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flected heat with pair of para-
bolic reflectors - - - - ib.

1573. Materials fitted for vessels to keep

liquids warm - - - - 129

1574. Advantage of a polished stove - ib.

1575. Helmets and cuirasses should be

polished - - - - - ib.

1576. Deposition of moisture on window

panes ..... ,//.

1577. Principles which explain the phe-

nomena of dew and hoar-frost - 131



CONTENTS.



Sect. Page

1578. Dew not deposited undera clouded

sky 132

1579. Production of artificial ice by ra-

diation in hot climates - - ib.

CHAP. XL

COMBUSTION.

1580. Heat developed or absorbed in che-

mical combination - - - ib.

1581. This effect explained by specific

heat of compound being less or
greater than that of components 133

1582. Or by heat being developed or ab-

sorbed by change of state - - ib.

1583. Combustion - - - ib.

1584. Flame - - - - ib.

1585. Agency of oxygen - - ib.

1586. Combustibles - - - 131

1587. Combustion explained - - ib.

1588. Temperature necessary to produce

combustion .... ib.

1589. Light of flame only superficial -135

1590. Illuminatingpowerof combustibles ib.

1591. Constituents of combustibles xised

for illumination ... ib.

1592. Spongy platinum rendered, incan-

descent by hydrogen - - ib.

1593. Quantity of heat developed by

combustibles .... 136

1594. Table of the quantities of heat

evolved in the combustion of
various bodies .... ib.

CHAP. XII.

ANIMAL HEAT.

1595. Temperature of organized bodies

not in equilibrium with sur-
rounding medium ... 138

1596. Temperature of the blood in the

human species - - - - ib.

1597. Researches of Davy to determine

the temperature of the blood - ib.



Sect. . Page

1598. Table I. showing the temperature of

theblood of 13 individuals in dif-
ferent climates. Tablell. showing
the temperature of the blood in 6
individuals in different climates.
Table III. showing the tempe-
rature of the blood in the same
individual at different hours of
the day. Table IV. showing the
limits between which the tem-
peratures of the blood in differ-
ent races was observed to vary
in India. Table V. showing the
temperature of the blood ob-
served in different species of ani-
mals 139

1599. Deductions from these observations 141

1600. Birds have the highest and am-

phibia the lowest temperature - 142

1601. Experiments of Breschet and Bec-

querel ib.

1602. Comparative temperature of the

blood in health and sickness - ib.

1603. Other experiments by Breschet and

Becquerel - - - - - ib.

1604. Experiments to ascertain the rate

of development of animal heat ib.

1605. Total quantity of heat explained

by chemical laws without any
special vital cause ... 143



CHAP. XIII.

THE SENSATION OF HEAT.

1606. Indications of the senses fallacious

1607. Sense of touch, a fallacious mea-

sure of heat -

1608. Its indications contradictory - i't.

1609. These contradictions explained > 14S

1610. Examples of the fallacious impres-

sions produced by objects on the
touch -

1611. Feats of fire-eaters explained - ib.



BOOK II.

Magnetism.



CHAP. I.

DEFINITIONS AND PRIMARY PHENOMENA.

Sect. Page

1612. Natural magnets : loadstone - - 149

1613. Artificial magnets - - - ib.

1614. Neutral line or equator : poles - ib.

1615. Experimental illustrations of them 150

1616. Experimental illustration of the

distribution of the magnetic
force - - - - - - ib.

1617. Varying intensity of magnetic force

indicated by a pendulum - - 151



Sect. . Page

1618. Curve representing the varying

intensity 151

1619. Magnetic attraction and repulsion 152

1620. Like poles repel, unlike attract - ib.

1621. Magnets arrange themselves mu-

tually parallel with poles re-
versed 153

1622. Magnetic axis - - - - id.

1623. How ascertained experimentally - ib.

1624. Hypothesis of two fluids, boreal and

austral ..... 155

1625. Condition of the natural or un-

magnetized state ... ib.



CONTENTS.



Sect. Page
1626. Condition of the magnetized state loo
1627. Coercive force - - - - 156
1628. Coercive force insensible in soft


Sect. Page
1658. The magnetic equator - - - 17U
Its form and position not regular - ib.
Variation of the dip going north or


pered steel - ib.
1629. Magnetic substances - - - ib.

CHAP. II.

MAGNETISM BY INDUCTION.

1630. Soft iron rendered temporarily
magnetic - - - - - ib.


Lines of equal dip- - - - 171
1659. Magnetic meridians - - - ib.
1660. Method of ascertaining the decli-
nation of the needles - - ib,
Local declinations - - - 172
1661. Lines of no declination called ago-

1662. Declination in different longitudes
at equator and in lat. 45 - - ib.
1663. Isogonic lines - - - - 173


without contact - - - -157


1665. Position of magnetic poles - - ib.


1633. Magnets with poles reversed neu-
tralize each other - ib.
1631. A magnet broken at equator pro-
duces two magnets - - - 159


1667. Periodical variations of terrestrial
magnetism - ... ib.
1668. Intensity of terrestrial magnetism 175
1H69. Increases from equator to poles. - 176


not attended by its transfer be-
tween pole and pole - ib.
1636. The decomposition is molecular - ib.
1637. Coercive force of iron varies with
its molecular structure - - 160
163S. Effect of induction on hard iron or


1671. Their near coincidence with iso-
thermal lines .... ib.
1672. Equatorial and polar intensities - ib.
1673. Effect of the terrestrial magnetism
on soft iron - - - - ib.
1674. Its effects on steel bars - - 177


1639. Fcrms of magnetic needles and
bars 161
1640. Compound magnet - - - ib.
1641. Effects of heat on magnetism - 162
1642. A red heat destroys the magnetism
of iron .....<&
1643. Different magnetic bodies lose their
magnetism at different tempera-


1676. Disturbances in the magnetic in-
tensity - - - 179
1G77. Influence of the aurora borealis - ib.

CHAP. IV.

MAGNETIZATION.


1644. Heat opposed to induction - - ib.
1645. Induced magnetism rendered per-
manent by hammering and other
mechanical effects - - - ib.
1646. Compounds of iron differently sus-
ceptible of magnetism - - 163
1647. Compounds of other magnetic
bodies not susceptible - - .
1643. Magnets with consequent points - ib.

CHAP. III.

TERRESTRIAL MAGNETISM.

1644. Analogy of the earth to a magnet 164
1650. The azimuth compass - 165


1678. Effects of induction - - - ib.
1679. Their application in the produc-
tion of artificial magnets - -180
1680. Best material for artificial magnets ib.
1681. Best form for bar magnets - - ib.
1682. Horse-shoe magnets - - - ib.
1683. Methods of producing artificial
magnets by friction - - - 181
1684. Method of single touch - - ib.
1685. Method of double touch - - 182
1686. Inapplicable to compass needles
and long bars - - - - 183
1687. Magnetic saturation - - - ib.
1688. Limit of magnetic force - - ib.
1689. Influence of the temper of the bar
on the coercive force - - 184
1690. Effects of terrestrial magnetism on


16.32. The dipping-needle - - -167
1653. Analysis of magnetic phenomena
of the earth - - - - ib.
I6.H. Magnetic meridian - - - 168
1655. Declination or variation - - ib.
1656. Magnetic polarity of the earth - ib.
1G57. Change of direction ofthedipping-


1601. Means of preserving magnetic bars
from these effects by armatures
or keepers - - - 185
1692. Magnetism may lie preserved by
terrestrial induction - - 186
1693. Com]H)tind magnets - - - ib.
1694. Magnetized tracings on a steel


Complete analogy of the earth to a


1695. Influence of heat on magnetic bars ib.




Astatic needle - - - 187



BOOK III.

Electricity.



EPULSIO.NS.



Sect. Page

16ii. Electrical effects - - - - 189
1697. Origin of the name " electricity " ib.
16^8. The electric fluid - - - - 190
lt>99 Positive and negative electricity - 191

1700. Hypothesis of a single electric fluid ib.

1701. Hypothesis of two fluids - - l'J2

1702. Results of scientific research inde-

pendent of these hypotheses - ib.

1703. Hypothesis of two fluids preferred ib.

1704. Explanation of the above effects

produced by the pith balls - ib.

1705. Electricity developed by various

bodies 193

1706. Origin of the terms vitreous and

resinous fluids - - - - ib.

1707. No certain test to determine which

of the bodies submitted to fric-
tion receives positive and nega-
tive electricity - ib.

1708. Classification of positive and nega-

tive substances - - - - 194

1709. Method of producing electricity by

glass and silk with amalgams - 195



; CHAP. n.

CONDUCTION.

1710. Conducting power - - - 196

1711. Conductors and non-conductors - ib.

1712. Classification of conductors accord-

ing to the degrees of their con-
ducting power - ib.

1713. Insul-itors 197

1714. Insulating stools ... - ib.

1715. Electrics and non-electrics obso-

lete terms - - - - - ib.

1716. Two persons reciprocally charged

with contrary electricities placed
on insulating stools - - - 198

1717. Atmosphere a non-conductor - ib.

1718. Karefied air a non-conductor - ib.

1719. Use of the silk string which sus-

pends pith balls - - - 199

1720. Water a conductor - - ib.

1721. Insulators must be kept dry - ib.

1722. No certain test to distinguish con-

ductors from non-conductors - ib.

1723. Conducting power variously af-

fected by temperature - - 2CO

1724. Effects produced by touching an

electrified body by a conductor
which is not insulated - - ib.

1725. Effect produced when the touching

conductor is insulated - - 201

1726. Why the earth is called the com-

mon reservoir - ib,

1727. Electricity passes by preference on

the best conductors - ib.



CHAP. lit.

INDUCTION.

Sect. Page

1728. Action of electricity at a distance 202

1729. Induction defined - - - ib.
17JO. Experimental exhibition of its ef-

fects ...... 203

17.31. Effects of sudden inductive action 205

1732. Example in the case of a frog - ib.

1733. Inductive shock of the human

body ...... 206

1734. Development of electricity by in-

duction - - - - - ib.



CHAP. IV.

ELECTRICAL MACHINES.

1735. Parts of electrical machines - - 207

1736. The common c>lindrical machine ib.

1737. Nairne's cylinder machine - - 209

1738. Common plate machine - - ib.
17o9. Armstrong's hydro- electrical ma-

chine - - - - -210

1740. Appendages to electrical machines 212

1741. Insulating stools - ib.

1742. Discharging rods - - - 213

1743. Jointed dischargers - ib.

1744. Universal discharger ... ib.



CHAP. V.

CONDENSER AND ELECTROHIOROUS.

1745. Reciprocal inductive effects of two

conductors -
17+n. Principle of the condenser -

1747. Dissimulated or latent electricity

1748. Free electricity -

1749. Forms of condenser

1750. Collecting and condensing plates

1751. Cuthbertson's condenser

1752. The electrophorous

CHAP. VI.

ELECTROSCOPES.



1753. General principle of electroscopes 220

1754. Pith ball electroscope - - - 221

1755. Needle electroscope ... ib.

1756. Coulomb's electroscope - - 222

1757. Quadrant electrometer - - ib.

1758. Hold leal' electroscopes - - - ib.

1759. Condensing electroscope - - 2i!3

CHAP. VII.

THE LEVDEN JAR.

1760. The Leyden jar - - - - 227

1761. Effect of the metallic coating - 228



Sect. Page
1762. Water may be substituted for the
metallic coating - - -229
1763. Experimental proof that the
charge adheres to the glass and
not to the coating ... ib.


CHAP. X.

THERMAL EFFECTS OF ELECTRICITY.

Sect. Page
1799. A current of electricity passing
over a conductor raises its tem-


11(3. Charging a series of jars by cascade 231
1766. Electric battery - ... ft.
1767. Common electric battery - - 32
1768. Method of indicating and estimat-
ing amount of charge - - ib.

CHAP. VIII.

LAWS OF ELECTRICAL FORCES.

1769. Electric forces investigated by
Coulomb 234
1770. Proof-plane 235
1771. Law of electrical force similar to
that of gravitation - ib.
1772. Distribution of the electric fluid
on conductors - 236
1773. It is confined to their surfaces - ib.
1774. How the distribution varies - - 237
1775. Distribution on an ellipsoid - - ib.
1776. Effects of edges and points - -ib.
1777. Experimental illustration of the
effect of a point ... 238
1778. Rotation produced by the reaction
of points - - - 239
1779. Another experimental illustration
of this principle - - - 240
1780. Electrical orrery - - - - ib.

CHAP. JX.


1SOO. Experimental verification Wire "
heated, fused, and bunit - - 250
1801. Thermal effects are greater as the
conducting power is less - ib.
1802. Ignition of metals . - - ib.
1803. Effect on fulminating silver - 251
1804. Electric pistol - - ib.
18()5. Ether and alcohol ignited - ib.
1806. Resinous powder burnt - 252
1807. Gunpowder exploded - - ib.
1808. Electric mortar - - ib.
1809. Kinnersley's electrometer - ib.

CHAP. XI.

-LUMINOUS EFFECTS OF ELECTRICITY.

1810. Electric fluid not luminous - - 253
1811. Conditions under which light is
developed by an electric current ib.
1812. The electric spark - - - 254
1813. Electric aigrette - - - - 255
1814. The length of the spark - - ib.
1815. Discontinuous conductors produce
luminous effects - - - ib.
1816. Various experimental illustrations ib.
1817. Effect of rarefied air - - -250
1818. Experimental imitation of the
auroral light - - - - 257
1819. Phosphorescent effect of the spark ib.
1820. Leichtenberg's figures - - - ib.
18521. Ex|>eriments indicating specific
differences between the two


1781. Attractions and repulsions of elec-


1822. Electric light above the barometric


trified bodies - - - - 241
1782. Action of an electrified body on a
non-conductor not electrified - ib.
1783. Action of an electrified body on a
non-conductor charged with like


1823. Cavendish's electric barometer - 259
1824. Luminous effects produced by im-
perfect conductors - ib.
1825. Attempts to explain electric light
The thermal hypothesis - ib.


1,84. Its action on a non-conductor
charged with opposite electricity ib.
1785. Us action on a non-conductor not


182S. Hypothesis of decomposition and
recomposition - 260
1827. Cracking noise attending electric
spark 61


1786. Its action on a conductor charged
with like electricity - - - 243
1/87. Its act ion upon a conductor charged
with opposite electricity - - 244
1788. Attractions and repulsions of pith
balls explained - - - - ib.
1/89. Strong electric charges rupture
imperfect conductors Card
pierced by discharge of jar - 245
1/90. Curious fact observed by M.


CHAP. XII.

PHYSIOLOGICAL EFFECTS OF ELECTRICITY.

1828. Electric shock explained - - ih.
1829. Secondary shock - - - - 262
1830. Effect produced on the skin by
proximity to an electrified body ib.
1831. Effect of the spark taken on the
knuckle 263


1791. Wood and glass broken by dis-


1832. Methods of limiting and regulat-
ing the shock by a jar - - ib.


1792. EleWrica. belf, .' I -' I ^




1 /93. Repulsion of electrified threads - 247
1'iH- Cu ^ s em * 1 ot repulsion of pith


1834. Phenomena observed in the au-
topsis after death by the shock ib.


1795. Electrical dance - - - . J*'
1796. Curious experiments on electrified


derate discharges ... ,$.
1836. Effects upon a succession of pa-


1797. Experiment with electrified sealing *


charge - - - - - ib.


1798. Electrical see-saw . 249


1S37. RemarkableexperimentsofNollet,
Dr. Watson, and others - id.



CONTENTS.



ELECTRICITY.



Page
1838. Phenomena which supply the basis

of the electro-chemical theory - 261



Sect. ' Page

1839. Faradav's experimental illustra-
tion of this - - - -265

1S40. Effect of an electric discharge on

a magnetic needle - ib.

1841. Experimental illustration of this - 266



BOOK IV.

Voltaic Electricity.



CHAP. I.

SIMPLE VOLTAIC COMBINATION.

Sect. Page

1842. Discovery of galvanism - -267

1843. Volta's correction of galvanic

theory - - - 268



1845. Contact hypothesis of Volta - ib.

1846. Electro-motive force - - - ib.

1847. Classification of bodies according

to their electro-motive property 270

1848. Relation of electro-motive force

to susceptibility of oxydation - 271

1849. Analogy of electro-motive action

to induction - ib.

1850. Electro-motive action of gases and

liquids ..... 272

1851. Difference of opinion as to origin

of electro- motive action - -273

1852. Polar arrangement of the fluids in

all electro-motive combinations 274

1853. Positive and negative poles - - ib.

1854. Electro-motive effect of a liquid

interposed between two solid
conductors - ib.

1855. Electro-motive action of two

liquids between two solids - 276

1856. Practical examples of such combi-

nations - - - - - ib.

1857. Most powerful combinations deter-

mined ..... 277

1858. Form of electro-motive combina-

tion ...... ib.

1859. Volta's 6rst combination - - 278

1860. Vollaston's combination - - ib.

1861. Hare's spiral arrangement - - ib.

1862. Amalgamation of the zinc - - ib.
Ib63. Cylindrical combinations with one

fluid ...... 279

1864. Cylindrical combinations with two

fluids ..... 280

1865. Grove's battery - ib.
18fi6. Bunsen's battery - ... ib.

1867. Daniel's constant battery - - 281

1868. Pouillet's modification of Daniel's

battery ..... ib.

1869. Advantages and disadvantages of

these several systems - - 282

1870. Smee's battery .... ,b.

1871. Wheatstone's system - - - 283

1872. Bagration's system ... ib.

1873. Becquerel's system - ib.

1874. Schonbein's modification of Bun-

sen's battern .... 284



Sect. Page

1875. Grove's gas electro-motive appa-
ratus - - - - - -284



CHAP. II.

VOLTAIC BATTERIES.

1876. Volta's invention of the pile - -

1877. Explanation of the principle of the

pile

1878. Effect of the imperfect liquid con-

ductors - - - - -

1879. Method of developing electricity

in great quantity -

1880. Distinction between quantity and

intensity important -

1881. Volta's Brst pile - - - -

1882. The couronne des tasses

1883. Cruikshank's arrangement -

1884. Wollaston's arrangement

1885. Heliacal pile of Faculty of Sciences

at Paris

1886. Mode of forming piles -

1887. Conductors connecting the ele-

ments -'-...

1888. Pile may be placed at any distance

from place of experiment -

1889. Memorable piles Davy's pile at

Royal Institution -

1890. Napoleon's pile at Polytechnic

School -

1891. Children's great plate battery

1892. Hare's deflagrator
18!'3. Stratingh's deflagrator -

1894. Pepys' pile at London Institution

1895. Powerful batteries on Daniel's and

Grove's principles -

1896. Dry piles -

1897. Deluc's pile



ic's pile

1898. Zamboni's pile

1899. Piles of a single metal -

1900. Ritter's secondary piles



CHAP. HI.

VOLTAIC CURRENTS.

1901. The voltaic current - ib.

1902. Direction of the current - .297
190a Poles of the pile, how distinguished 298

1904. Voltaic current - ib.

1905. Case in which the earth completes

the circuit - - - 299

1906. Methods of connecting the poles

with the earth - - - - SCO



CONTENTS.



Sect. Page

1!)07. Various denominations of currents 300

1908. The electric fluid forming the cur-

rent not necessarily in motion - ib.

1909. Method of coating the conducting

wire - - - 301

1910. Supports of conducting wire- - ib.
19U. Ampere's reotrope to reverse the

1912. Pohl's reotrope - - - - 303

1913. Electrodes ib.

1914. Floating supports for conducting

wire 304

1915. Ampere's apparatus for supporting

moveable currents - ib.



1916. Mutual action of magnets and cur-

rents

1917. Electro-magnetism '-

1918. Direction of the mutual forces ex-

erted by a rectilinear current on
the poles of a magnet

1919. Circular motion of magnetic pole

round a fixed current

1920. Circular motion of a current round

a magnetic pole -

1921. Apparatus to illustrate experiment-

ally these effects -

1922. Apparatus to exhibit direction of

force impressed by a rectilinear
current on a magnetic pole

1923. Apparatus to measure the inten-

sity of this force - - -

1924. Intensity varies inversely as the

distance - - ...

1925. Case in which the current is with-

in but not at the centre of the

circle in which the pole revolves

19^6. Action of a current on a magnet,

both poles being free - - I

1927. Case in which the current is out-

side the circle described by the

1928. Case in which the current passes

through the circle - -

1929. Case in which the

within the circle ...

1930. Apparatus to illustrate eleutro-
, , magnetic rotation ...
TJjl. To cause either pole of a magnet

to revolve round a fixed voltaic
current - ....

1932. To cause a moveable current to

revolve round the fixed pole of
a magnet -

1933. Ampere's method -

1J34. To make a magnet turn on its own
axis by a current parallel to it -



urrent passes



CHAP. V.



RECIPROCAL INFLUENCE OF CIRCULATING
CURRENTS AND MAGNETS.



1935. Front and back of circulating cur-

rent - - _ . . .

1936. Axis of current - - . .
1337. Ueciprocal action of circulating

current and magnetic pole -



Sect. Page

1938. Intensity of the force vanishes

when distance of pole bears a
very great ratio to diameter of
current - 322

1939. But directive power of pole con-

tinues ib.

J940. Spiral and heliacal currents - - ib.

1941. Expedient to render circulating

currents moveable - 323

1942. Rotatory motion imparted to cir-

cular current by a magnetic pole ib.

1943. Progressive motion imparted to it 324

1944. Reciprocal action of the current on

pole ib.

1945. Action of a magnet on a circular

floating current ... ib.

1946. Reciprocal action of the current on

magnet - - - - - 325

1947. Case of instable equilibrium of the

current - - - - - ib.
1918. Case of a spiral current - - ib.

1949. Circular or spiral currents exercise

same action as a magnet - - 326

1950. Case of heliacal current - - ib.

1951. Method of neutralizing effect of

the progressive motion of such a
current - - - - -id.

1952. Right-handed and left-handed he-

lices ib.

1933. Front of current on each kind - ib.

1954. Magnetic properties of heliacal cur-

rents, their poles determined - ib.

1955. Experimental illustration of these

properties - - - 327

1956. The front of a circulating current

has the properties of a south and
the back those of a north mag-
netic pole - - - - - ib.

1957. Adaptation of an heliacal current

to Ampere's and Delarive's ap-
paratus - 323

1958. Action of an heliacal current on a

magnetic needle placed in its
axis 329



ELECTRO-MAGNETIC INDUCTION.

Inductive effect of a voltaic cur-
rent upon a magnet -

Magnetic induction of an heliacal
current - - ...

Polarity produced by the induction
of heliacal current ...

Consequent points produced -

Inductive action of common elec-



magnetized positively and nega-
tively

Results of Savary's experiments -

Magnetism imparted to the needle

affected by the non-magnetic

substance which surrounds it -

Formation of powerful electro-



force of magnet -
Electro-magnet of Faculty of Sci-



1970. Form of electro-magnets in general 33o

1971. Electro-magnetic power applied as

mechanical agent ... ib.



CONTEXTS.



Sect. Page
1972. Electro-motive power applied in
workshop of M. Frotnent - - 337
1973. Electro-motive machines con-
structed by him ... 339
1974. Applied as a sonometer- - -343
1975. Momentary current by induction - ib.
1976. Experimental illustration - - 344
1977. Momentary currents produced by
magnetic induction - - - 345
1978. Experimental illustrations - - ib.
1979. Inductive effects produced by a
permanent magnet revolving
under an electro-magnet - - 346
7!>80. Use of a contact breaker - - 348
1981. Magneto-electric machine - - ib.
1982. Effects of this machine, its medical
use 350
1983. Inductive effects of the successive
convolutions of the same helix ib.


Sect. Page
2003. The dip of a current illustrated by
Ampere's rectangle ... 362

CHAP. VIII.

RECIPROCAL INFLUENCE OF VOLTAIC
CURRENTS.

2004. Results of Ampere's researches - 363
2005. Reciprocal action of rectilinear
currents - - - 364
2006. Action of a spiral or heliacal cur-
rent on a rectilinear current - ib.
2007. Mutual action of diverging or con-
verging rectilinear currents - 365
2008. Experimental illustrations of this ib.
2009. Mutual action of rectilinear cur-
rents which are not in the same
plane 366
2010. Mutual action of different parts of
the same current ... 367
2011. Ampere's experimental verifica-
tion of this - ... ib.
2012. Action of an indefinite rectilinear
current on a finite rectilinear



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