

called

Is

decomposition.

—

Decomposition of Potassium Chlorate.

At. 6.
PoBefore I heat it the
coarse grains or crystals should be reduced to powder: I
grind it in a mortar (Fig. f>). I jmt two

tassium chlorate

is

a white solid.

grams of the powder into the
tube,i Fig. 4.

This

6.

lime-water into a second tube,

and provide a good cork

for paeh.

I put the

the litmus.

I then put the end of the rubber tube over into the iimewater in e, and close b with its cork, in order to keep its

oxygen for use further on.
At length the boiling chlui'ate thickens, and soon
T]ie tube

must be

ou die end of

!i

uleaii aiid dry.

wire or stick,

is

j\

^

'T^r'which lias

-

experiments
appeared in both these

heated in oxygen?

.>

_I wind the cud of

r

after

piece of diy cloth, or a sponge

convenient for wiping tubes.

of

iire,

Fis

5,

and then lower

it

a small wire around a

Notice
on the spark.
produced
is
charcoal wastes away.

over lime-water.

What

shake

little

into the ox; gen

effect

Whether the
Win the oxygen brighten a
mouth of
1 now cover the

After a while 1 put a match-flame into the mouth of
it burns with unusual brightness.
This shows that the tube is filled with oxygen.

'

L

Fig. 5.

e,

end of the

the tube and see that

tied

chlorate it is hrst
heating potassium
substanj^j iinlik
two
afterwLd broken into
Jted
the
white
^
«
One is the
,tself and each other.

chloiate
Ihe
ox.jgen.
other is
iguition-tubc, and the

The F«rs.-Ky

fill

rubber tube into the litmus, and then heat the chlorate just
as I did the red oxide before. Watch for and describe

The changes in the chlorate.
The bubbles from the pipe in

water?

ignition-

quantity will

about one inch of the tube. 1 put three
or four cubic centimeters of blue litmus
solution into one test-tube, b, and as much

^4^^^^
Fls.

17

CHEMICAL CHANGES.

CHEMICAL CHANGES.

16

it briskly.

niatch-fi.ne afterwards ?

the tube with

my

iingei

and


CHEMItiTRY OF WATER.

G4

3. If'ind the boilmg-point of alcohol. Fig. SO.
4. Find the hoWmg-point of a mixture of alcohol mid watfir
made in the proportion of one volume of alcohol to

two volumes of water.

1

Use the appaiiitus shown in Fig. 30.
Xote the temperature when the boiling begins,
Tvu'u tlie lamp low and let the Iwiling go on slowly
until about 5

cc.

of distillate is canglit.

Tlien change the

test-tnbe.

JJote the boiling-point again,

Kepeat this suveral times, and then eompare the distilby their odoi-s and by means of a match-fiame.
Whieh eontains tlie most alcohol
Does the liquid in the flask still contain alcohol ?

lates,

''

boiling-] loint

two liquids wliieli have not the same
can be roughly separated by this process of

distillation.

It is called fractioiuil dht'dhition.

The

5.

fact is that

Find hy

evaj^oration,

whether the water in use hoh/s any

solid matter in solution.

How, by
dei',

the use of

ean you find

water eontains

?

how

tin.'

balaiic-e

ATMOSPHEKT:.
CHEMISTHY OV THE

and the graduated

cyliii-

iinieh of this mineral substance the

ivr-d veai-s

to be an
ago the aiv was thought

°'LlvoiiS''Spe.lme„t.-Tl,,.arP=.,*,»rf>irf.l»...e

CBByflSTltY OF

66

inci'eased. wliUt;
islied.

the quantity of air in the receiver dimin-

For some time longer

done.

lie

had

less aiv in tlic

heat was kept up, but no

tlie

further eliaiige took place, and

tliis

part of

tlie

apparatus than at

work

fiist,

«ai5

sliown

by the iuereory rising in the jar, but instead of the air
wliieh was lost lie liad tlie new red substance in tlie flask.
"What wa? this red sulistance
To iind out, Lavoisier
heated it in a tube so tixed that any gas whieli shoidd be
produced would be caught in a vessel over mercury. The
red substanee beciuno black, then began to waste away
while bubbles of a colorless gas were cauglit in the vessel
prepared fiu' tlie piu'pose, aiid globules of shining mercury
gatliered on the walls of the tube above the heated part.
"What was tlie colorless gas? Lavoisier plunged a caudleflame into it
the candle burned with a dazzling light.
'/

quickly, and
some other things will burn more
sulphur, and afterwanl
may be used instead. Let us try

plrur a,nd

phosphorus.
jj^..

was oxj/ijen.
whence came this oxygen

mouth

liut

it iva.s

heated with

'.'

Lavoisier's experiment pj'oved that

oxygen

ajid nitrogen

are two constituents of

air.
There arc indeed a few other
atmosphere beside these, but in eoni|iarison
with these the quantity of them is small.
Oxygen and
nitrogen are the two chief constituents of the air.

gasiis

in the

NITROGEN,

When
leaves

a substance burns in air

the

nitrogen.

Lavoisier

it takes the oxygen and
burned mercury, but sul-

my

bottle.

shape the

1

low

to the sulphur,

shown

bottle

and put a

ri?, 31.

bottom up.vard over

it,

as

Describe

in Fig. 34.

The flame of the sulphur.
is over.
The action of the water when the burning
standing.
time
long
after
The change in the gas
£;.

air

gas I'alled nitrogen.

of

the shalthis cup, place the cuji on
set fire
water-pan,
the
water in

T}k'

must have given it to the mercury, and so the experiment proved that oxygen is one constituent ol' air.
In till! flask and the glass jar (Fig. 33) there was still left
a large quantity of air-like substance. But on ])lungiiig a
candle-flaiiie into it the flame was put out as it would hav<;
been iu water. Plainly it was not air. In fact it was the

much

is

moistened
or better with a paste of
in
sulphur
put
I
plaster of Paris.

to cojiibine with the mer-

air in Lavoisier's flask

cork
a slice half an inch thick Irom a
than
the
smaller

(.ut

cup
top of the cork into a shallow
erayou-powdei-,
and rub it well with

gas

cury wlien

^5._I

which

;

The

67

CHEMISTRY OF THE ATMOSPHERE.

THE ATMOSPHERE.

U—'^

^i^f'

^

"* ph'isphorns, not larger tlian a
holding
wheat, with aiiutln^r bottle

l"'^''"

ROod-si«Hl kernel of

did the sulphur, and
action of the water afterward,
a-ain describe the flame, the
after standing some
the appearance of the gas inside

about

"Hi)

cc.

1

treat

it

just

iis

I

and

time over water.
But the handling of iihosphorns
is

(lone

bums

with great

care.

the flesh (^uelly.

is

dangerous, unless

it

Phosphorus takes fire easily and
Cut it under water, lift the piece

gentle contact with filterwith the knife-blade, dry it by
J^cver handle phosphorus
paper, and put it into a dry cup.
cai'e.
without using the greatest
the bottle used in Ex. 43 has
^a; ^,5 —When the gas in
glass or of cardboard under
of
sciuare
clear I slip a
out of the water, turn it
the mouth of the bottle, lift it
table
and leave it covered.
the
on
it
mouth upward, stand

become


CHEMISTRY OF THE ATMOSPHERE.

68
I

CHEMISTRY OF THE ATMOSPHERE.

at once jguitu a match, iniuover the bottle, aiul
insert

the flajne;

thii i.itrogeii will (pieiich

it.

I leave the bottle

uncovered.

1 tiuat the bottle used in Ex. 44 in the same
the nitrogen again puts out the flame. 1 leave
this
bottle, also, uncovered.

way

;

—

I now again insert a match-flame in the bottle

uncovered, and afterwai'd in the other.
The flame
not quenehed.

Properties of Nitrogen,
(Exa.

4;i,

44).

It is lighter

weighs fourteen times as much iis a liter of hydrogen.
quench fire (Ex. 45), because it cannot iinite with
in fact, nitrotlie elements of the fuel as oxygen does,
It will

gen is tlie least
quench fire, bnt

ifi

life also.

Wliat does this prove?

—

EX.47.

I now aiid a little blue litmus-water to the
water in the bottle in which sulphur was burned.
Mote the change of oolor. Compare Ex. 8.

What

causes this change of color

JSX.4S.

—

I

aild blue

Ex. 45;

it

Can you explahi this change of color?
Burning of Sulphur.
Sulj^hur, when burning with

its

—

blue

if

the elements.

breathed insteail of

It

will jiot only

it

not the jiresence o£ nitrogen, which carrses death
nitrogen

is

breathed.

Other Constituents of Air.

— The

air

when pure
contains

also

proved by placing
a 'piece of caustic potash in an open dish. The potash
will very soon become wet, and if left for some time it
will be dissolved by the water which it takes from the air.
Try it. The moisture to be seen on the outside of a vessel
This

of ice-water in

aummer

is

the eoiulensed water-va|>or of the

is

T)ew and hoar-frost are also the water of the

combines with oxygen, and the two
become sulphiu- dioxide. The water soon dissolves the
whitish vapor and ri.ses into the vessel, and at last fills

air.

just the space wiiieh the

lime-water, which

first,

become covered in a few hours with a white cnist.
This crust is the same substance which is seen

feeiilc

flame,

oxygen of the air oixaipied at
while the nitrogen of the same air remains above
the

M-atn- (Ex.

4;!).

The sulphur dioxide shows
reddening the

hliie

its

presence in the water by
it did in Ex. S.

litmus, Ex. 47, as

— When

Burning of Phosphorus.
the a<^tion is much the same.
gen of the

air

and forms

phosphorus is used
It combines with the oxy-

ph(}sphori<: oxide, wliieh

fills

the

vessel as

a milk-white va)Jor. Water soon dissolves this
oxide, and the nitrogen of the air is left as before.

The phosphoric oxide

also

shows

by reddening blue litmus (Ex.

its

48).

quench

air it will

cannot be poisonous, since we inhale it
with every breath without injury. It is the oxygen of the
air that sustains life, and it is the absence of oxygen, and

Yet

water in form of invisible vapor.

uncovered in

left

at^tive of

';

litmus- water to the water in the

second bottle which w-as
changes from blue to red.

—

Nitrogen is a colorless gas
than air (Ex. 46), but a liter of

it

first left

Jix. 46.

69

presence in the ivater

changed by cold from vapor

The

ail'

it

if left

This

is

shown by

ex[iosed in an open vessel will

has received carbon dioxide (Ex.

also contains

air,

liquid and solid forms.

air also contains carbon dioxide.

water after

The

t
ammonia

Try

it.

in lime-

7).

in very small quantities.

Nitrogen, oxygen, water-vapor, carbon dioxide, and am-

monia are the

regulai- constituents of the

next question

is,

How much

found in air ?
The Analysis of Air.

to be

many

atmosphere.

— "We

set out

now

cubic centimeters of nitrogen and liow

gen and carbon dioxide

Our

of e:ich of these substances

ther(f ai'e in

100

cc.

to find

many
of

is

bow

of oxy-

air.


CHEMISTRY OF THE ATMOSPHERE.

70

To do

I'vui

into

this

we

imprison a vesselfiil of

will

which

aliijuid

it

will abaoi-b both

CHEMISTRY OF THE ATMOSPHFAiE.

and then
oxygen and

air,

tlift

the carbon dioxide completely, and leave the nitrof^en.

We

pan then measure the niti'ogeu which is left, and we can
find out how much there was oi the other two, by measur-

below the covk and open the piiich-eock p a moment, to
I
let the liquid run down and fill the tubes completely.
carefully take off the drop, which hangs
at the lower end of the tidie below the
cork, with

ing the liquid which has gone into the tube to take their

Ex.

49.

— OuK

Apparatus.

35) to hold the

diameter, will do

diameter

is

—I

take a test-tube,

A

air.

t

(Fig,

six-inch tube, ^ inch in

an eight-inch tube of the same

;

The rubber

better.

stopper,

c, is

so

large that its small end will enter the tube only

about a half-inch.

It

two

lias

lioles

;

cock, p,

by which

to close

it

The lower end
I fix

walls

may

F is

rod

be pinched so aa

and

s into

c,

and

its

shown

the rod

in Fig.

',Hj,

minute

J

put the

tlu?

eork.

get in.
I left the hole in the cork open, be-

cause
oi'

if it

were not open the pressure

the cork would crowd the air below,

^'^- ^'
and there would be too much in the
tube; and then, too, handling the tube warmed it, and the
volume of air changes with heat.

With

a small glass funnel.

the hole open, the air in the

tube soon comes to be just as warm
arid just as mucli pressed as the air

Whenever a gas of any kind
measured its tcmiierature and

pressure must be the savie as those of
outside.
is

re-

to he

the air oiitaidc.

s.

Liquid. — To

absorb the oxy-

The a b.sobption.

gen and carbon dioxide gases I use
a mixture of pyrogallie acid and po-

the pinch-cock }>; a

TuF.

tassium hydrate.

FiB

solid

acid

water

;

it

and pour on

it

will soon dissolve.

10

ec.

To

36.

of

flow

this

FiB 35.

T then avid 5 cc. of strong solution of potassium hydrate,

Mid

ft once pour

it

into the funnel.

Ivext, i

—

I

now

press

stream of
the liquid falls into t at once, and
then drops follow, or, if the tube be
slightly inedined, a slender stream will

I take a small teaspoonfnl of the

E

air-tiglitjas seen in

after a

;

upper

and

^M'^ft

have now imprisoned a tubeful of air
none can get out, and no more can

I place the funiiel in the clam]i of the

move

8

np over the cork

I

over the stem of F, and then

support, as

filter-paper.

f

the open hole of

of h I stretch over

the tube in the cork

end

its

completely.

Fig. 37,

to close

one I have a solid rod of glass, s ; for the other,
a glass tube reaching j'ust a very little below the
cork, as shown.
A piece of thin rubber tubing,
There is a pinchk, is cut about six inches long.
Fig. aa.

a piece of

\i press the tube
until the joint is

place.

71

hold the dish

down

its

side.

little

It will continue

to enter as long as there is

any oxy-

gen or carbon dioxide for it to absorb, and then stop.
The gas which is left in the tube is nitrogen.