Page 4, line 17, for this read the-p. 9, second last line of note, supply evidence after such -p. 14, 1. 32, for destiny read density-p. 50, l. 12, for exposition read opposition-p. 64, 1. 22, for there are more, particularly four, aspects read there are particularly four aspects-p. 96, 1. 25, for of the axis, read of the prism,-p. 103, 1. 5, for 23:33. read 23:33.-p. 136, 1. 11, for rays read rings-p. 144, after the last word supply one-p. 170, 1. 3, for change read chargep. 200, 1. 30, for 1o; read 1;-p. 215, 1. 21, for molecule read molecules-p. 238, 1. 19, for Fig. 39, read Fig. 37,-p. 253, l. 35, for 20.7, read 29.7,-p. 276, 1. 17, for Hyposulphuric read Hyposulphureous-p. 476, last line, for protoxide read peroxide-p. 600, 1. 18, delete and

CONTENTS.

BOOK I. ON THE STRUCTURE AND ACTION OF

MATTER.

MATTER.

Page

THREE orders of agents usually assumed to exist, mind, im-

ponderables, and impenetrable matter-three first books of

this work to be occupied with the phenomena of matter, the

fourth with those of mind-matter must possess form, a

necessary property of a substance having a limited exten-

tion-possesses elasticity, hence not indifferent to every state

of existence-is of two kinds, hard or atomic, and motorial

or subtile matter, .

PONDERABLE OR ATOMIC MATTER

Is the hard or impenetrable part of an atom-the least parts

of matter excessively minute-the specific particles of bodies

possessed of different weights, magnitudes, and forms-ob-

ject of this work to maintain that the material universe con-

sists of homogeneous atoms, which, united in various ways,

constitute the specific particles of chemical and natural bo-

dies,

1-2

3-6

INPONDERABLE OR SUBTILE MATTER

Is an invisible substance investing every atom or group of
atoms which possesses unity-its peculiar nature-gives rise
to the phenomena of attraction or confluence, repulsion or
elasticity, and rotation-depends for the phenomena which
it produces upon the region of the nucleus which it invests-
its laws illustrated-when crowning angles of atoms, it pro-
duces confluence or attraction between two bodies-over
surfaces it produces the phenomena of impenetrability or re-
pulsion-is often confounded with heat-the object of its
action is the development of bodies symmetrical on opposite
sides of an equator-the polarity is the same at both extre

Page

-

mities of the axis of a molecule, and of a consecutive kind

at the equator

intrinsic atomic action ceases when the

polarity of the equatorial region balances that of the polar

regions, that is, when the molecule has made the nearest

possible approach to a spheroidal form-the law of imita-

tion stated,

6-45

НЕАТ.

Consists in a tremulous movement in the atoms of bodies-

angles chiefly vibrate-energy of the subtile matter attached

to them diminished, while that opposite the faces increased

-hence heat diminishes attractive and increases repulsive

energy-hence also solid and liquid bodies expand accord-

ing to a different law from aëriform-capacity for heat de-

pends on atomic structure-specific heat, &c. physico-che-

mical opinions of Newton-different states of matter illus-

trated-action of compressed and uncompressed gases giving

rise to undulation and radiation,

45-67

BOOK II. OF THE RADIANT MEDIUM.

Its existence indisputable-before we know its structure, we

cannot infer whether it will occasion retardations in heavenly

bodies or not-cannot be absolutely different from other

aëriform media-doctrine of emanation incredible-structure

of radiant medium deduced from the principles of the first

book-may be confirmed or not by the phenomena of physical

optics and radiant heat-radiant matter the common vapour

of concrete matter-phenomena of its development in the

Torricellian tube-is a gravitating medium-is condensed

around stars and large planets--is of different densities in

different gases-affects their weight-hence an error of the

balance, which may be corrected by a knowledge of refrac-

tive power of a gas-radiant medium capable of three mo-

tions-polarized excitement producing light and colours,

atomic tremor producing radiant heat, and mechanical com-

pression and dilatation producing sounds if any sensible

effect,

68-79

OF LIGHT.

Senses in which the term is used. Newton's description of

rays of light perfectly applicable to the views here advan-

ced-when radiant medium is in a state of unexcited repose

there is darkness to human eye-vision arises from polarized

excitement shooting along the atoms of the radiant medium,

and continued in the radiant matter involved in the struc-

ture of the eye without interruption to the sensorium-de-

finitions of an atom-of a single ray of light-of a perfect

ray-of a molecule of a chromatic axis-phenomena of

illumination,

Page

79-82

PHYSICAL OPTICS.

Velocity with which lumeniferous excitement is conducted or

shoots along—intensity of illumination depends both on

the luminous object and that illuminated-radiant medium

compressed gives rise to undulation instead of radiation.

during propagation of light, and constitutes a photosphere,

-the illuminating influence of sun at planets nearly ex-

pressed by same formula as gravitation-the phenomena of

the interference of rays necessary consequences from the

principles here advanced-colour depends on a difference

in the quality or polarity of light-structure of the sunbeam

investigated-neutral axes crossing each other at right angles

in the base of a ray-phenomena of the prismatic spectrum

shewn to be necessary consequences of destroying the

metry of a sunbeam-different colours must give rise to

different intervals-quantity of positive to negative tints in

a ray of white light is as 2' 3'-negative polarity always

more expanded than the corresponding quantity of posi-

tive,

82-103

OF REFLECTION.

At all angles between the perpendicular and a certain obliquity

a partial reflection only possible-the phenomena of polari-

zation, and of the interference and non-interference of pecu-

liarly polarized rays shewn to be necessary consequences

from the structure of a perfect ray cleft at a transparent sur-

face,
103-109

b

OF TRANSMISSION.

Cause of transparency and opacity-mechanism by which re-

fraction is occasioned-light must be polarized by oblique

transmission-photomotive pile,

Page

109-116

OF DOUBLE REFRACTION.

Lumeniferous excitement must be constituted in media com-
posed of polarized molecules in a specific manner, as it is
in the tessular radiant medium in a specific manner-hence
double refraction-phenomena of doubly refracting spar,
agate, tourmaline, metals and metallic oxides,
116-122

OF CHROMATICS.

Colour depends on quality not quantity of light-bodies not

self-luminous cannot change the quality of the light which

illuminates them-phenomena of solar spectrum explained.

Cause of Frauenhofer's lines-why only across the spec-

trum-the decomposition of sunbeam not the only cause of

colour-the phenomena of chromatic axes investigated-the

colours of thin plates are displays of chromatic polarity-the

results of Newton and Arago as to coloured rings shewn to

be necessary consequences of the views here advanced-me-

chanism which produces the colours of natural bodies, of

doubly refracting laminæ, &c.

123-150

OF VISION.

When there is a difference in the natural state of excitement

of the radiant atoms, which constitute the optic apparatus

within, and that of the atoms which constitute the radiant

medium without, reciprocal action goes on, which produces

vision-colour of pigment on the choroid is index of that

state of excitement which cannot produce vision-diurnal

and nocturnal animals-structure of optic nerve-cause of

the complementary colours seen in various cases-the phe-

nomena of internal vision examined-how spectra and

dreams may be produced,

150-162