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BRIEF RETROSPECT

OF THE

EIGHTEENTH CENTURY,

IN THREE VOLUMES : i ^

CONTAINING ^>^„^i^iCAL ^^ll^^

A SKETCH

OF THE REVOLUTIONS AND IMPROVEMENTS

IN

SCIENCE, ARTS, AND LITERATURE,

DURING THAT PERIOD.

7^

BY SAMUEL MILLER, A.M.

ONE OF THE MINISTERS OF THE UNITED PRESBYTERIAN CHURCHES IJ*
THE CITY OF NEW YORK, MEMBER OF THE AMERICAN PHILO-
SOPHICAL SOCIETY, AND CORRESPONDING MEMBER 01-
THE HISTORICAL SOCIETY OF MASSACHUSETTS.

VOL. I.

Printed at New York.

LONDON:
HEPRINTED FOR J. JOHNSON, ST. PALL's CHURCHYAJtE.

1805.

By S. Hamilton, Shoe Lane, Fleet Street,

TO

JOHN DICKINSON, ESQ. LL. D.

LATE PRESIDENT OF THE STATE OF DELAWARE,

AND

PRESIDENT OF THE SUPREME EXECUTIVE COUNCIL

or THE

COMMONWEALTH OF PENNSYLVANIA.
DEAR SIR,

J N finding your name prefixed to the follow-
ing pages, without permission, I trust you
will feel no emotion more unfavourable than
that of surprise. I know not, indeed, to
w^hom I could dedicate such a w^ork as this
with more propriety than to an elegant
scholar, a comprehensive observer of a large
portion of the century attempted to be re-
viewed, a master of so many of its literary
and scientific improvements, a conspicuous
actor in some of its most memorable and im-
portant transactions, an able and eloquent
defender of his country's rights, a munificent
patron of American literature, and (if pei^onal
or local feelings may be allowed to intrude) a
uniform and affectionate friend of my ho-

A 2 • ■ \

IV DEDICATION.

iioured parents, and one of the most illustrious
of those Avho owe their birth to my native
state.

Among the numerous opinions expressed in
these volumes, you will, no doubt, find some
Vhich totally differ from vour own ; and
others which more attentive and enlarged
views would have taught me considerably to
modify or amend. Of the former you will
not consider this public address as implying
or soliciting your approbation. Of the latter
I am confident you will be disposed to form
a candid and even an indulgent estimate.

But with respect to some of the leading
opinions delivered in the following sheets, I
am happy in the assurance that you perfectly
coincide v/ith me. To all that is said of the
perfect hai-mony between the Religion of
Christ and genuine Philosophy, and of the
illustration and support which the former has
received at every successive step of the latter
in the last age; to every unfavourable judg-
ment pronounced on tliose theories, falsely
called i)ljil()sophy, which pervert reason, con-
Irndict Kevelation, and blaspheme its divine
Aiillur; ;ni(l to e\ery expression of satisfac-
tion at the progress of elegant letters and sub-

DEDICATION, V

stantial science, as tending to promote the dig-
nity and happiness of man — to opinions and
sentiments like these, 1 knoiv too much of
your character to doubt of receiving your
sanction.

Those who, hke yourself, contemplate every
department of human affairs through the me-
dium of Christian principles, while they see
much tb deplore, see also much to approve
and admire in the history of science for the
last. age. What effect the knowledge be-
queathed by that age may have on the har-
mony, virtue and happiness of mankind in
the one on which we have entered, is known
only to infmite Wisdom. Let us, however,
indulge in favourable anticipations as long as
we can. In all events we are assured, that
this, as well as all the other fruits of human
genius and activity, will be made conducive
to the welfare of the good, in a more eji-
lightened and a more happy world.

I am, dear sir.

With much respect.
Your obliged and obedient servant,

SAMUEL MILLER.

New Tork, Nov. 25,1803.

PREFACE.

A SIMPLE history of this publication will be^t;
unfold its design, and will form the best apology
for its mimcrous imperfections. On tlie first day
of January, in the year 1801, the author being
called, in the course of his pastoral duty, to de-
liver a sermon, instead of choosing the topics of
address most usual at the commencement of a nezv
yeaVy it occurred to him as more proper, in enter-
ing on a new century^ to attempt a revie\v of the
preceding age, and to deduce from the prominent
features of that period such moral and religious
reflexions as might be suited to the occasion. A
discourse, formed on this plan, was accordingly
delivered. Some wdio heard it were pleased to
express a wish that it might be published. After
determining to comply with this wish, it was at
fu'st intended to publish the original discourse,
with some amplification ; to add a large body of
notes for the illustration of its several parts ; and
to comprise the wdiole in a single volume. Pro-
posals were issued for the publication in this form,
and a number of subscribers gave their names for
its encouragement. <

Little progress had been made in pre})aring the
work, on this plan, for the jiress, before the ob-
jections to such a mode of arranging tiie materials
appeared so many and cogent, that it Avas at
leiigth thought best to lay aside the form of a

viii PREFACE.

sermon, and to adopt a plan that would admit of
more minuteness of detail, and of greater freedom
in the choice and exhibition of facts. This alte-
ration in the structure of the work led to an exten-
sioi> of its limits ; materials insensibly accumu-
lated; and that portion which was originally in-
tended to be comprised in a third or fourth part
of a single volume gradually swelled into two
volumes*.

It is probable that one of the first reflexions
made by most readers of the following pages will
be, that the plan is too extensiye to be well exe-
cuted by any individual ; and that it was peculiarly
presumptuous, in one of comparatively small read-
ing, and who could not obtain access to ample
libraries, to undertake such a work. The author
feels the justness and weight of this reflexion; and
is sensible that to present a full and satisfactory
view of any one of the departments embraced by
this Retrospect, would be a task beyond his
powers, would afford abundant employment, for
many years, to a mind much more mature, active,
and enlightened than his, Wh}^ then, it will be
asked, did iie adventure on so arduous an enterprise?
In answer to this question, he must ingenuously
confess, that he engaged without any due considera-
tion, and did not begin suitably to estimate the
extent and dilhcidty of the task till he had pro-
ceeded too far to retract. He is also bound in
candoiir to declare, that his own instruction and
im))rovoment were among his principal motives in
undertaking and i)rosecuting this work. Being per-
* 'J'hc (jrio-iiiLil cdrtion is in two volumes.

PREFACE. 17^

suaded that writing on a subject is one of the best
means of methodising and correcting one's, own
views of it; and hoping that, while he informed
himself, he might amuse, if not instruct, otiiers, he
submitted to the toils of collecting and arranging
the materials which are here presented. If none
of his readers should be able to .derive either enter-
tainment or information from the following sheets,
he has the satisfaction of reflecting, that he himself
derived both from the labour of preparing them
for the press.

Though the greater part of this work consists
of compilations, yet the winter claims to be some-
thing more than a mere compiler. He has offered,
where he thought proper, opinions, reflexions, and
reasonings of his own ; and though nicmy of these
are adopted, perhaps too hastily, from others, there
are some of which all the praise and all the blame
belong to himself. He is not, however, solicitous
to discriminate, even if it were possible, between
these several parts of the work. If the exhibition
of facts and opinions, so far as it goes, be toler-
ably just, the question whence they originated is
of little consequence to the reader.

With respect to the division and arrangement
of the subjects, it was judged advisable to adopt
rather a popular than a scientijic plan. T\\\s plan
is, no doubt, liable to some objections; but it ap-
peared better suited to the purj)Ose in view than any
other that presented itself. The reader will observe
that the sciences of Theology, Morals, and PolUicSy
are not noticed in this First Fart, i he reason of

X PREFACE.

the Oiiiission is, that it appeared most proper to
leave what may be said concerning the revolutions
and improvements in these t hree interesting depart-
ments of science, respectively, to stand as preli-
minaries to the three remaining divisions of the
work, in which some account will be attempted of
the great events in the Clii'istian Church, in the
Moral World, and in Political Principles and Esta-
blishments, during the last century. It was sup-
posed that, in this connexion, the rise, progress, and
influence of new systems, and modes of thinking,
might be exhibited wnth greater advantage, and
perused with more satisfaction.

As the author aimed at nothing more than a
brief retrospect of the period to which this work
is devoted, it was impossible for him to do more,
consistently with his plan, than to mention the
principal discoveries, inventions, improvements,
and WTiters, under each head ; and even these
could only be noticed with great brevity, and in
very general terms. To have attempted minute
details, and particular explanations, would have
extended the work to many volumes. With respect
to the choice which has been made of facts and
names, the degrees of importance ascribed to them,
and the pro{)ortion of room and attention allotted
to each, dintrc;nt readers will, no doubt, entertain
dilTer(>nl opinions. Every one will be apt to suppose
that the particular names and studies to which he is
most attach' (I, are not noticed with sufficient re-
spect, or dwelt upon at sufiicient length. The au-
thor can oidy say, that, in general, he indulged in
Xtiovf or Icos ])rolixity, according to his ideas of the

PREFACE. xi

importance of the several subjects, the extent of
his acquaintance with them, or the degree in which
they interested his own mind. That, from such a
multiphcity of objects, he often selected injudiciously,
and made an erroneous estimate of their compara-
tive value, is altogether probable.

Although the very nature of the work required
that all the subjects brought into view should be
treated superficially, and that nothing more than
rapid outlines should be attempted, yet the intel-
ligent reader will, doubtless, discern, that the mode
of treating some of the subjects manifests a very
small and partial acquaintance with them. For the
want of more just and enlarged views, the author
fears he has often written in a crude and unsatis-
factory manner on topics which might, in the same
compass, have been better discussed. In some in-
stances, however, he has failed of giving a more
satisfactory account of the additions made to
science, by distinguished individuals, from another
cause: where it would have been impossible to
state the precise limits of what each has done to
advance our knowledge of a particular subject,
without going into a discussion of many pages,
little more is frequently attempted than to give a
list of the names of those individuals, on the pre-
sumption that the inquisitive reader will seek for a
more full account of their respective claims else-
where.

In enumerating the. principal writers on the va-
rious subjects reviewed, it will be observed, that
those who have written in the English language

Xll

PKEFACE.

engage the larp:est siiare of the author's attention.
The reason of this is obvious ; he is best acquaint-
od with such writers; and, from his ignorance
of most of the languages of the continent of
li,urope, he has probably failed of mentioning
many works quite as worthy of respectful notice
as otiiers on which he has bestowed liigh praise.
Perhaps a still more formal apology will be deemed
necessary for the disposition to introduce Ameri-
(Mn writers and publications, even of moderate
character, which he has so frequently discovered.
Eut, beside indulging a natural partiality for his
o>\n country, which is at least pardonable, he
was desirous of collecting and exhibiting as much
information on the subject of American literature
as the nature of his undertaking admitted. And
as no 'attempt to give a general historical view
of this subject has evcT been before made; as a
considerable portion even of the humble and
meagre records from wliich he has drawn his ma-
terials, arc daily perishing; and as peculiar cir-
cumstances sometimes give to literary characters
and events a relative importance, beyond their
absolute value, he thought it advisable to take
notice of more obscure names, and of smaller
publications, than could with propriety have been
mentioned in countries of a more mature literary
character. Perhaps, however, in his zeal to collect
every thing he could find on this subject, he has
sometimes descended too low.

Should any reader be offended by the language
of paiKigyric, m liich is frequently bestowed on the
intillectuid and scientific endowments of some

PREFACE. xHi

distinguished abettors of heresy or of infidelity,
he is entreated to remember that justice is due to
all men. A man who is a bad Christian may be
a very excellent mathematician, astronomer, or
chemist ; and one who denies or blasphemes the
Saviour, may write profoundly and instructively
on some branches of science highly interesting to
mankind. It is proper to commiserate the mistakes
of such persons, to abhor their blasphemy, and to
warn men against their fatal delusions ; but it is
surely difficult to see either the justice or utility of
withholding from them that praise of genius or of
learning to which they are fairly entitled.

It will probably be remarked, by the intelligent
reader, that a due proportion between the parts
of this work, according to the relative importance
and extent of each subject, is not ahvays preser-
ved. Had the manuscript been completed before
any part of it was sent to the press, faults of this
kind would, no doubt, have been, in some de-
gree, avoided ; but the truth is, that the first
})ages of the manuscript were put into the hands
of the printer before a single chapter of the work
had been fully written ; and each successive sheet
was prepared, from the matei-ieils previously col-
lected, at the call of the printer, and amidst
the hurry of incessant professional labours. It
is scarcely necessary to add, that this race with
tiie press frequently rendered impossible that labo-
rious investigatio.n, ar^d that careful correction
which were highly desirable: nor coald the au-
thor excuse himself for conduct so manifestly in-
iliscreet, had he duly considered beibrehand the

xlv PPvEFACE.

nature «intl magnitude of the engagement. But
it must be acknowledged, that as he entered on
the work without duly appreciating the arduous-
ness of his undertaking, so every s.tep in the pur-
suit convinced liim more and more of its extent
and difficulty ; that in the prosecution of his task
he wished a hundred times he had never under-
taken it; and that now it is brought to a close, few
readers can l)e more sensible than he is himself of
its numerous and .great defects.

It will be observed, that three parts of the ori-
ginal plan yet remain to be executed. Whether
the execution of the whole will be attempted • de-
pends, in some measure, on the reception which
shall be given to this First Fart. The author is
particularly desirous of completing the fourth and
last division; viz. that which relates to the Lite-
rature, Science, Revolutions, and principal Events
of the Christian Church during the last age ; and
even if he should be compelled to abandon the two
intermediate divisions, he cherishes the hope of
being able, if his life should be spared, to lay some-
thing before the public on this favourite subject.

CONTENTS

THE FIRST VOLUME.

Page
INTRODUCTION 1

PART I.

On the Revolutions and Improvements in Science, Arts,
AND Literature, during the Eighteenth Century ... 9

CHAPTER L Mechanical Philosophy 14

§ 1. Electricity 23

§ 2. Galvanism 31

%S. Magnetism 36

§ 4. Motion and Moving Forces 41

§ 5. Hydraulics 46

§6. Pneumatics 51

§7. Optics.,,,^ 59

§ 8. Astronomy 69

General Observations 90

CHAPTER IL Chemical Philosophy 92

CHAPTER in. Natural History 140

§ 1. Zoology 143

%2. Botany 163

§ 3. Mineralogy 188

§ 4. Geology 203

§ 5. Meteorology 242

§ 6. Hydrology 254

CHAPTER IV. Medicine 258

§ 1. Anatomy 261

§ 2. Physiology 277

§3. Theory and Practice of Physic 311

% 4. Surgejy and Obstetrics 368

Additional Notes 379

BRIEF RETROSPECT

OF THE

EIGHTEENTH CENTURY.

INTRODUCTION.

1 HE oldest historian in the world, and the only
one in whose information and faithfulness we can
place unlimited confidence, tells us, that, in the
beginning, when God created the heavens and the
earth, he said. Let t fierce be lights in the firmament
of the heaven^ to divide the day from the night; and
let them be for signs ^ and for seasons^ and for days,
and for years. Without recurring to the regular
motions of these celestial orbs, time would pass
unnoticed and unmeasured. Its flight, in itself, is
not an object of sense ; we neither see nor hear it.
But by observing t\\^ diurnal revolutions of the
heavenly bodies, we acquire the conception of
days ; by dividing these days, v/e form hours and
minutes; and, by multiplying them, we gain the
ideas of months, years, and ages. Like all the
rest of the works and ways of God, these means of
marking the progi'css of time, and ascertaining its
portions, are adapted to promote both physical
Vol. I. B

^ INTRODUCTION.

and moral advantage. To the philosopher they
furnish inestimable rules and principles of calcula-
tion 3 to the man of business they present measures
and stimulants to industry; and, above all, to the
christian they offer continual memorials of the end
of life, and unceasing excitements to moral ex-
ertion.

Hence the close of one year, and the commence--
ment of another, are generally marked by mutual
congratulations, by a peculiar train of reflexions,
by new plans and undertakings, and by charac-
teristic changes in domestic, social, and political
affairs. They form a period which interests the feel-
ings, and constitutes a prominent point in the life
of almost every man.

But, on reaching the termination of an active
and eventful century, and entering upon a new
one, the emotions of the reflecting mind are still
more strong,, and the impressions made more va-
rious and interesting. This is a transition, which
few indi\ iduals at present on earth have before wit-
nessed, and which few now living will ever again
behold. At such a period it is natural, and it i^
useful, to pause ; to review the extensive scene ^ to
estimate what has been done ; to inquire whether
we have grown wiser and better, or the reverse >.
and to derive those lessons of wisdom from the
^vhole, which rational beings oUght ever to draw
from experience. While the student of chronology
is disputuig about tt^ time when tl^e old century
terminated, and the new one began* j and v/hile

'^- It wouhl be neitbcr convenient nor seasonable to attempt, in
Uiis plvlce, a discussion of the question, when the nineteenth cen-
tury conim(?ticecl." The autJior takes for granted, that it com-

INTRODUCTION. C5

the astronomer sees nothing in this period but the
completion of a certain number of planetary revo-
lutions, and the commencement of another series ;
the man of true wisdom is employed in attending
to other objects, and in pursuing different inquiries.
Rich were the stores of instruction, and great the
improvement, which an ancient king received from
retui^ningy after a long course of action^ and look-
ing upon all the zvorks which his hands had wrought^
and the, labour zvhich he had laboitred to do. It
was upon this calm retracing of his steps, that he
discovered, more fully than ever before, wherein
he had been profitably employed ; and in what re-
spects his unwearied exertions had been but vanity
and vexation of spirit.

Standing, therefore, as we do, upon the threshold
of a NEW CENTURY, it may prove both amusing and
instructive to take a hasty retrospect of that to
which we have just bidden adieu. In this retro-
spect, the scene which lies before us is large and
various. On w^hatever part we cast the eye, im-
portant objects, and interesting lessons, present
themselves to view. Out of these it will only be
possible to select a few of the most conspicuous
and striking, and to display each with the utmost
brevity.

menced on the first day of January, 1801. In this "opinion he is
supported by the decision of many of those who are best qualified
to judge on the subject. De Lalande, the great French astro-
nomer, tells us that the same question was discussed with great
warmth at the close of the seventeenth century ; and that many
pamphlets were written with a view to settle it, of several of
which he is possessed. He decides, witliout hesitation, that the
century commenced on the day above-mentioned. — Sec Dc Lu-
lande*s History of Astronomy for 1799-

B2

4 INTRODUCTION.

• He who attempts to take a view, even the most
superficial, of human nature, and of human affairs,
within any given period, will soon find that the
ol)jcct w hich he undertakes to survey, is complex
and multiform. Man, always variable, and never
consistent, imparts this character to every thing
tliat he touches. To give the history of a single
mind for a single day; to mark with justice its
revolutions, its progress, its acquirements, and its
retrocessions ; to form an estimate of the good, or
of the evil, which, within this time, it may have
]>roduced ; and to trace, in accurate lines, wherein
its character on that day differed from its character
on the preceding ; is a task which can appear easy
only to ignorance and inexperience. And in pro-
portion as the number of minds to be contemplated
increases, or the length of the time in question is
extended, the difficulties of the undertaking mul-
tiply, and it becomes, in every respect, more ar- .
duous. How numerous the difliculties, then, of
I'stimating the operations and the progress of the
Jiuman race for a hunclred years !

Another source of doubt and mistake also arises
here, beside that which is occasioned by the com-
plexness and confusion of the scene. Who can
distinguish between revoluiioii and improvement in
human affairs ? Who can undertake to say in what
cases they are synonymous terms, and when they
are directly opposite? If every change were to be
considered an advantage, it would follow, of course,
that the strides of civilised man, in every species
of improvement, during the last century, have been
j)rodigious. But, alas ! this principle cannot be
admitted by the cautious inquirer, or the friend of

INTRODUCTION. O

human happiness. The passion for novelty and
change, so universal and unceasing, has doubtless
often indulged itself at the expense of real good,
and substantial enjoyment.

A wise man, and an inspired writer, has told
us, that there is no new thing under the sun. Is
there ami thing xvhereof it may be said, See, this is
neza F It hath been already of old time, zvliich icas
before us. This passage, like many others of a
similar kind, is doubtless not to be interpreted as
declaring literally, that there never have been, nor
ever can be, any schemes, events, or discoveries,,
entitled to the appellation of nexv ; but as teach-
ing us, in a strong and figurative manner, that the
projects and improvements of human genius arc
frequently sinking into forgetful n ess, and rising
again ; that old systems are daily revived, clothed
in new dresses, decorated with new names, and
palmed on the world as creatures of modern birth ;
and that very few of the boasted efforts of genius,,
either in Solomon's days, or at any subsequent
period, could be called entirely original. The
smallest acquaintance with history is sufficient to
convince any one, that this is a just representation.
That there are some things peculiar to certain
periods and countries, will not be disputed; but
that these are fewer in number, and the peculiarity
much smaller in degree, than transient observers
imagine, is certainly also true. Hence arises a
further difficulty in deciding wherein one age dif-
fers from another. History is not an instructress
sufficiently minute and patient, to enable us always
to judge promptly and accurately on this subject.

'' It affords some astoni'shment," savs a late

b INTRODUCTION. *

writer, " and much curious speculation to the re-
flecting mind, that, probably, not a system of phi-
losophy exists among the moderns, which had not
its foundation laid upon some one opinion or ano-
ther of the ancient theorists, and the outlines of
which may not be found in such of their writings
as have come down to our time. Even the New-
tonian doctrine of gravitation was not unknown to
Lucretius ; for that poet, in his first book, attempts
to refute the idea that the universe had a centre,
to which all things tend by their natural gravity.
That the central point had the strongest power of
attraction, was equally an hypothesis of Sir Isaac
Newton and the ancient stoics *." The ingenious
writer might have extended his remark much far-
ther, and have gone into a very amusing detail on
this subject. Some facts, tending to confirm his
position, will appear in the following pages |. Let
us beware, however, of carrying the principle be-
yond due bounds.

A difficulty also arises, in attempting to make
the proposed estimate, from the disposition of man
to magnify present objects. It is an old remark,
that iinportant persons and scenes acquire an addi-
tional magnitude in our eyes when viewed from a
distance. But it is as true, that the same error of

* Drake's Literary HovrSy vol. i. p. 12^ 13.

t Those who wish to see this subject farther elucidated; may
consult a very amusing work of M, Dutens, entitled Origine des
Decouvertes attributes aux Modernes , Sj-c . 2 vols. 8vo. Paris, 1/66.
And although the impartial reader will frequently perceive, tliat
the author carries his determination to withhold from tlie moderns
the credit due to them, for many dii5coveries, to an extravagant and
ridiculous length, yet the work undoubtedly contains much in-
structive and valuable matter.

IKtRODUCTION. 7

intellectual vision occurs daily with respect to ob-
jects seen near at hand. Men have always beej)
unduly disposed to consider tlieir own times ^fs dis-
tinguished, above all others, by remarkable events.
The virtue or the vice, the knowledge or tJie igiio-
rance, the discoveries or the destructions, which
we personally witness, or of which we have recently
heard, are apt. to impress us more deeply, and to
be estimated more highly in the history of man,
than their real importance deserves. Hence no-
thing is more common than to hear men express
an opinion, that the country and the period in
w4iich their lot is cast are more awfully degenerate,
or more extensively enlightened,, accordin"g to the
occurrence or the object which happens to occupy
their minds, than the world ever before witnessed.
No doubt, a portion of this prejudice and partiality
cleaves to every mind, and must always interpose
an obstacle in the way of him who would- accu-
rately calculate the magnitude, and justly exhibit
the features, of recent events.

But, after making every allowance for errors in
calculation which may arise from these several
sources, it will probably be acknowledged, that
the century of which we have just taken leave has
produced an unusual number of revolutions, and
at least some improvements, — In litj-ratuke and

SCIENCE in POLITICAL PRINCIPLES ^md ESTABLISH-
MENTS— in the moral world — and in the christian

CHURCH.

To think of surveying each of these wide fields,
throughout its whole extent; and es})ecially to
think of conducting the survey with the miiuit«'-
ness of observation, and the profundity of research.

g INTRODUCTION.

which would become a philosophic inquirer ; are,
at present, out of the question. Had the writer
temefity enough to engage in such a plan, or the
presumption to assume so high a character, the
variety and immensity of the task would soon
convince him of his error. The most brief and
rapid sketches only will, therefore, be attempted,
on each of the above heads of inquiry.

PART FIRST.

ON THE REVOLUTIONS AND IMPROVEMENTS IN
SCIENCE, ARTS, AND LITERATURE, DURING THE
EIGHTEENTH CENTURY.

It is justly remarked, by an acute modern writer*,
that the history of learning and science is much
less uniform than that of civil affairs ; that the wars,
negotiations, and politics of one age more resemble
those of another, than the literary and scientific
taste. He explains this obvious fact by observing,
that, in public and polftical transactions, ambition,
honour, malice, revenge, and the various turbulent
passions of man, are the prime movers ; and that
these passions are not only the same in every age,
but are also stubborn, intractable, and by no means
susceptible of the. same variety of modification,
which frequently takes place in the literary taste
and habits of different times. The former we can
scarcely expect any thing human to control ; but
the latter may be and are every day affected by
education, by example, and by a thousand circum-
stances which it would be difficult to enumerate.

It has often been made a question, whether
mankind have effected any real progress in know-
ledge during the eighteenth century. There are
not a few who maintain tlie negative; who con-

. * Hume's Essaysy vol. i. p. 110,

10 Uevolutions and Improvements

tend, that although this period has been abundantly
productive of new theories, specious plans, and
oppositions of science falselij so called; yet that
little, if any thing, has been done toward the cul-
tivation of solid learning and real science, since^
our fathers of the seventeenth century fell asleep.
h\ the opinion, and in the language of such, the
present ' race of men are " a generation of triflers
and profligates, sciohsts in learning, hypocrites in
virtue, and formalists in good breeding ; wise only
"when they follow their predecessors, and visionary
fools whenever they attempt to deviate from, or
go beyond, them.'* Wit^h these cynical critics
novelty is degeneracy ; and every thing which
bears the name of invention, discovery, or im-
provement, is useless, if not dangerous innovation.
But this indiscriminate opposition to the claims of
modern times is evidently dictated rather by pre-
judice, than by enlightened views and impartial
observation. Though a change of circumstances
may produce dillerent degrees or kinds of excel-
lence in the elforts of intellect ; yet the native
powers of man are doubtless the same in all ages.
It must- be admitted, indeed, that in some of the
branf:hes of human knowledge the last age has added
but little to the attainments of the preceding; and
that many things which superficial readers consider
as new, were long since familiarly known, and as
well practised as at the present day. In works of
genius, there seems no good ground ta represent
the ])resent generation as possessing any peculiar
or transcendent excellence^ Perhaps a candid in-
fjuirer would even say, that in this respect we
rather fall below than rise above the standards of

in Scie?ice, Arts, ajid Literature. 1 1

former times ; and for this fact plausible if not sa-
tisfactory reasons may be assigned. But still,
amidst multiplied false theories, and much pompous
jargon, which have been too prevalent in the world
during the last century; though the field of enter-
prise, ,in this department of human exertion, has
been more remarkable for the number of labourers
employed in it, than for the success of their la-
bours 'y though luxuriant foliage, more than sub-
stantial fruit, has abounded ; yet much, within this
period, has been doile. New and important truth
has been elicited : discoveries of a highly inter-
esting nature have been made : systems of philoso-
phy have assumed a more regular, consistent, and
dignified form : and various departments of learn-
ing have been purged of the dregs, and rescued
from the rubbish, with which the ignorance and
the inexperience of former times had encumbered
them.

At the close of the seventeenth century the
stupendous mind of Newton, and the penetrating
genius of Locke, had laid their systems of matter
and of mind before the world. Like pioneers in
an arduous siege, they had many formidable ob-
stacles to remove — many labyrinths to explore —
and the power of numberless enemies to overcome.
But they accomplished the mighty enterprise.
With cautious, but firm and dauntless step, they
made their way to the intrenchments of fortified
error ; they scaled her walls , forced her confident
and blustering champions to retreiit ; and planted
the standard of truth, where the banner of igno-
rance and of falsehood had so long waved.

It can scarcelybe supposed, indeed, that these great

12 Rcvoluticns and Impi'ovements

men taught nothing hut the truth, and far le:ss that
they taught the zvhole truth. They were falhble
mortals. They were liable to err. They did err.
But their achievements in the respective regions of
knowledge which they explored and cultivated,
were so splendid, as to command the admh^ation
not only of their countrymen and contemporaries,
but of the civilised world, and of posterity. Be-
side all the light they individually threw on the
departments of science which they undertook
to investigate, each commencied, or rendered po-
pular, a mode of philosophising in his particular
sphere, equally new, grand, and interesting; and
they may be said to have laid the foundation of
all the ma2:nificent structures that have been
since erected.

To Newton no successor has hitherto appeared.
The chair which he left has never since been filled.
It is probable no effort of the human mind, to rear
a rational and permanent system of philosophy, was
ever attended with such a degree oi success as that
which he made. Certainly no other system ever at-
tained such extensive and undisputed empire in
science. It is founded on principles so precise,
connected, and hrm ; it explains, with such lumi-
nous clearness, most of the phenomena of the hea-
vens whicii had been observed before his time, as
well as of those which the persevering industry, and
the more perfect instruments, of later astronomers
have made known ; and instead of being under-
mined or discredited, has been so remarkably
illustrated and conhrmedj by the labours of subset
(juent inquirers ; that every thing like efficient oppo-
i^ition seems to have been long since given up ; and

ill Science^ ArtS:, and Literature. 13

the admiring world appears no longer to hesitate
in placing the discoveries of this wonderful genius
among the most important that were ever made
by man, and among the very few which may justly
lay claim to immortality.

And if the intellectual system of Locke have
gained a sway less general and potent, than th(?
physical doctrines of his great contemporary ; still,
perhaps, his genius ought to be considered as but
little inferior. A\'hat though a {^w respectable me-
taphysicians, since his day, have pointed out some
errours in his principles, and suggested some valua-
ble improvements in his philosophy of mind ? They
were taught by him to think and to reason. They
stood on ground which his wisdom and diligence
had gained. As long as the human faculties con-
tinue to be objects of study, this illustrious man
must be considered one of the greatest fathers of
knowledge, and his writings as forming a distin-
guished a^ra in the history of science.

But though no, builders in the temple of science
have risen to the same rank with those master
WORKMEN, whose names have been mentioned ;
yet many distinguished men, within the period of
which we are speaking, have contributed their
labours to enlarge, to simplifv, to strengthen, and
to adorn the edifice, with honourable success. Of
these, time would fail us to recount even the prin-
cipal names. The most general and superficial
views only of their laudable achievements can be
faer^ giyen.

14

CHAPTER I.

MECHANICAL PHILOSOPHY.

U NDER this general head is included the whole
of that extensive branch of science, " which ex-
plains the sensible motions of the bodies of the
universe, with the view to discover their causes, to
account for subordinate phenomena, and to im-
prove art." In this department of science, the pro-
gress of the last century has been astonishingly
great. New fields of inquiry have been opened 3
splendid discoveries have been made; and facts,
apparently discordant, have been connected and
systematised, to an extent which does signal honour
to human capacity, and wdiich far surpasses what
the most sanguine projectors of former times had
reason to anticipate. And the paths to yet farther
improvements in this science are so clearly marked
out, that nothing seems requisite but honest in-
dustry, patience, and persevering attention, to en-
able future adventurers to penetrate into regions of
knowledge, at present far removed from the sight
of man.

Though the Newtonian Philosophy is, perhaps,
one of the noblest products of human genius ever
given to llie world ; yet that great interpreter of
nature was by no means free from mistake, wiiich
b'jsets and characterises all human labours. — His

Chap. I.] Mechanical Philosophy. \d

errours, which probably, all things considered,
were as few as ever mingled themselves with
so extensive and important a system, were, some
of them, corrected by his successors; who, wiiile
they could distinguish spots in this luminary
of science, yet were not backward to pay due
homage to his general and splendid excellence. —
But, though he had many philosophical adversaries,
who called in question his right to the honour of
certain discoveries, and vv'ho opposed particular
doctrines, there were ^ew who ventured to declare
war against the leading principles of his system.
This however was done by some, respectable both
for their learning and talents.

Among these, perhaps none are more worthy
of notice than the celebrated John Hutchinson *„
of Great Britain, and his followers, who occupy a
considerable space in the scientific history of the
eighteenth century. Mr. Hutchinson, dissatisfied
with the prevalence of Newton's opinions, and^
perhaps, feeling some envy at his extended fame^
undertook to disprove the doctrines displayed in
his Principia, as hostile to revelation, and, of con-
sequence, false. To effect this, he published, m
1724, the first part of a large and learned work,
which he called Moses's Principia, in which he
ridiculed the doctrine of gravitation as impious and
absurd; and in 1727, the second part, in which he
delivered what he supposed to be the true prin-
ciples of scripture philosophy. This singular phi-
losopher taught; that the sacred writings are in-

* Born in Yorksliire, in 1674, and died in 1/37. He was,,
V;ljidoubtedly, a man of respectable talents, and great learning.

16 Mechanical Philosophy. [Chap. L

tended to instruct ns in all physical as well as
moral and spiritual truth : that the Hebrew text
of the Bible is not only, in every respect, entire,
as it came from God; but also that every word of
it is pregnant with philosophical, as well as theo-
logical, meaning. Hence his hypothesis is chiefly
founded on arbitrary and fanciful interpretations
of Hebrew words, from the hidden meaning of
which he and his followers supposed themselves to-
have drawn the richest stores of various kinds of
knowledge.

According to Hutchinson, " all things are con-
tained in the substance of God, and his substance
extends to infinite space. Heaven and earth,
space and matter, are created things, and consist
of solid atoms; those of the earth adhering in
bodies or dense fluids — those of Heaven in orbs,
darkness, fire, light, and clouds. The universe is
full of these solid atoms: in other words, crea-
tion is a plenum. The matter of the heavens is
fluid ; it is also tniite, and has circumferential
limits or extremities, though it extends through
all created space, from the sun, its centre, beyond
the remotest fixed stars. This matter of the hea-
vens consists of sphi't, or air, light and ^fire, as
three of its principal modifications. The sun is
the fire-place which sets all this matter in motion,
melting, expanding, and throwing it off to the
most distant confines of creation, where it is
cooled, consolidated, and pressed back again, to
be melted anew, and sent forth a second time;
and so on. The solid atoms are of different sizes
and figures ; so that, when one portion of them
congeals, or forms into grains, there arc pores

Chap. I.] Mechanical Philosophy. 17

among them large enough to permit atoms of a
smaller size to pass freely through. The condi-
tion of the matter of the heavens, under the ac-
tion of fire at the sun, was chamah; the stretims
of light from the sun, moon, and stars, were
ashteroth; and the grains of air returning fiom
the circumference of the heavens to the sun, were
baalim. Concrete matter, however, is often so
constituted as not to be permeable \ciy easily,
but to resist. The several sorts of atoms cOiU-
posing the fluid matter which occupies iminea-
surabJe space, are the moving powers by winch
God acts upon ai>d regulates the machinery of
the universe. The more compact or unyielding
modifications of it constitute the great orbs, or
machines, to be urged along by their impulse.
Tiie latter are the chariots, and the former the
drivers. When, therefore, light, impelled by the
sun, strikes the side of such a body as the earth
we inhabit, it excites heat in that part, and the
spirit, or air, being rarefied, or made to recede
thereby, motion is communicated to the whole
orb. The motion thus begun, is promoted and
continued by the vast and incessant pressure of
the dark, cold, and dense matter on the opposite
side. And thus the globe being started by the
lessening of pressure on one side, and the aug-
mentation of it on the other, its diurnal and an-
nual revolutions were soon impressed upon it by
a little variation of tlie forces. The like reason-
ing he applied to the moon, and to all the other
planets and their satellites. By the operation of
lightj thus sent out from the sun, and acting upon
the other fluid matter of the heavens, and upou
Vol. I. C

18 Mechanical Philosophl/. [Chap. I,

the celestial orbs, they become enlightened, waiin-
cd, or inflamed: spirit, or air^ pushed in with
irresistible compression ^ and motion, rotation,
and progression were accounted for, without
having recourse to such miserable terms as pro-
jection, gravitation, or attraction*.'*

These vv^ild and fanciful opinions attracted much
attention in Great Britain, and were embraced by
some learned and respectable men ; especially by
those who entertained the groundless fear, that
Newton's system of philosophy was hostile to reve-
lation. Among these the celebrated Parkhurst,
bishop Home, and the rev. Mr. Jones of Nay-
land, were, perhaps, the most able and distinguish-
ed.— But, notwitlistanding the weight of a few
names, which appeared on the side of this hypo-
thesis, before the close of the eighteenth century
it had lost a large portion of its advocates; and
both the admiration and the knowledge of Hut-

* After examining, with considerable care, Hutchinson^s
Works, in 12 vols Svo, printed in 1/48, I did not dare to under-
take the arduous task of exliibiting the opinions scattered through
his erudite but obscure pages, in a short compass, and in my own
language. I have therefore taken the above abstract from the
Medical Repository, vol. iv, pp. 281,282. Those who wish to-
obtain a farther knowledge of the peculiar notions of this singular
man, witbjut the trouble of wading through his dull and tedious
volumes, will find a tolerably distinct and comprehensive account
oi' ihem, in the State of the Republic of Letters, kc, vol. v, for die
year l/'iO. See also Addltiomd Notes — (A). It i^ curious to
observe, that while the ilutchinsoniuns so libendly censure the
followers of New ton for giving too much activity to matter, they
fall into the same error (as they call it) in an equal degree. But,
in truth, if Xewton'j idea of uttrnctiic poncr be examined, it will
be found only another mode of expression for a continual Divine
vgcncy, cxrrted accordini^ to a certain law.

Chap. I.] Mechanical Philosophy. 19

chitlson*s voluminous writings had nearly disap-
peared*.

Another opponent' of the Newtonian system was
Godfred WiUiam Leibnitz, a philosopher of Lcipsic,
in Germany, whose celebrated theory demands our
notice. He taught that the whole universe is
made up of monads, that is, simple substances with-
out parts or figure, each of which is, by the Creator,
in the beginning of its existence, endowed with
certain active and perceptive powers, sufficient to
produce all the changes which it undergoes, from
the beginning to eternity ; which changes, though
they ma}^ seem to us to be the effects of causes
operating from without, are only the gradual and
successive evolutions of the monad^s own internal
powers, which would have produced the same mo-
tions and changes, although there had been no
other being in the universe. He supposed, farther,
that the universe is completely filled with monads,
without any chasm or void, and thereby every
body acts upon every other body, according to its
vicinity or distance, and is mutually reacted upon by
every other body ; hence he considered every mo-
nad as a kind of living mirror, which reCccts tlie
^vhole universe, according to its point of view, and
represents the whole more or less distinctly. The
adoption of this visionary system led Leibnitz to
oppose, with considerable warmth, several of tne
leading doctrines of Newton, and espec ally his
great principle of gravitation. Tiie hostility of tlie
German philosopher toward the illustrious Hntou
was particularly displayed in his contiovci jy with

* See Additional Notes — (B).
C 2

^6 Mechanical Philosophy. [ChaI*. I.

the learned and acute Dr. Samuel Clarke. Tho
papers which gave rise to this controversy, toge-
ther ivith the various answers, replies, and re-
joinders which took place in the course of it, were
transmitted from the one party to the other,
through the hands of queen Caroline, consort of
George I, and the patron and correspondent of
Leibnitz. They were afterwards published, and
hold an important' place in the philosophical his-
tory of the age.

Soon after the theory of monads was published.
Christian Wolfe, a philosopher of Breslau, formed,
on the foundation of this theory, a new system of
Cosmology, digested and demonstrated in a mathe-
matical method. He was one of the most volu-
minous writers in philosophy which the century
afforded, and is considered as the great interpreter
and advocate of the Leibnitz ian system-.

Another theory of matter^ which distinguished
the eighteenth century, was that of Father Bosco-
vich *, a learned Jesuit of Italy. — Newton paid
little attention to the individual atoms of which
matter is composed. The attraction and repulsion
of which he spoke, appear to refer chiefl}^ to the
laws of motion of the larger bodies which we be-
hold. He expressed a suspicion, indeed, that " As
ihe great movements of the solar system are regu-

* Roger Joseph Boscovidi was born at Ragusa in 1/11, and
died at Milan in l/b/. When the order of Jesuits was sup-
pressed, he was invited to Paris, and made director of the optical
instruments of the marine j in which office he was led to im-
prove the tlix;ory of achromalic glasses. He returned to Italy in
1/83. His philosophical works ai'c numerous, profound, and ele-
gant. He published a poem, entitled, Dc Solis ac Luna Dcfec*
tibiis, which is hii^hly esteemed.

Chap. I.] Mechanical Philosophy, 21

lated by universal gravitation ; so the mutual ac-
tions of the particles of matter are produced and
regulated by tendencies of a similar kind, equally,
but not more, inexplicable, and the principles of
yvhxch. are to be discovered by as careful an atten-
tion to the phenomena, and by the same patient
thinking w^hich he had employed on the planetary
motions." But he seems to have willingly yielded,
to some abJe and diligent inquirer who should come
after him, both the labour and the honour of ex-
ploring this extensive field of speculation.

Such an inquirer was the illustrious Boseovich, a
man equally distinguished for the purity of his
moral and religious character, the depth of his eru-
dition, and the native vigour and acuteness of his
.mind. A iew years after the death of the great
British philosopher, he published a new theory of
matter. In this theory, the whole mass of which
the bodies of the universe are composed, is sup-
posed to consist of an exceeding great, yet fmite,
number of simple, - indivisible, inextended atoms.
These atoms are endued by the Creator with re-
pulsive and attractive forces, which ^ ary according
to the distance. At very small distances the par-
ticles of matter repel each other; and this repul-
sive force increases beyond all limits, as the di-
stances are diminished ; and will, consequently, for
ever prevent actual contact. When the particles
of matter are removed to sensible distances, the
repulsive is exchanged for an attractive force, which
decreases in an inverse ratio with the squares oi the
distances, and extends beyond the sphere of the
most remote comets. Beside these repulsive and
attractive forces^ the particles of matter have that

03 Mechanical Philosophy. [Chap. I.

vis inertiie which is admitted by ahuost all modern
philosophers. These atoms, endued with these
forces and properties, form the basis of this cele-
brated system; a system unquestionably among
the most remarkable that have been proposed to
the world in modern times, and which leads to
consequences in a very high degree interesting*.
This system has been, in substance, adopted by
many of the learned in various parts of Europe ;
and is supposed, by those who embrace it, to af-
ford a veiy satisfactory solution of many difficulties
to which former theories evidently gave rise; to
explain most happily the various phenomena of
matter to which its principles extend ; and to re-
ceive confirmation by the experiments and disco-
veiies of every day. If we may rely on the doc-
trines of the ingenious ItaHan, the stumbling-blocks
of the infinite divisibility and impenetrahililij of
matter will be taken oat of the way ; many of the
most fruitful sources of perplexity and dispute re-
specting extension, elasticity, &c. will be cut off;
a large portion of the difficulties attending the
ajjiniiies, attractions, and combinations in chemical
philosophy, hereafter to be noticed, will diminish,
if not disai)pear ; and the path to a just understand-
ing of all the physical sciences will be simplified
and smoothed in a very pleasing degree |.

* See Jdditional Notes — (Cj.

f The author has never yet been able to procure a copy of the
'Yhcoria Philosopftut Naturalis oi' Boscovich, published hi J 758;
but a \ ery satisfactory abstract of tlie work is given in the Supplt^
mmt to the Encijclopivdla, JatcJy pubHshed by Dr. Gl^g. The
system is, in some of its parts, so intricate, and throughout so in-
volved in fpathcmatical calculation, that a more full account of it
could not be given in the present skQtch. It is charged, by soniOj

Sect. I] Electricity. S3

But, beside these new theories and ingenious
.discussions, respecting the general principles and
properties of matter, ahnost all the particular de-
partments of mechanical philosophy have been
investigated with great diligence and success,
Ihroughout the whole of the period under consi-
deration.

SECTION I.

ELECTRICITY.

Concerning Electricity, that powerful and still
n^vsterious agent, philosophers of the last age have
made splendid discoveries. At the beginning of
the eighteenth century, this branch of science
could hardly be said to have a place in systems of
philosophy. Its phenomena had been so little the
subject of experiment, and its laws had been so
little comprehended or methodised, that scarcely
any thing which deserves the name of theory on
the subject, was then presented to the workl. It
is true, a number of facts were then known, and
some experiments had been made, in order to elu-
cidate this dark recess of science. But they were
known, for the most part, only as insulated facts,
without any correct idea of the relation siii)sistin.2:
between them, or of the general principles upon
which they depended. The principal of these facts
had been brought to light by Dr. Gilbert, Mr. Boyle,

^^itll having an atheistical foundation and tendency. Of t]\o
ground of this charge too Uttlc is know n hy the writer to attempt,
a dibcussion of it.

9i Mechanical Philosophy, [Chap. L

and sir Isaac Newton; but they continued to lie
in uncertainty and confusion, until 1709, when
Mr. Hawksbee, an English gentleman, wrote on
the subject, and distinguished himself by the ex-
periments and discoveries which he announced.
He first took notice of the great electric powers of
glass, together with a variety of phenomena relat-
ing to electrical attraction and repulsion ; insomuch
that his writings and experiments form a grand sera
in this branch of knowledge. From the time of
Mr. Hawksbee's publication, near twenty years
elapsed before any farther discoveries or improve-
ments were suggested.

In 1729, the fundamental distinction between
conductors and 7ionconduciors was first ascertained
by Stephen Gray, a i3ritish philosopher, who had
for some time before amused himself with electrical
experiments, and who was now accidentally led to
the discovery of this important principle. Soon
afterwards M. du Fay, member of the Academy
of Sciences at Paris, in repeating Mr. Gray's ex-
periments, unexpectedly perceived, for the first
time, that dilference in the attractive powers of
different bodies, which he supposed to arise from
two different species of electric fluids, and which
he denominated the vitreous and resinous electri-
cities. Tlie drawing a spark from the living body
was also first observed by this gentleman, and his
companion, tlie abbe Nollet. The next person
who distinguished himself in this part of science
was Dr. Desaguliers, who, though he added but
little to the knowledge before possessed, yet made
some valuable experiments, and invented some
iechnical lerms^ such as conductor, electric per se, (S( c..

Sect. L] ElecfrkUij. ^

which have proved highly convenient, and are still
iu use. About 1742 electricity began to excite
attention, and became the subject of much inquiry
in Germany. Professor Bozc, of Wittemburgh,
and professor Winckler, of Leipsic, invented several
improvements in tiie apparatus for conducting ex^
periments. Dr. Ludolf, of Berlin, first succeeded
ill setting fire to inflammable substances by the
electric fluid ; and Mr. Waitz, Mr. Allamand,
and others, made some new observations, though
chief] V of the smaller kind. To the experiments
in Germany succeeded those of Dr. William \A'at-
6on, in Great Britain. He first ascertained that
the friction of an electric did not produce, but only
collectedy the mysterious matter which wrought
such powerful effects ; and also made a number of
other interesting additions to the knowledge before
existing on the subject. The year 1745 was di-
stinguished by a discovery still more remarkable
and important than any that preceded it — viz. the
jnethod of giving a shock, by accumulating the
electric fluid in ajar, and discharging it by means
of a conductor. Tiiis discovery was made by
Mr. von Kleist, dean of the cathedral in Camin;
and the next year the experiment being repeated
in a dilYerent manner, and with better success, by
Mr. Cunocus, of Ley den, the jar so filled became
generally known by the name of the Leydai phial^
which it has retained to the present day. Suoa
afterwards, Mr. Gralalh, a German, first contrived
to increase tlie shock by charging several phials at
the same time, and making what is now called a
'battery.

About the same time experiments began to be

26 Mechanical Philosophy. [Chap.!.

made of the effects produced by electricity on
finimal bodies. In these inquiries the abbe Nollet
greatly distinguished himself. He pursued his in-
.vestigations with singular ingenuity, labour, and
expense; and opened a new and noble field of
electrical discoveries. The application of electri-
city to gro'\\'ing vegetables was first made by
Air. Maimbra;^, of Edinburgh, ^vho found that, in
certain cases, it expedited the progress of vegeta-
tion. In these experiments he was followed by
tlie abbe Nollet, M. Jallabert of Geneva, Mr. Boze
before-mcnUoiied, and a number of others on the
continent of Europe, who all drew the same con*
elusions*.

In the midst of the general attention, and the
deep interest which this subject now began to ex-
cite throughout the philosophic world, Dr. Frank-
lin, in 1752, after ha\ing been for some time en-
gaged iu making new and interesting experiments,
discovered the identity of the electric fluid and lights
ning-f-y a discovery of the greatest practical utility j

* See Additional Notes — (D).

t There are persons who believe, but probably without suffi-
cient foundation, tliat ihis fact, and several otlicrs relating to
electricity, generally supposed to be modern discoveries, were
known to the ancients. Those who wish to see tliis opinion in-
geniously and learnedly defended, w^ill be gratified by a perusal
of M. Duteub' work, bi-fore quoted ; and also, an interesting paper
in the Memoirs of the Literary and Philosophical Society of Man-
chester, vol. iii, by William Falconer, M, D. F. R. S. To which
may be added a curious passage in signer Boccalini's Advertise-
vtcntsfrom Parnassus (Century 1, Chap.-iO,) published more than
one hundred years before the date of Franklin's discovery. For
a reference to this passage, I ajii indebted to the rev. Dr. Nisbet,
president of Dickinson College, Pennsylvania ; -a gentleman
whose profound erudilioUj embracing the literature and science

Sect. I.] Electricity. 57

and, perhaps, tlie only one, in the science nmler
consideration, which was the result of preconceived
opinion, and of experiments instituted witli an ex-
press view to ascertain the trutli. Dr. Frankhn's
ideas were soon afterwards conhrmed by Messrs.
Dahbard and Dclor, of France ; who had come to
a similar conclusion before they were informed of
what had been done on the other side of the Atlantic.
The same illustrious Amei'ican also first discovered,
in conjunction with his friend Mr. Thomas Hop-
kinson, the peculiar power of pointed bodies to
draw olf the electrical matter more effectual ly, and
at a greater distance, than others; founded on
w^hich was his ingenious invention for defending
houses from the destiuctive effects of lightning,
by the use of metallic conductors. About the same
time, Dr. Franklin's friend, Mr. Kinnersly, distin-
guished himself by rediscovering the apparently
contrary electricities of glass and resin, or sulphur,
which M. du Fay had long before observed, but with
the discovery of which he and Dr. Franklin were
both unacquainted *. To solve the difficidty arising
from this fact, the doctor, instead of recurring to
the supposition of two d liferent kinds of electric
matter, as the French philosopher had -done, pro-
posed his celebrated theory of positive and negative
electricity, or the pins and minus states of bodies
charged with this fluid ; a theory which had been
before suggested by Dr. Watson, and which was

pf almost all cultivated languages, is well known to tlie public ;
and with wliOhC friendship I consider it one of ihe most happy cir-
cumstances of my life to be honoured.

• * See Experiments and Observations on Electn'citi/, &c., b)' Ben-
jamin Ffaiikhn, LL.D. F.R.S. London, 4Lo. l/oy.

558 Mechanical Philosophy. [Chap. I.

afterwards generally received throughout the scien-
tific \^'orld ; and, though by no means without op-
position, still continues to hold a more extensive
influence than any other.

Electricity seems to have been first applied to
medical purposes by Mr. Kratzenstein, professor
of medicine at Halle, in 1744. From that period
it gradually grew into notice, by means of the ex-
periments of the abbe Nollet, Jallabert of Ge-
neva, Sauvages of Montpellier, Bohadsch of
Prague, Dr. Watson before mentioned. Dr. Frank-
lin, and many others. The medical virtues of this
wonderful fluid soon excited attention and inquiry
throughout the scientific world. And although
the repetition of experiments, which has been con-
stantly going on from that period to the present,
has served to correct many errors into which the
enthusiastic fell in the beginning; yet electricity,
^fter undergoing many revolutions of fashion, is
now well established as an important article of the
Materia Medica.

After the interesting discoveries of Dr. Frank-
lin, the next great experimenters and discoverers
in electricity were Mr. Canton of Great Britain,
signor Bcccaria of Italy, and Mr. Wilcke of Ger-
many, w ho considerably enlarged the sphere of our
knowledge respecting the conducting powers of
different substances, and threw farther light on
t\\Q plus and minus states of electrics. The doc-
trine of Franklin, that these two states arise from
a redundancy or deficiency of the same matter,
was but little opposed, until 17»59, when Mr. Sym-
mer, an English philosopher, revived the ideas of
du Fay, w.ith .squic new .modifications of his own»

Sect. I.] Electriciti/. gg

He taught the existence of two electric fluids, not
independent, but always coexistent, and coun-
teracting one another*. In this opinion he 1ms
been followed by some gentlemen of very respect-
able ciiaracter in Great Britain and on tlie con-
tinent of Europe ; though by far the greater num-
ber of the learned appear still to be in favour of
the Franklinian theory f.

The progressive improvements of electrical ma-
chines, and of the various instruments for exhibit-
ing the phenomena of this science, have generally
kept pace with the gradual developement of its
principles. Hence the honour of tliese improve-
ments is, in general, due to the gentlemen already
named. Beside these, several artists of respectable
character have done much to forward the mecha-
nical part of this branch of philosophy.

Soon after the grand discoveries of Franklin,
Mr. ^^pinus, a philosopher of high character in the
Imperial Academy of St. Petersburg, assuming
his principles, offered to the world some new and
interesting views on this branch of science. Struck
with the .resemblance between the phenomena of
electricity and magnetism, and believing that the
attractions and repulsions of each might be reduced
to regular and similar classes, he attempted to
throw the laws of both into a perfectly systematic
form, and to introduce the most precise matlienia-
tical calculations into regions w hich were before

* See Additional Notes — (E).

f The above-stated flicts, relating to the ii?e and progress of
electricity, are chietly taken from Dr. Fdestiey'a liisiory vf JHec^
trieiti/, 1/94., London^ 4to.

30 MccJianical Philosoph}/, [Chap, L

supposed, from their indefinite and mysterious
character, least of all susceptible of being explored
in this manner *. It is believed by many, that this
hypotliesis, to the uncpiestionable claim of inge-
nuity adds that of being foimded in truth ; and
that it will probably lead to the solution of many
diificulties hitherto deemed insolvable. However
this may be, it must be confessed the ingenious
Russian has enabled us, by his mathematical prin-
ciples, to class many of the phenomena of which
he treats, with a plausible precision, and to pre-
dict the result of proposed experiments with very
pleasing success f.

During the last thirty years of the eighteenth
century, though it cannot be said that so much has
been done in electricity as in the like period im-
mediately preceding; yet several important disco-
veries, within that time, have been announced.
The inventions of the clecfropJioruSy and the con-
ikniscr, by professor \^olta, and of the douhler of
electricity, by the rev. JSIr. Bennet, of Great
Britain ; the discovery of the effects produced by
the electric matter on permanently elastic fluids,
and on water, by Mr. Cavendish, and others ; and
the new results of experiments, with respect to
the influence of electricity on vegetables, by Dr.
Ingenhousz, and Messrs. Ilouiand, d'Ormoy, Car^
moy, and others, of France, may be considered
among tiie most interesting of recent improve-

.* See AdiUtiomil Notes— CF).

f See 'Ihcoriu Elcctricitutis ct Ma^netlsmiy 175f), Petersburg,
4to. See also a good abst' .ici of tiu- v-.uetrines ot >i:i^piuus, m the
SuppUmc/it to the J'JLj/iidpiLilui, pubu.:.iied by Dr. Giei^.

Sect» II.] Galvanism. 31

ments*. Mr. Cavendish and lord Mahon are the
only disthiguished writers on electricity, in the
English language, who have attempted, like iEpi-
mis, to introduce the mathematical form of inves-
tigation into this science. The publications of
Dr. Priestley, Mr. Cavallo, and Mr. Adams, on the
subject, are also worthy of honourable notice. The
first, beside his excellent History of Elcctricitijy
instituted a number of original experiments ; sug-
gested many important inquiries^ improved the
electrical apparatus ; and, on the whole, did much
to advance our knowledge of this branch of philo-
sophy. The latter gentlemen, in addition to many
new experiments, have presented to the world
condensed and very satisfactory views of the sub-
ject, both in a philosophical and 'medical view, and
have contributed much to render it popular and
useful

SECTION II.

GALVANISM.

To this chapter belongs some notice of that
principle, or influence, discovered a few years ago
by Dr. Galvani, a philosopher of Bologna, and
since, in honour of him, denominated Galvanism.
It was first called A7ii??ial Electricity, a name which
had been, for a number of years before, given to

* For a more full account of the above recent di^'coveries and
improvements, see the last vol. of Cazallo's FlectrlcUy, 3 vols,
8vo edition 1/95, and the art, £lectnciti/ in the Encj/clopadia,
and t}i& Siipplf'^icnt,

S2 Mechanical PJiilosophy. [Chap. Iw

a rcmarkal)Ie property observed in several fished,
of conveying a shock, or a benumbing sensation,
to those who touched them *. But this property
was always found to be extinct or dormant in such
animals immediately after their death f. In 1762,
Sulzer, a German, in his Theory of agreeable and
disagreeable Sensations, gave some hints of a curi-
ous effect resulting from the junction of two pieces
of different kinds of metal, and applying them,
thus joined, to the tongue; but these hints seem
to have been disrej^arded, and were soon buried in
oblivion. In 1791 professor Galvani announced a
discovery made by hiin, that the muscles of dead
animals might be stimulated and brought into ac-
tion, by means both of artificial and atmospherical
dectricity. He also discovered, that, independent
of any collection of the electric fluid for the pur-
pose, the same action might be produced in the
dead animal, or even in a detached limb, merely by
making a communication between the nerves and
the muscles with substances that are conductors of
the electric matter J. Galvani*s first experiments
were made on de^di frogs ; but the discovery, soon
after being announced, was pursued ; experiments
were made on different animals ; and a number of
new facts, tending to show the connexion betvvcen
Galvanism and electricity, and the circumstances

* These are the torpedo, tlie gymnotiis clcctrkus, tlie sifunm
ckctricKs, and a fourth, found near one of tJic Co7noro islands, by
lieut. William Patterson, of A\hich an account is given in the
7C>lli vol. of the Philosophical Transaciiom.

t See Additional Notes — (G).

X Aloj/sii Galvani de Viribus Electric iiatia, Sec. 4to, BonoDiac,
i7yi'

Sect.II.1 Galvaiiism. 53

ill' which they differ, were brauglit to light by
professor Volta, and Dr. Eusebius Valli, pf ItaJy;
by Mr. von Humboldt, and Dr. Ptaff, of Germany i
by Dr. Munro, Dr. Fowler, Mr. Cavallo, and Dr.
Lhid, of Great Britain ; and by Coulomb, Four-
croy, Sabbatier, P^lletan, and others, of France.

Hitherto this influence or agent had been chiefly
investigated with reference to its operation on
animal substances. Flei\ce its popular name was,
for a considerable time, animal electricity. But it
being soon found, that its agency was more exten-
sive; that it possessed pov ers not indicated by
this denomination ; and that of course the reten-
tion of this name would lead to error, the word
Galvanism was adopted in its stead. This exten-
sion of the Galvanic principle was connected with
new discoveries and improvements, from various
quarters ; these, however, for a considerable time,
were generally small, and unimportant in their
nature.

But among all the recent discoveries in Galva-
nism^ that made by professor Volta, in 1800, is
most remarkable in its nature, and most interest-
ing in its relations. His mode of constructing a
pilCy for condensing, retaining, and communicating
a perpetual current of the Galvanic injluencc, is
generall}^ known*. The curious phenomena which

* The pile of Volta is thus formed. Take a number of plates
ofsUver, an equal number of zhw, and the same number of pieces
of card or tvoollen cloth. ].,et tJiese last be uell soaked in v:ater,
or water saturated with common salt, or, which is perhaps still
better, with nitre. A. pile is then to be formed of these sub-
stances, in the following manner. A piece of zinc, a piece of
silver, and a piece of wet cloth or card, arc to be succes^-ively

Vol, I. D

:Si Mechanical Philosophy. [Chap, I.

this pile exhibits; the coiinexiion which these phe-
nomena indicate with the principles both of elec-
tricity and of chemistry ; and the nmnerous expe-
riments and siiccef^sive improvements in the ma-
nagement of tliis Galvanic battery by .Me3sr$. Car-
lisle, Nicholson, Crnickshank, Davy, and others,.
of Great Britain ; by van Marum, of Holland ;
and by Fourcroy^ \'auquelin, and Thenard, af
France, have not only excited much attention in
the scientific world, but may also be ranked among
tlic rich additions to philosophy which modern
times have produced.

-It must be admitted, however, that little more
has been done,, in this new branch of philosophy,
tlian to ascertain a number of facts, sometimes

placed. on each other ^ tlien another piece of ziiic, aiad so on in
the order of the first layer. In this manner, the pieces are to be
arranged, or in any other manner, provided a regular alternation
l)e oliserved, until the requisite number shall be laid. The in-
urnment is then lit for use. The pieces of card should be- some-
^ iiat less than the pieces of metal, and, after being well moisten-
"t.!, should be gently squeezed before they are applied, that the
superfluous moisture may not run down the pile, or insinuate
ithclf between the pieces of metal.

U he instrument constructed in this manner affiords a perpetunl
cuncnt of the Galvanic influence ; and if one hand be applied t€?
tlie lov.est plate, and another to tlie uppermost, a shock is felt, a?
often as the contact is repeated. The shock received fronj thi^'i.
pile is somewhat like that ' given by a Leyden phial ; but more
nearly resembles that given by a Toi^cdo, w hich animal this appa-
ratus also resembles in giving incessant shocks. The inteilsit)^ of
tlui charge , is, Jio\ve\ er, too small to make its way tluougii .the
dry skin. J it. is Lliereforc necessary that each hand should be well
v.clted, and a piece of metal be grasped in each to make tlie
LoucJi ; — and the larger the piece of meud' which is thus l^eld in
the hand, the stronger ihv. shock. Garaett's Mfuils of Phihsi
\u\. i, p. 10, Uc.

Sect. II.] Galvanism. 55

contradictory in their aspect, and generally inex-
plicable, without either forming a theory sutlici-
ently fixed or luminous to satisfy the inquirer, or
instructing us in what manner this principle may
be applied for the benefit of mankind*. Professor
Galvani, signor Volta, and several other distin-
guished experimenters, have supposed the Gal-
vanic phenomena to arise from. the operation of
the electric fluid. They observed that this sub-
stance seemed to move with rapidity ; that it pro-
duced a sensation similar to the electric shock ;
that it passed with facilit}^ through metals, and
other conductors of electricity ; while it was stop-
ped in its course by glass, sealing-wax, and other
substances which we know to be nonconductors
of the electric matter. Others, on the contrary,
observing several phenomena, which were thought
to be incompatible with the known laws of electri-
city, or inexplicable by them, have rejected this
opinion, and resorted to difterent means of solving
the difficulty.

M. Fabroni, who made a number of ingenious
experiments in Galvanism, was the first who sys-
tematically attempted to prove that the eft'ects
which he observed arose from chemical .causes f.
This opinion has led to much curious investigation;
and various experiments evince that the ag^nt in
question produces, most powerfully, some effects,

* Since the above was written, very curious information has
been received from Germany, respecting the application of (^a/-
vanism to medical purposes. It appears to possess great etficacy
in removing many diseases arising from nervous derangement and
muscular debility.

t See Nicholson's JPhilosophical Journal, vol. iii, p. 308.
D2

36 Mechanical Philosophy. [Chap. I.

])artiinilarly decomposifions, which have been hr-
tlierto considered as belonging to the province of
chemistry alone *. At the close of the century this
question was far from being satisfactorily solved.
But as the subject has excited so much attention
among philosophers, in every part of Europe, and
as new facts will probably be brought to light
every day, we may hope that the time is not very
distant, when a sufficient number of facts will be
arranged to form a consistent and satisfactory
theory, and when Galvanism will take its place
among the most dignified and useful of the
sciences f.

SECTION III.

MAGNETISM.

This branch of philosophy, during the same pe-
riod, has been an object of less attention than elec-
tricity, and of fewer speculations j probably on ac-
count of the smaller range of its phenomena, and
its being less capable of popular exhibition. Still,
however, it has been considerably cultivated, and
has received some important improvements, since
the time of Dr. Gilbert, the great father of mag-
net ical philosophy. The number of facts concern-
ing this mysterious kind of attraction has been
greatly augmented. U he points in which it resem-
bles, and those in which it differs from electricity,

' See Atfditiunal Notts — (JI).

t l''<>r further infonnation on this fiubject, see the SupploJient
to tlic Encj/clf)pa;dia, art. Galvanism. See also GarneU'* AiumIs
of Philosophy lor 1 bOO.

Sect. III.] Mai^uc/ism. T;

have been more satisfactoriiy ascertained ; and a
nearer approach made than Ibrmerly to a systema-
tic arrangement of the magnetic laws.

The unexpected and daring introduction of ma-
thematical principles and demonstration into tin;
dark regions of electriciijj, by Mr. /l^pinus, was
mentioned, in a former page, as one of the signal
improvements of the last century, lliis ingeniouji
philosopher has done the same in viagnctistn^ and
with equal success^. And though this subjection
of the magnetic principles to the most precise and
definite of all species of investigation does not ap-
pear to have led, as yet, to any extraordinary dis-
coveries, or radical reforms in tbeory ; yet it has
been by no means without its use, and may con-
duct to invaluable acquisitions f.

The Mariner's Compass, within the period in
question, has been considerably imjjroved. Tliis
important instrument, after its invention in ISOL^
long remained in a rude and imperfect state. But
Dr. Knight's discovery of the mode of making ar-
tificial magnets, about the year 1744, together
with the results of some other experiments, en-
abled him to render the compass much more con-
venient and useful J. To his improvements may be
added the further emendations of Mr. Smeaton and
Mr. M'Culloch, both of Great Britain.

The variation of the magnetic needle has been a
subject of much attention and of much ingenious
speculation, during the past century. The obser-

* Tvntamcn Thcorict Magn. ct Elect r. Pclrop. 1750.
t See Additional Notes — (1).
1 S(^c Additiomil Notes — f/vj.

3$ Mechanical Philosophy. [Chap. I.

vations made by Dr. Halley, and published in
1701, ill the form of a variation char^t, were of
great use to navigators, and contributed not a lit-
tle toward reducing the principles of this variation
to something like an intelligible form. The next
attempt of the same kind, worthy of notice, was
tliat of Euler. This philosopher, equally remark-
able for the extent of his learning, and the vigour
and comprehensiveness of his mind, undertook,
about the middle of the century, to account for the
magnetic irregularities, and to ascertain the posi-
tion of the needle in every part of the earth. He
executed his task with singular ingenuity and per-
severance, and with a plausible appearance of
success. But his theory, and the whole structure
founded upon it, were soon found liable to such
objections, that they were considered of little value,
excepting so far as they might furnish a guide in
the further prosecution of the inquiry. Since the
time of Euler, many others have exerted their ge-
nius in the same investigation; but without pro-
ducing more certainty or satisfaction. Among tlie
Jatest explorers of this dark but important sub-
ject, Mr. Churchman, a respectable citizen of
America, deserves to be honourably mentioned.
He has, in his own opinion, made valuable im-
pro\ ements on the theories of Halley and of Eider ;
corrected various errors into which those great
philosophers fell ; and given an hypothesis which
bids fair to be of more practical utility than theirs
to the nautical adventurer. How soon this hypo-
thesis may be brought to the test of a complete
course of experiments, or how it may bear this
test, when subjected to it, are questions yet to be

SicT. in.] Magnetism. 39

solved. In the mean time, the ingenuity, zeal,
and perseverance, evinced in Mr. Churchman's late
publications on this subject, deserve the attention,
the thanks, and tiie encouragement of the j^inloso-
phic world*.

Many other writers, of acknowledged scientific
eminence, have distinguished themselves by new
experiments, and ingenious hypotheses on mag-
netic attraction, within the period of which we
are speaking. Among these may be mentioned
Muschenbroeck j", Whiston, Celsius J, van Swiu>
den, Lambert §, Euler||, Knight ^f, Mitchel, Can-
ton, and Cavallo. To detail the opinions enter-
tained, and the facts successively brought to light
by each, would far exceed our prescribed limits.
But, after all the inquiries of these philosophers,
it must be acknowledged that " clouds and dark-
ness rest" upon this part of science ; that even its
general principles are little understood; and that
we are yet far from being furnished ^vith materials
for a satisfactory system on the subject. Perhaps
another century may accomplish this, which, when

* See Churchman's Magnetic AtluHy 4to, 3(lt?clitlon, 1800.

f Dissert. Phj/sico-Experijuenlalis de Magncte.

X Tentamina Magnetica, 4to. Also Manoirs on the Analogy hc-
twecn Elect, and J^Iag. 3 vols, 8vo, 1/85.

§ The experiments and calculations of M. Lambert, on the
fiolarity and variations of the magnetic needle, deserve particu-
lar attention. He was a very accurate and sagacious philusij-
pher. See the Memoirs of the Academy of Ikrlin, for 1/ JU, pub-
lished in 1758.

II Euleri Opitscula, torn, iii, conlinens Thcoriam Magnctis, Ber-
lin, 1751.

% An Attempt to explain the Fhenomcna of yadirc hy Tso Prin-
ciples, ^x'. 4 to, 1748.

40- Mechanical Philosophi). [Chap. L

A iewecl in its various relations, must be regarded as
a p\mA desideralum'm. philosophy*.

In 1774 arose the idea of a certain sympathy
c?(isting betwf'n the magnet and the human
bod^ , by means of which the former might be ap-
plied to the cure of diseases. This opinion ap-
pears to have originated with father Hehl, of,
Gernlany, who greatly recommended the use of
the magnet in medicine. On some experiments-
and suggestions of Hehl, the famous Mesmer, a
(jerman physician, about the year I766 erected
Iiis fanciful system oi Animal Magnetism. The noise
made by the opinions and arts of this celebrated
empiric, and his coadjutors, in Germany, in France,
and indeed, though in a less degree, throughout
every other part of Europe, is well known to all
acquainted with the literary history of that period;
as well as the detection, the decline, and the final
disgrace of them and their principles j*.

M. Prevost, of Geneva, in 1788, published a
new doctrine concerning Magnetism, in an inge-
nious and interesting dissertation on the subject.
In this work he expresses a belief that there are
tiio magnetic Jiuuls, which, by their union, com-
I)ose a thinly which he calls combined fluid. These
two fluids, he thinks, are both elastic like air ; the
particles of each attract those of its own kind, but
not so strongly as those of the opposite kind. A
strong elective attraction, which the combined fluid

* See Additional Notes — (L).

t For an amuhing a« count of the noise and pretensions made
by Me.-,mer, see Willicirs Ltcturts on Ditt and Rcgimtn, &c.
Sec also Report of the Coninriishioners appointed by the French
King to examine into Animal Magnetism.

Sfxt. IV.] Motion and Moving Forces. 41

possesses for iron, decomposes part of tlie fluid m
the iron, and each of its ingredients occupies oj)po-
site ends of the bar. Bars in this state approach,
if the ends nearest each other contain dilTercnt in-
gredients, but recede if they contain the same*.

SECTION IV.

MOTION AND MOVING FORCES.

This part of science also, within the century
under consideration, has received no small im-
provement. The laws of motion^ as laid down by
sir Isaac Newton, though found, hy succeeding
philosophers, to be in general correct, were yet by
no means perfectly so. His princi})les of motion
in resisting mediums particularly failed, when
brought to the test of accurate experiment. Nu-
merous have been the attempts to supply the de-
fects, and to correct the errors of these principles :
among which the labours of D. Bernoulli, and of
M. d'Alembert, deserve to be considered as by
far the most distinguished and successful. The
latter in particular, in the course of his investiga-
tions, discovered a general rule, adequate to the
determination of many important questions in the
science of motion, and applying to the most com-
pound and perplexing cases f.

The inaccuracy of Newton's principles, with
regard to projectiles, was first ascertained and an-
nounced by M. Ressons, a French artillerist, in
I7I6. Nothing material, however, was. done to-

* See Essai sur rOn'gine dcs Forces Magniti(^iiC6; l/SS.
t Condorcct on the Mind, p. 2/5.

44 Mechanical Philosoph/. [Chap. L

ward the establishment of new and more just Jaws^
till 1742, when Benjamin Robins, of Great Britain^
published his New Principles of Gunnery, a very
able and interesting work.

Mr, Robins certainly did more to improve the
science of military projectiles than any individual,
not to say than all other individuals, who had gone
before him. He made a great number of well-de-
vised and important experiments ; and, in the work
above-mentioned, left a lasting monument both of
genius and of labour.

From the experiments detailed in this work,
which was published in 1742, it incontestably ap-
peared, that the resistance made by the air to pro-
jectiles which have a rapid motion, is much greater
than had been supposed by Newton and Huygens ;
that it is, indeed, so great, that the path described
by any shot whatever is very different from the
curve of a parabola^ and, consequently, that all
applications of that conic section to gunnery are
false and useless. Mr. Robins's experiments were
made with shot of one ounce weight only : it was,
therefore, much to be wished, that such persons as
had opportunity might repeat the same experi-
ments with balls of a larger size. Mr. Charles Hut-
ton, of the Royal Military Academy at Woolwich,
performed this service to science. He even used
in his experiments balls from twenty to jifty
ounces weight. The result of these experiments
confirmed Mr. Robins's principles in the most am-
ple manner.

Mr. Robins, however, in estimating the mecha-
nical force of Giinpoxoder, fell into an error, which
has been since corrected by the acute and perse-

Sect. IV.] Motmi and Moving Forces. 43

vering count Rumford* of America. The former
states this force, according to his experiments, to
be 1000 times as great as tlie mean pressure of
the atmosphere ; while the celebrated Daniel Ber-
noulli determined it to be not less than 10000
times as great. Such a dilference of opinion led
count Rumford to pursue a course of experiments,
of which some were published in the Philosophical
Transactions for 1781, and the remainder in the
Transactions of the same Society for 1797; witli
the view principally of determining the initial ex-
pansive force of Gunpowder, hy one of these ex-
periments it appeared, that, calculating even on
Mr. Robins's own principles, the force of Gun-
powder, instead of being 1 000 times, must at least
be 1308 times as great as the mean pressure of
the atmosphere. From this experiment the count
thought himself warranted in concluding, that the
principles assumed by Mr. Robins were erroneous,
and that his mode of ascertaining the force of
Gunpowder could never satisfactorily determine it.
Despairing of success in that way, he resolved to
make an attempt for ascertaining this force by ac-
tual measurement; and, after many unsuccessful
experiments, he was at length led to conclude that
this force was at least .50000 times as great as the
mean pressure of the atmosphere -j-.

In addition to the hiquiries of these British phi-
losophers, several mgeuious men on the contineiU
of Europe contributed to the extension and con-
firmation of Robins s theory. Jn this list M. u'An-

* See Additional Notes — (M).

-f Runiford's rhilosophical Jj^nsuvf', 8vo.

"44 Mechanical Philosophy. [Chap. I.

toni, of 'Italy, and Messrs. d'Arcy and le Roy,
of France, are entitled to particular distinction*.
I^cside these, many experiments have been made,
and valuable ideas suggested, respecting motion
in resisting mediums, by Gravesande, by J. Ber-
noulli, by Euler, by Simpson, by M. Bouguer;
and by AI. Condorcet, abbe Bossut, chevaliers
Buat and Borda, and other members of the Royal
Academy of Sciences at Paris. And although this
part of mechanical philosophy can scarcely be said
yet to have received satisfactory elucidation ; still
much has been done toward the attainment of this
object by the mathematicians and artists of the
last age ; and especially by those of France, who,
in the various parts of science immediately subser-
vient to the business of the Engineer, have cer-
tainly, in modern times, exceeded all the rest of
the world.

The discoveries and improvements made, in the
course of the last century, with respect to the con-
struction and motion oi pendulums, are neither few
nor unimportant. For the purpose of counteract-
ing the effects produced in the dimensions of the
pendulum by heat and cold, from which disorder
and error necessarily arise, the contrivances of in-
genious men have been numerous and successful.
For the purpose, also, of regulating the curve m
which this body shall move, various devices and
calculations have been adopted. The principal of
these improvements are, the Mercurial Pendulum,
invented by George Graham ; the Gridiron Pen-
dulum ; that formed with a rod of baked and var-

* Uuiion's M(it/u-matic(d Dictionari/.

Sect. IV.] Motion and Moving Forces. 4.5

iiished wood; the contrivances, by means of 2i flexi-
ble rod, and other apparatus, to make the pendu-
lum move in the curve of a c^jcloid; to say notliini^
of many other ingenious inventions to regulate the
motions and to extend the application of this im-
portant instrument.

In that part of philosophy which relates to the
structure and motion of machines, manv great
minds have been employed, in the course of the
kist age, and not without making some advances
in this department of science. — M. Amontons, of
the Royal Academy of Sciences at Paris, about the
beginning of the century, very successfully deve-
loped some of tlie general laws of machinery.
After him Mr. Emerson, of Great Britain, a dis-
tinguished mathematician, investigated and svs-
tematised this subject, with still more practical
care and accuracy. In 1735 the celebrated Euler
undertook to give a general and systematic \\e\v
of machines, in order to found a complete theory,
immediately conducive to the improvement of me-
chanics. In 1743 he published tlie first part of
his theory, containing many new dynamical theo-
rems of great importance''^. He afterwards prose-
cuted the subject further I, and with so nmch suc-
cess, as to excite deep regret that he had not
continued his useful labours. Since the experi-
ments and publications of Euler, many philoso-
phers of inferior name have turned their attention
to the same inquiry ; but without laying the scien-
tific world under the same obligations, by exhibit-

* Comment. Pdropolituni. torn. i.

t Conimeni. Petrop. lom. iii^ aud yiar.. Acad. Berlin, ];''i7 ai:^
1752.

46 Meclianical PhUosophj, [Chap. I,

ing original or very interesting views of the sub-
ject. Among these it would be improper to pass,
v/ithout respectful notice, the vakiable services
rendered to practical mechanics by Mr. Smeaton
and Mr. Dramah, both of Great Britain. The in-
stances of the ingenious application of mechanical
principles to the construction of different machines,
hy which the last century is distinguished, are too
numerous, and the authors of many of them too
well known, to render a detailed view of them pro-
per in this place.

SECTION V.

HYDRAULICS.

In the principles and practice of this part of sci-
ence great improvements have been made, by the
philosophers of the last age. To calculate upon
sure and accurate grounds the resistance and mo-
tion of dense fluids, so as to furnish a residt which
might be relied on by engineers, and other mecha-
nics, was considered at the beginning of the cen-
tury one of the most interesting and difficult pro-
blems in mechanical philosophy. Newton first
endeavoured to reduce the laws of moving fluids
to the ])recise form of mathematical calculation.
In this, however, thougli he displayed great inge-
nuity, he was unsuccessful. His demonstrations,
when brought to the test of practice, were found in-
accurate and inappHcable. Guglielmini,a celebrated
Italian, siiccetded Iiim, assuming his principles, and
aiming to attain the object in view by the same

^EGT,V,] Ilydraulics. 47

path. He also failed ; his calcukitions turning out
equally remote from the truth with those of his
illustrious predecessor. After Guglielmini, j^ro-
fcssor Micliclotti, ol Turin, D. Bernoulli, of Swit-
zerland, and the abbe Bossut, of Paris, instituted
many experiments, to ascertain the theory or me-
chanism of hydraulic motion. The last gentleman,
in particular, conducted his experiments with great
labour, care, and perseverance, published a very
important work on the subject, and opened a
path of inquiry in this field of science, so new, and
in a manner so judicious, that he must aUvaj^s be
considered as holding a high rank in the hydraulic
history of the age in which he lived. After all,
how^ever, he left the subject very imperfectly ex-
plored. Bossut was succeeded by his countryman,
the chevalier Buat, who took up the inquiry where
the abbe had left it> prosecuted it with singular
skill and assiduity, and formed a system much
nearer to the truth than all who had gone before
him. — But distinguished as the chevalier has justly
rendered himself, by his achievements in tliis
branch of philosophy, he cannot be said so much
to have discovered nev/ principles, as to have
classed and systematised, with great skill and in-
genuity, the principles flowing from IVl. d'Aiem-
bert's im wearied experiments and calculations on
this subject. Still the HxjdrauUque of Buat may
be considered the most ingenious, comprehensive,
9nd practical work, on the department of science
©f which it treats, to be found in any language.
The great excellence of this work is, that its doc-
trines are deduced not so much from mathematical

48 Mechanical PhllosopJijj. [Chap. I.

calculation, as from a laborious comparison of
facts. It furnishes most important information to
the cnc^ineer ; and enables liim now to resolve, with
sufficient precision, many questions, in answer ta
which little ])ut conjecture, and that too often most
mischievously wide of the truth, could be offered
before. In short, the gCxieral proposition, deduced
from the chevalier's numerous facts and experi-
ments, respecting the motion of fluids, has been
pronounced one of the most valuable results of mo-
dern inquiry *.

Much light has been thrown, during the last
century, on the doctrine of Tides. Newton was
the first who gave a satisfactory explanation of this
subject. He showed that the tides are caused by
the attraction of the sun and moon, and laid down
some of the general laws of this attraction. But
it has been remarked, that the wide steps taken by
this philosopher, in his investigation, left ordinary
minds frequently at a loss ; and that many of his
principles require very great mathematical know-
ledge to satisfy us of their truth. Accordingly the
Academy of Sciences at Paris, soon after the death
of the illustrious Briton, wishing to have this as
well as some other parts of philosophy exhibited
in a satisfactory, and, as far as could be, in a popu-
lar manner, published a prize question relative to
the tides. This produced three excellent disserta-
tions on the subject, by Mr. Maclaurin, D. Ber-
noulli, and Euler. Of these the work of Bernoulli
is considered the best, and is, perhaps, the most

^ See Emyclopa:dia, Art. Water-Works^

Sect. V.] Hydraulics, 49

complete extant*. And it is worthy of observar
tion, that while he threw greater Jight tlian all
who had gone be'Vrf^ him on the subject which he
immediately undertook to illustrate, he furnished
an additional and very powerful argument in sup-
port of the Nemtonian system.

The construction of Aqueducts has been render-
ed, by the labours of modern philosophers, more
simple, easy, and precise. And, in consequence
of these improvements, they have, within the last
century, greatly increased in number. For tlie
valuable experiments and discoveries which have
been made on this subject, we are principally in-
debted to the great hydraulic philosophers on
the continent, whose names were before men-
tioned. To those names may be added the di-
stinguished experimenters and observers, on the
same subject, Desaguliers, Belidor, de Parcieux,
and Perronet, who successively laboured to deduce
a system of doctrines from the numerous facts
before them; and whose very mistakes contribut-
ed to elucidate this obscure branch of science,
which, however, is yet far from being M\y under-
stood.

* The abbe Bernardin de St. Pierre, in a late work, entitled
Etudes de la NaUire, rejects the Newtonian theory of Tides, and
ascribes this class of phenomena to the liquefaction of the polar
ice and snow. To this amiable writer the praise of ingenuity,
and of possessing a happy talent of amusing and interesting his
readers, cannot be denied. Neither can it be questioned that his
work contains a consid<?rable portion of sound and pleasing pliilo-
.sophy. But surely this and some other of his doctrines arc utterly
unworthy of a mind, which had been conversant \^ ith the inquiries
and the writings of the great practical philosophers oi the eigh-
teenth century.

Vol, I. E

50 Mechanical Philosophy. [Chap. T,

Verv i^reat improvements have also been made,
durin"- the period in question, in the principles and
construction of Water-Mills. The proper mode
of adjusting forces, and calculating velocities, in
this, as well as in almost every other branch of hy-
draulics, has long been considered among the most
difficult problems in philosophy. — Dr. Desaguliers,
early in the century, made a number of experi-
ments on mills, and suggested some important im-
provements in their principles and construction.
About the same time, M. Belidor, of France,
Mr. Emerson, of Britain, and J. Bernoulli, em-
pIo}^ed their great learning and talents on this sub-
ject, and made considerable progress in its illus-
tration. These were followed by Mr. Lambert,
of Berlin, Mr. Elvius, of Sweden, Professor Karst-
ner, of Gottingen, M. de Parcieux, before men-
tioned, and Messrs. Smeaton, Barker, and Burns,
of Great Britain. To attempt an enumeration in
detail of all the inventions, discoveries, and usefld
suggestions produced by these several philosophers
and artists, would swell this account beyond all
bounds. It is sufficient to say, that although that
part of the science of hydraulics which relates to
mills did not arrive at absolute certainty and per-
fection in their hands; yet they made so many
.successive additions to the knowledge of preceding
theorists, that to each large acknowledgements are
due from the friends of human improvement. Nor
ought the still later inquiries of Mr. Waring of
Philadelphia, on the same subject, to be forgotten.
His memoir on the )7iaximum velocity of a wheel
or other body, moved by a giveu quantity of iluid,
may be regarded as a singular monument of accu-

Sect. VI.] Pneumatics. 51

rate and successful investigation*. The theory of
millsy which he deduces from his experiments and
calculations, -is said to correspond with fact, to a
degree greatly beyond all other attempts f.

The various improvements which the last cen-
tury produced in the construction of pumps, are
also worthy of notice. Since the doctrine of the
pressure of the atmosphere has been reduced to a
regular system, and the general laws of moving
fluids have been better understood, several advan-
tages in the formation and management of this
class of engines naturally followed. Those who
most distinguished themselves during the century,
by inventions, or laborious investigations, on this
subject, are Messrs. Hadley, Desaguliers, Haskins,
and Beighton, of Great Britain, Messrs. J. and D.
Bernoulli, and Wirtz, of Switzerland, and Messrs.
Pitot, Bossut, Belidor, de la Borda, d'Alembert,
de la Grange, and de Buat, of France.

SECTION VT.

PNEUMATICS.

In Pneumatics, or that science which treats of
the mechanical properties of elastic fluids, modern
discoveries and improvements have been very nu-

111.

* See Trans. 'Amer. Philos;. Society, vol.

t Mr. Waring \v^s an obscure character, • a native and resident
of Philadelphia. He belonged to the Society of Friends, and
taught a school in that city. Though little known, he was a
real philosopher. He died of the pestilence which raged in tltat
city in 1703.

E2

52 Mechanical Philosophy, [Chap. I.

meroiis and important. Ever since the famous
Torricellian experiment, in the seventeenth cen-
tury, proved that air was a gravitating substance,
the attention of philosophers has been employed,
with great success, in investigating the properties,
and ascertaining the laws of this fluid. By nume-
rous and patient inquiries, they have gone far to-
ward reducing to regular system the principles
which govern the density, the weight, the elasti-
city, and the motions of the atmosphere. And
the various mechanical properties of air, as they
became, in succession, better understood, have been
rendered subservient to the utility of man, by tlieir
application to the arts of life.

The Barometer has, within the last century, re-
ceived many and very important improvements,
from Rowning, de Luc, Roy, Shuckburgh, Cas-
well, Nairne, Jones, and others*. The application
of this instrument to the measurement of altitudes
was first suggested by Dr. Halley, and afterwards
better explained and systematised, by several of
the gentlemen just mentioned, especially by the
celebrated M. de Luc, of Geneva. The Air-Pump,
during the same period, was much improved by
liawksbee, Gravesande, abbe Nollet, Smeaton,
Russell, the rev. Dr. Prince, of Salem in Ame-
rica f, Lavoisier, and fmally Cuthbertson, of Am-
sterdam; by the last of whom, we are taught
to beheve, this machine has been carried to a
degree of perfection beyond which little advance-

* See Ejwj/clopa:dia, Art. Barometer and Pneumatics. Sea
alio Philosophical Transactions^ vol. Ixxvii.

t Sec the TransuQiions of the Jmcr. A^ad, of Arts and Sciences,
vol. i.

Sect. VI.] Pneumatics. 53

ment is to be expected. That part of pneu-
matics, also, which relates to the construction of
Chimneys, the comfort of human habitations, and
the economy of fuel, has been, in modern times,
the subject of much inquiry, and very useful im-
provement, by Dr. Desaguliers and Mr. Anderson,
of Great Britain, and by the illustrious Americans,
Franklin, count Rumford, and many others. To
which may be added a number, almost countless,
of wind instruments and machines, which modern
ingenuity has invented, and which have grown
out of our increasing knowledge of the qualities
and laws of the important fluid in which we are
immersed.

In this period, beyond all doubt, we are to place
the invention of Balloons. In 1729, Bartholomew
Gusman, a Jesuit, of Lisbon, caused an aerostatic
machine, in the form of a bird, to be constructed ;
and made it to ascend, by means of a fire kindled
under it, in the presence of the king, queen, and
a great concourse of spectators. Unfortunately,
in rising, it struck against a cornice, was torn, and
fell to the ground. The inventor proposed renew-
ing his experiment ; but the people had denounced
him to the Inquisition as a sorcerer, and he with-
drew into Spain, w^here he died in an hospital.

In 1766, the Hon. Henry Cavendish discovered
that inflammable air (the hydrogen gas of the
French nomenclaturists) was at least seven times
as light as common air. It soon afterwards oc-
curred to the celebrated Dr. Black, that if a thin
bag were filled with this gaseous substance, it
would, according to the established laws of specific
gravity, rise in the common atmosphcn^j but he

54 Mechanical Philosophy. [Chap. I.

did not pursue the inquiry. The same idea was
next conceived by Mr. Cavallo, to whom is gene-
rally^ ascribed the honour of commencing the ex^
periments on this subject. He had made but little
progress, however, in these experiments, when
the discovery of Stephen and John Montgolfier,
paper-manufacturers of France, was announced in
1 782, and engaged the attention of the philosophi-
cal world. Observing the natural ascent of smoke
and clouds in the atmosphere, those artists were
led to suppose that heated air, if enclosed in a
suitable covering, would also prove buoyant. Ac-
cordingly, after several smaller experiments, by
which this idea was fully confirmed, they inflated
a large balloon with rarefied air, on the 5th of
June, 1783, which immediately and rapidly rose
to the height of six thousand feet, and answered
their most sanguine expectations, It was soon
found that machines of this kind might be so con-
trived as to convey small animals, and even human
beings, through the air with ease. The first hu-
man adventurer in tjiis aerial navigation was M.
Pilatre de Rozier, a daring Frenchman ; who rose
in a large balloon, froni a garden in the city of
Paris, on the 15th of October, 1783, and remained
a considerable time suspended in the air. He
rnade several aerial voyages of greater extent after-
wards, and in two of them was attended bj other
persons. In a short time, however, the use of rare-
fied air in aerostation was, for the most part, laid
aside, as inconvenient and unsafe^ and recurring
once more to the discovery of Mr. Cavendish, the
philosophers of Paris concluded that a balloon, in-
flated with inflan^imable air, would answer all the

Sect, VL] Pneumatics. 55

purposes of that contrived by the Montgoltiers,
and would also possess several additional advant-
ages. They made their first experiment on the
23d of August, 1783, which was attended with
complete success 3 and the hrst human beings who
ventured to ascend in a balloon raised upon this
plan were Messrs. Charles and Roberts, who rose
from Paris, on the 1st day of December in the
same year. The inflammable air balloons have
been generally used since that time \ many aerial
voyages have been performed in Europe and Ame-
rica; and what is remarkable, out of all the numer-
ous instances of such hazardous enterprise, only
one is recollected, which was attended with any
fatal accident*.

The invention of balloons, though far-famed and
brilliant, cannot be considered as having hitherto
added much to the comfort or utilitj^ of man. The
only practical purposes which it has been made
to subserve, are those of aiding in meteorological
inquiries, and inspecting the fortifications and re-
connoitring the camp of an enemy, which coidd
not be approached by other means. It has been
applied to this latter purpose in at least one, if not
more instances, by the French engineers, during
the late warf. But who can undertake to assign
the limits beyond which the ingenuity and the
enterprise of man shall not pass ? Though this spe-

* This is a reference to the doatli of jNI. PiJntre de Ro-
zier and M. Remain ^ who rose in a balloon, from Roulogne, in
the month of June, 1/85, and after having been a mile high, for
about half an hour, the balloon took fire, and the two adventurers
were dashed to pieces by their fall.

I Gregory's Economi/ of Nature, 2d edit., vol. i, p. 500'.

56 Mechanical Philosophy. [Chap. I.

cies of navigation labours under difficulties which
appear at present insurmountable; though the
want of some means to control and regulate the
movements of the aerial vessel is so essential as to
excite a fear that it cannot be supplied ; yet who
can tell what further experience and discoveries
may produce ? Who can tell but another century
may give rise to such improvements, that navigat-
ing the air may be as safis, as easy, and rendered
subservient to as many practical purposes, as navi-
gating the ocean ? It must be acknowledged, in-
deed, that this is not very probable^ but things
more unexpected, and more remote from our habits
of thinking, have doubtless occurred.

Under this head, also, properly come the great
improvements which have been lately made in
Steam Engines, doubtless among the most import-
ant and useful kinds of machinery that human
ingenuity ever contrived. The idea of making
steam subservient to powerful mechanical opera-
tions seems to have been first entertained by the
marquis of Worcester, in the reign of Charles II
of England. But little more was done, either by
him, or during his time, than to speculate on the
subject. It was not till the close of the seventeenth
century that captain Savary, an ingenious and
enterprising man, actually erected several steam
engines, and obtained a patent for what he consi-
dered his own invention. He afterwards improved
and simplified his machines himself; but the im-
provements which they have undergone since hi^
time, are still more numerous. For these im-
provements the world is principally indebted to
Mr. Newcomen, Mr. Beighton, and above all to

Sect. VI.] Pneumatics. 57

Mr. Watt, who, with an ardour, an acuteness,
and a philosophic comprehension, which do him
immortal honour, has so extended the principles
of these machines, so increased their power, so
successfully obviated the difficulties and inconve-
niences attending their operation, so accommodat-
ed their construction to peculiar circumstances, and
carried the economy of steam, and, consequently,
of fuel, to such an astonishing extent, that he may
be ranked among the greatest mechanical geniuses
and benefactors of mankind that tlie eighteenth
century has produced*.

The application of steam to the purposes of
cookery, and of propelling vessels on the water,
is also to be ranked among modern inventions.
To the latter of these objects several persons of
America have paid particular attention, and with
promising success. And although it must be
granted that formidable difficulties have arisen in
the execution of all the plans hitherto proposed,
yet to doubt of the practicability of ultimately
overcoming these difficulties, can scarcely be
thought either to gratify a mind of true philosophic
enterprise, or to be worthy of such a mind.

Late navigators and travellers have furnished
valuable materials towards forming a theory of
the zvlnds. It must be acknowledged that nothing
entirely satisfactory has yet been offered to the
world on this subject. Still many facts have been
brought to light ; important discoveries liave been
made; and from the number and talents of tho
gentlemen who have been for some time engaged

* See AddUiona I Notcs-^ ( Nj .

58 Mechanical Philosophy, [Chap. I,

in exploring this dark recess of philosophy, still
greater advances in our knowledge of it may soon
be expected. For some instructive publications on
this subject, we are indebted to Dr. Halley, and
Mr. Dalton, of Great Britain ; Mr, Kirwan, of Ire-
land ; and Messrs. de Luc and Prevost, of Geneva.
Various instruments, which answer valuable pur-
poses for measuring the direction, the force, and
the velocity of winds, have also been invented,
within a few years past, by Dr. Linn, Mr. Picker-
ing, and others of Great Britain. These inven-
tions have been denominated the Jnetnoscope, the
Anemometer, &c.

Finally, the doctrines of Acoustics have been
very successfully illustrated, since the time of
Newton, by various inquirers. Many facts re-
lating to the velocity, the intenseness, and the ge-
neral principles of sounds, have been established
by numerous experiments. The capacity of dif-
ferent bodies to propagate sound has become
better understood by the investigations of modern
philosophers. Mr, Hawksbee, of Great Britain,
first showed that sound is propagated further in
dense than in rarefied air ; M. Brisson, of France,
and others, demonstrated, by various interesting
experiments, that a medium more dense than air
conveys sound still better than this fluid; and Dr.
Young, of Dublin, has, within a few years, made
some new and instructive inquiries into the prin-.
ciples of acoustics. To which may be added the
interesting experiments lately made, showing the
different intensity, and the variety of tones of
sound, in different gases, by several philosophers.

That the different gases have different degree^

Sect. VII.] Optics. 59

of power in the propagation of sound, both with
respect to intensity and tone, has been known
since the year 1786; about which time Dr. Priest-
ley, and professor Perolle, of Turin, instituted a
set of experiments on this subject, in which they
substantially agreed. Since that time professor
Jacquin, of Vienna, at the desire of Dr. Chladiii,
undertook a new course of experiments, witli a
view to the investigation of this subject. The re-
sults of these experiments are so different, and
even contradictory, ^vhen compared with the for-
mer, that it is difficult to say on wliich side the
truth lies,

SECTION VIL

OPTICS. ' ■

In this science great improvements have taken
place in modern times. In 1704 Sir Isaac Nc\v-
ton first published his grand work on Optics ; and
although many of his most interesting discoveries
were made and announced towards the close of the
seventeenth century, yet the collection and pub-
lication of them, in a systematic form, was reserved
to be one of the distinguishing honours of the
eighteenth. How numerous and important these
discoveries were, is generally known. He ascer-
tained the different refrangibility of the rays of
light; he made some progress in exploring the
principles and laws of colours, v/hieh had been so
little understood before his time; he first explained
the physical cause, and laid down with mathema-
tical precision, the general laws of the reflection

60 Mechanical Philosophy. [Chap. I.

and refraction of light ; beside many other valua-
ble, but less important additions to the science of
optics. It must be acknowledged that his doc-
trines are by no means free from errors and de-
fects ; but these are few in comparison of their
great merits, and have been chiefly corrected or
supplied by the labours of subsequent philoso-
phers.

Since the discoveries of Newton many important
additions have been made to our knowledge of the
nature and properties of Light. The materiality
of this substance, and the great velocity of its mo-
tion, were more fully illustrated and confirmed
than they had been before, by Dr. Bradley and
Mr. Molyneux, in 172?. A few years afterwards
M. Bouguer, a celebrated French philosopher, dis-
tinguished himself by his experiments and observa-
tions on the same substance 5 particularly on the
laws of its reflection and refraction. On this sub-
Jt^ct, indeed, he is placed, by a very adequate
judge, among the most eminent observers and dis-
coverers whom the eighteenth century produced*.
Another species of action of other bodies on the
rays of light, producing what philosophers have
called inflection and deflectioUy was suggested by
the illustrious Dr. llittenhouse of America f, but

* Sec Priestley's History of Optics, 4to, London, 17/2', from
which many of the facts related in this sketch are taken.

They who have perused tliis work need not be informed, that
it is a very interesting one, and that the labours of Dr. Priestley,
in collecting so many historical facts relative to the science of
Optics, together with his own experiments, hints, and inquiries
on the subject, entitle him to an honourable station among those
who have deserved well of tliis science in the eighteenth century.

t Trmi^actiom American Philosophical SocictJ/, vol. ii.

Sect. VII.] Optics. 61

was first demonstrated by the ingenious experi-
ments of Mr. Brougham*. From tliese and other
facts, it appears that light is operated upon by
material substances ; that it is subjected to the
laws of attraction, and, of consequence, possesses
gravity. In the same spliere of experiment and
observation may be mentioned Dr. Smith and
Mr. Mitchel, of Great Britain, who made many
valuable computations with respect to the inten-
sity, and the best mode of measuring this subtle
fluid. The property which various bodies, botii
animal and vegetable, possess of imbibing and
emitting light, has also been hivestigated with
more success by modern philosophers than during
any former period. To which may be added, that
a multitude of facts of the most interesting kind^
relating to the effects of light on animal, vegetable,
and mineral substances, have been made known
within a ^ew years past ; and the nature and prin-
ciples of some of these effects ingeniously and sa-
tisfactorily explored.

The theory and laws of Vision have received
very great elucidation during the last age. Bishop
Berkeley, in his Essay towards a Theory of Vision,
published in 1709, solved many difficulties which
had attended the subject, and threw much new
light upon it. He distinguished more accurately
than any who had gone before him, between the
immediate objects of sight, and those of the other
senses, which become early and insensibly associ-
ated with them. He first showed that distance,
of itself, cannot be determined immediately by

* Philosophical Transactions for 1796.

02 Mechanical Philosophij. [Chap. I.

sight alone ; but that we learn to judge of it by
certain sensations and perceptions which are con-
nected with it. He led the way, also, in pointing
out the difference between that extension and Jigiire
which we discover by means of vision, and that
which we perceive by touch. By means of these
investigations and discoveries he enabled philoso-
phers to account for many phenomena in optics,
of which the most learned had before given Yery
erroneous accounts, or acknowledged themselves
unable to furnish any satisfactory solutions. About
the same time some valuable experiments and in-
structive works on the seat and principles of vision
were published by M. de la Hire, M. le Cat,
M. Bouguer, and several other French philoso-
phers. To these succeeded the inquiries of Har-
ris, Porterfield, Jurin, Smith, and still more re-
cently of Reid * and Wells f . In particular, the
very difficult question of apparent magnitude and
distaiice has been treated with great ability by
Berkeley and Harris ; the phenomena of single
and double vision have been solved by several of
the persons above mentioned ; and many remark-
able fallacies of vision explained by Mr. Melvillcj
M. Bouguer, and others.

The principles and laws of Colours have also
been much better understood since the commence-
ment of the eighteenth century than- before. On
this subject it seems now to be generally agreed,
that the immortal Newton fell into essential mis-

* Inquiry into the Human Mind on the Principles of Common
t An Essay upon Sinj^le Vision, &c. 8vo. 1 792.

Sect.VIL] Optics. 63

takes. His idea, that the colours of bodies depend
on the magnitude of their elementary particles,
has, it is believed, at present, few advocates. Aiter
him this subject was considered, though in a more
practical way, and with reference to the art of
dyeing, by several French philosophers ; especially
by Dufay, "Hellot, and Macqaer, who conducted
their inquiries with great ability, pains, and per-
severance, at the national expense. More reccntiv,
Mr. Delaval, of Great Britain, rehning on the con-
jectures of Newton, attempted to deduce the
varieties of colour from the different densities and
inflammability of bodies. I'his w^ork was for some
time popular; but appears lately to liave given
way, in the public opinion, to the more enlighten-
ed and correct philosophy delivered on this sul)ject
by M. Berthollet, and Dr. Bancroft, who ibund
the whole doctrine of colours on ehemicat princi-
ples— supposing that particular bodies redect, trans-
mit, or absorb particular rays of light, in conse-
quence of certain affinities, or elective attractions^
existing between the differently coloured matters,
and the different rays of light, reflected, transmit-
ted, absorbed, or made latent*.

But the discoveries and improvements in tiie
construction of optical instruments^ which the last
age produced, are still more brilliant and interest-
ing than any hitherto mentioned. Much was
done, during the period in question, in the im-
provement of Telescopes. The Refracting Tele-
scope was first in use. In this instrument no sig-

* See Experimaital Researches conceiminu; the Philo.sophj/ of Pcr-
njancnt Colours, by Edward Bancroft, M. D.l^. R. S. 179'^-

(34 . Mechanical Philosophy. [Chap. I.

nal advantages of construction seem to have been
devised from the time of Huygens, till the middle
of the eighteenth century. It was then that Mr.
Dollond, a celebrated artist of Great Britain, dis-
covered a method of correcting the inconvenience
and errors arising from the different refrangibility
of the solar rays ; a difficulty, which, since the time
of Newton, had been generally considered as in-
surmountable. He ascertained that lenses of crown
tmd o^ flint glass might be so prepared and adjust-
ed as to correct the refractive, and of course the
chromatic, powers of each other. On this disco-
very he founded the construction of his celebrated
Achromatic Telescope, which, doubtless, deserves
to be ranked among the most valuable acquisitions
of the age*. Mr. Dollond pursued this improve-
ment by increasing the number of glasses, with so
much success, as to make the refracting instru-
ments of his time superior to the reflecting of equal
length. The principle which he discovered was
explored still further, and the Telescope which he
contrived carried to a higher degree of perfection
soon afterwards, by Mr. Zeiher, of Petersburgh,
who ascertained, by experiments, that increasing
the quantity of lead in the formation of lenses,
augmented the power so much desired in this in-
strument. It ought, perhaps, to be mentioned,
that the hints and publications of the celebrated
Euler on this subject, though found erroneous,
probably contributed something to Mr. Dollond's
discovery; and that the distinguished mathemati-
cians, Clairaut and d'Alembert, about the same

* Sfce Additional Notes — (0),

Sect. VII.] Optics. (iJ

time, rendered themselves very conspicuous among
the philosophers of Europe, by their ingenious cal-
culations and suggestions, in aid of the achromatic
instrument.

A new method of constructing ^^c//;v;wrt/zc Tde-
scopes was discovered, a few years ago, by professor
llobert Blair, of Edinburgh. This method consists
in the use of one or more Jliu'd mediums, of which
the dispersive powers, being opposed to each other,
correct the focal irregularities not only of the ex-
treme rays of the Newtonian Spectrum, but like-
wise of those near the middle; to which former
opticians had little, if at all, attended. From some
cause or other, however, this kind of achromatic
telescope has not been much used.

But, from the necessary imperfection, and tlio
small limits to which the dioptric plan of magnify-
ing distant objects is confined, the improvement
of the Reflecting Telescope became, early in tlie
century, an object of particular attention. This
instrument, which had been invented, in the pre-
ceding centuryj by Mr. James Gregory, of Aber-
deen, and which had been executed, on a different
plan, by sir Isaac Newton, was greatly improved
by Mr. Hadlej', who, in 1719, presented a very
powerful Telescope of this kind to the Royal So-
ciety. In 1734 Mr. Short, an ingenious artist of
Edinburgh, devised still further improvements in
this instrument. These were chiefly eilected by a
new method which he discovered of grinding mir-
rors. But the secret art which enabled him to
do this with so much success, is said to have died
witli him. After, him, Mr. Mudge, of Plymouth, by
making specula of a composition uf dillcreut metals.

65 Mechanical Philosophy, [Chap. I.

and by inventing a method of grinding them to
a true figure, which had been considered so diffi-
cult a problem by his predecessors, effected yet
greater improvements. Mr. Mudge was followed
by his countryman, Mr. Edwards, who also la-
boured, with some success, on the same instru-
ment ; but this has been since done much more ef-
fectually by Mr. Watson, an artist of London still
living. It was, however, reserved for the great astro-
nomer Herschel, to furnish the world with reflect-
ing telescopes of the most wonderful magnifying
power*. The extraordinary extent to which he
has carried his improvements, and the astonishing
discoveries which they have enabled him to make,
are too recent, and too well known, to make a de-
tail of them necessary here.

During the period which we are considering,
mici'oscopes have been also carried to a very high
degree of perfection. In 1702 Mr. Wilson in-
vented one, of the single kind, which is still much
in use. In 1710 Mr. Adams presented to the
Royal Society another, also single, but of much
greater magnifying power. To which succeeded,
soon afterwards, the ingenious device of Mr. Grey,
of a temporary microscope, by means of a globule
of water. In 1738 or 1739, Mr. Lieberkuhn
made two very important improvements in micro-
scopes, by the invention of the Solar Microscope,
and that for viewing opaque objects. These were
followed by the reflecting microscope of Dr. Smith,
said to be superior to all others. Beside those

* Tiie great Telescope of Herschel, 40 feet in length, is un-
doubtedly entitled to a conspicuous place among the wonder s.

OF THE EIGHTEKNTH CKNTURY.

SfiCT.VII.] Optics, G7

above mentioned, discoveries and improvements
relative to microscopes, too numerous to be re-
counted, have been made by philosophers and
practical opticians. The most conspicuous of these
are Culpeppei-j Baker, Ellis, Lyonet, Martin, CufT,
Adams, and Withering 5 who have either contrived
microscopes suitable for particular purposes, or
suggested inventions and additions of more general
application.

There is probably no division of this review,
under which another modern invention, the Ttlt-
graphy may with more propriety be placed than
this. Though something like Telegraphic com-
munications had been attempted many centuries
before, on particular military or civil emergencies ^
yet nothing of this kind was reduced to regular
system, or much known, till the beginning of the
eighteenth century*, when M. Amontons, of
France, exhibited a telegraph on a new and con-
venient plan. It was not^ however, until after the
commencement of the French revolution that this
machine was generally applied to useful purposes,
or became an object of much attention. Toward
the end of the year 1793 M. Chappe announced
an invention under this name. Whether he were
acquainted wdth the contrivance of M. Amontons
is not known ^ but be this as it may, his was
nearly on the same plan. Tlie invention of M.

* It is said by a writer in the Philosophical Magazine of Lon-
don, that the celebrated Robert Hooke, the contemporar>- and
friend of Boyle, invented a Ttltgraph, on the same gt;iicral plan
as those which have been since used ; and formally arjiounced
and described it, m a paper read beiurc tlie Koyal Scc:^'.
May 21st, 1684.

F2

^S Mechanical Philosophy. [Chap. I.

Chappc immediately became an object of public
attention. Additions and alterations in his plan
were proposed, some of them highly advan-
tageous; and telegraphs of different kinds came
into use in various parts of the continent of Europe,
and in Great Britain. How great the importance
of this channel of intelligence is at present, and
how much more so it may be rendered by those
improvements in its construction and management
which we may reasonably expect to take place,
will readily occur to every mind. To say nothing
of the dispatch with which information might be
conveyed, by this means, in time of war, and
the evils of various kinds it might prevent, it may
hereafter become an instrument of commercial
communication of the highest utility, and be ren-
dered subservient to many valuable national pur-
poses*.

The late experiments and conclusions of Dr.
Ilerschel, with respect to the rays of light and
heat, are curious, and highly interesting^. He
seems to have demonstrated that the ditTerept
prismatic colours have different degrees of tempe-
rature ; that radiant heat, as well as light, is not
only refrangible, but also subject to the laws of
dispersion, arising from its different refrangibility;
that those rays of light which have the greatest
illumijiating power are the yellou^ and those vvhicli

••' Mr. Jonathnn Grout, of Massachusetts, in l/pQ, invented a
Telegraph on a plan which is said to be essentially ditterent froHi
any now in use in Europe. It has been for some time in opera-
tion between Boston and Martha's Vineyard, at which distance
(90 miles) Mr. Grout has asked a question and received an an-
-j»\rer in Icsi than ten minutes.

Sect. VIII.] Astronomy. 69

have the greatest heating ^oweT the red; and, of
course, tliat, contrary to the general belief, the
ma.\imum of illiunination, and the maximum of
heat, do not comcide*.

SECTION VIII.

ASTRONOMY.

Though this subject is mentioned last, it holds a
very conspicuous place among those branches of
mechanical })hiIosophy which have received great
accessions of discovery and improvement during
the century in question, At the beginning of tliis
period the Principia of the immortal Newton had
given a new face to astronomical science f. Much
had been done by his predecessors, and especially
by the sagacious Kepler, to prepare the way for

^ See Transactions of the Rojjal Societi/^ for 1800.

-}• Aniong the honour^ of the eighteenth century, it ought to
be considered as none of the least, that the immortal Newton
lived the last 27 years of his life, and closed his glorious career in
this age. The character of this stupendous Genius is too well
known to require any details on the subject in this place ; but as
his name so frequently occurs in these volumes, and especially in
the section on Astronomy, it may not be improper to compress
into a few lines the following facts and dates concerning him. —
He was born in Lincolnshire, in the year l642. He was educat-
ed at the University of Cambridge ; wh^re he graduated A. B. in
1664, and A. M. in 1663.. He had made some of his greatest
discoveries, and had laid the foundation of his Principia and his
Optics, before he was 24 years of age. He was made Warden of
the IMint in l6g6, and Master of tliai institution in 1699, which
office he held till his death, which took place in 1/27, i» the
8.5 th year of his age. He received the honour of kniqhthood from
queen Anne, in 1/05.

^d Mechanical Philosophy, [Chap. I.

his grand discoveries ; but it was reserved for this
himinary of the first magnitude to shed a degree
of light on the Jaws of our planetary system, which
has served to guide every exertion, and point out
the way to the progress which has since been made.
It was he who first applied the simple principle of
gravitation to account for the movements of the
celestial bodies ; who laid down the laws of this
great and all pervading attraction ; and thence, by
the assistance of a sublime geometry, deduced the
revolutions of the planetary orbs, both primary
and secondary, including the minute irregularities
of each, with some errors indeed, but with a degree
of conformity to nature and subsequent observa-
tion, which must ever astonish and delight the in-
quiring mind. The British philosopher leaving
astronom.y in this improved state, no wonder that
those who came after him should at once, with
growing ardour, and with greater ease, pursue a
course which he had so happily marked out.

At the beginning of the century under review,
we find Flamstead*, the first Astronomer Royal of
England, devoting himself to this science with
great zeal and success. He particularly directed
his attention to ihe Jixed stars ; and after a series
of patient and most laborious observations, pub-
lished, in 1719, a catalogue of stars, more exten-
sive and accurate than had ever been formed .by
one man. To him, both in office, and in astrono-
mical fame, succeeded Dr. Ilallcy|, who made a

* The Rev. John Flnmstoad was born in l646; appointed As-
tronomer Jloyal in 16/4 ; and died in 1719.

t Edmund Halley was born in Londori, in the year \65Q ; suc-
o^f-ded Flamhtcad as Astronomer Royal in l/ic) ; and died in 1742.

Sect, VIII.] yfstrono7?ii/. 71

number of important discoveries, and useful pub-
lications. Among many others which might be
mentioned, he discovered the Accekration of the
Moon, and gave a very ingenious method of find-
ing her parallax. He composed tables of the Sun,
the Moon, and all the planets. He also recom-
mended the mode of ascertaining the Longitude
by Lunar Observations ; a mode which has been
since much improved, and generally adopted ^ and
which is, at present, the most certain guide of the
mariner. After him, at the head of the Royal Ob-
servatory was placed Dr. Bradley, who greatly
distinguished himself as a practical astronomer.
He was the first who made observations with suffi-
cient accuracy to detect the smaller inequalities
in the motions of the planets and fixed stars. By
means of this accuracy, he discovered, in 1727} the
aberration of the stars^ a phenomenon produced by
the compound motion of the earth, and the ra} s of
light ; and furnishing new proof, both of the mate-
riality and amazing velocity of light, and also of
the reality of that motion which had been ascribed
to the earth. The same gentleman, in 17^7? dis-
covered the nutation of the earth's axis — that libra-
tory motion, which is occasioned by the inclina-
tion of the moon's orbit to the ecliptic, and the re-
trograde revolution of her nodes ; thus, in the
course of ten years, making two of the most im-
portant additions to astronomical knowledge that
\X\e century produced*.

* The Rev. James Bratlley was born in the year l6()2, and
educated at Oxford. On the death of Dr. Halley he was ap-
pointed Astronomer Roynl, in which office he continued till his
death, which took place in 17<)2.

72 Mechanical Philosophy, [Chap. I.

AVhile these noble and successful exertions were
making in Great Britain, to improve the science of
astronomy, the philosophers of France were em-
ploying themselves in the same field of inquiry,
and with very honourable success. The real figure
of the globe we inhabit had not been, before this
time, satisfactorily ascertained. M. Cassini, the
Astronomer Royal at Paris, believed its figure to
be that of a prolate spheroid, or in other words,
that the polai^' diameter was greater than the equa-
torial; while Newton had been led, by his prin-
ciples, to a conclusion directly opposite, and had
taught that it must be an oblate spheroid^ or flattened
at the poles. To determine the question, between
these contending parties, the French Royal Aca-
demy of Sciences, under the authority and patron-
age of Lewis XV, resolved to have two degrees
of the meridian measured, the one as near the
Equator, and the other as near the Pole, as pos-
sible. For this purpose, one company of philoso-
phers, consisting of Messrs. Godin, Condamine,
and Bouguer, to whom the King of Spain added
don Ulloa and don Juan, was dispatched, in
173.5, to South America; and another company,
consisting of Messrs. Maupertuis, Clairault, Ca-
mus, Ic Monier, and Outhior, attended by pro-
fessor Celsius, of Upsal, was sent to Lapland.
These companies, after devoting several years to
the task committed to them, and encountering nu-
merous difficulties in the prosecution of it, at length
completed their design. The result proved to be
an ample confirmation of Newton's opinion ; for
a degree near the Pole being found to measure
more than one near the Enuator, they necessarily

Sect. VIII.] Astronomy. 73

inferred that the polar degree must be part of a
larger circle*.

At the be.2^inning of the eighteenth century, our
knowledge of the Moon was extremely defective.
Since that period, so many discoveries have heeu
made respecting this attendant on our earth, and
the laws of her motion have been so ably and dili-
gently investigated, that this part of astronomy
may now be ranked among those which are most
fully known and understood. For these investiga-
tions we are mdebted to Clalrault, d'Alembert,
Euler, Mayer, Simpson, AValmsly, Burg, Bouvard,
de la Grange, de la Place, and others. By the
labours of these great astronomers, the inequalities
in the moon's motion have been detected, ascer-
tained, and reduced to a system ; accurate Lunar
7\ibles have been formed; and the theory of this
satellite has been carried to such a degree of per-
fection, that her place in the heavens may be com-
puted with a degree of precision, which would
have been pronounced, a few years ago, altogetlier
impossible. With respect to the condition and
aspect of the moon^s siirfac€y many important dis-
coveries have been made, and much valuable in-
formation given to the world, by Mr. Schroeter f,
a celebrated astronomer of Goettingcn, and hy

•^ It is impossible to recollect the attempt by M. Bernartlin ^'e
St. Pierre, in his Studies of Nature, to revive the opinion of Cns-
6uii on this subject without surprise. That so learned and inge-
nious a man should oppose such distinct mathematical demonstra-
tion, is one of those caprices of respectable minds not easily to be
iiccounted for.

f See SdenotopograpJiisch'c Fnr^viaiW, kc. by JoIiMn, H: ro-
py rnus Schroctei'j 'ito, l/Oi.

74 - Mechanical Philosoplii/, [Chap. I,

Dr. I lerschel, of Great Britain ; who, by the aid of
very powerful and accurate instruments, and with
the skill and perseverance for which they are so
eminently distinguished, have made surprising pro-
gress in investigating this department of the lunar
phenomena.

A\'hen Newton died, several of the inequalities
of the planetary motions, arising from the disturb-
ing forces of various bodies, were with difficidty
reconciled with the astronomical principles which
he had laid down. These inequalities have been
successively investigated since that time, their
causes ascertained, their laws fixed, their perfect
consistency with the Newtonian theory demon-,
strated, and thus a very formidable objection to
that theory satisfactorily removed. — It is known to
mathematicians, that this celebrated philosopher,
calculating the effect of the sun's force in pro-
ducing the precession of the equinoxes^ fell into an
errour, and made it \^'i,'&, by one half, than the
truth. The true quantity of this motion was first
determined by M. d'Alembert, in 1749^ who
also, in the course of his inquiries, more fully ex-
plained the nutation of the eartKs axisy which had
been discovered a few years before by Dr. Brad-
ley. With no less diligence the inequalities in
the revolutions of all the planets, and especially
of Jupiter and Saturn, have been examined, ascer-
tained, and reduced to regular principles. lu
these difficult investigations, many astronomers
have employed themselves, in the course of the last
century, and by their labours rendered important
services to this science , but, perhaps, none of the
number deserve more honourable distinction than

Sect. VIII.] A^ojiomy. 75

Euler, de la Place, and de la Grange, whose ac
curate observations, and rigid and delicate ana-
lyses, with a view to explore the anomalies in
question, display great penetration, diligence, and
perseverance.

The year 1781 was rendered remarkable by the
discovery of a nexv primary Planet. This disco-
very was made by the celebrated Herschel, an
astronomer of Hanover, residing in Great Britain.
He had, for a number of years, distinguished him-
self by his successful exertions in augmenting the
powers of optical instruments, and particularly
in improving the reflecting telescope. With an
instrument of this kind, of great excellence, he
first determined the existence of the Planet, which
he denominated Georgium Sidus, in honour of the
British King ; but which is now generally called,
by the consent of astronomers, after his own name.
From his observations, and those of others, it has
been since found that this planet is attended by six
secondaries, and much progress has been made in
ascertaining the respective times and laws of their
revolutions*.

But this discovery is not the only one which
will transmit the name of Dr. Herschel to poste-
. rity with distinguished honour. In 1787, he dis-
covered a sixth satelHte of Saturn, and the year
after a seventh, attending the same planet. He
ascertained the rotation of Saturn's Ring, which
may be regarded as one of the most important
additions made to astronomical science since those
of Dr. Bradley. He discovered a second ring be-

♦ Additional Sotcs—CP)-

7(J Mechanical Philosophi/. [Chap. L

loni^-ing to that planet, and actually observed fixed
^tars between this and the one before known*
} Je discovered also around the same planet a qicin^
tuple belt of spots, by which he ascertained the re-
ality and the time of its diurnal motion. He has
published new and valuable observations on the
gun, the moon, and indeed on almost all the bo-
dies belonging to the solar system. He has greatly
enlarged our acquaintance with the fixed stars;
and, in a word, so much extended our knowledge
of astronomy, that his life may be considered as
forming one of the most important asras ii,i the his-
tory of this branch of philosophy.

This celebrated Astronomer has given a very
sublime and curious account of the Construction of
the HeavenSy with his discovery of some thousands
of nebuLzy or clouds of stars ; many of which are
much larger collections of stars, than all those
together which are visible to our naked eyes, added
to those which form the galaxy, or milky zone
tliat surrounds us*. He observes, that in the
vicinity of those clusters of stars there are proper-.
tionally fewer stars than in other parts of the hea-r
vens ; and hence he concludes that they have at-
tracted each other, on the supposition that inlhiite
space Avas at first equally sprinkled with them.
Dr. Ilcrschel thinks he has further shown, that the
whole sidereal system is gradually moving round

* Democritus, many ac:e.s ago, affirmed that the MilLy JVa^
was produced b} the united splendour of many small stars, as wc
arc told by Plutarch.

A-'j/iOx.rfrvj tohKujY aoii rj.iy.pw k7a c'J\cyjJov arr'Ttp-Zv trviKt^o
r;^ca5v:^v cc/.atjXo;^ (ruvavycf.7y.r/ Oicc rv;y TTUKyi^criv. Plutarch.
De Placit. Lib. iii. Cap. 1 .

SEcr.VIII.] Astronomy. 77

some centre, which may be an opaque mass of
matter*.

At the close of the seventeenth century, the re-
spective distances of the several planets from the
sun were far from being accurately determined.
These, by successive observations, have been since
ascertained, with a great degree of precision ; and
the various astronomical uses which this knowledge
is calculated to subserve, have been displayed in
the most satisfactory manner. Particularly the
observations made by many philosophers on the
transits of Venus and Mercury, which the eigh-
teenth century exhibited, have thrown much liglit
on this subject, and on several questions of great
importance in astronomy.

It is but a few years since our knovvlcdgc of
Cornets Vvas in its infancy. Dr. Halley, at the be-
ginning of the period under consideration, made
the first attempt to give a systematic view of this
part of the science in his Synopsis Astronomic
Cometicce, published in 1705. But his inquiries
concerning these excentric bodies, though inge-
nious and highly valuable, were far from being
adequate or satisfactory. By the labours of mo-
dern astronomers, our acquaintance with the co-
mets has been wonderfully extended. Sixty-eight
new ones have been observed ; the return of many
of them has been ascertained and demonstrated f,

* See Philosophical Transactions, vol. Ixxix.

t M. de la Lande, in his Histoiy of jUtronoiij, for the year
1801, intimates, that the observations which took place in the
course of that year have made it questionable whether the doc-
trine long entertained, and con^iidered by him and other astrono-
mers as settled, that comets revohe, be not erroneous. This doubt

7S Mechartical Philosophy, [Chap. I,

and many curious facts respecting them discovered,
and received ample illustration. The learned and
indcflitiffable labours of father Boscovich, and of
M. de la Place, for determining the orbits of
comets, have been long known and praised by
astronomers. The great works of M. Pingre, and
of sir Henry Engiefield, in this branch of astro-
nomical philosophy, are entitled to a place among
the most full and useful of those which have ap-
peared on the subject*. But beside what has
been effected by the useful inquiries of these gen-
tlemen, the observations of many others, and par-
ticularly of de Lalande, and his countrymen.
Messier and Mechain, and also of Burckhardt, an
illustrious German astronomer, have contributed
much to extend our knowledge of comets. It is
further worthy of remark, that the difficulty of
making observations on comets has been, w^ithin
a iQw years, greatly diminished. The methods of
calculating their elements are now short and easy,
in comparison with what they were half a century
ago. Operations which then occupied many days,
may now be dispatched with accuracy, in a few
hours.

The importance of accurate observations on the
Jixed stars, in order to ascertain their motion,
places, and relative circumstances, is known to

V. Ill probably soon receive a solution, if the spirit of zeal and in-
dustry should continue \vhich at present animates many European
philosophers.

* Treatise on Comets, by M. Pingre, 2 vols, 4to, Paris, 1783.
The Detenu inntion of the Orbits of Comets, accordivg to the Methods,
of father i)o^Qo\n:\\y and M. de la Place, "with new and complete
Tables, by sir Henry Englefield, 4to, 1799.

Sect. VIIL] Aslronom^, 79

every astronomer. It is to the stars we arc obJiged
to refer all the motions of the sun, the planets, and
the comets. In this part of the science under
consideration much has been done during the last
century. The catalogue of stars formed by Flam-
stead, was before mentioned as one of the most
complete ever derived from the labours of an indi-
vidual. To this succeeded the observations and
catalogues of de la Caille, Bradley, and Mayer,
which it is scarcely necessary to say were highly
valuable. After these, Mr. Bode, of Berlin, pub-
lished, in 1782, a very extensive and im})roved
catalogue, which is greatly esteemed among astro-
nomers. He was followed by the celebrated baron
von Zach, of Gotha, whose catalogues and tables,
in many respects, excelled all that had preceded
them. Beside these, the public has been favoured
with interesting accounts of new stars, by Hers-
chel, Maskelyne, the elder Lalande, and many
others*. The number discovered by the power-
ful instruments of Herschel, in particular, is almost
incredibly great. But the last, and the most
complete series of observations ever made in this
department of astronomy, is that lately announced
by de Lalande the elder, and his nephew, le
Francais Lalande, who, with the assistance of the
ingenious and enterprising wife of the latter, have
determined the places o{ fifty thousand stars, from
the Pole to two or three degrees below the Tropic
of Capricorn f.
We may also reckon among the great astrono-

* See Additional Notes — (Q).

t See Lalande's History of Astronomy for 1800,

80 Mechanical Philosophy. [Chap. 1.

mical improvements of the last age, the formation
of many Tables^ exhibiting the places and motions
of the heavenly bodies. Among these are the
Cometarial Tables of Dr. Halley, since enlarged
and corrected by many hands, and particularly by
a number of eminent French astronomers. To the
same list also belong Tables of the Sun and Moo7iy
by le Monier, and de la Hire; the Sola?' Tables
of de la Caille, Dawes, de Lambre, and von Zach -,
and the successively improved Lima?' Tables of
Clairault, Euler, Mayer, Mason, and fmally, of
Burckhardt, founded on the observations of Burg
and Bouvard. Tables of all the primary PlanetSy
and their Secondaries, have been completed during
the period in question; among the most valuable
of which are those of Bradley, Cassini, de Lambre,
Wargentin, Vidal, Oriani, Schubert, Burckhardt,
and de Lalande. Tables of Parallax and Refrac-
tion have been formed by Bradley, Dimthorne,
and Shepherd, particularly the last, whose work is
a wonderful miOnmnent of industry and perseve-
rance. To these might be added a multitude of
others, published by individuals, and learned socie-
ties, various sets of which may be found in modem
books of astronomy. Those printed in de La-
lande's great systematic work, are probably ex-
ceeded by none extant in fulness and accuracy.
By means of these Tables, many complex calcula-
tions, which, without their aid, would cost the
labour of several hours, or even days, may now be
performed in an eighth or tenth part of the time
M'hich thoy formerly employed, and with much
greater assurance of a true result.

Previous to the eighteenth century, though

Sect. VIII.] Astronomy^ 81

Eclipses, of various kinds, had been observed and
calculated, yet these operations had rarely been
made subservient to any important practical pur-
pose. Y\ ithin a few years past, philosophers have
paid more attention to this part of astronomy.
Methods have been devised of calculating eclipses
with more ease and expedition than before. Large
collections of these calculations have been made,
for a long series of years, with the view of de-
ducing from them the longitude of cities, and
determining other astronomical and geographical
questions. Among those who have distinguished
themselves in this branch of astronomy, Mr. Tries-
necker, of Gemiany, and M. Goudin, of France,
are entitled to peculiar honour*.

To discover an easy and certain method of fmd-
ing the lorigitiide, has long been a grand dcsuk-

* The attempt made by certain infidels, during the eighteenth
century, to derive an argument against the chronology of the sa-
cred writings from some astronomical records, said to be found
in Asia, is well known j as are also the ample refutation cf tlieir
reasoning, and the total disappointment of their hopes from this
quarter. We have been recently informed, that some of tho,
learned men of France, connected witli the late military expedi-
tion to Egypt, assert, that in the course of their inquiries in that
country, they discovered astronomical records, which prove the
age of the world to be many thousands of years greater tlian the
gacred history represents it. It is not the part of a wise man to
answer a 7natter before he heareth it; and therefore until more shall
be known concerning the facts stated, and the reasonings employ-
ed by these men, it would be improper to attempt a discussion of
the subject. But the extreme fallacy to which arguments derived
from sources of this kind are liable, must be obvious to ewery
astronomer} and he must have liule acquaintance with the his-
tory of hvjfnan knowledge who does not know, that as'^ertion^ a3
bold as those in question have more tlian once been demonstrated

Vol. I. - G

S2 Mechankat Philosophy. [Chap. L

ratiim among astronomers and navigators. la
1714, an association was fonned in Great Britain,
under the denomination of the Board of Longitude,
aided by the authority and patronage of the go-
vernment. The exertions and the Hberahty of this
body have done honour to their age and country,
and in a very considerable degree "attained their im-
portant object. The most approved mode of as-
certaining the longitude now in use, viz. by ob-
serving the distance of the momi from the sun, or
from certain stars, though repeated!}^ suggested,
was never reduced to practice till the eighteenth
century. In promoting this object Dr. Halley
early distinguished himself. To him succeeded
several others, who formed Lunar Tables , with a
view to facilitate the necessary calculations; but
among these, none laboured with so much success
as professor Mayer*, of Gottingen, whose tables
were brought to such a degree of accuracy -as to be
thought worthy of a large premium from the Board
of Longitude before mentioned. Mayer's tables
were afterwards improved by Mr. Charles Mason,
of England, who reached a still greater degree of
precision in his calculations. And finally, to the
lev. Dr. Maskelyne, the present Astronomer Royal^

to be false ; that expectations as sanguine have been often blast-
ed J and that modern discoveries in science, and tlie observations
of trax'cllers, instead of discrediting the sacred history, have uni-
formly tended to illustrate and confirm it. See Additional
Notes— (R).

* Tobias Mayer, the celebrated astronomer, v/as born in Ger-
many in the year 1723, and died in 1762. For his Astronomical
tables and Precepts, the English Board of Longitude gave his
widow 3000/. sterhng.

Sgct.VIII.] Astronomy. 83

is due the honour of contributing much toward the
perfection of the plan, and of introducing it into
general practice.

Another method of finding the Longitude, by
observations on the Eclipses of Jupiter's moons,
though practised as early as 1688, has yet been
much improved during the period under discussion.
For these improvements, which are chiefly found-
ed on the superior extent and accuracy of modern
tables, -we are indebted principally to Drs. Bradley
and Pound, M. Cassini the younger, Mr. Wargen-
tin, and Tvl. Delambre, the tables of the last of
whom have been generally adopted in man}' of the
late nautical almanacks. A third mode of deter-
mining the Longitude, by well regulated Time-
keepers, is almost wholly a production of the last
age. For although some attempts of the kind
were made in the preceding century, nothing elfec-
tual was done until 1714, when Henry Sully, an
Englishman, published a small tract at Vienna, on
the subject of watch-making, and annouAced some
improvements in the art, with a view to the Lon-
gitude, which were said to be valuable, and attend-
ed wath success. This plan, however, was after-
wards bro'ught much nearer to perfection, by the
ingenious and persevering labours of John Harri-
son, also of England, w4io, in 1726, produced a
time-keeper of such uncommon accuracy as not to
err above one second in a month, for ten years
together. Watches of a similar kind, which have
proved of great utility to navigators, were also
formed soon after Harrison*s^ by Kendal, Arnold,
and others of Great Britain, and by Ic Roy, Ber-
thoud, and several other distingnislied French

G2

84 Mechanical Philosophy, [Chap. L

artists. The happy efTects of these discoveries and
improvements in aiding navigation, and, of course,
their favourable influence on commerce and the
interests of humanity, are so obvious as not to re-
quire formal explanation.

But no age, assuredly, can vie with the last, in
the accuracy and astonishing powers of the astro-
nomical instruments which it produced. The prin-
cipal ones, among those of an optical kind, were
mentioned in a former part of this chapter, and
need not be again recounted. In addition to these,
many curious instruments and machineSy serving to
ilhistrate and exemplify the principles of astro-
nomy, have been devised by several ingenious men.
The first deserving of notice is the Orrery y invent-
ed by Mr. George Graham, an English mathemati-
cal-instrument-maker, and presented to George I*.
The next is a machine, under the same name, con-
trived by Mr. James Ferguson, also of England,
and inckiding some improvements on the fonmer.
To tJiese succeeded a Plaiietainum, of very curious
structure, by Mr. William Jones, of London, and
the celebrated astronomical Sphere^ by Dr. Long,
professor in the university of Cambridge; to say
nothing of a multitude of other inventions of a
similar kind, by diflerent artists and astronomers.

* Thf origin of the name given to this machine is as follows.
Mr. llov.lcy^ a iiiatliematical-instrarnent-maker, having obtained
one from Graham, the inventor, to be sent abroad, with some of
his own instruments, he copied it, and made one for the Eari of
Orrtry. Sir Richard Steele, who l^ncw nothing of Mr. Graham's
right to the invention, thinking to compliment the noble encou*
ragcr, called it an Orrcr>/, and .gave Rowley the praise due t^
Graiiam.

Sect. VIII.] Astronomy. 85

But among all the contrivances of this nature
which have been executed by modern artists, the
machine invented by the illustrious American,
Dr. David Rittenhoase, and modestly called by
him an Orrery^ after the production ol" (riaham, is
by far the most curious and valual)le, whether we
consider its beautiful and ingenious structure, or
the extent and accuracy with v/hich it displays the
celestial phenomena*.

Among the instruments for making astronomical
observations, invented during the last century,
there is none more important than the celebrated
Quadrant, invented by Mr. Godfrey, of Philadel-
phia, though afterwards claimed as a production
of Mr. Hadley, whose name it still bears |. The
inestimable value of this instrument, for various
purposes, and especially for the direction of the
mariner, is. well known. Since the original plan
of constructing it was announced, improvements
of much value have been suggested by the rev. Dr.
Ewing*|, provost of the university of Pennsylvania,
by professor Patterson §, of the same institution,
and by Mr. Magellan, of London. AVe may next
mention the Astronomical or Equatorial Sector, an
instrument of great utility, invented by the ingeni-

* For a fiirther account of this celebrated Onny, see the
Transactions of the American Philosophical Societi/, vol. i. Those
who wish to see a brief and comprehensive view of the genius,
character, and works of Dr. Rittenhoase, will find a good sketch
of them in an Euloi^iiim, pronounced in honour of his memory,
before the American Philosopliiad Society, by Dr. Rusii.

f See Additional Notes — (S).

X Transactions of the American Philosophical Society, vul i.

§ Ibid. vol. iv.

SQ Mechanical Philosophy. [Chaf. L

ous Mr. GraPiam, before mentioned ; the Transit
and Equal Altitude Instrument, first made for le
Monnier, the French astronomer, by Mr. Sisson,
of London 3 and the Grand Astronomical Circle,
by the chevalier de Borda and others, the most
complete and comprehensive instrmnent in use
among astronomers, being in fact a kind of port-
able observatory, and probably carrying the deli-
cate accuracy of its indications to nearly as great
a length as human art will admit. Nor ought it
to be omitted here, that the method of graduating
astronomical instruments has, within the last
age, received the most astonishing improvements.
Mr. Bird, of London, was long distinguished in
this line ; but more recently his countryman, Mr.
Ramsden, has invented a method incomparably
more easy, expeditious, and accurate than any
before known. The abridgement of labour by
this new method is scarcely credible. An opera-
tion which cost Mr. Bird several days, we are
told, can now be performed much better upon
Mr. Ramsden's plan, and nearly in as many mi-
nutes.

Beside the invention of new astronomical in-
struments, the last age is also remarkable for the
great improvement of almost all that were before
known, and in use. The services, by these means,
rendered to astronomy by the artists mentioned in
the hjGt paragraph, and also by Short, Graham,
Ilerschel, Troughton, M. Lenoir, and others, ai-e
too numerous and important to be adequately ac-
knowledged in this place. These improvements
have, no doubt, served great Iv to abridge the labour

Sect. VIII.] Astronomy. 8?

of astronomical calculations, and to confer new ac-
curacy upon every part of the science.

At the concUision of the seventeenth century,
the number of regularly established and endowed
public Observatories was small. It is believed that
only tivo^ or at most three, of any distinction existed
at that time. Within the last century, the number
of these institutions has greatly increased. They
are now established in almost every part of Europe ;
richly furnished with the best apparatus for making
observations; and continually sending forth dis-
coveries and improvements, as the best evidence of
their utilit}^.

But astronomy has not only been enriched by
the augmentation of its own immediate stores;
it has been also improved, during the period in
question, by the collateral aid of other sciences
and arts. The improvements in the viechanic artSy
hy furnishing the astronomer with more perfect
instruments, have materially furthered him in his
course. The discoveries in dynamics and optics,
and the refinements which have taken place in ina-
thematical science, though apparently of small mo-
ment when considered in themsehes, yet, when
applied to astronomical investigations, have proved
highly important and useful. Formerly astronomy
could only be improved through the mediuni of
acaial observation; but when the great Newtonian
theory of the solar system was once established, a
new path of inquiry, and new grounds of calcula-
tion, were laid down. Data, from that period,
werc!^ afforded for ascertaining, with great ])ret^ision,
the orbits, the revolutions, and the inequalllie.^ of

"8S Mechanical Philosophy. [Chap. I.

the several planetary bodies; and new light and
aid poured in on every side, from the geometrician
and the artist, as well as from the immediate in-
quirer in this sublime science.

Under this head it is proper to mention the in-
troduction of the New or Gregorian Style of chro-
nology into Great Britain in 1752. In 1.582 pope
Gregory XIII, finding perplexity to arise in the
computation of time, from some errors in the
Julian Calendar, which, antecedently to that pe-
riod, had been used throughout Christendom,
thought proper to order the formation and adop-
tion of a new style of reckoning. The astronomers
and mathematicians whom he summoned to Rome
for this purpose, after spending several years in
investigating the subject, and adjusting the prin-
ciples of another system, produced what has been
since called the Gregorian Calendar. In form-
ing this method of computation ten days were an-
ticipated or taken away from the old Calendar, and
a plan attempted for maintaining a greater degree
of accuracy, by a proper distribution of Epacts
through the year. The Gregorian Style, thus
formed, was soon adopted by all the catholic
states, and in most of the protestant countries, be-
fore the commencement of the eighteenth century.
In Britain, however, and her dependencies, and in a
few other protestant states, the Julian or Old Style
was not given up for a number of years after-
wards. In 1 752, however, by an act of the British
parliament, the Gregorian Calendar was adopted ;
and, at the same time, the Ecclesiastical Year,
which had before commenced on the 25th of March,

Sect. VIII.] Astronomy, 89

was made to coincide with the Civil Tear, and
ordered, like that, to be computed from the first of
January"^.

Beside the gi'eat names, and the important dis-
coveries and improvements above detailed, it would
be easy to add to the list many others wor-
thy of notice. The numerous observations and
writings of Ferguson, Lax, \^ince, and others of
Great Britain ; of Bailly, de Parceval, Beniier, Se-
jour, and Duvaucel, of France ; of Lambert, Gri&-
chow. Gibers, von Wahl, Wurm, and Klugcl, of
Germany; of Bianchini, Frisi, Manfredi, Zanotti,
Gddi, Cagnoli, and Oriani, in Italy; of Klingensti-
erna. Mallet, Prosperin, and Melanderhielni, in
Sweden; of Roemer, Loowenoern, Bugge, and
Wurbierg, in Denmark; and of many others, in
almost every part of Europe, who have all contri-
buted something to the astronomical improvements
of the age, and facilitated the acquisition of astro-
nomical knowledge.

Nor has America been destitute of zealous stu-
dents, and successful observers in astronomy. Be-
side the illustrious Rittenhouse, before mentioned,
whose name alone would rescue his country from
the charge of deficiency in astronomical genius,
we can boast of Golden |, Winthrop, Evving, Bow-

•* It is scarcely necessary to inform the intelligent reader that
■fhe delay of adopting this Calendar in Britain till 17.52, rendered
it necessary to drop eleven days, instead of te^i.

f See Principles of Action in Matter , and the Motion of the Pla-
cets explained from those Principles, &c. by Cadwallader Colden,
Esq. 4to, London, Dodsley, 1753. And also a siib;,equent pub-
lication by the same author, in the form of a Letter to the Earl of
Macclesfield, explaining tlie doctrines contained in tlie former
work. Mr. Colden \\ as, for some years prior to the American

PO Mechanical PhilosopJuj. [Chap. I,

doi]i, Madison, Page, Patterson, Ellicott, Willard,
and several others*, who, if they have not made
splendid discoveries, or great additions to astro-
nomical science, have yet published useful obser-
vations, and contributed to promote that degree
of taste for this branch of philosophy which exists
in our country.

From the foregoing review, it appears, that aK.
most every i>art of mechanical philosophy, during
the eighteenth century, has undergone great and
radical improvements ; and that the path is evi-
dently marked out to still greater and mare in-
teresting attainments. In Electricity^ GalvanisWy
Pneiunatics, Optics, and Astronomy, the additions
to our knowledge," during this period, are pre-
eminently conspicuous. For much of this pro-
gress we are indebted to accident ; but our obliga-
tions are also great to the genius and industry of
individuals, and the labours and publications of
many learned societies, who have with honourable
zeal and perseverance encouraged experiments and
enterprises of discovery, and collected and made
known a multitude of important focts. It is also

revolution, lieutenant-governor of the province of New- York.
Whatever may be thought of some of the opinions exhibited in
these publications, they display genius, learning, andj, for the
country in which they v/ere written, an unusual taste for mathe-
mntical and astronomical incjuiries.

•* I'he specimens which have been given to the public of th©
astronomical learning and skill of most of tlie gentlemen men»
tioned above, and of some other Americans, may be found in the
volumes of Transact icnis which have been published by the AmerU
can Philoscphkal Society, and in the Memoirs of the American
Acadtnvj of Arts and Sciences.

Chap. I.] Mechanical Philosophy. 91

a remarkable characteristic of the age, that every
branch of natural philosophy has been investigated
in modern times, in a more practical manner than
it ever had been before, and more extensively and
generally applied to purposco of economy and the
arts. While the explorers of science have gratified
liberal curiosity, and gained reputation for them-
selves, their inquiries have been rendered subservient
to the abridgement of labour; the increase both of
expedition and elegance of workmanship, in manu-
factures ; and the promotion of human comfort, to
a degree beyond all former precedent. In short,
the number of heads and of hands at work, in the
various departments of mechanical philosophy, at
the close of the century under consideration, was
imquestionably much greater than it ever had been
since science was an object of human study. That
much further, and more satisfactory light, therefore,
may be expected to break in upon us, at no great
distance of time, on many points at present in-
volved in darkness, can hardly be doubted. " But
the subject," says an eloquent writer, " is still
greater than our exertions, and must for ever mock
the efforts of the human race to exhaust it. ^^'ell
did lord Bacon compare natural philosophy to a
pyramid ; its basis is indeed the history of nature,
of which we know a little, and conjecture much ;
but its top is, without doubt, hid high among the
clouds. It is the ivork xvhich God xcorkclh from
the beginning to the end, infinite and inscrutable*."

* Bishop Watson's Chemical Essai/s, vol, i.- p. 15.

§2

CHAPTER IL

CHEMICAL PHILOSOPHY.

As Mechanical Philosophy has respect to those
motions of the larger bodies of the universe which
fall under the inspection of our senses, so Chemi-
cal Philosophy is the science which explains tlK)se
motions that take place among the minute com-
ponent parts of bodies, and that are known chiefly
hy the effects which they produce ; in other words,
its object is, " to ascertain the ingredients that en-
ter into the composition of bodies — to examine the
nature of these ingredients, the manner in which,
and the iav^'s by which, they combine, and the pro-
perties resulting from their combination.*' It may
safely be asserted, that there is no branch of sci-
ence in which the discoveries and improvements,
daring the last century, have been more numerous,
or more important, than in this. Indeed, such has
been their number, and their ititeresting nature,
that to exhibit them in detail would be to fill many
volumes.

Though some of the facts and principles which
enter into all the systems of modern chemistry have
been known for many centuries, and indeed as far
back as history reaches ; yet, as a regular science,
it could scarcely be said to have had an existence
prior to the middle of the seventeenth century. It

Chap. II.] Chemical Philosophy, 93

was about that time that the learned societies in
Europe began to be formed, and the reign of Al-
chemy to decline. In the imjuiries then instituted
in chemical philosophy, the celei^rated Mr. Boyle
led the way. His speculations and experiments
on light, heat, air, water, and other subjects allied
to those, were in several respects useful, and pre-
pared the way for subsequent improvements. To
his learned labours succeeded those of Dr. jMayow,
who not only prosecuted the inquiries commenced
by Boyle, but had also the honour of devising
others, equally new and important. He went far
in discovering some of the properties of that por-
tion of the atmosphere which has been since called
vital air and oxygen^ and ascertained the necessity
of its presence for the purposes of combustion and
respiration*. The discoveries and the works of
this experimental philosopher, however, notwith-
standing their curious and valuable nature, had
fallen into oblivion, and a century after their
publication were scarcely at all known among the
learned of Europe.

In the list of luminaries in chemical science, the
immortal Newton next appears. Though his mind
was chiefly occunied in exploring other regions of
philosophy, he was by no means regardless of this;
and about the beginning of the eighteenth cen-
tury he first suggested the idea of arranging the
phenomena of chemistry under the head of a pe-
culiar species of attraction. The chemists who
lived before this great philosopher supposed that
all solvents, or substances capable of dissol nng

* Tractatu3 Quinque Mcdko-Phpid, p. 12 and 10(5.

94 Chemical Pldlosopliy. [Chap. IL

others, were composed of particles which had the
fomi of wedges or hooks ; that solution consisted
in the insinuation of these wedges or hooks, be-
tween the particles of the bodies to be dissolved ;
and that chemical combination was merely the
linking of the different particles together, by means
of holes in one set of them, into which the hooks
or the wedges of the other set were thrust. Such
explanations, absurd as tJiey may appear, were
generally fashionable, until Newton ftrst ascribed
the chemical union of bodies to an attraction be-
tween the particles themselves : a doctrine which
was soon unanimously received, and has continued
ever since to prevail. The nature and laws of this
attraction were afterwards better explained and
systematised by Mr. Geoffroy, a philosopher of
France, who invented a method of representing the
different chemical affmities by figures and diagrams,
and arranging them in tables ; a method which has
since been generally received into practice, and
greatly contributed to the facility and advancement
of this science.

■ Contemporary with Geoffrey was Boerhaave,
who, among the various objects to which he direct-
ed his great and excellent mind, gendered himself
conspicuous by his attention to chemistry. He
made many new experiments, and improved almost
^very part of chemical philosophy which was then
known. He was particidarly distinguished by
maintaining, in opposition to Boyle and Newton,
that heat was a real specific substance, a fluid uni-
versally diffused, and one of the most important
agents in nature. In supporting this doctrine he
triumphed over his illustrious opponents, and esta-

Chap. IL] Chemical Philosophy. 9o

blished a principle which has been in substance
generally adopted by the piiiiosophical world since
that time.

At an early period of the eighteenth century
Stahl, an eminent German chemist, published his
theory of Phlogistoii, wliich produced one of the
most remarkable revolutions in chemical philosoj)hy
that ever occurred*. This theory had been in-
vented and published, in the preceding century, by
Becher, a philosopher of Germany ; but he died
before it obtained that character and currency
which it afterwards acquired. It was reserved for
Stahi to adopt and systematise his doctrines in a
manner so plausible and consistent as to secure for
them a general reception. According to this cele-
brated theorist there is only one substance in na-
ture capable of combustion, which, therefore, he
called Phlogiston ; and all those bodies which can
be made to burn contain more or less of it. Com-
bustion is merely the separation of this substance,
which, during the process, flies off, leaving behind
the incombustible body with which it was connect-
ed. He supposed the conversion of sulphur into
an acid, by the action of heat, most completely to
illustrate and confirm his doctrine; and, indeed,

* George Ernest Stahl was born in Franconia, in J660, auJ
died in 1/34^ in the 75th year of his age. He was undoubteJIy
a man of great talents and learning, and the author of many
valuable works ; the most important of which relate to hi.s sys-
tems of Medicine and of Chemistrj/. He publislied an edition of
the Phj/sica Subterranea of Becher, after tlie death of that great
chemist, and adopted the theory which tliis work displayed ; but
he simplified and improved it so much, that he made it entirely
his own 5 and accordingly it has been ever since known by tixc
nzme of the StaJdian theoi-v.

g6 CheJiiical Philosophy, [Chap. IL

so ingeniously devised, and so extremely plausible
were his experiments on this subject, that he was
considered as having satisfactorily established, both
in the analytic and synthetic methods, the principle
for which he contended. Objections, it is true,
were made to this theory, for it was soon found
that sulphur would not burn, if air were completely
excluded, and that the sulphuric acid was heavier
than the supposed compound from which it was
produced. But still the phlogistic doctrine prevail-
ed. The simple, luminous, and satisfactory man-
ner in which it appeared to account for various
phenomena, and the numerous facts which seemed
to give it support, aided by the ingenious refme-
ments of its partisans, for a considerable time bore
down all opposition.

The theory of Stahl maintained its ground for
more than half a century. It commanded the
general assent of chemical philosophers, and was
especially adopted and defended by some of the
most eminent men which the age produced. And
although it is now rejected by a great majority of
those who cultivate the science of chemistry, yet
neither the ingenuity of the system, nor the talents
of its author, can for a moment be questioned.
Indeed, the doctrine of this great man, though at
present generally considered as erroneous, was by
no means a useless effort. Before the publica-
tion of his theory, the different branches of this
science had been studied in a manner too de-
tached and unsystematic; experiments had been
made with too little accuracy ; and scarcely any
luminous and generalising views had yet been given
of the subject. In the fair and ingenious fabric of

Chap. II.] Chemical Philosophy), 97

Stahl, the scattered fragments produced by preced-
ing inquirers were arranged and combined ; expe-
riments began to be conducted with a spirit of
more acute and precise observation ; and the \vlioIe
aspect of this department of philosophy became
more regular and scientific. ,

Assuming his theory, as in general the only true
one, and proceeding on its fundamental principles,
the philosophers who followed him devised consi-
derable improvements, and made many important
discoveries. The rev. Dr. Hales revived the pur-
suit of pneumatic chemistry, which had been gene-
rally neglected since the time of Mayow ; and, in-
deed, the honour of being the father of this branch
of the science belongs more eminently to him than
to any other individual*. He found that many
substances were readily convertible from the fixed
to the gaseous state, and vice versa ; he carried his
inquiries into the effects of fermentation, dissolu-
tion, combination, combustion, and respiration,
further than any who had gone before him ; he
made great improvements in the necessary machi-
nery and apparatus for pneumatic experiments ;
and, on the whole, w^as the author of many valua-
ble additions to the science.

The doctrine of Latent Heat was first taught by
Dr. Black, of the university of Edinburgh, in the
year 1757- His discovery, and the doctrine which
he founded on this discovery, may be considered

* The rev. Stephen Hales, D. D., was born in 1677. He
was a great chemist and vegetable physiologist. Beside many
Gommunications to the Royal Society, he published two vo-
lumes of Statical Essays^, which are highly esteemed. He died
in 1761.

Vol. I. H

gs Chemical Philosophy, [Chap. II.

as comprised in the following propositions. When-
ever a solid is converted into a fluid, it combines
with a certain portion of caloric, without any aug-
mentation of its temperature, and it is this portion
of caloric which occasions the change. When this
fluid is reconverted into a solid, the caloric which
produced the fluidity leaves it without any dimi-
nution of its temperature ; and it is this abstraction
which occasions the change. Thus the combina-
tion of a certain portion of caloric with ice causes
it to become water , and the abstraction of a cer-
tain portion of caloric from water causes it to be-
come ice. Water, then, is a compound of ice and
caloric ; and, in general, all fluids are combinations
of the solid to which they may be converted by
cold, and a certain portion of caloric. The same
principle, according to this philosopher, applies to
the conversion of liquids into elastic fluids^ or the
reverse ; this conversion and reconversion depend-
ing on the addition or abstraction of caloric. To
this caloric Dr. Black gave the name of latent heaty
because its presence is not indicated by the ther-
mometer. The great importance of this discovery,
and the extensive application which has been since
made of it, in explaining fluidity, congelation, eva-
poration, animal heat, and many other phenomena,
render the period of its annunciation to the world
one of the most interesting ceras in the history of
chemical science.

In the mean time, sir Torbern Bergman, an
illustrious Swede, was busily engaged in exploring
the same de])artment of philosophy *. In the

•* Sir Torbern Bergman was born in tht; year 1/35, ami
♦lied in 1/84. lie i.s beyond all doubt, entitled to a place

Chap. II.] Chemical Philosophi/, 99

course of liis inquiries, he threw great light on the
subject of elective at fractions; enlarged and ex-
plained more satisfactorily the tables of affinities ;
gave much new and valuable information relative
to the constitution of volcanic and other mineral
substances ; made a considerable reform in the
nomenclature of the science, and accomplished so
large an amount of improvement, that he may
be justly styled one of the great fathers of che-
mistry. Contemponiry with Bergman was his
celebrated countryman Scheele, one of the most
extraordinary men and distinguished philosophers
of the age in which he lived*. He has been justly

among the greatest men of his age. He was highly distin-
guished as a chemist, mineralogist, geometrician, and astronomer.
In the two first-mentioned branches of science he was particularly
eminent. In the history of chemistry, fev/ names occur more
frequently, or are associated Mi th more important services, than
his.

* Chai-les William Scheele was born Dec. 19, 1/42. He was
bound an apprentice, when very young, to an apothecary at Got-
tenburg, where he first felt the impulse of tliat genius which
afterwards made him so conspicuous. He durst not, indeed, de-
vote himself openly to chemical experiments ; but he contrived
to make himself master of the science by devoting those hours to
study which were assigned to him for sleep. He afterwards
went to Sweden, and settled as an apothecary at Koping. Here
Bergman first found him, saw his merit, and encouraged itj
adopted his opinions, defended him with zeal, and took upon
himself the charge of publishing his treatises. Encouraged and
excited by this magnanimous patronage, the genius of Scheele,
though unassisted by education or wealth, burst forth with asto-
nishing lustre. To wonderful acuteness, ardour, and persevering
diligence in his philosophical investigations, he addcxl singular
purity and amiableness of moral and social character. His out-
ward appearance, however, was by no means expressive of that
great mind which lay concealed, as it were, under a veil. He
died in ]786, in the 44tii year of his age.

II 2

100 Chemical Philofophy, [Ohat. II.

called the Newton of chemistry. Without the aid
of education or of wealth, his genius burst forth,
and slione with astonishing histre ; insomuch that
at the age of forty-four, when he died — an age at
which most other great men have but begun to at-
tract pubHc attention — he had finished a career of
discoveries whicli have no equal in the annals of
chemistry. He made new and ingenious analyses
of many bodies, the composition of which had
never before been accurately investigated. He
discovered vital or oxygenous air, about the same
time with Dr. Priestley, and without any know-
ledge of what had been done by that celebrated
philosopher. He discovered a number of new
acids, and exceedingly enlarged the lists of chemi-
cal substances. He made known a number of new
paints and dyes, and in various ways contributed
to the progress of arts and manufactures. In short,
he instituted such a variety of original and inter-
esting experiments, and threw so much light on
almost every branch of chemical science, that a
vplume might be filled with their history, and with
the praises of his ingenuity, diligence, enterprise^
and success.

Next in this honourable catalogue stands Dr.
Priestley, whose fame as the author of numberless
valuable experiments, and many important disco-
veries, is known in every part of the world where
philosophy is cultivated. His labours, particularly
in pneumatic chemistry, have been extensive,
various, and persevering, to a wonderful degree.
Among many other services rendered to this branch
of science, he discovered the 7iilroiis and oxygenous
airs; he lu'st exhibited acids iiud alkalies in the

Chap. II.] Chemical Philosophi/, lui

gaseous form ; he discovered the power of vegeta-
tion to restore vitiated air*; he ascertained the
influence of light in enabling vegetables to yield
pure air ; and elucidated both the principles of
respiration, and the influence of oxygenous air
on the blood. But the great extent and value
of his inquiries, respecting the analyses of tlie at-
mosphere, and the production of various factitious
airs, can be fully understood only by the perusal of
his instructive volumes on these subjects.

To the list of successive luminaries in chemistry,
now under review, it would be improper not to
add the name of M. Macquer, who contributed
in an eminent degree to the advancement of che-
mical knowledge by his excellent works, long held
in the highest esteem in every part of Europe.
His ingenious experiments and numerous discove-
ries, particularly respecting arsenic^ dyes, and earths^
will ever entitle him to honour and gratitude from
philosophers. By the labours of these great men,
and of many others — whose names might vvith pro-
priety be mentioned, did not our limits forbid such
an enlargement of the list — the boundaries of che-
mical philosophy had been more extended, and its
stores of experiment and discovery more enriched,
within the twenty years immediately preceding the
introduction of the theory of the French academi-
cians, than in any whole century before.

But some of the discoveries made bj' these aud
other chemists must be more particularly detailed,
in order to present the reader with a tolerable

* See Additional Notes — (T),

102 Chemical Philosophy. [Cuap. II.

view of the progress made in chemical science at
this eventful period.

Not long after Dr. Black had published his doc-
trine of Latent Heat, his discovery of Carbonic
Acid gave additional lustre to his character, and
formed a new sera in the history of chemistry.

Paracelsus and Van Helmont were acquainted
with the fact, that air is extricated from solid
bodies during certain processes ; and the latter gave
to air thus produced the name of gas, by which
word he meant to express every thing which is
driven oft from bodies in the state of vapour by
heat. Boyle called these kinds of air artificial airs,
and suspected that they might be different from
the air of the atmosphere. Hales ascertained the
quantity of air that could be extricated from a
gi'cat variety of bodies, and showed that it formed
an essential part of their composition. Dr. Black
proved that the substances called //w^, magnesia,
and alkalies, are compounds, consisting of a pecu-
liar species of air, and pure lime, magnesia, and
alkali. To this species of air he gave the name of
fixed air, because it existed in these bodies in a
fixed state, though he knew not the materials of
which it is composed. The air or gas was after-
wards investigated by Dr. Priestley, and a great
number of its properties ascertained. From these
properties Mr. Keir first concluded that it was
acid; and tliis opinion was soon confirmed by the
experiments of Bergman, Fontana, and others.
Dr. Priestley at first suspected that this acid en-
tered as an ckment into the composition of atmo-
spherical air ; and Bergman, adopting the same

Chap. II.] Chanical Piiilosophy. 105

opinion, gave it the name of aerial acid. Mr.
Bewly called it mephitic acid, because it could not
be respired without occasioning death. Mr. Keir
called it calcareous acid; and, at last, M. Lavoi-
sier, after discovering that it is formed by the com-
bination of carbon and oxygen^ gave it the name of
carbonic acid gas, which it now generally bears *.

The discovery oi inflammable hydrogenous air, in
1766, deserves also to be recorded as a remarkable
event. This air was obtained by Dr. Mayow, and
afterwards by Dr. Hales, from various substances,
and had been known, long before, in mines, under
the name of ih^ Jire damp. But Mr. Henry Caven-
dish ought to be considered as its real discoverer ;
since it was he who, in the year above-mentioned,
first examined it, pointed out the difference be-
tween it and atmospheric air, and ascertained the
greatest number of its properties f. It was found
by M. Lavoisier to be twelve times as light as
common air. Its nonrespirable character was
more fully determined by Scheele, Fontana, and
Davy. The products resulting from the combina-
tion of hydrogen with the sulphuric, phosplwric,
and ca?'bonic acids, were discovered and investigat-
ed principally by Scheele, Bergman, Fourcro}-,
Vauquelin, Gengembre, Kirwan, and Volta. It
was first called Hydrogen by the French academi-
cians, because it enters into the composition of
wafer.

A short time after the discovery of Mr. Caven-

* Thomson's Chemistry. In some sentences the autlior hnf
borrowed not only the facts, but also the language of thi'^ respect-
able writer.
' f Pidlosophioul Transactions for I'^QQ.

104 Chemical Philosophi/. [Chap. II.

dish, pneumatic chemistry was enriched by the adr
dition o{ Azotic gas to the list of substances before
known. — This gas was discovered in 1772 by Dr,
Rutherford, noAV professor of botany in the univer-
sity of Edinburgh, and an account of it published
in his thesis De Acre Mephiti.co^ in the same year,
M. Lavoisier, in 1115, made known this gas as ^
component part of atmospheric air. About the
same time it was procured by Scheele, and proved
to be a distinct fluid. Its specific gravity has been
investigated and determined by Kirwan and La-
voisier, the latter of whom makes it 0.00 11 o, or to
common air as 942.6 to 1000. The combustibility
of azotic gas, and the production of nitric acid by
this process, were first discovered by Mr. Caven-
dish, and communicated to the Royal Society in
1785. The name Azote was given to this gas by
the French academicians, and is derived from its
incapacity to support life.

The discovery of Oxygen was another very im-
portant step in the course of chemical improve-
ment. The gas, the base of which is commonly
known by this denomination, was discovered by
Dr. Priestley, on the 1st of August, 17/4, and
called by him dephlogisticated air. Mr. Scheele,
of Sweden, as was before observed, discovered it in
1775, without any previous knowledge of what
Dr. Priestley had done ^ and gave it the name of
empyreal air. Condorcet gave it first the name of
vital airy and M. Lavoisier afterwards gave it the
name of oxygen gas, which is now generally
adopted.

The discovery of this substance, and the inves-
tigation of its properties, deserve to be ranked

Chap. II.] Chemical Philosophy. 105

among the most importaut e\ ents recorded in the
history of chemistry. The explanation which they
have afforded to the principles of coinbustioiiy re^
spiration, aciditij, &c. places their value in a very
interesting point of light. To this discovery, and
these investigations, we may trace the commence-
ment of that grand revolution in chemical science,
which was soon afterwards established.

Paracelsus believed that there was only one acid
principle in nature, which communicated taste and
solubility to the bodies with which it was combined.
Becher embraced the same opinion, and added to
it, that this acid principle was a compound of earth
and zvater, which he considered as two elements.
Stahl, as we have seen, adopted the theory of Be-
cher, and endeavoured to prove that the acid prin-
ciple is sulphuric acid, of which, according to him,
.all the other acids are mere compounds; but his
proofs were only conjectures or vague experiments,
from which nothing could be deduced. Neverthe-
less, his opinion, like every other wiiich he advanced
in chemistry, continued to have supporters for a
long time, and was even sanctioned by Macquer.
At last its defects began to be perceived. Kcrg-
man and Scheele declared openly against it ; and
their discoveries, together with those of Lavoisier,
demonstrated the falsehood of both parts of the
theory, by showing that sul})huric acid does not
exist in the other acids, and that it is not com-
posed of water and earth, but ol sulphur aiici
oxygen.

The opinion, however, that acidity is owing to
some principle common to all the salts, w^as not
abandoned, YV^allerius, Meyer, and Sage, had ad-

106 Chemical Philosophy . [Chap. II.

vanced different theories in succession about the
nature of this principle ; but as they were formed
rather on conjecture and analogy than direct proof,
they obtained but few advocates. At last M.
I^voisier, in 1778, by a number of ingenious and
accurate experiments proved that several com-
bustible substances, when united with oxygen,
form acids ; that a great number of acids contain
oxygen ; and that, when this principle is separated
from them, they lose their acid properties. He
concluded, therefore, that oxygen is the acidifying
principle, as the wond imports, and that acids are
nothing more than combustible substances com-
bined Vv'ith oxygen, and differing from one another
according to the nature of the combustible basis.
This doctrine has been since confirmed by experi-
ment, and is now generally received among che*-
mists*.

For our knowledge of the composition of atmo-
spheric air, we are indebted to the chemical philo-
sophers of this period. The first step in this in-
quiry was taken by that unwearied experimenter.
Dr. Priestley, in 1774, by the discovery of oxygen
gas. This gas, according to the prevailing theory
of tl>c time, he considered as air totally deprived
of phlogiston. Azotic gas, on the other hand,
was air saturated with phlogiston. Hence he con-
sidered common air as oxygen gas combined with
an indefinite portion of phlogiston, and varying in
purity according to that portion, being always pure
in an inverse proportion to the quantity of phlo-
giston it contained.

* TJionjson's Chemistri/.

Chap . II .] Chem leal Pit ilosophy, 1 07

While Dr. Priestley was making experiments on
oxygen gas, Scheele, of Sweden, proceeded to the
analysis of air in a different manner. Froni iirs
experiments he concluded that common air is com-
pounded of two diilerent elastic fluids, viz. foul
mvy which constitutes more than two thirds of the
whole, and another air, which is alone capable of
-supporting flame and animal life, and to which he
gave the name of empyreal air. The foul air of
Scheele was the same with the phlogisticated air of
Priestley ; and the empyreal air of the former ^\ as
the same with the depJdogisticated air of the latter,
or with what is at present called oxygen gas.

While Scheele was occupied with these experi-
ments, Lavoisier was assiduously employed on the
same subject, and was led, by a different road, to
precisely the same conclusions. He found that
common air is composed of azotic and oxygen
gases ; and, from a variety of experiments, he de-
termined the proportions to be 73 parts of azotic
gas, and '21 parts of oxygen gas. These experi-
ments were made in the year 177(>.

The discovery of the composition of zcater, before
alluded to, next follows in the list of those bril-
liant acquisitions which distiuguish the annals of
chemical science during this period. — ^\'ater v.as
believed, by the ancients, to be one of the fcuir
elements of which every other body is composed.
The opinion of its being a simple substance seems
generally to liave prevailed until the year 17^ 1 , when
Mr. Henry Cavendish, of Great Britain, discovered,
by several experiments, that it is a compound, and
formed by the union of oxygen and hydrogen. In
iifew mx)nths afterwards, the conclusion of Mr. Ca-

108 Cheynical PJiilosophy. [Chap. II.

vendish was confirmed by the experiments of M.
Lavoisier and others: insomuch, that, during the
last fifteen or twenty years, the composition of
water has been generally considered as one of the
best estabhshed facts in chemistry. It has been
decomposed and recomposedy and found to consist of
^5 parts, by weight, of oxygen, and 15 of hydrogen.

This discovery soon began to change the princi-
ples of chemical science. By furnishing a satisfac-
tory explanation of many phenomena which were
formerly difficult of explanation, if not wholly in-
explicable, it has perhaps contributed more than
any other single discovery to promote the progress
of this branch of philosophy.

All the great chemists, Avhose names have been
mentioned, were at this time votaries of the phlo-
gistic theory of Stahl. Their experiments and dis-
coveries, indeed, were sometimes found to militate
strongly against this popular doctrine, and some
of them ventured occasionally to call in question
its leading principles. Still, however, discerning
no preferable ground on which to rest, and fmding
some ingenious devices to reconcile discordant ap-
pearances, they adhered, in general, to the opi-
nions of the illustrious German. But the fair
structure of this great philosopher was doomed,
like most human labours, to be soon overturned by
the restless hand of innovation. The experiments
on jnetals ; the discovery of various facts and prin-
ciples with respect to the matter of heat; and
especially the discovery of oxygeiiy and of the com-
position of ivateVy began to produce a conviction
in the minds of some leading chemists in France,
that liie doctrine of phlogiston was utterly insulh-

Chap, IL] Chemical Philosophy. 109

cient to account for the phenomena which they
witnessed. Macquer and Bay en seem to have beea
among the first who deciared llieir dissatisfaction
with Stahl's theory. Their objections were adopted
by a number of contemporary hiquirers; but they
contented themselves with an ingenious mo(hfica-
tion of the system, instead of an entire ahanddii-
ment of it. To these objections succeeded a num-
ber of papers, in tlie Annates (k Chiniie, and the
Journal de Physique, hy Lavoisier arid others, which
indicated a growing dissatisfaction with the fx^j)u-
lar opinions, gradually introduced new modes of
reasoning, and promised the approach of a grand
■epoch in the history of this science.

But it was not only the doctrines of chemistry
that called for reform. Complaints had been long
made, that the nomenclature of the science was in-
accurate, perplexed, and inadequate*. To remove
these complaints, many attempts h.ad been made
hj chemical philosophers. It has been already ob-
served, that Bergman laboured much to forward this
branch of improvement, Scheele contributed to
the correction of several old names, and added
many new ones to the list; and Macquer discarded
a number of the ancient terms, and substituted
others less exceptionable in their place. Still, how-

* Sorae of the most femiliar preparations were distiaguished, b/
tlie old chemists, by the most ridiculous and unmeaning names.
They loaded their nomenclature with such jargon as the tollow-
ing : Liver of sulphur — merciLry of life — hiiitci of (miifnotiy — horned
mooji-^he double secret — the coialirfic secret — the Milt of mnvy zir-
iiies — the foliated earth of tartar, &ic. To the.^e, some still more
capricious and inconvenient might be iidded. I'he dillicultie.s ^d
the mischief of retaining such a language must be apparent to every
chemist.

110 Chemical Philosophy, [Chap. IL

ever, the evil, notwithstanding these partial re-
forms, continued and increased, until it became a
serious impediment in the course of the student.
Hitherto the number of objects which had engaged
the attention of chemists, had been comparatively
small. The acids amounted only to^five ; the earths
to four ; the metals to tzcelve or fourteen ; and the
neutral salts hardly exceeded twenty. To remember
the names of so small a number of bodies, how-
ever inaccurate, or injudiciously selected, was no
difficult task ; but Avhen the discoveries of Hales,
Black, and Cavendish, had laid the foundation of
pneumatic chemistry, the boundaries of the science
began to enlarge with inconceivable rapidity, and
the number of objects became, in themselves, and
in their combinations, little short of immense. To
have borne the names of all these objects in the
memory, without any catenation between them
upon philosophic principles, without establishing
a system of mutual dependance and relation more
simple and intelligible than had hitherto been
done, would have been a task beyond ordinary
powers. Such was the state of things, when a va-
riety of concurring circumstances led to another
and a greater revolution than had before occurred.
As early as 178^2 M. de Morveau (now M. Guy-
ton) proposed a general reform in the language
of chemistry. At that time he had undertaken
the management of the chemical part of the Ency-
eloped ie J\Ic'thodiguc^\ Before entering on the ex-
ecution of this great task, he thought it proper to

* Sec the ^lemoirs of JMorveau, Lavoisier, and Fourcroy, read
before the Royal Academy on this subject, in St. John's Method
vf Chcmxat Nomenclature, tjc. 8vo. London. I/bS.

Chap. II.] Chemical Philosophi/: 1 1 1

lay the outlines of his plan before the most eminent
chemists of France, that his labours, w hen com-
pleted, might have the stamp and authority of a
national system. To this end, he published a
memoir, after reducing to a regular form the va-
rious doctrines which had been, for a number of
years, maturing in the minds of several of them,
explaining his ideas on the subject of the proposed
reform, exhibiting the principles on which he was
about to proceed, and giving, at the same time, a
new nomenclature, to which lie invited tlie atten-
tion and the criticism of the philosophical world.
After this publication by Guyton, several years
-elapsed before any thing decisive was done. He
continued to labour in the improvement of his
nomenclature ; but at length, sensible of the mag-
nitude and difficulty of the undertaking, he deter-
mined to avail himself of the advice and assistance
of the members of the Hoyal Academy. For this
purpose, he particularly associated with himself
Messrs. Lavoisier*, Berthollet, and de Fourcroy.
These four gentlemen, after spending much time
on the subject; after combining their Icivrning and
wisdom in many patient consultations f; at length,
in the month of April, 1787, presented to the aca-
demy their new antiphlogistic theory, accompanied
with a new nomenclature, made out on the prin-
ciples before laid down by Guyton, and wXiidi
were both, in a few weeks afterwards, published
to the world J. About the same time was pub-

* See Additional Sates — (U).

f See the Journal de Physique for the month of May In that year.

X Tliis body of chemical doctrines is sometimes <:alled the Lu-

■joisicrian system. Coii;;iderlijg the agency i?e had hi its foir^a-

110| Chemical Philosophy, [Chap. II.

lished a new table of symbols and chemical cha-
racters, by Messrs. Hassenfratz and Adet, formed
upon the principles of the proposed system, and
fitted to illustrate the learned labours of their
countrymen, which it accompanied. This table is
generally supposed to contain many improvements
on those of GeoiiVoy, Bergman, and Culien.

To give in detail a distinct account of all the
changes included in this new plan, would far ex-
ceed the limits prescribed to the present sketch.
The following brief statement may suffice. Stahl
and his followers had ahvays supposed the metals
to be compound substances, made up of a certain
calx or earth, and phlogiston; but the new theo-
rists, believing that there was no proof of such
composition, set them down in their tables as
simple bodies. The advocates for the former hypo-
thesis had long contended that sulphur, pjhosphoriis„
azotic air, and various other substances of a like
kind, were also compounds ; whereas the believers
in the new system took for granted that such conv-
position could not be proved. In the old doc-
trine, zvatej' was placed among the simple bodies;
but by the experiments of Cavendish and others,,
it was thought sufficient evidence had been given,
that it is a compound substance. According to
the former theory, the acid principle was consi-
dered as a compound of earth and water; the only
radical acid in nature was supposed to be the

tlon, this is scarcely ascribing too much to Lavoisier ; for though-
many of the leading experiments on which the theory is founded
were made by others, yet the task of digesting, arranj^ing, and com-
bining the whole into a consistent and regular system, was prin-
cipal ]y performed by hixn.

Chap. II.J Chemical Philosophy. 115

sulphuric, and all others ditVerent combinations ol'
this primitive one: while, according to th(.' latter
doctrine, the acids are many in number, and rc-
sidt from the union of oxygen to dilTerent acicUfia-
ble bases. In short, while the disciples of Staid
undertook to account for almost all the phenomena
of chemistry by the aid of phlogiston, the associ-
ated academicians considered it as a creature of ^.
the fancy, which had no real existence; and taught
that all the facts and appearances in this science
may be more satisfactorily explained without the
aid of this imaginary substance. To these parti-
culars it may be added, that, in this new tlieory,
the number of chemical objects is greatly increased,
and that articles which had occupied an inferior
place in the old tables, are here made to hold a
more conspicuous and important station.

The nomenclature in which this new theory was
clothed, also deserves our notice. It was formed
on the five following principles, laid doivn ]>y
Gu3^ton in the memoir above mentioned — viz.
1. That every substance should be denominated
by a naine, and not by a phrase. 2. That the
nanoes should be, as much as possible, expressive
of the nature of the things intended to be signified
by them. 3. That when the character of the sub-
stance to be named was not sufficiently known
to determine on a denomination expressive of its
nature, a name without meaning should be pre-
ferred to one which might give an erroneous idea.
4. That, in the choice of new denominations, those
wdiich had their root in the most generally know n
dead languages, should be prefeireJ, in order
that the word might be suggested by the sense, and

Vol. I. I

114 Chemical Philosophy. ' [Chap. II.

the sense by the word. And, 5. That the denomi-
nations should be arranged with care, to suit the
genius of the language for which they were pro-
posed. In conformity with these principles, the
new terms introduced were taken, for the most
part, from the Greek language; some from the
Latin ; and a few are formed by a mixture of syl-
lables from each : and, that the change might not
be carried to an unnecessary extent, as many of
the old names were retained as could be made to
incorporate with the new system. These deno-
minations were arranged in systematic order, and
the whole plan so constructed that the substances
brought to light by succeeding discoveries miglit
be placed under their proper heads, without de-
rangement or disadvantage.

For some time after its publication, this new
system of doctrines and of nomenclature was re-
ceived by French chemists only, and indeed was
by no means without opposition, even among
them. Some members of the academy entered
their protest against it, in moderate and respectful,
but firm, language*. While they acknowledged
that the phhgistic theory was attended with diffi-
culties, they expressed a fear that the antiphlogistic
plan was attended with as many, and of not less
magnitude. Instead of moving to reject it, how-
ever, they proposed that it should be submitted
to the trial of time, to the test of experiments, and
to the elucidating influence of contending inquiries
and opinions. This was accordingly done. The
academy gave it to the world, without pronouncing

■* See their representation, in the Mc?noirs of the Royal Academy
for June, 1787.

Chip. II.] Chemical Philosophij. 1 15

on its merits, and it soon became the popular sy-
stem of France.

The next year after tlie publication of the new-
theory and nomenclature by the Royal Academy,
they were exhibited in an English dress, and began
to be more generally studied than before by Bri-
tish chemists. Among these, the number of con-
verts to the improved doctrines and language soon
became considerable. But this favourable recep-
tion was by no means universal : Dr. Black, Dr.
Priestley, Mr. Kirwan, and Mr. Keir, with a few
other conspicuous characters, took their stand
among the opposing party ; and se^ eral of them
wrote largely and ably against the new opinions
and terms. It is obvious that any system opposed
by such men must have serious obstacles to en-
counter. But the system in question made its way
^vith wonderful success, amidst all opposition.
Early in the year 1791? ^^i"- Kirwan, after com-
bating in defence of phlogiston for a long time,
and with admirable prowess, laid down his arms,
and declared himself a convert to the new doc-
trine. In tlRe same month Dr. Black gave up his
objections, and went over to the antiphlogistian
ranks. And, among all the distinguished British
chemical philosophers. Dr. Priestley and Mr. Keir
alone adhered to the opposition with which they
set out. The former, especially, it must be ac-
knowledged, defended the phlogistic citadel with
a degree of skill, firmness, and force; and dis-
played an extent of resources, and a dignified
zeal in the warfare, which must do him immortal
honour among all who respect talents, and to \vhom

science is dear.

I 2

116. Ch em ical Ph ilosophy. [Chap. II .

Dr. Priestley uniformly continued to object
that the fundamental principles of the new theory
are erroneous, and that, of course, much of its
language is altogether improper. He contended,
with unabating confidence, that the metals are
compound bodies^ that xoaier is a simple sub-
stance ; that fixed air is formed by the union of in-
flammable and dephlogisticated airs ^ that phlogis-
ticated air, or azote, is not a simple but a com-
pound substance; that the antiphlogistic doctrine
rests upon a foundation narrow and precarious,
and professes to derive its support from experi-
ments ie\N in number, ambiguous in their nature,
and explicable on either hypothesis with nearly
equal ease; and, on the whole, that discarding
phlogiston is so far from diminishing the difficulties
of the chemical inquirer, that it multiplies and ex-
tends them*. In defending each of these positions,
this illustrious veteran in science has undoubtedly
exliibited astonishing industry, as well as great
erudition and acuteness. How far the result of the
controversy will justify his perseverance, it is diffi-
cult, and would certainly be presumptuous in one
comparatively little acquainted with the subject,
to predict. But when so great a majority of the
philosophical world agree in supporting the doc-
trines which he opposed, it is, perhaps, rather
more probable that the phlogistic theory will be
ultimately pronounced the weaker. At all events,
however, he is a])undantly entitled to the honour
of having made the best of his cause.

\i\ Germany, and the neighbouring countries on

* See his late work. The Doctrine of Phloglstoji Eslablinhcd, &c.^

Chap. II.] Chemical Pliilosop/ij/, [ \ 7

the contiuciif, the French doctrines and nomen-
clature made their way rather more slowly than in
Great Britain. Nearly two years after they had
met with a general reception amoni^ the British
chemists, they were introducec^ to those of Ger-
many, chiefly by van Mens and Girtanner. They
were received, on this introduction, in a favour-
able manner; and, after surmounting the first pre-
judices which a change so radical and extensive
is always apt to excite, soon became generally po-
/pular. Since that time tlie prevalence of the new
system has become almost universal. Indeed, there
is no example, since the revival of learning, of a
theory being more promptly and generally receiv-
ed, of defended with more ability and zeal, by the
great body of philosophers, in all parts of the
w^orld, than this. If we except Dr. Priestley, Mr.
Keir, and the Lunar Society of Birmingham, in
Great Britain; M. Sage, and a few others, in
France ; and Crell, Mayer, Gmelin, and Westrumb,
in Germany, we now hear of no distinguished ad-
vocates for the old opinions.

Beside the signal revolution in chemical theory
A\'hich has been stated, every part of the century
under consideration, and es])ecially the latter half
of it, has abounded in experiments and discoveries
of great importance, particularly \\hen consi-
dered with reference to their systematic rcla-

tioilS.

Few questions in science have given rise to mor(^
discussion than that which relates ta the nature of
Heat. Whether it be a distinct sul)stance, or a
mere quality of substance, lias long been the suh-
ject of disputation. 15y the ancient philosophers

118 Chemical Philosophif, [Chap. II.

heat seems to have been considered as a pecuhar
subtile fluid or element; and this opinion appears
to have prevailed until the time of lord Bacon.
That philosopher was the first, it is believed, who
advanced the hypothesis that heat is a quality of
matter, and depends on a peculiar vibration of its
particles. This opinion was afterwards adopted by
Boyle and Newton, whose authority rendered it
considerably popular : the ancient opinion, how-
ever, w^as still held by many. Boerhaave, at an
early period of the eighteenth century, entered the
lists against Newton on this subject, and main-
tained, w ith great force of argument, that heat is
a distinct substance. From the time of Boerhaave
till towards the close of the century ujider review,
this doctrine Avas almost universally received.
Stahl, Macquer, Black, Priestley, Scheele, Bergman,
Lavoisier, Crawford, Irvine, Kirwan, Pictet, de la
Place, and most other distinguished chemists, t^iough
differing as to som^e details of opinion on this sub-
ject, all agree in considering heat as a distinct
positive substance.

But, towards the close of the century, the doc-
trine of Bacon was revived by count Rumford and
Mr. Davy. These philosophers, observing that
caloric continues to be extricated from a body
subjected to friction, so long as the friction is kept
up, and the t(^xture or form of the body is not de-
stroyed; and that this heat-yielding process goes on
to an indefiulle extent ; concluded that this plieno-
menon is inexpUcable on the supposition of heat
being matter; and that those effects which have
been referred to tlie operation of a peculiar calorific
matter, depend entirely on a i-ibratory motion of the

Chap. II.] Chemical Philosophy. 119

particles of bodies; and that, from the generation,
communication, or abstraction, of this motion, all
the phenomena ascribed to caloric are to be ex-
plained*.

This doctrine, however, has but few advocates.
The sultrages of modern philosophers are almost
unanimous in favour of the opinion that caloric,
or heat, is a distinct fluid. The latter opinion, in-
deed, seems to be confirmed, to a degree little short
of demonstration, by the late experiments of Dr.
Herschel on this subject ; who has shown, that the
rays o{ light, and the rays of heat, emitted from the
sun, are distinct and separable ; that the latter, as
w^ell as the former, are refracted by transparent
bodies, and r^ec^ec? by polished surfaces ; and that
both consist of particles which mutually repel
each other, and which produce no sensible eflect
upon the weight of other bodies f.

It cannot be denied, indeed, that some difficulties
attend the doctrine of heat being a distinct and
positive substance. Nor is the following, which count
Rumford suggests, by any means one of the small-
est; viz. " that any thing which any insulated body,
or system of bodies, can continue to furnish, with-
(Hit limitation, cannot be a material substance."
Yet the electric fluid is granted, on all hands, to be
a distinct substance; and we know that this fluid
\?>cox\sX?int\yivivmshe{i,ivithout limitation, by means
of friction. On the whole, the old opinion scvms
still, with all its difiiculties, to stand on firmer

* See numforcVs Essays; and Coniributions to Mcdiail uvd
PJit/sical Knoivltdgt.

■\ riiilosoj^hical Transactions lor 1800.

\0Q Chemical Ph'dosophii. [Chap. II.

ground than any Other, and to have b}; far the great-
est number of advocates.

The doctrine of radiant heat, or that heat resem-
bles light in being propagated in rays, or right
lines, was, in some measure, knov/n to Mariotte,
Lambert, and Scheele ; \mt Vvas more clearly esta-
blished afterwards by the experiments of Saussure,
Pictet, and count liumford; and, fmally, the laws
of this propagation were more fully developed and
laid down by Dr. Herschel, in his celebrated ex-
periments on light and he- :.t before mentioned.

Count Rumford concluded, from his experiments,
that fluids do not conduct heat ; but he ascribes to
them what he denominates a carrying power: in
other words, he supposes, that, in heating fluids,
each particle must come in succession to the source
of heat, and receive its portion ; but that, among
the particles themsehes, all interchange and com-
munication of heat is impossible. The experi-
ments by which he considers himself as having
established this point are certainly striking, and
their results highlj^ curioirs; but the justness of his
conclusions has been called in question, and philo-
sophers do not seem to view his decision as abso-
lute and fmal. Further experiments must decide
the controversy.

The first person who made experiments oxi freez-
ing mixtures, was Mr. Fahrenheit, of Amsterdam,
at an early period of the' eighteenth century. J3ut
the subject was mucli more com])Ietely investigated
by Mr. Walker, in a paper published in the PJii-
losophical Transactions for 179'5. Since that time
several curious additional experiments have been
ma'le by professor Lowitz, of Petersburg ; parti-

CiiA?. II.] Chemical PhilosopJnj. 121

cularly the introduction of muriate of lime, m liicii
produces a very .2:reat degree of cold \\\\e\\ mixed
with snow. The e::periments of Lowitz have been
lately repe-ited and extended by Mr. Walker. By
means of tiie above-mentioned mixture, Mr. W.
H. Pep3^s, junior, of the London Philosophical So-
ciety, with the assistance of some friends, froze,
on the eighth of February, 1799, fifty-six ^:)onnds
avoirdupois of mercury into a solid mass. In this
process, the mercury in Fahrenheit's thermometer
sunk 6^i deg. below 0 — a degree of cold ne\ er be-
fore produced in Great Britain.

The inquiries of modern chemists into the nature
and properties of Ligiil have been scarcely less
numerous and interesting. Those discoveoes re-
specting this substance which fall under the science
of optics, have been mentioned in another place.
The capacity of other bodies to receive light, to
retain it in a fixed state, and after^vards• to part
with it, without alteration, was discovered by the
experiments of father Beccaria, Mr. Canton, Mr.
Wilson, and M. de Grosser. The affinity between
light and heat, and the similarity of their eiTects,
in certain cases, have been diligently investigated
by Dr. Franklin, Mr. Wedgewood, Messrs. Pictet,
Chaptal, and Dorthes, and especially by count
Kumford ami Di\ Herschel. The rt searches of M.
Berthollet and of Dr. Bancroft, in the philosophy
oi permanent colours, upon chemical principles^
wxrc mentioned in the preceding chapter. The (ex-
periments of Dr. Priestley, the abbe Tcssier, Dr.
Ingenhouz, and others, on the effects of light upon
growing vegetables, and the curious inquiries of
TJerschel, into the ditferent heating and illuminating

122 Chemical P kilo s'ophy. [Chap. II.

power of the different prismatic colours, are alsa
■worthy of notice in the list of modern discoveries*.
The importance of these inquiries, whether con si*
dered as insulated facts, or with reference to syste-
matic chemistry, will readily occur te every scien-
tific reader.

In 1769 Mr. Gahn, of Sweden, discovered that
phosphorus was contained in bones ; and his country-
man, Scheele, very soon afterwards invented a me-
thod of obtaining this substance from them. The
pvoperUes of phosphorus have been also more success-
fully investigated, during this period, than ever be-
fore, by Margraaf, Guyton, Lavoisier, and Pelletier.
The properties and combinations oi carbon have been
very ably examined, within a iew years past, by
many eminent philosophers. The power of this
substance, to correct impurities and to remove dis-
agreeable odours, has been shown by the experi-
ments of Mr. Lowitz, of Petersburg, and several
others. The discovery, by Mr. Tennant, that the
diamond is pure carbofi in a state of crystalliza-
iion'\, is by no means a small or uninteresting
step in the progress of chemical science.

As the diamond is not affected bv a considerable
heat, it was for many ages considered as incombus-
tible. Sir Isaac Newton, observing that combusti-
bles refract light more powerfully than other bodies^
and that the diamond possesses this property in
great perfection, suspected it, from that circum-
stance, to be capable of combustion. This singular
conjecture was verified in 1694, by the Florentine
Academicians, in the presence of Cosmo III, grand

* See Additional Notes — (V).

■j" Philosophical Trumactionsy 17^7-

Chap. II.] Ciicmical Philosophij. 123

duke of Tuscany. By means of a burning glass
they consumed several diamonds. Francis I, em
peror of Germany, afterwards witnessed tlie de-
struction of several more in the heat of a furnace.
These experiments were repeated by Ruueile,
Macquer, and Darcet, who proved that tlie dia-
mond was not merely evaporated, but actually
burnt, and that if air was excluded it underwent no
change.

No attempt, however, was made to ascertain the
product till 1772. Lavoisier, in a memoir pub-
lished that year, showed, that, when the diamond is
\y\xn\t, carbonic acid gas is obtained; and that there
is a striking analogy between it and charcoal. In
1785 Guyton-Morveau found that the diamond is
combustible when dropped into melted nitre ; that
it burns v/ithout leaving any residuum, and in a
manner analogous to charcoal. This experiment
was repeated with more precision by Mr. Tennant,
in 1797. The conclusion which he drew from it
was, that, when diamond is burnt, the whole of
the product is carbonic acid gas; tiiat a given
weight of diamond yields just as much carbonic
aoid gas as the same weight of charcoal ; and that
diamond and charcoal are both comi)Osod of the
very same substance — or rather, to speak more
precisely, diamond is pure carbon, whih^ chan^oal
is a compound of carbon, or diamond, and oxygen,
or it is what the French call an o.rijd of diamond.
Hence the dilFerence of colour, hardness, specific
gravity, and electrical properties, between com-
mon charcoal and the precioiLS stone called dla-
mond.

Since the commencement of the eighteenth cen-

124 Chemical Philosophy, [Chap. II.

tiiry, a number of new Metals have been discover-
ed, and the affinities and other properties of me-
tallip substances in general have been better un-
derstood than before. Those who most eminently
distinguished themselves in this department of
chemistry, were Margraaf, Cronstedt, Klaproth,
Scheele, Bergman, Vanquelin, Kirvvan, Proust,
Sage, and Lavoisier; to which might be added
many other names. New Earths have been disco-
vered, and their chemical properties ascertained,
by several of the able chemists last mentioned, and
also by Black, Gahn, Hope, Crawford, and Wedge-
wood. That class of chemical substances denomi-
nated AlJialies, has been better understood, of late
years, than in the preceding century. For our
knowledge of this department of the science in
question, we are particularly indebted to the inves-
tigations of du Hamel, Black, Meyer, Priestley,
Dieman, van Troostwyck, Bondt, Berthollet, and
Austin. Modern chemists have also discovered
many new Acids.

The acids known at the close of the eighteenth
century amount to about thirty^ the greater number
of which have been discovered vvithin the last/^);(?/
years. Of these, nearly one third Vvcre disco\'ored
by the celebrated Scheele, and the remainder clii'etly
by Margraaf, Priestley, Lavoisier, Vauquelin, Ber-
thollet, and Keir.

It was not till the century under review that
chemical analysis was applied to investigate the
composition of animal bodies. This has been at-
tempted by a number of modern chemists, and
witli very honourable success. Among these, the
inquiries of ScUeele, Grcii, Fourcroy, Vauquelin,

CiiAP. II.] Chemical P/iilosopIn;. ri.'>

and Girt^nncr, are eiilitlcd to very respectful no-
tice. But the elaborate researclies of Mr. ll;il-
ehet, in this interesting field of in(]uirv, arc ImUiI-
cularly well known, and do ecpial honour to his iu-
dustry and aeuteness*. I'he same depai'linrnt of
chemistry has also been explored, with great suc-
cess, by M. Alerat Guillott and otliers. 'Ihesc
investigations have led to important discoveries,
have thrown much light on the animal economy,
and furnished many indications for the iinpro\c-
ment of medicine and surgery.

Though vegetable pliijsiologj/ had been studied
with some degree of success, by several persons,
in the seventeenth century; yet, p\irsuing this
species of inquiry through the medium of cliemis-
try was scarcely thought of, and far less realised,
till the eighteenth. Within a few years past che-
mists have directed much attention to the struc-
ture, composition, and food of plants ; have greatly
extended, by this means, the limits of tiie science;
and have contributed much to the improvement of
botany, agriculture, the materia medica, and vari-
ous arts of life. Among those who have dis])Iay-
ed the greatest acuteness, zeal, and success, in tins
department of chemical inquiry, we may reckon
Dr. Hales and Dr. Priestley, of Great Britain ; Dr.
Ingenhouz and Mr. von Humbold, of Ciermany :
Mr. Sennebier and Mr. Saussure, of (jeneva ; and
several others.

The employment of chemistry by the miner alo-
gist, as a means of analysing the various substances

■^ Phliosophicul Transactions for IT^P ^"^ ^^^''^■
f Anjialcs de. Chymie, torn, xxxiv, p. ()«•

l<26 Chemical Phibsophy, [Chap, II.

"which come before him, was first undertaken in
the century under reviews Margraaf and Pott, of
Berhn, were among the earliest adventurers in this
new field of inquiry. They were succeeded by
.Neumann, Bergman, and Scheele, who displayed
great industry, address, and perseverance, in the
same course of investigation, and went much fur-
tlier than their predecessors. To these may be
added Klaproth, Sage, Vauquehn, Hatchett, and
many more; to whom we are indebted for many
new facts, and refined experiments, on the chemi-
cal properties of mineral bodies.

Since the grand revolution in chemical doctrines
and language, effected by the labours of the French
academicians, as above detailed, the new opinions,
and the proposals of further reform in this science,
have been numerous. Indeed, during the last fif-
teen or twenty years of the century, the number
of students and experimenters in chemistry has
been so prodigiously great, and the new plans an-
nounced for explaining and expressing its princi-
ples so multiplied and various, that a simple cata-
logue of them would fill many pages. All that
can be attempted in this brief sketch, is to men-
tion a few of those who have rendered themselves
conspicuous by their inquiries or publications on
chemical subjects.

A new nomenclature of chemistry was proposed,
in 1796, by professor Dickson, of Trinity college,
Dublin, and approved by his illustrious country-
man, Mr. Kirwan. In this plan of chemical de-
nominations there is an attempt to unite the ad-
vantages of both the principal systems, between
vyhich the philosophical w^orld was then called tq

Chap. II.] Chemical Philosophy. I'i7

choose. Many of the old names, discarded by tin?
French academicians, are restored by Dr. Dickson ;
while many substances, to which names are i^ivcii
by them, he has left out, as not sufficiently un(l(;r-
stood. He derives his new terms chielly from the
Latin, instead of the Qrcek lancjuage ; and he
prefers that mode of arrangement and classifica-
tion which assigns the generic rank to alkalies',
earths, and met ah:, and reserves the acids for tlic
distinction of species. He retains, however, oxy-
gen, and a few^ other words of Greek derivation.
The advantages which, in the o})inion of tlic Irish
professor, would arise from the adoption of this
iiomenclature, are, that tlie old books on chemistj-y
would thereby be more readily understood and
more valuable, and that the acquisition of the
science would be more simple and easy. l)r
Dickson's plan, though it undoubtedly does n(»
small honour to his learning and taste, has not, it
is believed, been adopted by any distinguished
teacher of this branch of philosol)h3^

It is proper also to take notice of a plan, by
Dr. Lubbock, of Great Britain, for removing the>
difficulties and terminating tlu coritroversy rt-
specting plilogiston. His idea of dividing all mat-
ter into two kinds— the principiuni proprium, and
the principium sorbite— Sind of accounting for all
chemical phenomena by the combinations of these,
is very ingeniously defended in his work on the
subject*. "No less worthy of respectful notice is
Mrs. Fulhame's attempt to correct the antiphlo-
gistic theory, by referring to water as the source

* JOissertatio Ph^'sico-Chenica, de Princlpio Soi

•hU:.

128 . Chemical PJiilosophy. [Chap. II.

of (^xygen in all oxydations ; a very honourable
monument of female enterprise and talents*. The
plan of a new nomenclature, by Mr. Vv'eiglib, a
German chemist, also indicates considerable learn-
ing and ability f. To these may be added some
proposed alterations in tjie French nomenclature,
b}' Dr. Pearson J, before mentioned, and by several
other ingenious writers. Though none of these
authors can be said to have produced revolutions
in the science of chemistry, or perhaps to have
suggested very important improvements, yet they
are entitled to a respectful notice in the chemical
history of the age.

In the course of the last six years. Dr. Mitchill,
the ingenious and learned professor of chemistry
in Columbia College, has proposed some new terms
in this science, and announced some new opinions,
of which it will be proper to take notice.

His doctrine oi pestilential fluids ^ which has been
laid before the public in various forms since r790>
holds the first place, both with respect to time
and importance. He supposes that the union of
azote and , oxygen, either in the form of oxyd or
acid, and moi;e especially in the latter, constitutes
the mischievous substance which, in its operation
on the human body, produces pestilence. In cor-
respondence with this opinion, he teaches that
alkaline and calcareous remedies are the most ef-
fectual means of disarming the force and obviat-
ing the destructive effects of this poison. At the

* Essay on Combust ion.
t Encyclopa'dia. Art. Chemistry.

X See his View of the French Nomenclature, 4to, 1/99.
London. " .

ChaP; II.] Chemical IVu'hsophf/, } 29

same time the professor proposed an alteration in
the nomenclature, agreeing with his new doctrine,
and illustrative of its princij)les. Considering azafe
as having an important ag(^ii(^y in the ])rocess of
putrefactlony he proposed to introduce the word
septan'^ instead of azot.e^ and hence denominated
the deleterious compounds above mentioned the
oxyd of septan, and septic acid. The various facts
and reasonings adduced by the professor in support
of these opinions, and the extensive application of
which he considers them as susceptible, ha\e been
so generally made known and discussed, both in
Europe and America, as to preclude the necessity
of giving further details.

In 1797 Di'. Mitchill, with a view to terminate
the controversy between the pldogistians and their
opponents, proposed to expunge hydrogen from
the nomenclature, and to introduce phlogiston ■\ in
its place. He suggested, that giving this old and
popular name to a known and defmite substance,
instead of using it in its former vague manner, and
ascribing to this substance those qualities which
had been formerly ascribed to a nonentity, would
go far toward reconciling many points of ditferencc
between the advocates of the old and the new sys-
tems, and would throw much light on many che-
mical phenomena. The same gentleman soon
afterwards proposed to discard the term caloriijiie,

* This word is derived from (rY^Tr:'}, puircfuc^o: hence o-r^rro;,
piitrcdus, and to crrprrov, ixhat peculiarly disposes bodies to rot.
Medical Repository, vol. ii> p. 50.

t Derived from j>\oyi^cu,.injlammo: hence to i^^Xoyisrov, the
principle of inflammabilitj/, or tliat which, in any subbtancc, burns
txith blaze,

Vol, I. K.

130 Chemical Philosophy, [Chap. II.

adopted by the French academicians, and to sub-
stitute the word anticrouon* in its stead. He sup-
posed, that denominating the matter of heat the
great principle of repulsion^ would lead to more
correct philosophical views with respect to this
substance, as well as render the language of che-
mistry more accurate. These several opinions and
proposals have been some time before the public ;
and, whatever may be the ultimate judgement of
chemists with regard to their adoption, the praise
of great learning, ingenuity, and industry, must
•undoubtedly be given to their author f.

Beside the revolutions and improvements in the
doctrines and in the language of chemistry which
have been detailed, various instruments and ma^
chines, of great value for measuring chemical sub-
stances, or facilitating chemical processes, have been
invented in the course of the last century. Of
some of the most important of these it will be pro-
per to give a short account.

At an early period of the century, while specu-
lations on the nature and properties of heat en-
gaged the attention of the philosophical -world,
various contrivances for measuring this fluid were

* Derived from the verb OLvriy-crju:, repdlo: hence rl «vr;-
yipouov, the principle of repulsion.

t Those who wish to see a more detailed account of Dr. Mit-
chill's new chemical opinions and terms, will find it "in his Expla^
nation of the Synopsis of Chemical Nomenclature and Arrangement,
&:c., lately published. Much information on this subject may
•ilso be found in the volumes of tlie Medical Repository y and in
several of tlie European journals. In these publications the
reader will see the respectful manner in which the inquiries of
the learned professor have been noticed in different parts of
tiirope.

CiiAP. II.] Chemical Philosophij. 1 .3 1

invented and adopted*. Tlir Thcnnomcfcr, wliicli
had been first used about the l)egliniing of the
preceding century, was constructed on a new aiul
improved plan, by sir Isaac Newton, in I70I. Me
chose, as fixed pohits of graduation, those at which
water freezes and boils; a clioice which the expe-
riments of succeeding philosophers have proved to
be the most wise and convenient. He also iutro-
duced the use of oil to fill the tube, instead of
alcohol, under an idea that the former was liable
to fewer disadvantages than the latter. 13iit, after
all the labours of sir Isaac, this important instru-
ment was imperfect, and could by no means be
considered as an exact standard for pointing out
the various degrees of temperature. Accordingly,
about the year 1724, Mr, Fahrenheit, of Amster-
dam, suggested the use of thermometers made \\ ith
mercurijy and presented one of this kind to the
Royal Society of London. It was soon found tiiat
this fluid was preferable to all others, being more
homogeneous, more easilj" freed from air, more
regularly expansible by diflerent degrees of heat,
and more difficult to congeal. Mr. Fahrenheit
also proposed a new mode of graduating the in-
strument. His thermometer has since come into
general use in Great Britain, America, and in tlut
various parts of the world in which British habits
prevail.

In 1750 M. Reaumur, a French philosoi^Iicr,
constructed a thermometer on a new plan. He
adopted a mode of graduation diflerent both from
Kewton and Fahrenheit, and resumed the u:>e ol

^- See Additional Notes — (W).
K2

13i2 Chemical Pkilosopky, [Chap. II.

alcohol. His plan was, of course, still far from
being perfect. The thermometer now in use in
France, and through a great part of the continent
of Europe, under the name of Reaumur's, ought
strictly to be called Mr. de Luc*s, who made a
very important alteration in M. Reaumur's mode
of graduating the instrument, and again exchanged
alcohol iov mercunj. In 173.'i M. de I'lsle, of Pe-
tersburg, constructed a mercurial thermometer,
which is generally used in Russia. Another, gra-
duated in a different manner, by Celsius, and
also filled with mercury, is most popular iu
Sweden *.

Beside these leading inventions and involutions
which the history of thermometers presents, the
plans which have been suggested in modern times,
for improving this instrument, are many and in-
genious. These have been successively proposed
by lord Cavendish in 1151 , by Mr. Six in. 1782 j
hy Dr. Rutherford m 1790; and still more recently
by Mr. Keith, whose new self-registering thermo-
meter is said to be the most ingenious, simple, and
perfect, of all that have hitherto appeared.

It was still, however, an important desideratum,
to fmd some easy and exact method of measuring
very high degrees of heat. Such a method was
not long since invented by Mr. Wedgwood, of
Staffordshire, a gentleman well known for his
great improvements in the art of pottery. After

- See Dr. Martliie's Essay on the Construction and Graduation
of Thermometers; one of the best works extant on this subject.
Mr. de Luc, of Geneva, and professor van Swindcn, of Francker,
have also written ably and instructively concerning Tiierxno-
meters.

Chap. II.] Chemical Philosophy. 133

many experiments'*', lie produced an instrument
which he called a Pyrometer^ and which, by means
of the contraction oi day, marks, witli much pre-
cision, the different degrees of heat, from 947° of
Fahrenheit's scale, to the greatest heat of a wind-
furnace.

It was first observed by Dr. Black, that dilTerent
bodies have different capacities for imbibing and
retaining heat. The fact was aftervvarfls noticed,
and the subject further investigated, by Drs. Irvine
and Crawford, and by professor Wilcke, of Stock-
holm. The last named gentleman called tlie quan-
tity of caloric necessary to raise the temperature of
substances a given number of degrees, their specific
heat. For measuring this heat an instrument was
contrived by Messrs. de la Place and Lavoisier, and
called by the latter a Calorimeter; the nature and
value of ^vhich may be seen in various books of
chemistry.

Another instrument, invented in modern times,
and which has engaged much of the attention of
chemists, is the Eudiometer \. This instrument was
invented by Dr. Priestley, and is used for ascer-
taining the purity of the atmospherical air, or the
quantity of oxygen contained in it, which is indi-
cated by tlie diminution of its volume on being
mixed with nitrous air. Tiie discovery of this pro-
perty of nitrous gas, and the invention founded
upon it, soon gave rise to many attempts to \m-
prove on the principle, a!Y<l to contrive eudiome-
ters of a more elegant and advantageous kind, and

* See Philosophical Tranmctions for 1/82, 1784, 1/86.
t See Additional NoU-s—(Xj.

134 Chemical PhilosopJii/. [ChaP. IL

with different materials. These attempts were
made, and various phms successively proposed, by
Cavendish, Fontana, Volta, Schcele, de Marti,
Guyton, Achard, Berthollet, Davy, and several
others. But the instrument, in its most favourable
form, is still liable to much uncertainty and inaCf
curacy in its application.

The machine for impregnating water with c^r-
bonic acid gas, or ^/ixed air, invented a few
years ago by Dr. Nooth, deserves to be respect-
fully mentioned,, as a monument of ingenuity,
and as a very useful piece of fiirniture for every
chemist and physician. Beside this, our list
might be enlarged by the enumeration of many
other instruments and machines which have
been added to the chemical apparatus in modern
times, and which have greatly contributed to the
ease, elegance, and perfection, of chemical experi-
ments.

After mentioning the great names, and the bril-
liant discoveries, which have been recounted in
the foregoing pages, it Avould be unjust to omit
taking notice of some other philosophers who have
distinguished themselves by their publications or
experiments in this branch of science. Among a
great number, whose names and labours will be
found honourably recorded in the scientific history
of the age, we may mention bishop Watson, Mr.
Nicholson, Dr. St. John, Mr. Henry, Mr. Cruik-
shank. Dr. Darwin, lord Dundonald, Mr. lyambe,
Air. Higgins, and Dr. Thomson, of Great Britain;
Messrs. Chaptal, Monge, Monnet, Beaume, Cadet,
Thouvenel, la Metherie, Adet, and Seguin, of
France; and van Ilomberg, Junckcr, Schroeder,

Chap. II.] Chemical Philosophy. 135

Wenzeljienkel, Jacquin, Meyer, Crell, and Hermb-
stadt, of Germany j to say nothing of many others,
equally entitled to praise, in almost every cultivat-
ed part of Europe*.

From the above general statement, it appears
that within the last half century the empire of
chemistry has been wonderfully extended. It is
but a short time since this science recognised, as
the subjects of her sway, only a few vie tab and
medicines. She has lately subjected to her sceptre
the various kinds of earths found in the composi-
tion of our globe; the different //^/(/^^ with which
we are conversant, whether of the aqueous or gase-
ous form; the various kinds of vegetable, animal^
and mineral bodies which surround us -, and almost
every substance capable of composition or analj^sis.
In short, she has extended her claims to every
species oi animate and inanimate matter, and main-
tains authority over a territory of physical science
w^hich may be called immense, when compared
with her former dominions.

But chemistry has not only gained, during the
eighteenth century, a great extent of empire ; it is
also distinguished for having acquired, in the same
period, a more practical and useful cast than
ever before. By its ancient cultivators chemistry
was chiefly regarded as an object of curiosity, or
as a source of amusement. But in the hands of
later chemists it has been converted into a very

* The contributions made to chemical knowledge by most of
i\\e above named gentlemen may be found either in distinct
works, published by themselves, or in the Philosophical Irnnsac-
tions, the Journal dc PhyuquCy the Annates dc Chimie, or other
scientific journals.

136 Chemical Philosophy. [Chap. II.

instructive, interesting, and invaluable science.
There is scarcely an art of human life which it is
not fitted to subserve; scarcely a department of
human inquiry or labour, either for health, plea-
sure, ornament, or profit, which it may not be
made, in its present improved state, eminently to
promote.

To the husbandman this science furnishes prin-
ciples and agents of inestimable value. It teaches
him ihefood of plants ; the choice and use of ma-
nures ; and the best means of promoting the
vigour, grow^th, productiveness, and preservation,
of the various vegetable tribes. To the manufaC'
turer chemistry has lately become equally fruitful
of instruction and assistance. In the arts of brew-
ings tanning, dyeing, and bleaching, its doctrines are
precious guides. In making soap, glass, potieryy
and all metallic wares, its principles are daily ap-
plied, and are capable of still more useful - appli-
cation as they become better understood. Indeed,
every mechanic art, in the diiferent processes of
which heat, moisture, solution, mixture, or fer-
mentation is necessary, must ever keep pace in
improvement with this branch of philosophy. To
the physician this science is of still greater value,
and is daily growing in importance. He learns
from it to compound his medicines ; to disarm
poisons of their force ; to adjust remedies to dis^
eases; and to adopt general means of preserv-
ing health. To the student of natural history the
doctrines of chemistry furnish instruction and as-
sistance at every step of his course ; as many of
Iiis inquiries can be prosecuted with success only
through the medium of careful analysis. To \\\b

Chap. II.] Chemical Philosophij. 137

public economist chemist r;. presents a treasure of
useful information. By means of this scienee alone
can he expect to attack with success tlie destroy-
ing pestilence, so far as it is an object of human
prevention, and to guard against other evils to
which the state of the elements gives rise. And to
the successful prosecution of numberless ])lans of
the philanthropist, some acquaintance with the
subject in question seems indispensably necessary.
Finally, to the domestic economist tliis science
abounds with pleasing and wholesome lessons. It
enables him to make a proper choice of meats and
drinks ; it directs him to those measures with re-
spect to aliment, cookery, clothing, and respiration,
which have the best tendency to promote health,
enjoyment, and cheapness of living; and it sets
him on his guard against many unseen evils, to
which those who are ignorant of its laws are con-
tinually exposed. In a word, from a speculative
science, >• chemistry, during the eighteenth century,
has become eminently and extensively a practical
one ; from an obscure, humble, and uninteresting
place among the objects of study, it has risen to a
high and dignified station ; and instead of merely
gratifying c: riosity, or furnishing amusement, it
promises a degree of utility, of which no one can
calculate the consequences, or see the end.

But wiiile the great im})rovemcnts which have
been made in chemical philosophy during the last
century are readily admitted, it may not be impro-
per, before closing this chapter, to take notice of
the gross abuses, which have been adopted by some
of the most celebrated cultivators of the science
in question, and which have contributed to lessen

i.'iS Chanlcal Philosophy. [Chap. II,

ifs value ill the view of many serious inquirers.
A few extravagant and enthusiastic votaries of
elK^mistry have undertaken, on chemical princi-
ples, to account for all the phenomena of 7notion,
lift, and mind^ and on those very facts which
clearly prove wise design, and the superintending
care of an infinite Intelligence, have attempted
to build a fabric of atheistical philosophy. This is
a striking instance of those opposiiions of sd-^
ence falsely so called, of which an inspired writer
speaks, and for which the past age has been re-
markably distinguished.

How far the present fashionable system of che-
mical doctrine and language may stand the test of
future experiments, and command the assent of
future generations, is far from being certain. He
who has attended to the course of things in the
short space of time since it was published, will see
little reason to expect for it that undisturbed and
permanent reign which its advocates have fondly
hoped. It is somewhere remarked by lord Bacon»
that the sciences are apt to suffer by being too-
soon reduced to a system. There are probably
few sciences to which this remark applies with
such peculiar force as to chemistry. The struc-
ture at present most popular is fair and beautiful.
An engaging simplicity reigns in ahiiost every
part. But many believe that this simplicity is de-
ceptive. Some of the doctrines which hold an im-
portant place in the fabric are too vague and con-
jectural to be admitted with full confidence, and
others are daily undergoing modifications, which
thrraten still further and more essential changes.
Notwithstanding the mathematical precision with

Chap. II.] Chemical Philosophy. 139

which the sanguine chenist affects to speak of his
axiomS;, .yQi how discCi daut are the resiiUs of dif-
ferent experiments ! These facts, it must be ac-
knowledged, " betray the huncuess of some re-,
ceived prmciples, and excite suspicions with re-
spect to the legitimacy of some capital analyses.'*
But tiie enlightened and enterprising philosopher
will not be discouraged by such proofs of the im-
perfection of human knowledge. The builders of
erroneous systems become indirectly the promoterj;
of truth, by contributing to the examination and
rejection of falsehood. The course of improve-
ment has always been found to make its way
through successive defiles of illusion, empiricism,
and false theory. In this course honesty, atten-
tion, and patient perseverance, are the great requi-
sites for obtaining success. With these, though we
cannot expect to develop all the mysteries of na-
ture, which is the prerogative of its Author alone;
yet we niay hope, in time, to detect analogies, to
ascertain laws, to systematise scattered fact?, and to
unlock treasures of science, which appear at present
far removed from human scrutiny, and against the
knowledge of which the feebleness of our powers
segms to raise an everlasting barrier.

uo

CIIAPTKR III.

NATURAL HISTORY,

1 HIS department of science scarcel}^ yields to
either of the preceding in the extent and vakie of
the improvements which it has received within
the period under consideration. Many of the ob-
jects, indeed, to which natural history relates, have
been, in some degree, known and studied by man,
from the earliest ages, as means of supplying the
Vvants, and obtaining the luxuries of life. Solo-
mon, the king of Israel, we are told, spake of frees,
from the cedar tree that is hi Lehano7i, even unto
the hyssop that springeth out of the tvall ; — he spake y
also, of beasts, and of birds, and of creeping thingSy
and of fishes^ , And, if we may judge from the
respectful terms in wliich such studies are men-
tioned, in this and in various other passages of
sacred scripture, we may conclude they were held
in high estimation in very early times. It was
not, however, until long after the revival of letters
and science in Europe, that natural history began
to receive the attention due to its importance.
Toward the close of the seventeenth century, after
several learned societies in Great Britain, and on
the continent, had been formed, the taste for thi:^

* 1 Kings iv, 33.

Chap. III.] Natural II istori/. \\\

branch of study commenced, and lins boon ovrr
since gradiiaJJy extending itself over the civilised
world.

At an early period of the eighteenth century,
many persons were busily employed in collecting
and publishing facts in Natural History, especially
in Zoology and Botany. Among these the nam*^
of the learned and indefatigable Albert Seba de-
serves particular notice. He resided in liollaiid,
was intimate with Boerhaave, and compiled hi.s
large work on Natural History under the patronage
of that eminent naturalist and pliysician. 'Hiis
w^ork, under the title of Thesaurus Rcruvi Natiira
liuw,y w^as published in 1754, in four vols, folio.
But though these inquirers rendered important
service to this department of philosophy, it was
rather by communicating a knowledge of details,
than by enlightened and correct philosophising on
the subjects which came before them. Scarcely
any thing had been effected, on a great .scale, pre-
vious to the appearance of Linuccus, an illustrious
Swede, who, by his first publications, in 17^^, giive
a new aspect to the whole science, and commenced
what has been with much justice styled the " golden
age" of Natural History. — Almost every thing that
had been done in the great business of Classifica'
tion, before his time, was confused, and exceedingly
defective; and, in some of the kingdoms of nature,
few attempts of the kind had been made. It is
not necessary to remind the intelligent reader how
much this deficiency must have perplexed and re-
tarded the inquirer, at every step of his course. It
was reserved for Linnaeus, a man equally distin-
guished for the benevolence and piety of liis heart,

142 Natural Jlistory, [Chap. III.

the extent of his learnmg, and the greatness of his
views, to remed}^ tlie defect. To his himinous and
expanded mind, the arduous task of generalising
and arranging seemed to be an easy and familiar
process. He introduced new methods of classifica-
tion into all the more important branches of natu-
ral Jiistory ; made large additions to its known
facts and principles; excited a thirst, before un-
equalled, for this kind of knowledge ; and pre-
pared the way for a great portion of the improve-
ments which have been made by succeeding na-
turalists.

While the last age produced much new light
in the philosophy of natural history, and added
immense riches to its former stores, it also gave
to this science new distinction as an object of
study in seminaries of learning. — At the close of
the seventeenth century, it is believed, only a few
professorships had been instituted, even in tlie most
distinguished universities, for instructing youth in
this interesting department of knowledge. Since
that time few^ important colleges or universities
have failed to add such professorships to their
former plans of instruction, and to place natural
history among the indispensable objects of atten-
tion in an academic course. By these and other
means new honours have been bestowed on this
branch of science, new encouragement given to
the 7A"A and exertions of inquirers, new roads to
improvement opened, and new opportunities af-
forded, at once, of diffusing a taste for investi-
gations of this nature, and of extending the infor-
mation which genius and industry had gained.

But it will be more satisfactory to take a brief

Sect. I.] Zoblogij, 143

view of the several kingdoms of nature, and to
state some leading facts concerning the progress
which has been made in each *.

SECTION I.

ZOOLOGY.

At the beginning of the eighteenth century con-
siderable progress had been made in this branch
of Natural History, by the inquiries and discoveries
of Harvey, Redi, Malpighi, Willoughby, and Raj'.
These illustrious men discarded several erroneous
doctrines which had long been received, particu-
larly the doctrine of equivocal generation, and
threw much light on the principles of physiology.
Ray, being dissatisfied with Aristotle's classifica-
tion of animals, invented a new one, founded on
the structure of the heart. To this he was ])arti-
cularly led by the discoveries of Harvey, relating
to the circulation of the blood, which had been a
little before announced, and excited much atten-
tion in the philosophical V\'orld. From the time
of Ray till that of Linnocus f , Zoology was culti-

* The coiitenls of tliis chapter have been principally collected
from Smith's Tracts on Natural History, and many other ^vork^.
on detached parts of tlie subject 3 some of whieli will be found
quoted, or referred to, in the following pages. For a knowled«;e
of some of the facts and names here detailed, 1 am indebted to
professor Barton, of Philadelphia, who, in a conversation on ilie
subject, furnished me with much valuable information, and with
profitable hints for directing my inquiries.

t This '•' Prince of Naturalists" is so well known, that a for-
mal account of him in this place is altogetlicr unnecessary. He

144 Natural Historr/. [Chap. III.

vated with considerable success, and received some
important accessions, as will appear from the
names of several naturalists hereafter to be men-
tioned. But the service rendered to this depart-
ment of science by the illustrious Swede was still
more in}i)ortant, and cannot be contemplated with-
out admiration. He described many new animals^
and formed a new arrangement and nomenclature,
in man}' respects original, and in general greatly
superior to any that had gone before him. From
this period writers on the various departments of
the animal kingdom began rapidly to increase in
number, in the extent of their information, and ift
the accurate and philosophical aspect of their de-
scriptions.

Soon after Linnaeus appeared M. Klein, of Dant-
zic, who strenuously combated a number of the
alterations proposed by that illustrious naturalist,
and signalised himself as his adversary. . Klein
gave to the w^orld'a new method of classification,,
founded on the toes, hoofs, &c. ; and by his multi-
farious works, on almost every department of
zoology, which he treated both systematically and
physiologically, rendered very important service to
the science. About the same time flourished M.
Brisson, a French naturalist of very high character,
and whose publications, particularly on Q^uadru-
peds and Birds, rank in the first class on their re-
spective subjects. Indeed, in the accuracy of his

was born at Roeshult, a village of Sweden, May 27, 1707. His
first great vork was published in 1732. Among the numerous
public lu^nours with which he was crowned, he was created
kniglit of the Polar Star in 1753, and ennobled in 1757. He died
in January, 1778, in the 7 1st year of his age.

Sect. L] Zoology. 145

descriptions, and the excellency of his plates, he
may even be pronounced superior to Linnaeus
himself. After Brisson may be mentioned his
countrjman the count de BufTon*, who, thoui;h
more sprightly and interesting as a writer, i^i whicli
he excels all other natural historians, is far less ac-
curate and philosophical. His neglect of regular
systematic arrangement is a great defect, and must
ever lessen the value of his works. He Mas a
zealous cultivator of zoology, and by his splendid
publications and captivating style made himself
admired throughout the scientific world. And
though many of his hypotheses are whimsical, ex-
travagant, and delusive, it must yet be allowed
that he did much to encourage and forward the
study of nature; that he made many observations
of great value ; that he collected a multitude of in-
teresting facts; and that his works hold a very
important place in the zoological history of the
age.

Contemporary with Buffon was Mr. Pennant, of
Great Britain, who is unquestionably entitled to
a place among the greatest zoologists of the
eighteenth century f. By his writings, as valua-
ble as they are voluminous, he contributed greatly
to the advancement of this branch of natural
history. He was the author of a new arrangement

* George le Clerc, count de Buffon, was l^-n in the year
1707, and died in l/SS.

f Thomas Pennant, LL. D. F.R.S., was born in Flintshire, in
North Wales, in the year 1/26, .ind died in 17j_)8. He cultivated
Zoology with great ardour, ability, and success ; and w as one of
the most voluminous writers of the age.
Vol. L L

146' Natural History. [Chap. 111.

of Quadrupeds, more nearly resembling Ray's, of
the former century, than any other. On this sub-
ject his work may be pronounced equal to any, if
not the best that has yet been presented to the
student of nature. Within the same period, pro-
fessor Blumenbach, of Goettingen, distinguished
himself by his zoological and ^^bysical inquiries,
and particularly by a new method of arranging
Q,uadi^peds. To these great names may be added
that of professor Pallas, of Petersburg, who, in
zoolo2:v, as well as in several other branches of
science, has done much, and is to be considered as
ranking with the very first, if not as standing at
the head of all the naturalists now living.

Beside these distinguished systematic writers
on the subject of zoology in general, particular
departments of the science have been cultivated,
and greatly improved, by men scarcely less emi-
nent, or less worthy of praise. Of some of these
inquiries and publications a brief notice w ill be
attempted.

It is proper to begin with the natural history of
the ^first Linnaean class, the Mammalia. On this
class, almost all the great writers whose names w^ere
just mentioned have made large and instructive
publications. In addition to what has been accom-
plished by them, especially by Linnaeus, Kleiny
Pennant, and Buffon, the labours of professor E.
Zimmerman^, of Brunswic, to throw light on this
class of animals, do him great honour. His con-
ception and execution of a %Gologlcal Chart, ac-
companying his work on the Mammalia, may be
considered as one of the most philosophical pro-

Sect. I.] Zoology, I47

ductions of the age. Tliis ingenious invention hai:
been extended and improved by M. JaulTret, a
distinguished naturahst of France. Beside these,
many others deserve notice for their successful la-
bours in illustrating particular parts of tlii,s exten-
sive field of inquiry.

Much has been done during the last century
toward completing the natural history of Ma?i,
In the list of experimenters and authors on this
subject, Albinus, a Dutch naturalist, holds the first
place, with respect to time*. He was a very great
anatomist; and was one of the first who attended,
in a scientific manner, to the seat of colour in
human beings. Among the writers on this sub-
ject it is also proper to take notice of Dr. John
Mitchell, an English physician, who resided a
number of years in Virginia. His Essai/ on the
Causes of the different Colours of People is con-
sidered as a very honourable monument o^ his
learning and talents f. The next important pub-
lication on the same branch of natural history wa^'
by the celebrated John Reinhold ForsterJ, who
threw considerable light upon it. He was follow-
ed by the rev. Dr. Smith, president of the college
of New Jerse}^ who, in his ingenious and learned
Essay on the Causes of the Variety of Complexion

* To Marcellus Malpighi, in the seventeenth century, we crwe
the discovery of the fact that the colour of negi-oes resides in tJie
corpus miicosum. This fact was also known to J. N. Pechlin, as
appears by his work De Hahitu et Colore Ethiopum, b:c., published
in 1677.

f Philosophical Transactions, vol. xliii.

X See Forster's Observations, ^c. 4to, 1779'
L 2

148 Natural History. [Chap. III.

and Fissure in the Human Species^, gave a very
instructive and interesting view of the subject*
The natural liistory of man has also been treated,
in a more general way, by Buffon and Vereyf, of
France^ by BlumenbachJ, Zimmermann§, Lud-
wig||,and Soemmering f, of Geniiany; and by pro-
fessor Pallas, of Russia. To which may be added
the great anatomical discoveries and improvem.ents
by the Monroes, Camper, the Hunters, Daubenton,
Bourgelat, and many others.

The attempts which were made during the
eighteenth century to throw light on the natural
history of man, through the medium of inquiries
concerning language, habits, religion, &c., are wor-
thy of particular notice. — In this department of
inquiry Mr. Jacob Bryant greatly distinguished
himself, by his Observations on Ancient History, and
his Analysis of Ancient Mythology. Next appeared
the Mo7ide Frimitif of M. Court de Gebelin-, a vo-
luminous work, which displaj's great learning, and
is by no means destitute of valuable information.
The Vocahidaria Comparativa of professor Pallas
is a wonderful monument of learned labour, and

* Dr. Smitli's Essay was favourably received^ not only in his
own country, but also in Great Britain, and on the continent of
Europe, where several editions of it were circulated^ in the En-
glish, French, and German languages.

f Natural History of Man, &c. 2 vols. 8vo.

% De Generis Hinnani Varietate Nativa, kc. Goettingen, 1 ^g5.

§ Geographical History of Man, &c. 8vo, 3 vols. Leipsic, J 7/8.

II Plan of a Natural History of the Human Species delineated^
kc. 1796.

% Essay on the Difference between the Conformation of the Euro*
pean and the Negro, &c.

S£CT, I.] Zoology. . 149

M^ill be highly interesting to ever}' enlightened
student of this part of natural history. — Still more
recently, new and important light has been thrown
on this subject by professor Barton, of Philadel-
phia, who, in his New Views of the Origin of the
Tribes and Nations of America^ has published Vo-
cahulai'ies of a number of Indian languages that
were never before committed to the press ; has
compared these with languages more generally
known, both on the eastern and western conti-
nents; and has thence deduced new evidence in
support of the opinion, that the nations of America
and those of Asia have a common origin.

The philosophy of man has been considered,
during this period, in a different view, in the cele-
brated publications of Hartley and Helvetius. Pro-
fessor Meiners, of Germany, has also written on the
Physical History of Man ; and M. Herder, of the
same country, has pubhshed Outlines of the History
of Man *. And, finally, the numerous voyagers and
travellers, with whom modern times have abounded,
have contributed greatly to enlarge our knowledge
of the human character and powers, and have
brought to light many facts toward the formation
of a satisfactory system on this subject.

In the naturayiistory of Quadrupeds, the amount
of improvement during the last century was very
great. All the distinguished systematic writers
before mentioned have rendered extensive and
important services to this branch of zoology;
and the names of many other respectable naturalists
mio-ht be enumerated, who have devoted their

♦ An En<yUsh translation of it has been published.

150 Natural IJistory. [Chap. Ill

investigations to particular species, and described
them with great accuracy and splendour. The
scientific journals and memoirs of learned spci-
eties, in every part of the century, exhibit a large
and very interesting account of discoveries, and
o^ new observations, by these diligent and useful
inquirers.

But among the various investigations in this de-
partment of natural history, which distinguish thd
eighteenth century, few are more curious than
those respecting the Fossil Bones of Animals now
no longer known in the living state. These re-
mains of animals, chiefly of the quadruped kind,
have been discovered at many different periods,
from the commencement of the century to its con-
clusion, and in almost every part of the world to
which naturalists have had free access. It is be-
lieved the first writer of any distinction on thii?
subject was Dr. Breynius, or Breyne, a German,
who, at an early period of the century, published
some papers on this branch of zoology in the Phi-
losophical Transactions. The next was the abbe
Fortis, who, in his Travels in Dahnatia, gave some
interestins: and instructive information on the
same subject. Among many others who have
distinguished themselves by their inquiries respect-
ing iht^se fossil hones, sir Hans Sloane, Daubenton,
Bufibn, Pallas *, Gmelin, and Dr. W. Hunter, deserve

* Professor Pallas expresses the fullest conviction, that the
fossil bones found in Siberia were carried thither by the Flood, or
by somu such great inundation as the sacred history describes.
His nisi idea was, that the climate was once warm enough to be
the native country ot the tlcphant, and that it had since undergone

Sect. I.] Zoblogi/. \5l

particular notice. M. Cuvier, of France, lias been
for some time engaged in a very extensive work
on this subject, which is Ukeh' to prove very in-
teresting^ to the philosophical workh He eiuune-
rates tzvenfii-fhrec species of bones which have been
found, all belonging to animals unknown at the
present day, and of the existence of which tliere is
no other trace than these relics. Of this number
txvelve v/ere determined by preceding inquirers, and
eleven he considers as bavins: been first discovered
and settled by himsdf. He speaks ^Iso of a num-
ber of other species, concerning which some un-
certainty still remains*.

Of these fossil bones none have attracted more
attention than those belonging to the unknown
animal denominated the Mmnmoth'\, fomid in
several parts of the world, and especially in North
America. A controversy for a long time existed.

a radical diange. But when he visited, during his travels, the
spots where these bones were found, he candidly renounced his
former hypothesis, and expressed a full conviction, in conformity
with the opinion of many other modern philosophers, tliat they
must have been carried thither by water -, and that nothing but a
«udden and general irruption of waters, such as the deluge is re-
pi«esented to have been, could have transported those bones from
their native regions so far to the nortli. In proof of this he in-
forms us, that the bones are generally found separate, as if scat-
tered by the waves; covered with a stratum of mud; and com-
monly intermixed with tlie remains of marine animals and plants.
— Coxe's Travels in Itussia.

^ See Additional Notes — (Y).

f The name mammoth is said to have been first given to this
animal in Russia. It is a cormption from mcmoth, a word deri\cd
from tlic Arabic.

152 Natural History. [Chap. Ill,

-^vhether this animal were a species of elephant or
not ', and both the affirmative and negative sides
of the question were confidently maintained by
eminent zoologists. It is probable the dispute
is now near being terminated, as, in the estima-
tion of good judges, proof little short of demon-
strative has appeared, confirming the opinion of
those who assign this far-famed animal to the ge^
nus elephas^.

Soon after the first publications of Linnaeus,
Qrnithologi/, or the history of the second class in
liis system, received considerable improvements
from Edwards |, an English naturalist, who, though
not remarkably distinguished as a systematic wri-
|;er, became eminent and useful by the accuracy of
)iis descriptions, and the excellence of his draw-
ings. To his labours succeeded those of Mr. Frisch,
a German, whose work is perhaps the most philo-
sophical and interesting that was ever published
on the subject. After him came the celebrated
Latham, of Dartford, the author of a work on or-
nithology, which is probably the n^pst extensive

* In the year 1801, Mr. C. W. Peale, of Philadelphia, proprie-
tor of the Museum in that city, and who has been for a number of
years distinguished by his taste for inquiries in natural history,
succeeded in obtaining two complete skeletons of the mammoth,
dug out of marlc-pits, in the state of New-York. From an in-
spection of these skeletons it appears that they are the remains
of elephants, ditiering but little, if any more, from either of the
two species now known, than these latter- do from each other.
Mr. Peale is certainly entitled to the thanks of every lover of na-
tural history for his zcal and exertions in this researcli.

t Gcoi-ge Edwards was born in the year 1(394, and died in
J 77^. His Natural Ilntory of Birds is in / vols. 4to.

Sect. I.] Zooiogi/. 153

and complete yet presented to the world. The
history of birds has also been well treated by Bris-
son* andBuffon, of France; and those o[ Africa
have been ably described by Vaillant, of the same
country. In addition to which, it may be worthy
of notice, that the plates published by order of the
king of France, and intended to accompany Buf-
fon's History of Birds, are certaiidy among the most
elegant specimens of human art ever executed to
promote the study of ornithology. Among tliose
who have contributed to the improvement of orni-
thology, Sparrman, of Sweden, is also entitled to an
honourable place. The plates of his Museum Carl~
soniamnn are among the best that were ever pub-
li^hed. They are said to be less tawdry and more
natural than tlifose of BafTon. A new classification
of Birds has been presented to the public by Paul
H. G. Moehring, of Germany, who died in 1 792 3
and, still more recently, a new arrangement of the
same class of animals has been made by la Cepede,
of France.

That department of zoology which includes the
Amphibia, or the tJiird Linnaean class, has also
been greatly extended and improved during the
eighteenth century. Beside Linnaeus, this class
was treated, with much ability, by Mr. Catesby,
an English gentleman, who resided for some time
in America f. Next to him. Dr. Garden, who spent

* The Ornithologk of Biisson has been prononnced, by some
good judges, to be, so idx as respects tlie description ot" the species
of birds, one of the most accurate works that Iia\c hitherto
appeared.

f Natural History of Carolina, Floridn, and the B'lhama Islands,
&e. By Mark Catesby. 2 vols, folio.

154 Natural History. . [Chap. Ill,

a number of years in South Carolina, communi-
cated much new light with respect to the ani-
mals generally, and especially the Amphibia^ of
the new world*. Dr. RusselFs great work on
ihe Serpents of the Coromandel Coast f is a pro-
duction of the highest ext^ellence in its kind, the
publication of which was an important event in the
progress of natural history. The Serpents have
also beeii largely treated of by the celebrated Fon-
tana; and still more recently by M. la Cepede, of
France, who formed a new arrangement of them,
founded chiefly on the scales^ and bearing, in se-
veral respects, a considerable resemblance to that
of Linnaeus. The same writer has published a
work on Oviparous Quadrupeds ^ in which he has
much improved on the labours of the great Swedish
naturalist. The Frogs have been ably treated by
Roesel, a German naturalist. The natural history
of the Tortoise has been very ably and completely
executed by Schoepf, a distinguished writer of Ger-
many; and also by Schneider, of the same country.
The fascinating power ascribed to serpents hdi^heen
the subject of considerable discussion during the
pei'iod under review. Those who have examined
this subject in the most philosophical manner are
M. laCepede, professor Blumenbach, and especially
professor Barton, of Philadelphia, wiiose Essay on

* Dr. Garden, who was a respectable physician of Charlestown,
in South Carolina, coinmiinicated to I^innteus mtich valuable in-
formation concerning the animals of America. Few names occur
mure fr<;quendy, or are mentioned wilii more honour in the %-
atcina Natura-, than his.

t A)i. Account of Indian Scrpc-nts, &c. By Patrick Russell, M.D^
r.ll.S. folio.

Sect. I.] Zodlogi/. 155

this subject is, perhaj^s, tlie most satisfactory hi-
therto presented to the student of natural history.

Dr. Robert Townson, a respectable naturahst of
Great Britain, has contributed to extend our know-
ledge of the physiology of the Amphibia, His
Tracts and Observations in Natural History ami
Piiysiology, published in 1799? contain many origi-
nal observations concerning the respiration, absur]j-
tion, &c., of this class of animals.

Within the same period, Ichthyology^ or the his-
tory of the fourth Linnaean class, has been culti-
vated with great diligence and success. Lewis
Marsigli, an Italian, by his Historia Maris, piil>-
lished in 172o, and by his work on the Danube^
published in 1726, gave much new and valuable in-
formation on this subject. The PJiilosophia Ich-
thyologica of Artedi*, first given to the public in
1738, may be considered as one of the most im-
portant works on fishes, which the age produced.
Next to Artedi came Linnaeus, who greatly distin-
guished himself by a new arrangement of this class
of animals, and by improving, in various respects,
their natural history. He was followed by Gouan,
of Montpellier, who, in his Historia Piscium, pul>
lishedin 1770, adopted the Linna^an arrangement,
and rendered important service to this part of zoo-
logy. About the year 1786, M. Broussonet, of
France, made a very instructive' present to natu-
ralists, in his work on the rare fishes, and those
which had been before badly described. But, of

* Artedi was a Swede, the contemporary and friend of Linnars.
He Avas born in 1705, two yejrs beibrehis illustrious coumr)-man ;
and died in 1/35, being accidentally drowned in a canal at Am-

steidani.

156 Natural Historii, [Chap. III.

all the \\Titers on this branch of zoological inquiry,
Mark Eleazer Bloch, a Jew physician of Berlin, is
said to be the most able and complete. To which
may be added, that La Cepede, before mentioned,
has commenced the publication of an extensive
work on fishes, of which great expectations are
fomied*.

In addition to the great ichthyologists already
mentioned, several other names are entitled to re-
spectful notice.— Professor Monro's celebrated work
on the physiology of fishes has been long and
highly commended. Gronovius, Scopoli, and Klein
have also written instructively on this class of the
animal kingdom.

The inquiries and discoveries with respect to
the Insect a, the ^fifth class in the Linnsean arrange-
ment, have also been numerous and highly impor-
tant during tlie period in question. Swammerdam
was one of the first who paid particular attention
to insects. He was followed by madame Merian,
a celebrated German lady-j-, v/ho, by her work on
the Insects of Surinam, rendered very important
services to Entomology. This illustrious female
naturalist was followed by Linnaeus, who first pro-
duced a systematic arrangement of insects, at once

* This great ichthyologist has already given four quarto vo-
lumes of his work to the public, containing a description of 309
fishes, of which 54 were before unknown to naturalists. When
finished, it will probably be the most complete and splendid work,
on ihis branch of natural history, in existence. — Garnet's Annuls ef
Vhilosopliy for ISOO.

t Moiia Sibylla Merian was born in 164/, and died in 1717,
Her great work, entitled Surinaamsche Insecten (folio 1705), was,
at the time of its publication, one of the most magnificent that
Lad ever been produced in Europe.

Sect. I.] Zoology, 157

sufficiently comprehensive, and, in a due degree, mi-
nute in its distinctions. He distributed all insects
into seven orders, i^ik'mg the distinctive marks from
variations in the structure of the wings, or the en-
tire absence of these organs. While the great
Swede vi^as engaged in these inquiries, Reaumur \
of France ; Lyonet, of Holland j and Bonnettf, of
Geneva, also distinguished themselves by their ro
spective publicacions in entomology; and, though
with different relative merits, decidedly improved
upon all who had gone before them.

In this department of zoology also, within the
period which we are considering, Drury and Do-
novan of England; Geoffi'ey of France; FabriciusJ,
of Denmark; De Geer, of Sweden; and, latest of
all, Olivier §, of France; have laboured with great
diligence and success. With respect to the dific-
rent degrees of honour due to these celebrated na-
turalists, it is not easy, within small limits, to state
them with precise justice. The best judges seem to

* Rene Antoine Fcrckault de Reaumur was born at Rochelle in
l683, and died in 175/. Kis History of Injects, in 6 vols 4to,
is certainly one of the greatest works of the age in which he lived.

t Charles Bonnett was born in 1/20, at Geneva, where he
died in 1793. He was one of the most distinguished men of the
eighteenth century. His*inquiries and publications on Insects and
the Vermes are greatly esteemed, and have been much celebrated
anaong naturalists.

X Fabricius formed a new system essentially different from that
of Linnaeus. He efhiploys, for the foundation of his arrangement,
the diversities in those parts of the organisation witli which in-
sects take their /oof/. — ^The arrangement of Linn«us is commonlf
preferred, especially in Great Britain j but that of Fabricius hss
many admirers on the continent of Europe.

§ Of Olivier' s work it is not easy to speak decidedly, as it ii
yet in an unfinished state.

158 Natural History. [Chap. III.

agree in assis^iiing to Reaumur and Fabricius the
first rank*. Beside these, Frisch, Rosenhof, Klee-
nian, Roesel, Sulzer, Schafer, and several other
German entomologists, have written on this class
of animals. In the present list, professor Pallas is
also entitled to -a distinguished place. His Icones
Insectarum is a very valuable work. The insects
without loings liave been very ably described by J,
Herlet, of Germany. To these names may be added
that of Dr. Smith, the Linnceus of Great Britain,
whose account of the rarer lepidopterous insects of
Georgia, is entitled to a place among the most splen-
did, accurate, arid valuable zoological works of the

agef.

In the investigation of the Vermes, the sixth and
last class of Linnaeus, the advances made in mo-
dern times have been no less eminent. The first
writer to be mentioned under this head is Donati,
whose work on the vermes of the Adriatic -is con-
sidered as highly instructive and important. After
him, professor Bohadsch, of Prague, laboured much
to improve the history of this class of animals, and
with great success. Bohadsch was followed by M.
Cuvier, of France, who proposed a new arrange-
ment, and rendered considerable service to this

* When Pv.eaumur and Fabricius are mentioned together, and a
place assigned them in the first rank of entomologists, it is to be
remembered that each has a different kind of excellence. Fabricius
is a great technical or systematic entomologist 3 but he has done^
comparatively speaking, little in regard to the physiology or phi-
losophy of the subject. In this point of view nothing has ap-
peared tliat will bear a comparison with the great work of
Reaumur.

t The NaUcral History of the Rarer Lfpidopterous Insects of
Georgia, &c. 2 vols, folio^ 1798.

Sect. I.] Zoology. 1.59.

branch of zoology. The vermes have also been
treated, either generally or n\ part, by Job. A.
Murray, Jac. Tbeod. Klein, N. G. Le.o>kn, and Ze-
der, all of Germany. The human vermes Jiave been
\^y ably treated by BIocli, before mentioned. Tlu*
vermes infesting the intestines of animals, general! v,
have been examined and described in a verv sa-
tisfactory^ manner, by Goeze and Scbranck, of Ger-
many. The discoveries of Peysonnel, of France,
with respect to Corals and Corallines, form one of
the most interesting parts in the modern annals of
natural historj^ Corals, at the beginning of the
eighteenth century, were reckoned among t J io num-
ber of marine plants. In this rank they continued
to stand, until M. Peysonnel, by a series of ob-
servations and experiments, from about the year
1720 to 17'50, ascertained their animal nature. His
doctrine was confirmed by the successive inquiries
of Trembly, Donati, B. de Jussieu, and, finally,
of the ingenious and accurate Mr. Ellis, whose
work on this genus of animal substances is cer-
tainly among the best extant*. The celebrated
Spallanzani, of Italy, also paid particular atten-
tion to the corallines, and wrote ably on the suh-
ject. On the fourth order of vermes, Zoop/njla,
professor Pallas, of Russia, has given to the pub-
lic a very valuable work, of which the systema-
tic arrangement, and' philosophical accuracy, must
ever recommend it to the discerning inquirer.
The iifth order^ or Infusoria, has been treated with
great successive improvements, by Bennett, of Ge-

* Essay toi\:ard the Natural History of the Corallines, and other
Marim Productions of the like Kind. 4 to. 1/75.

160 jSlatural History. [Chap. Ill

neva; Keedliaim, of Great Britain; Adanson, of
France; Spallanzani, of Italy; and, above all, by
Muller, of Denmark: the last of whom has inves-
tigated and exhibited this department of zoology in
a manner more extensive, complete, and satisfac-
tory, than any of his predecessors.

Most of the naturalists above mentioned not only'
VtTOte v^ith great ability on the several subjects
connected with their names, but also made large
additions to the facts and specimens made known
by preceding inquirers. Few of them failed to con-
nect with the ingenuity of system a large mass of
new and useful information. A considerable num-
ber of new Quadrupeds have been brought to light
during the period of which we are speaking, and
added to the old lists. The species of Birds ar-
ranged and described by Linnasus amounted to
near a thousand : since that time the nmnber has
been more than doubled, by the inquiries of the
great ornithologists already mentioned; and also
by the discoveries of sir Joseph Banks, Mauduit,
Desfontaines, Dombey, Vaillant, and many others*.
The class Amphibia^ though not so much extended,
by the discovery of new genera and species, as
some of the other classes, has yet received consi-
derable augmentation in this way. Of Fishes, Lin-
naeus described shout four hundred species-, but,
since he wrote, the catalogue has been so mucii en-
larged by circumnavigators and travellers, that they
now amount to considerably more than o?ie thou-

* According tq the latest accounts given by M. la Cepede,
who has introduced, as was before observed, a new arrange-
ment of birds, there are now known tivo thousand Jive hundred
find thirty-six species.

Sect. I.} Zoology. IGl

sand. The number of new species of Insects dis-
covered at different periods of the century is pro-
digiously great. Before the time of Lin uncus,
scarcely more than two hundred species were known.
In the last editions of his works he described about
three thousand. There are now known more than
twenti) thousand species. The same augnientatiun
has taken pluce with respect to the Venues, a class
which, in the hands of Ellis, Pallas, Muller, and
others before mentioned, has wonderfully enlarged
its bounds.

Though America, during the period under
review, has not produced many distinguished
inquirers in zoology, it can boast of some who
have rendered themselves conspicuous by pursuits
of this nature. Mr. Catesby, and Dr. Garden, be-
fore mentioned, though not native Americans, re-
sided long in that country, and threw much light
on the animal kingdom, as it appears beyond
the Atlantic. Mr. Glover, a planter of Virgi-
nia, also communicated to the public some valu-
able information respecting American zoology*.
Mr. William Bartram, of Pennsylvania, an indefa-
tigable and well informed student of nature, added
considerably to the number of facts before known
concerning the animals of the southern and western
parts of the United States, and the adjacent terri-
tory f. Still more recently Dr. Barton, professor
of Natural History in the University of Pennsyiva-

* The principal part of Mr. Glover's comrauiiications respect-
ing American zoology appeared in the Phibsoplucjl Transactions,
about the year 1/40.

- t Trarels through North and South Carolina, Gcoi-'^la, East and
mst Florida, &c., from J 773 to 1778.
Vob. I, M

1 52 Natural History. [Chap. IIL

nia, has made very respectable additions to the
zoological science of that country ; and displayed a
degree of genius, diligence, learning, and zeal, in
this pursuit, which do honour to the rising re-
public, and bid fair to place him among the
most accomplished and useful naturalists of his
time^. Beside the labours of these and other
scientific inquirers of Americaf, a large amount of
information respecting the animals of that continent
have been derived from intelligent foreigners, who
have either visited and explored the interior of the
country at different periods of the century under
review, or devoted themselves to the acquisition of
knoAvledge, from various sources, respecting the
new world. Among these, Gronovius, Sarragin J,

* See Fragments of the Natural History of Pennsylvania, Essay
on the fascinating Foivcr ascribed to ScrpeiUs, &c., and several me-
moirs on particular articles in zoology in the American Philoso-
phical Transactions.

t It would be easy to mention tlie names of many respectable
American gentlemen, who have done honour to themselves by
giving new and valuable descriptions of particular animals M'hich
came under their observation. In such a list, Mr. Jefferson, Dr.
Mitchill, the rev. Mr.Heckewelder, and a number of others, would
be entitled to distinction. To these might be added the names of
the rev. Drs. Belknap and Williams, who, in their respective
histories of Ncw-I lump shire and Vermont y after the example of
Mr. Jefferson in his JSotes on Virginia, have given valuable
catalogues of tlie native animals of tliose States. But it is impos-
sible for the author, consistently with the hmits which he has
prescribed to himself, to indulge the disposition which he feels to
enter into such details.

X M. Sarragin, a French physician, \\ ho resided for some time
in Cannula, well deserves to be added to the list of those who
Imvc considerably extended our accjuaintance with the animal and
\ e.i':etai;le productions of the higher parts of North America. Hi!<
J'iil-rcnt mcm^u-s were pubii^hcJ b'jJ.vvccn the years l/OG and

Sect. II.] Botany. 163

Kalm, Schoepf, Buffon, and several others, deserve
to be mentioned with honour.

SECTION II.

BOTANY.

In this branch of natural history tlie succession
of discoveries and improvements, which the period
before us has displayed, is in the highest degree
honourable to modern science. At the opening
of the eighteenth century. Botanical Philosophy,
though it had been long cultivated, was still in a
very confused and imperfect state. Numerous had
been the attempts to arrange the vegetable tril)cs
into an intelligible system, but great disorder and
deficiency appeared in every plan. Among these
attempts the most respectable and successful were
those of Ray and Rivinus. The former, an English
clergyman, before mentioned, had proposed his
method to the world in 1682; but afterwards pre-
sented it in a new and improved form in 1703. He
arranged all known vegetables under thirty-three
classes, deriving the distinguishing character of each
chiefly from the fruit. His system, though un-
doubtedly much superior to any which had been
devised by his predecessors, was still very defective;
and the characters of his plants were so many and

172B. His anatomical histories of the Bearer, Musk-rat and Por-^
cupine, are vahiable. M. Sarragin hkewise distinguished himsch
by a publication on the Sugar Maple (Acer Snccharinum) of that
country. The remarkable family of plants denominated Sarace-
nia was so named in honour of this writer, by tlie illustrious
Tournefort.

:m 2

164 Natural History. [Chap. III^

various, as to create an intricacy in a high degree
perplexing and painful to the student. To the method
of Ray, succeeded that of Rivinus, a professor of Bo-
tany in the university of Leipsic. This learned
man was the first who laid aside the distinction be-
tween herbs and trees, which had been universally
adopted by those who went before him. Relin-
quishing also the pursuit of natural affinities, and
convinced of the insufficiency of characteristic marks
drawn principally from the fruit, he attached him-
self to the Jloxvery as furnishing characters abun*
dantly numerous, distinguishing, and permanent.
He reduced the number of the classes to eighteen,
which were distinguished from each other by the
perfection and distribution of the Jlozvers, and par-
ticularly by the regularity and number of x\\e petals.
Rivinus did not live to complete the publication of
his system j the whole of which was finally laid be-
fore the w^orld in 171 1, by one of his disciples.

After the system of Rivinus, the next worthy
of attention is that of Tournefort. This great bo-
tanist set out with reviving the distinction of plants
into herbs and trees, which had been exploded by
Rivinus. In his method there are twenty-two
classes, and one hundred and twenty-two orders,
denominated sections: the former founded on the
regularity and figure of the petals, together with
the situation of the receptacle of the flowers; the
latter on the pistillum and calyx. Botanical writers
generally speak of Tournefort's as the first re-
gular and complete arrangement. He was cer-
tainly the first vvlio ascertained and exhibited the
genera oi ^\'ca\\.s in a scientific manner ; and, indeed,
in general merit as a systematic writer, he went

Sect. II.] Botany. 165

far beyond all his predecessors. About the same
time. Dr. Paul Hermann, professor of Botany at
Leyden, proposed a new system*. He augmented
the number of classes to twenty-five, founding their
characters chiefly on the circumstances of the seed.
He divided his classes into eighty-two sections or
orders, having for their basis the number of petals,
seeds, capsules , and cells; the figure of the seeds
mid petals J and the disposition of the Jlozvej^s. This
system appears to have gained but little popularity.
To the method of Hermann succeeded tliat of Dr.
Boerhaave, first published in 1710, and afterwards,
with great additions, in 1720. He made a sort of
combination of the systems of Ray, Tournefort, and
Henri ann, with additions and improvements from
his own great mind. He increased the number of
classes still further, to thirty-four, which were sub-
divided into one hundred and four sections or or-
ders; the characters of which were derived from
the habit or general appearance of the plants, com-
bined with all the parts of fructification. He was
the first who employed the stamina and style in
determining the genus. To this luminary of science
botany is much indebted. He introduced many
new genera into his system; and w^as universally
considered as one of the most successful inquirers
and instructive writers of his time on this subject.

Next to the system of Boerhaave, the records ot'
botany present us with the method of Christian

* Paul Hermann was a native of Saxony, and died in 1O95.
This learned man not only presented to the world botanical wri-
tings of great value, but also engravings of plants, which are ex-
ecuted with much delicacy, considering the period in which he
lived.

1(56 Natural History. [Chap. III.

Kiiaiit, a German, who proposed what was after-
wards styled " the system of Rivinus inverted."
This plan was published, in 1716, under the title of
Methodus Plantarmn Genuina. It embraced seven-
teen classes, founded on the number of the petals
alone ; and one hundred and twenty-one orders,
distincfuished by the fruit. Knaut was followed
by Dr. Hales, before mentioned, whose celebrated
work on " Vegetable Statics'* threw much light
upon the physiology of plants, and indeed entitles
him to the honour of being considered the great
flither of this branch of botanical science. To Hales
succeeded Micheli, an Italian, whose Nova Genera
Planfarum must be ranked among the fundamental
works of the age, as it doubtless formed an impor-
tant step in the course of reformation and improve-
ment. Contemporary with Knaut, was Magnol,
a celebrated professor of botany at Montpellier,
whose system was published in \ V'^O. He divided the
vegetable kingdom into fifteen classes, which deriv-
t/d their characters entirely from ihe calyx; and these,
according to him, embraced fifty-five orders, whose
distinguishing characters were taken from ihe^figiire
of the calijx, petals, and seeds ; from the disposition
oi i\\e flowers ; from Xheniunher o^ petals ; and from
the substance of the fruit. In 1720, the same year
in which Magnol published his system, there w^as
another offered to the world by Julius Pontedera,
a nobleman of Pisa. He attempted to combine
the systems of Tournefort and liivinus.

Such was' the state of botanical philosophy until
the year 1735; confused, intricate, unsettled, and
exhibiting little but successive revolutions. And,
if all the systems of classification were "\ague5- un-

Sect. II.] Bota?i}/. io7

satisfactory, and perplexing, the language in use
among the different instructors in this science was
at least equally so. Almost every part of the dif-
ferent nomenclatures, at this time, was loaded with
uncouth, erroneous, or supernumerary words, and
even barbarous sentences of description, which ex-
ceedingly increased the difficulties of the learner.
Besides, numerous voyagers and travellers were
now constantly enriching botany with new trea-
sures, brought from every quarter of the earth ;
and while the names of those before known already
loaded the memory, it became necessary to pro\ide
new ones, for the successive discoveries which were
daily demanding attention. In a word, so great
was the number of new species presenting them-
selves from every direction, and such the perplexity
arising from defective arrangement, that botany
became in danger of relapsing again into anarchy
and total disorder*.

In this stage of the science Linnceus appeared.
Endued with genius and learning; having a taste
for researches in natural history rising to a sublime
enthusiasm, and a disposition for persevering indus-
try ; he cultivated, with particular diligence, the
science of botany. In 1735 he published a new
system as the result of his labours, which produced
a memorable tera in this branch of philosophy. This
is usually called the Sexual Siistcm, from its foun-
dation being laid in the doctrine, that plants are mdlc
^ndfemaky and propagate their species in a inaniu r
somewhat analogous to tiiat of animiils. Linnieus

* See Tracts on K^tural History, by James E. Smitii^ M. I").
F.R.S.

168 Natural History, [Chap. III.

divided the whole vegetable kingdom into twenty-
four classes; the distinguishing characters of which
he founded on the number, the place of insertion,
the projwrtion, the co7inection, and the disposition, of
the stamina. These classes he subdivided into one
hundred and twenty- eight orders. In the first thir-
teen classes, the orders are taken from the number
and circumstances of the pistilla. In the fourteenth
and fifteenth from the pericarpium ; and in all the
remaining classes from the number and circum-
stances of the stamina, excepting the twenty-fourth,
which, from the parts of fructification being invi-
sible, cannot be subjected to the grand principle of
arrangement on which the system proceeds.

With respect to the fundamental doctrine of the
sexes of plants, on which this method of classifica-
tion rests, the honour of giving birth to it is said
not to be due to the great Swedish naturalist. The
ancients had some ideas of the doctrine, hut they
were vague and imperfect. We are informed by
Aristotle, that Empedocles particularly taught that
the sexes icere united in plants; and also that the
use of the farina fmcundans of the male palm, in
impregnating the female, was very well known in
his day. It appears, also, from several passages in
Pliny, that he, as well as other naturalists of that
time, extended the distinction of sexes, and the
use of tlie male dust, to plants in general. Accord-
ingly, it is certain that the ancient cultivators per-
ceived the necessity, and were in the constant ha-
bit, with respect to several species of vegetables, of
promoting the operation of the male flower on the
female, in order to the production of fruit ; still,
being inattentive to the structure of flowers, and

Sect. II.] Botany. 169

ignorant of tlio offices belonging to the several
parts, they remained unacquainted with the true
process of nature, tliough it was daily open to their
observation *.

Thus this celebrated doctrine rested in apparent
forgetfuhiess, until I676, when Dr. Grew, a dis-
tinguished botanist of England, who had been long
employed in microscopical observations and expe-
riments on plants, mentioned the fact, and sug-
gested its importance, in a paper read before the
Royal Society in the month of November of that
year. lie expressed an opinion that the stamina
and styli of vegetables are analogous to the organs
of generation in animals, and adapted by nature to
answer the same purpose ; and that the potlen pro-
bably emits certain mmfic effluvia^ which may pro-
duce impregnation. The sexual doctrine was fur-
ther confirmed by the observations and experiments
of Camerarius, in 169-5. In 1702, a small publi-
cation, by John Henry Burkhard, a German phy-
sician, appeared in the form of an " Epislle to Leib-
nitz ;" in which the author not only adopted the
idea of the sexes of plants, but also suggested tlie
possibility of forming an arrangement of vegetables
according to the difference of the parts of genera-
tion!. A few years afterward, two botanists of

* SeeDatens's Origine, &c. and Piilteney's Historical and Bio.
graphical Sketches of Botany in England, 2 vols. 8vo. l/()0.

t About die year 1738, when the growing fame of Linnaeus
made him an object of envy among some of his contemporaries,
professor Hcister, of Helmstadt, one of his antagonists, charged
him with having taken liis system, without acknowledgement,
from the abovementioned work of Burkhard. Linn.Tus, how-
ever, it appears, proved that he never saw this obscure pcrfonh-

170 Natural History. [Chap. IIL

France, GeolTroy in 1711, and Vaillant in 1718,
declared themselves in favour of Grew's opinion;
while Tournefort and his friends opposed it vv^ith
equal v/cirmth*. In Great Britain, Blair, Bradley,
Fairchild, and Miller, also appeared on the side of
Grew's doctrine; but Alston, and some others,
long retained their hostility against it with una-
bating zeal.

Such was the state of opinion with regard to this
doctrine, when Linna3us adopted, unfolded, and
made a splendid application of it to botanical sci-
ence. And although we cannot ascribe to him the

ance; and even if he had, his friends contended, that it would
have detracted httle from his merit, that another had dighthj sug-
gested a plan which he so abli/ executed, — See Stoever's Life of
Linmvus, translated by Trapp, 4to, 1794. — Professor Barton lately
informed me, that he had seen a copy of Burkhard's publication, in
the Loganian Library, at Philadelphia, and tliat he considered
the sexual doctrine, to have been very distinctly suggested by the
author as the foundation of botanical arrangement.

* It is remarkable that the beautiful Latin Poem of M. de la
Croix, entitled Connubia Florum, of which the sexual doctrine
fi^rms the foundation, was published as early as 1/27. Some no-
tice will be taken of this performance hereafter.

It is also worthy of notice, that James Logan, esq., a learned
and ingenious gentleman of Philadelphia, who was afterwards
president of the council, and chief justice of Pennsylvania, in-
stituted a set of experiments on maize, with a particular view to
the investigation of the sexual doctrine. An account of these ex-
periments was first communicated in a letter to Peter Collinson,
F.Il.S,, in 1735, and printed in the Philosophical Transactions, vol.
.^cxxvi. This r.ccount was afterwards enlarged, and published in
Latin, at Leydcn, in 173(), under the title oi Experimenta ct Me-
htcmata de Pluntarum Generatione ; and republished with an
EugliMi translation, by Dr. Fothergill, in 8vb, 1747.- These ex-
jjcriments were considered and appealed to as among the most de-
cisive in establishing the doctrine they were intended lo illustrate
and ccnfirm. — Vultcncfs Sketches, kc. vol. ii, p. '27S.

Sect. II.] Botany. I7I

original discovery, yet he confirmed, extended, and
improved it, and made it the basis of a system, which
has commanded greater admiration and been more
generally received than any before oiTered to the
world. It will appear evident, on the slightest con-
sideration of the subject, that the task of arrange-
ment, in the vegetable kingdom, is a very per-
plexing and (liflicult one; and that every artificial
classification must involve sacrifices of family re-
semblance, and natural connexion. But the phi-
losophers of every country seem to have yielded to
Linnaeus the praise of having formed a system, on
the w^hole, superior to all hitherto proposed.

But it was not only in the doctrines and arrani^e-
vient of botany, but also in the nomenclature of the
science, that this distinguished natural historian
excelled all his predecessors. He created a new
language, so simple, methodical, and convenient,
that it has been pronounced likely to stand the test
of ages, even if his sexual opinions should be dis-
carded. In forming this language, he retained all
the old names, which were consistent with his new-
principles ; he adopted such others from the Greek
and Latin, as were short, expressive, and sono-
rous; he dismissed the periphrastic and tedious de-
scriptions of the former schools; he introduced tri-
vial names, by which one, or at most two adjec-
tives, distinguish a plant from all its other relative
species*; in a word, he formed a language so sim-

* The following will serve as a specimen oi the convenience
and utility of the trivial names invented and applied by Linn.xus.
A kind of Grass, before his time, was called Gravun Xcrampcli'
num, Miliacca, prdtcnuis ramusaque sparsa panicida; sive Xerampc-
lino congener, nrvcnsc, astivum ; irravien minutissimo scmine. I Ic gave
it a name consisting of two words, Poabulbosuj which designated

175 Natural History. [Chap. III.

pie and luminous, and so adjusted its several parts
to his improved doctrines, that the acquisition of
tlie science of botany became a far more easy task
than before. In fact, this was so much the case,
that, instead of remaining an abstruse study, con-
Ihied to the schools, as formerly, it was converted
into an agreeable amusement to persons of leisure
in all ranks and situations.

The new classification and nomenclature of Lin-
naeus soon attracted general attention. At first,
as might have been expected, they met with pow-
erful opposition. When they first made their ap-
pearance in Great Britain, Sloane, Dillenius, and
other English naturalists, opposed them with
warmth. Alston, of Scotland, retaining his old
prejudices, did the same; insomuch that the influ-
ence of the doctrines taught by Ray threatened,
for some time, to triumph over those delivered by
Linnasus. This opposition, however, soon, began
to decline. As the works of the illustrious philo-
sopher of Upsal increased in number and circula-
tion, the weight and superiority of his opinions
were gradually manifested, until, at length, the pub-
he adoption of the Linnaean system by professor
Martyn of Cambridge, and professor Hope of
Edinburgh; the adaptation of Ray's Flora Angli-
cana to this arrangement, by Hudson, about the
year 1760; and, fnially, the favourable reception
given to the Swedish doctrines by the College of
Physicians of London ; completed the establishment
of the Sexual System in Great Britain.

the plant more distinctly and intelligibly than the long and per-
plexing description before used. — Stoever's Life ofLinnaus, p. 201 .

Sect. II.] Bolajiy. 173

The opposition to this system was no where
stronger or more persevering than in France, where
the authority of Touniefort had long been so liigU
and imposing ; and where so many great botanisu
resided, each jealous for the honour of his country,
and for the reputation of iiis own opinions. It is
true, several of tiie naturalists of that country em-
braced the system of the illustrious Swede. Among
these, Sauvages, Gouan, Gerard, and le Monnier,
deserve to be particularly named. But by far the
greater number became his adversaries, and those
most distinguished by their learning and talents.
The system which they opposed, however, gradu-
ally rose into importance, and extended its empire.
Personal prejudices, and national jealousies, w^ere
slowly yielded. And although it can by no means
be said, even now, to be universally adopted, yet it
is incomparably more popular than any other; and
even those who reject some of the opinions wliich
it involves, generally adopt its language as the most
convenient and philosophical any where to be
found *-

But the immediate achievements of Liim<TRUs
himself, in botanical philosophy, were not the only
services which he rendered to this science. His
researches and publications excited a general thirst
for this kind of knowledge. From the school wliich
he formed, many distinguished characters arose,
who did honour to their instructor, and who greatly
extended and improved his system. A number of
these, incited by the zeal and the example of this
patriarch in science, undertook distant voyages,

* Piiltcney's Histon'ail and Biographical Sketches of Botany j 8fC.

174 Natural History. [Chap. III.

and tedious and hazardous journeys, for the pur-
pose of exploring such regions of the earth as were
before unknown; and thus daily brought home
new stores of knowledge from every quarter of the
globe.

Since the publication of the Sexual System^ se-^
veral new methods of classification have been pro
posed, and still more numerous plans suggested,
for modifying and improving that of Linnaeus.
Among the former of these the following are most
conspicuous. Beside his sexual system, the great
Swedish naturalist founded a method of arrange-
ment on the form and other circumstances of the
calyx. To this method, which he published in the
year 17375 he gave the name of Methodus Caly-*
chia. In this system the vegetable kingdom is
divided into eighteen classes. In the same year
Christian Gottlieb Ludwig, a native of Silesia, and
a professor at Leipsic, published a new method,
in which he divided vegetables into twenty classes,
taking their distinctive characters from thejioiver*.
Next followed the natural method of van Royen,
professor at Leyden, exhibited in his Prodromus
Florae Leydenensis, published in 1740, and which
sustained a high character among botanists for in-
genuity and elegance. To this succeeded that of
baron Haller, one of the greatest men of the age
in which he lived. He proposed, in 174:2, a new
natural system, founded on an assemblage of the
various characters chosen by others. The botani-

* Ludwig was the author of several valuable works, of which
his JiLstitutiones Jlistorico-Physica: Regni Vcgetabilis, Sec, printed
at Leipsic in lydjj is the principal one.

Sect. II.] Botanxf. 1 7J

cal works of this philosopher rank in the very first
class. He was a warm opponent of Linnaeus, and
sometimes, in this scientific warfare, departt^l from
that mildness and urbanity wliicli he owed both
to himself and his adversary*. After Mailer, Ber-
nard de Jussieu, of France, published a new me-
thod of classification, also a natural one. To hini
succeeded his countryman la Marck, the author
of the botanical part of the Encyclopedic Mttho-
diquCy who formed a \\e\w system. But although
the works of the two last-named writers arc in-
structive and valuable, they are comparatively lit-
tle known or followed out of their own country.
In 17«51 the celebrated nosologist, Francis Boissier
Sauvages, of Montpellier, published his Mcthodus
Foliorum, seu Plant cc Florae Monspcliensis juxla
Foiiorum Ordincjn. In this work the author has
attempted an arrangement of plants from the
situation or position of the leaves. It is believed
that no succeeding botanist has adopted this me-
thod. In 1764 professor Gleditsch, of Berlin, pub-
lished a system, in some respects new, but differ-
ing so little from that of Linnaeus, especially witli
respect to his ordinal distinctions, that it act^uiivd
but little celebrity.

The light thwwn on Vegetable Physiology forms,
one of the most brilliant honours of the period
under review. Little had been done in tliis
branch of botanical science before the commence-
ment of the eighteenth century. Grew and Mal-
pighi, indeed, of the preceding age, had instituted

■^- Tracts QU Natural Jlistorj/, by Jame_-< KdwarJ Smith.

176 Natural History. [Chap. III.

some enlightened inquiries into the structure of
plants; but they made little progress, compared
with what has since been done. Early in the cen-
tury under review, the rev. Dr. Hales, of Great
Britain, pursued this investigation with great acute-
ness and diligence, and in his Vegetable Statics
presented the world with a mass of information
which will be long read and admired. About the
same time, Duhamel, of France, was busily and
successfully engaged in similar inquiries, and in his
Physique des Arbres, and other publications, threw
much new light on this part of botanical science.
Duhamel was followed by Charles Bonnett, of Ge-
neva, who proved one of the most distmguished
vegetable physiologists of the age. His Traite des
Feuilles is particularly curious and valuable.

Towards the close of the seventeenth century
some attention had been paid to the different kinds
of Hairsy which constitute a downy covering upon
the surfaces of vegetables. But it was not till the
year 1745, that this subject was treated in tlie
full and masterly manner it deserved. In that
year M. J, Stephen Guettard, a very ingenious and
learned French botanist, began to publish his ob-
servations on the hairs and glands of plants.
These observations he continued during several
succeeding years. He has even established a bo*
tanical Method, deduced from the form, the situa-
tion, and other circumstances, of the hairy and
other glandular appearances on the surface of
plants. He has shown, w^hat perhaps w^ould hardly
have been suspected, that these appearances are,
in general, constant and uniform in all the plant3

Sect. IL] Botany. I77

of tlie same family or genus. Hence, he lias ob-
served that they constitute good gaieric, but not
specific characters *.

Sir John Hill, after much inquiry in ve^-etable
physiology, pubhshed, in 1773, a very extensive
workj which has been commonly called his Vegeta-
ble Sijstem, in which he proposes a method of ar-
rangement founded on the internal slructure of
plants. About the same time, M. Tillet, of France,
and the celebrated Spallanzani, of Italy, published
the results of their observations and experiments
on the organs and functions of vegetables, wiiich
have been generally considered as highly valuable.
Beside what has been done by these naturalists,
new light has been thrown on vegetable physio-
logy by professor Walker and Dr. Darwin, of Great
Britain ^ by des Fontaines and Vauquelin, of
France ; by Pontedera^ of Italy -, hy Sennebier, and
Saussure, senior and junior, of Geneva j and by
Plenck and Reichel, of Germany.

But among the vegetable anatomists and physio-
logists who flourished towards the close of the
eighteenth century, Joseph Ga^rtner^ of Germany^
deserves particular distinction. This great botanist
was born in the year 1732, and died in 1792. He
early devoted himself to the fruit of vegetables,
not only as a part of vegetable physiology which
had been too much neglected, but also as furnish-
ing one of the best grounds of botanical arrange-
ment. A method of this kind he exhibited in his
great work, Dc Friictibus et Seminibits Plantanemy
the first volume of which was published in 1788,

* Barton's Elements of Botany,
Vol. I. N

178. Natural History. [Chap. III.

and the second in 1791; a work which abounds
with valuable instruction in botanical science; and
though the method which it contains is by no
means free from objections, the author is entitled
to much commendation for his labour, and must
ever be ranked among those who have made large
contributions to our knowledge of the vegetable
kingdom.

The modern discoveries in chemistry have con-
tributed much to enlarge our acquaintance with
the composition, food, and growth of plants. Se-
veral of the vegetable physiologists mentioned in
the foregoing paragraphs have rendered important
aid to this branch of inquiry. To these may be
added Priestley, of Great Britain; Hassenfratz,
Fourcroy, Chaptal, Giobert, and Parmentier, of
France; and Ingenhousz atid von Humboldt, of
Germany; whose experiments and various works
have thrown new and very important light on some
of the laws of vegetation.

Professor Tlmnberg, of Upsal, proposed j a few
years ago, to alter the method of Linnaeus, by sup-
pressing the classes Gijnandria^ Monoeciay Dioecia,
and Folygamia^ and assigning to other classes the ve-
getables arranged by Linnseus and hisfollowers under
these denominations. The professor has pursued
this method in his Flora Japonica, and in his Fro-
jdromus Florae Capensis. It is not generally consi-
dered as an impro^'cment on the method of Lin-
ncpus, but rather as rendering it, on the whole,
still more artificial and perplexed. In this altera-
tion, however, he has been followed by Gmelin,
Withering, Swartz, and several other eminent bo-
tanists.

Sect. 11. ] Sotcuiy. 179

Botanical methods cither partl}^ or wliolly ori-
ginal have been proposed, at diflerent periods of
the century, by Vaillant and Adanson, of France ;
by Alston, of Great Britain; and by Hcister, Nec-
ker, and Medicus, of Germany. Alterations in
the Linnaean system have also been suggested by
Schrcber, sir ^\'illiam Jones, and others. — But the
author has not sufficient knowledge of any of them
to attempt an account of their nature or merits.

Dr. Darwin, in his Botanic Garden^ and his Phy-
tologia, assuming the system of Linnaeus, with
some proposed alterations, exhibits great learning,
geniusj and taste. He carries further than any
preceding botanist the idea oi plants being an infe-
rior order of animals, and ascribes to them sensa-
tion, volition, passion, affection, virtue, and vice.
Indeed, he pushes the doctrine to such an extra-
vagant length, and founds upon it so many fanci-
ful positions and reasonings, that the sober and
wary inquirer must often l)e offended at the ob-
vious triumph of a lawless fancy over the cautious
spirit of philosophy.

The botanists who have inquired with diligence,
or described with abilit}', in particular branches of
this science, within the period under review, arc
too numerous to be recounted. The Crypivga?nia
have been ably treated by Micheli, before men-
tioned, by Hedwig, Tode, M. Bulliard, professor
Batsch, M. de Beauvois, and by Dickson nnd
Masson*. llie Mosses have been faithfully and

•^ Perhaps no class of phmts has been iiivcsligatcd since the
time of LiDn;«'U5 with greater zeal and labour than tJie Cnfioga^
wia. Indeed, the plants of this class have been investigated with
A 5pecie= of zeal, which led a late botanist, M. de Xecker, to

>' -2.

180 Natural History. [Chap. III.

successfully investigated by professor Dillenius%
of Oxford, by Bridel, of Gotha, by Zoega, of Den-
mark, and otiiers. The Lichens -have been exa-
mined and described with great care, by Acharius,
of Sweden f, and by Hagen and Hoffman, of Ger-
many : the Ferns by Phimier J, of France, by Ma-
ratti, of Italy, by Bolton, of England, and by those
above named, who have treated generally of the^
class to which they belong. The Grasses have
been investigated and described by Scheuchzer,.
Schreber, Curtis, and many more : the Oaks of
North America, by du Roi, of Germany, and with
unusual elegance by M, Michaux, of France : the
Ferula^ or AssafiCtida-planty by professor Hope, of
Edinburgh : the Geranium, by professor Bunnann,
M. I'Heretier, and the abbe Cavanilles § : the Cot-
ton-plant, by van Rohr, of Denmark: the Coffce-
tree^ by Ellis, of Great Britain : the Tea-tree^ by

denominate the enthusiastic rage for inquiries after them^ Crj/pto-
jnania.

* John Jacob Dillenlus was born in Germany in l687; came
to England in lyil; and was appointed professor of botany in tlie
university of Ox.tord about the year iT'ipj which oftice he held
till his death, in lyAy. Dillenlus wrote a number of botanical pub-
lications ; but that which has more than any other immortalised
his name is the Historia Musconim, Sec, 4to, 1/41. Indeed, his
discoveries in the natural history of the Mosses were so numerous
and briUiant, that he deserves more than any otlier individual to
be called the father of this branch of botany.

f See his Lichcnographia: Suecice Prodromus, 8vo, 1798'

X Father Plumier was one of the first good writers on the
I'trn^, His Traice dcs Foiigcrcs de VAm^riqve, published in 1705,
holds a high rank among the works on this part of botany.

§ The work of this latter gentleman on the Ceranimn is very
elegant. He has enumerated and described one hundred and
tii-enti/-eight ifecies.

Sect. II.] Botanij, 18 1

Dr. Lettsom : and the Tobacco-plant, by Mr. Ta-
tham: not to particularise a number of valuable
descriptions, almost countless, of new and curious
plants to be found in the memoirs of the Lin-
lucan Socic/j/ of Great Britain, and other asso-
ciations of a similar kind in dificrent parts of
Europe. To these may be added, not as publica-
tions of the fnst class, but as doing honour to the
Infancy of botanical science in America, the na-
tural history of the Pcrsimmon-trec, by Dr. Wood-
house ; of the Tobacco-plant, by Dr. Brailsford ; of
the Phytolacca, or Poke, by Dr. Schultz -, of the
Slramoniiun, or James-Tow fi-need, by Dr. Cooper;
and of the Sumach, by Dr. liorsefield, all of the
United States*.

But beside these botanical writers, who have
published useful accounts of particular classes, or-
<k^rs, genera, or species, of plants, the last century
has abounded beyond all former example with
works on the plants of particular countries, or
smaller districts. The plants of Great Britain
have been either collected, or ably described, du-
ring this period, by Dillenius, Alston, Miller,
Blackstone, Hudson, Lightfoot, llobson, Curtis,
Withering, Berkenhout, and Smith. To this list
of writers on English botany, may be added pro-
fessor Martyn, w ho has written ably on the sub-
ject ; Mr. Relhan, who has given a valuable Flora
Cantabrigiensis ; !Mr. Abbot, whose Flora Bed/or-
diensis is also a useful work- and Mr. Sowerby,
whose English Botany, and English Fungi, are wor-
thy of much commendation. Hill and Wilson have

* See Additional Noics^(Zj.

182 Natural History, [Chap. III.

also written on English plants. The plants of Ire-
land have been described by Threlkeld, Keogh, and
Smith; those of France, by Goiian, Gerard, Mag*
nol, Adanson, Balliard, Jussieu, la Marck, and
several late botanists; those of Szvitzerland, by
Haller ; of Holland, by Commelin and Boerhaave ;
oi Germany, by Crantz and Jacqiiin; oi Italy, hy
Micheli and Allioni ; of Spain, by the abbe Cava-
nilles ; of Russia, by Pallas ; of Denmark, with
great splendour, by Oeder, Muller, and their asso-
ciates; of Lapland, by I^innseus; of Siberia, by
Gmelin ; of Egypt and Palestine, by Celsius, Hasr
selquist, and others; of Amboyna, by Rumphiusj,
of Ceylon, by Burmann; of Coivmandel, by Rox-
burgh; of Japan and the Cape of Good Hope^
by Koempfer and Thunberg ; of the Mauritius,
by Willemet ; of Cochin China, by Loureiro ; of
New Holland, by Smith; of the West-India
Islands, by Sloane, Browne, Houstoun, Plumier,
Jacquin, and Svvartz ; of particular parts of
North America, by Banister*, Vernon, Kreigf,

* John Banister, an Englishman, who settled in Yirginia to-
ward the latter end of the seventeenth century, and devoted hinj-
self to the investigation of the plants of that part of America,
lie not only collected plants, but also described them, and him-
self drew the figures of the rare species. He became a victim to
his favourite pursuit. In one of his excursions for collecting
plants, he fell from the rocks and perished. His botanical friends
did honour to his memory, by calling a plants of the decandrous
class, Banisttria.

t About the beginning of the eighteenth century, Wiljic.m
Vernon, an Englishman, and Davjd Kreig, a German physician,
led by their genius for botany, made a voyage to Murj/land ; where
they resided for a considerable time, and examined its vegetable
productions. They returned to Europe, after having collected au
Herbarium of several hundred uc^a and undescribcd plants.

Sect. II.] Botany. 183

Catesby*, Mitchell f. Garden, Gallissonierrc J»
Kalin§, Wangeuheim, Sclioepf||, and Walter Y,

* For some account of Mark Catcsby, see vol. ii, chapter 26,
of this work. His Natural History of Oirolinu, kc, was, at tlic
time of its publication, in 1730 — 1/43, the most splendid work of
the kind that Great Britain ever produced j and, indeed, it had
scarcely a rival in magnificence on earth. Many of the most
beautiful and useful plants were, in this performance, for the fir«.t
time, exhibited in their true proportions and natural colours.
I'he number of subjects described and figured in tJie work is as
follows: Plants 171, Suadrupcds g. Birds 111, Amphibia J 3,
Fishes 46, Insects 3 1 .

t Dr. John Mitchell, an Englishman, was sent to Virqinin,
m 1741, for the purpose of investigating the botanical treasures
of America. After having discovered many new genera and
species, he returned to England, about tjie year J 748. He trans-
mitted not only to his countrymen, but also to Linnaeus, mucli
valuable information respecting American plants. Tlie great
Swedish botanist viewed him with so much respect, that he took
care to jjerpctuate his name, by giving it to an American plant,
tJie Miichelia Ilepcns.

X The marquis de la Gallissonierre, who, about the middle of
the century, was governor of Canada. He explored the natural
history of that coiuitry with great industry, and returned to Trance
laden with botanical riches. — Kalm's Traiufls,

§ A Swedish botanist, who was sent, in 17*i8» to A.merica, for
Ihe purpose of discovering and collecting plants. After remain-
ing between two and three years in the country, and collecting
many new plants, in ^vhich pursuit he iravelled through Pcnnsi,l-
lania, Neiv Jersey, Neiv York, and Canadn, he returned to Sue-
den, and died in 1779. — Sec his Travels, tran.^ated by For.^ler.
2 vols 8vo, 1773.

II Wangenheim anc| Schoepf were tvo l^otanists who came to
America with the German troops, during the late revolutionary
war. Their works on American pl^Ls, thougii by no means ei\-
titled to a place in the first class orWtanical publications, are yet
of considerable value.

^ Thomas Walter, a planter of South Curo/ina, who published,
in 17S8, Flora Carolinian't , a work of respectable character.

184 Natural Historic, [Chap. IIL

and by Clayton*, Bartram-f, ColdenJ, Muh-
lenberg §, Marshall II, Barton^, and Cutler** ; and
the plants of different portions of South America^
by Plumier, Aublet, mad. Merian, dqn Ruiz, don
Pavon, and others ; and of the South-Sea Islands^
by the indefatigable Dr. Forster, whose Nova Ge-
nera Plantarum may be considered as one of the

* Dr. Clayton, '^ a native and resident of Virginia. This ac-
curate observer passed a long life in exploring and describing th«
plants of his country; and is supposed to have enlarged the bota-
nical catalogue as much as any man who ever lived." Notes on
Virgijiia. — Clayton's Flora Virginica appears to have been first
published about the year 1743. It was afterwards republished by
Gronovius, at Leyden, in 1762. It holds ^ very important sta*
tion in the history of botany.

f See Additional Notes — (A A.)

X Cadwallader Colden, esq., lieutenant-governor of the province
of New York, who was before mentioned. He had a great fond-
ness for botanical studies. He made very valuable communica-
tions of American plants to Linnaeus, especially those \vhich ap-
pear under the title of Plantce Coldenhamenses, m the Acta Up-
salmsia, for 1743 and 1744; and his name is mentioned fre-
quently, and with great respect, in the Species Plantarum of that
diotingi^iished botanist. This gentleman's daughter, IVIiss Colden,
was also fond of botany, and corresponded with Linnaeus j who,
in honour of one or both of them, in his Flora Zcylanica, gave to
a plant of tlie Tetrandrous class, the name of Coldema. — Stoever's
Life of Linnwus, and Pulteney's Sketches.

§ Index Florae Lancastricnsis. Vols, iii and iy of the Trans-
actions of tlie American Philosophical Societi/.

II Arbustrum Americanum, 8vo, 1785.

% Collection for an Essay towards a Materia Medica of the
United Slates; and other publications. Since the close of the
century Dr. Barton has published an elementary work on botany,
which is highly honouratJp^to him. See Additional Notes —
(hB.)

** An Account of some of the Vegetable Productions naturally
growing in Americay by Manasseh Cutler, D. D. — Memoirs of th(
American Academy of Arts and Sciaias, vol. i.

Sect. II.] Botany, 1S.>

most valuable additions made to ])otauical science
since the tinrie of Linnaeus. Tho FLornla of tlioso
islands by his son. Dr. George Forstcr, has also
contributed to enlarge the sphere of our knowledge
on this subject.

The catalogue of plants enumerated by thc^' great
botanist of Sweden last mentioned amounted to
about ten thousand. Of these he actually described
about eight thousand The number suice disco-
vered and added to the list is very great. Beside
the numerous discoveries of new plants by some of
the celebrated systematic writers before mentioned,
M. Commerson, of France, in the course of his cir-
cumnavigation with Bougainville, found n^ar Jif-
teen hundred new species. M. Dombey, of the
same country, and don Mutis, of Spain, discovered
a still greater number in South America. M. Des-
fontaines brought to light near four hundred non-
descripts, found in Africa. Dr. Sibthorp brought
tU'O hundred new species from the Archipelago ;
professor Thunberg six hundred from Japan ; M.
Swartz more than eiglit hundred from the M'cst-
India Islands; and M. Michaux more than four
hundred from the Levant, Persia, and Xorth \\\\c-
rica. To these may be added the several thousands
brpught from almost every quarter of the globe
by sir IlansSloane*, Messrs. Lagerstroem, Osbeck,

* Sir Hans Sloane was born in I^cl^^d, April l5, \iy60. He
studied medicine in London, \\liere he long practised phytic with
great dignity and reputation. In l687 he went to the island of
Jamaica, in the character of physician to the dnkc of Albemarle,
and touched at Madeira^ IJurUadoc.t, \r,i$, and St. Kuts. He
remained in Jamaica about fifteen months ; returned to London
iin \QSij; was chosen secretary of the lV>yal Society in \0i)2 ;

1S6 Natural Jlistoy. [Chap. Ill,

Toren, and Dahlber.j^, Dr. Solander, Dr. Sparman,
sir Joseph Banks, Dr. Forster, and a long cata-
logue of modern circumnavigators ^nd travellers,
insomuch that the species now known and de-
scribed considerably exceed ticenty thousand"^.

To the details above stated, it is proper to sub-
join, that the eighteenth century has been pro-
duptive, beyond all former precedent, of great ele-
gance ii^ the execution of drawings and dcscrip-
tiom of plants. These are too numerous and too
well known to render any particular account of
them necessary here. It is sufficient to say, that
all the means of communicating a knowledge of
botany, whether we refer to the convenient no-
menclatiu-ef now in use, to the modern concise

created a baronet on the accession of George I to the throne of
Great Britain, being the ^rst English physician on whom an here-
ditary title of honour had been conferred 3 was advanc^ed to the
presidency of the lloyal Society in 1727 -, and died in 1^52. To
sir Hans Sloane the science of botany is greatly indebted. His
discoveries in the West-India islands were very numprpus and
valuable. These discoveries, though actually made in the seven*
tecnth century, were not fully laid before the public till the be-
ginning of the eighteenth. In 1707 he published the first vo-
lume of his great work, entitled A Voi/age to the Islands Madeira,
Barbadocs, kc. ; and in 1/25 he completed it, by the publication
of the second volume. This work may be considered as one of
the most valuable presents made to botanical science in the course
of tlic agr. — Pulteney's Skcic/ies.

* See Berkenhout's Sj/nopsis cf Xatirral Jliaioiy, 2 vols, 12mo^
1/89.

t Condorcct, in his Pane gyric on Linna:us, expresses himself
thus : — '' Linnaus has been reproached with having rendered too
ef/^y tiie nomenclature of botany, and occasioned thereby the ap-
pearance of a great number of small works. This objection seems
only TO prove what progress botany has made under him. No-
thir.g, p<.TLap.^j. (^ iiicci better hov; far a L-ciencc b advauee-Jj tli.ia

Sect. II.] Botany. I87

aiid intelligible style o^ description, to the spiotulid
representations of niiture, by means of accurate
^figures "^ and coloured -plates whicli every where
assist the stndent, or to the nmltiplication of Bota-
nic Gar dens f, and of Her bar la, as appendages to
seats of science, may be said to have reached
a stage of improvement, within a few years, whicli
the human mind never before contemplated, 'riuj
recent exhibition of the Linniean system bv Dr.
Thornton, of London, is not only highly honuiir-
Jible to himself and his country, but probably, also.

the facility of writing books of mediocrity on such a science, and
fhe difficulty of composing works which contain novelty of mat-
ter."— Stoever's Life of Linmeus.

* S<?e Additional Noles—CC C.)

t Though Botanic Gardens have been greatly multiplied, during
the last century, in Europe, by scientilic individuals, and by semi-
naries of learning, North America has never been able to boost
of a single establishment which deser\ ed the name. I'his dcii-
ciency is now likely to be in some measure supplied, so far as it
respects tlie state of Neu York, by the laudable zeal of Dr. David
Hosack, professor of botany in Columbia college. I'iiis gentle-
man has lately purchased ground for a botanic garden, in the n ici-
iiity of tlie city of New York j and is going on, at his own ex-
pense, to furnish it with the necessary stores of indigenous and
exotic plants, for rendering it a useful and ornamental institution.
It is to. be hoped tliat his exertions will be seconded by public
aid; and that the state of New York, already eminently di.siiu-
giiish,ed fqr its rapid progress in wealth and improvement, will
not suffer the weight of suj)porting such an establishment to tall
on an individual ; who, attcr all his care to acconipli>h himsell" J'ur
this branch of iustruclion, in a foreign country, anil his zeal in
i^brming the best private botanical library in the United Slates,
cannot be expected to devote all his resources to an object w hich
ought to be fostered by public munihcence, and cherished as one
ol the honours of tlie atate. See Jdditioiud 2^'o:r^ — (D D.J

ISS Natural I J is tort/, [Chap. UI.

in suj-jcrb maj^nificence and accuracy^ >vithout an
equal on earth*.

SECTION IlL

IVIINERALOGY.

This department of natural history has also,
^s ithin the period under review, passed through va
rious revolutions, and received numerous improve-
ments equallv fundamental and important. From
the time of Aristotle, the first distinguished mine-
ralogist, to that of Becher, a learned German, little
had been done in this science, except bringing
together, and gradually increasing, a wilderness of
facts, without system or order. Becher, toward
the latter end of the seventeenth century, turning
his attention with zeal toward this subject, be-
came the father of regular mineralogy. After him.
a number of adventurers in this field of inquiry ap-
peared, but they did little more than make large
collections of mineral substances, and class them
according to the old rules. Among the principal
of tliese were Hierne, a Swede, who gave an ample
and very valuable account of the fossils of his own
country; Woodward f and Charleton, English na-
turalists, who made curious collections and enu-

* This is tho opinion of Dr. Darwin, whose taste or informa-
tion on this subject will not be questioned. — Pht/tohu^ia.

f Woodward instituted a professorship of mineralogy about the
year 1/20, in the university of Cambridge, to which he left his

culkction -of minerals lis a lejiiH-y^ " ,

Sect. III.] MbwiUibi^ij, 1S9

meratioiis of iniiieral specimens ; and Brachmcl, of
Sweden, who threw much new light <*n this kiiig-
<lom of ndture, as it appeared in that ])art of
Europe. To these sueeeedtd Liiuueus. This gnat
man, about the year 17^0, proposed a new chissi-
fication of mineral bodies, and was tlie fir.st \\\ny
distributed them into classes, orders, <j^eneriiy and
species. But his arrangement was essentially de-
fective. He divided substances >\hoIly accordint^
to their external appearances, such as .figure, co-
lour, hardness, and other sensible qualities, and, of
course, threw together the most heterogeneous and
opposite kinds. He devised sjjecific names, how-
ever, of great excellence ; and he is entitled to much
honour for his concise and elegant sketch of the
Saxa, which had been little noticed before.

Linnajiis was followed by his countryman M'al-
ierius, -who, in 1747, published an important mine-
ralogical work, in which he adopted the Linna^an
system, with considerable alterations and improve-
ments, by himself and the learned Brov/al, bishop
of Abo"^. About the same time V'augel, a re-
spectable philosopher of Germany, presented to
the public a new system of mineralogy, of consi-
derable value. In 1748 appeared the voluminous
work of Dr. Hill, under the title oi System a Mine-
ralogi'cu?n, which v/as important, as it gave a gene-
ral account of the fossils of England ; but his per-
plexed and barbarous nomenclature rendered it
much less useful than it might otherwise have

* See the Preface to Cronstedf:i Minerdoiy, by MagcU.UJ.
The above-mentioned work of Wallertus was published about
twenty-tive years nftonvardj, widi great and spli-nd:d ijnpro\c-
nient5.

190 . Natural Ilislori/. [Chap. Ilf^

been*. Soon afterwards the inquirers and publics^-
tions in inineralogy began greatly to multiply,
especially in Germany and Sweden, which, from
the abundance of their mineral riches, have long
presented peculiar encouragements to the study of
this kingdom of nature.

Hitherto little or nothing had been done in the
invest israt ion of minerals throufjh the medium of
chemical analysis^. External characters continued
to form almost the sole ground of distinction and
arrangement. Hierne and Brachmel had, indeed^
some time before, suggested the plan of forming
a mineralogical system on chemical principles ;
but they did nothing more than suggest it. Mar-
graaf and Pott, two illustrious mineralogists of
Berlin, seem to have been the first who instituted,
>vith any remai-kable success, this kind of inquiry.
Their numerous and well-directed experiments
were generally made by means of heat^ and, ac-
cording to the language of chemistry, in the dry
cLhiij. About the same tiitie, Neumann^ a philoso-
pher of Germany^ distinguished himself by investi^
gating the nature of mineral substances by means
of acid incnstrua^y or in the moist zvay, These in-
qui lies opened a new and interesting field iu
this; science, led to many important discoveries, and
may be considered as one of the grand a^ras iu na-
tural history.

It was in this stage of mineralogical improve-
ment that Frederic Cronstedt, a nobleman of Sw c-

* AVylleriiis cliaracteiises this work, ns " Mirificis nominibus
potius- ontisLam (fuivn ornaUim."' See his Brcvis ItUroductia in Hh'
tunam Literal ium Mincraloi^icajU;, 8vOj Upsa]> 1779'

Sect. III.] Miner alogij, 1^1

den, and superintendant of the mines of that coim-
try, published an incomparable work, exliibiting
the elements of this science in a manner ^\nv^\u
larly clear, determinate, and jierspicuons*. Ihis
distinguished mineralogist assumed Mr. Pott's facts,
but improved much upon his labours, liu adopt-
ed a method of arrangement chiefly chemical ; and
has the honour of being the first w ho introduce<l
a natural classification, lie appears to have de-
rived a considerable portion of his knowledge from
van Swab, one of the masters of the mines, whose
name is little known in the scientific world, though
he communicated much information to almost all
the eminent naturalists of that country, who Nou-
rished during his time.

Though Pott and Margraaf did much in the
chemical analysis of minerals, and shed new light
on the science by this means, yet they left much
still to be done. They w^ere followed by Scheele
and Bergman f, who, with great ingenuity, perse-
verance, and success, pursued the same course, hi
the hands of the^e great philosophers, mineralogy
mav be said to have first assumed that hii^h rank
which it now holds. They not only made large
additions to the lists of mineral substances which
had been before given, but they also pursued the
analysis of these substances to a greater length
than their predecessors, ascertained new and more
clear distinctions, and gave the whule science a

* Wallcrius prouounccd Hiis \\*ork opus i'inc pari. It hns p.issed
through many editions, has been translated into niust of the Kary-
pean languages, and is still considered as one oi the bcai eleraifn-
tiny works on mineralog}' extant.

f ^ia^rapliia Minaalii,

1 92 Natural Itistofy. [Chap. Ill ■

more simple^ intelligible, and dignified aspect.
As long as this branch of natural history shall be
cultivated, a large share of gratitude and admira-
tion will be due from its votaries to Scheele and
Bei'gman.

Though the refinements of chemical analysis*
were carried to a great length by the celebrated
mineralogists last mentioned, and entitle them to"
high honours, yet they were afterwards exceeded
by Klaproth, of Berlin, who applied himself to the
analysis of minerals with a degree of zeal and per-
severance which no dilTiculties could discourage^
and with an ingenuity and accuracy which enabled
him to penetrate far beyond his predecessors. He
corrected many errors, and supplied important de^
fects in the analytic method. He invented new-
instruments of great value, and new processes,
more easy and expeditious, and of more certain
result, than those before in use. It is, perhaps, to
his labours, as much as to those of any individual,
that we are indebted for some of the most curious
knowledge in mineralogy that we possess. The
same course of refined and subtile chemical in-
vestigation, by which Klaproth was so much di-
stinguished, was pursued further by succeeding
chemists, and particularly by M. Vauquelin of
France.

Wliile this astonishing progress was making in
mineralogy, by means of chemical inquiry, the at-
tention to external characters, which had been for
j^oine time out of vogue, began to be resumed, and
led to considerable improvements in the diagnos-
tic rules, and in tlie nomenclature of the science.
For this we are cliiefly indebted to the celebrated

S^CT. III.] Miner alogi/. \ 93

Abraham G. Werner, of Freybprg, in Germany,
who certainly holds a place among the most distin-
guished mineralogists ol" tlie age. His principal
publication on thi^ subject appeared in 177 i,
and has commanded an unconnnon degree of at-
tention among philosophers. Though lie did not
wholly neglect the chemical properties of fossils,
^le devoted his chief attention to their external
characters, and made these the principal founda-
tion of his arrangement. He and his disciples in-
sisted, that the colour, shape, lustre, transparency,
texture, cohesion, density, feel, and general habitude
of mineral substances, furnish abundant I3- sufTicient
indications for distinguishing and arranging thcm"^.
And, indeed, the ingenuity and skill with which
they selected these characters, the judgement and
accuracy with which they learned to apply them,
and their wonderful success in forming a luminous
system on the principles which these sensihlc (|iia-
lities afforded, must be considered as pointing out
one of the most important periods in the liistury
of mineralogy.

Before this period, the nomenclature of mineral
bodies had been in a very perplexed and imperfect
state; insomuch, that, while rich stores of know-
ledge respecting them were possessed by many, ii
was extremely difficult to communicate this know-
ledge, for want of precise defmitions and descriptions.
The same substance, from some slight variations
in appearance, was often called by dilferent names ^
and diiferent substances, from some aflinities of ex-

* See his Treatise on the External Characters of Minerals,
Leipsic, 177-*-

Vol. J. O

1 94 Natural History. [Chap. III^

ternal character, by the same name. From these,
and other causes, the language of mineralogy was
long arbitrary, vague, and ambiguous; each author
using that which his caprice or his convenience
dictated. Many attempts were made to supply
this defect, and to obviate these difficulties, by
Linnaeus, Peithner, and others, but without much
effect. At length Werner undertook to make a
radical reform in the descriptive language of this
science, and published the result of his labours in
177-i. This nomenclature proved more precise,
accurate, and scientific, than mineralogists had ever
before possessed; and its illustrious author, by
afterwards uniting the descriptions of external cha-
racters (which he had formed with much taste and
skill) with terms indicating the chemical properties
of minerals, was enabled to publish, in 1780, the
best system of mineralogical language that is now
extant ''^.

Since the publication of Werner's system, almost
all the distinguished writers on mineralogy have
formed their arrangement and language on the
union of external characters and chemical proper-
ties. This is the case with the learned and inde-
fatigable Dr. Walker of Edinburgh, Messrs. Dau-
bcnton, Patrin, and Monge, of France, and Mr.
Kirwan of Ireland. All these gentlemen have in-
quired nuich, and written with ability, on this
branch of natural history. The last-named philo-
sopher, in particular, has rendered very important
services to mineralogical science, and, doubtless.

* 1'hi.s latter publication \\as in the form of 'Noins on Croii-

Sect. III.] Mineralogy. I95

deserves to be ranked among the greatest of its
benefactors now living*.

Beside the systematic writers just mentioned,
several naturalists of great eminence have founded
mineralogical distinctions on characters peculiar to
themselves, and have pursued their inquiries,
founded on these characters, to a very curious and
instructive length. Rome de Lisle of France, in
his Cry st alio graphic, published a few years since,
made a very ingenious application of geometry to
the phenomena of minerals, and exhihited a work
in which they were subjected to all the precise
principles of mathematical calculation. M. Bris-
son, another distinguished mineralogist of the same
country, proposed to found the leading character
of mineral bodies on the static principle, or their
relative specific gravities ; and in the exhibition of
his plan displayed much ingenuity and learning.
Scarcely inferior to any that have been mentioned
is the venerable M. Sage, also of France, who, in
the art of assaying, in tracing the connexion be-
tween the mineral and the other kingdoms of na-
ture, and by his experiments in chemical analysis,
has contributed much to improve this department
of natural history.

The subject of Crystallisation engaged much of
the attention of chemists and mineralogists during
the eighteenth century. The first attempt to ac-
count for this phenomenon, in any manner that
deserves the name of philosophical, was by sir Isaac
Newton. He supposed the aggregation which

* See Elements of Mineralogy, by Richard Kln^'aa, F. R. S.

&c. 2 vols, 8vo, 1794.

02

156 Xahiral Histoi^. [CiLtp. LH.

takes place in this instance to be produced by the
attraction w hich he had proved to exist between
the particles of all bodies, and which acts as soon
as these particles are brought within a certain
distance of each other by the evaporation of the
Jiq«id in which tlw^y are dissolved. The regularity
of their figure he explained, by supposing that,
while in a state of solution, they were arranged in
the liquid in regular rank and file ; the consequence
of which, as they ^re acted upon by a power which
at equal distances is equal, and at unequal distances
■unequal, will be crystals of determinate figures. —
Thie explanation, which is worthy of the luminous
and acute mind of its author, is now generally ad-
mitted as the true one, and has contributed much
towards the elucidation of the subject.

Still, however, there remained various pheno-
mena respecting crystallisation, which required to
"be more fully explained. To effect this, many at-
tempts have been made, and several theories form-
ed.— Rome de Lisle professed to have determined
-the j^rimitive form of every crystallised substance,
and to have ascertained that all other forms arc
only modifications of this. — Gahn, of Sweden, w^ent
further. I laving broken a calcareous spar of a par-
ticular kind (dog-tooth), he found that the crystal
was entirely composed of small rhombs, like those
of the primitive calcareous spar. — Bergman seized
npon this idea of his pupil ; and as he combined
an attention to geometry with physical science, he
demonstrated that every crystal is -composed of
other small . crystals, variously piled, but, in each
ease, according to certain laws of decrement.
These little elementary crystals are called by him

Sect. III.] Mineralogy. 1 97

constUuent parts of a crystal. lu tlils manner
Bergman developed the meelianical .strncture of.
vai'ious crystals, and showed thnt the primitive
form often lies coneealed in those wvy erystak
which appear to deviate fartliest from it.

AI. Hauy pursued the idea, and applied it to
various crystallised minerah:. II(; is supposed to
have shown, not only that every particular species
of crystal has a primitive figure, and that the varia-
tions axe owing to the dilferent ways in which the
pai'ticles am^ai^ge themselves ; but also to ha\ e de-
termined the laws according to which the decre-
ments take place, after certain data which he as^.
sumed. His theory of crystallisation has been
much celebrated. It is generally considered as iur
genious and plausible ; and certainly manifests a.
degree of diligence, zeal, and mathematical skill,
which entitle him to much connncndation ^.

In addition to the great systematic writers
whose names have been mentioned, considerable
service has been rendered to mineralogy, within
the period under consideration, by many others,
who have either collected, analysed, or discovered,
mineral productions. Among these it is proper
to enumerate, with some distinction, Lawson,
Townson, Jamison, Whitehurst, Lewis, Anderson,
Withering, and Garnet, of Great Britain; d'Argcn-
ville, Soulavie, Faujas, Macquart, Dolomieu, Mou-
net, Chaptal, Bomare, Fourrroy, Ihissenfratz, and
de la Metherie, of France; Ludwig, AVoltersdorlf,
Cai'theuser, baron Born, Debern, A'oii^t, Gellert,
Woulfe, Raspe, and many more, of Ciurmany ; de

'^ See Tilloch's Philosophical Mas'izinc, and Nicliolsou's Jounutl.

198 Nahtral History. [Chap. Ill,

Saussure, jim., of Geneva ; Rinman and Ferber, of
Sweden j Pallas, of Russia; d*Acosta, of Spain;
Camera, of Portugal ; and Gioenni, Fabroni, and
Spallanzani, of Italy.

The us^ of the Blow-Pipe, for the purpose of
assaying mineral bodies in the dry zoay, was first
introduced by van Swab, a little before the mid-
dle of the century. The importance of this appa-
ratus in mineralogy, and the great ease with which
it enables the experimenter to conduct his investi-
gations, render its introduction by no means an
inconsiderable aera in the history of the science.
After van Swab, the Blow-Pipe was much im-
proved, and more extensively applied, by Cron-
fjtedt, Bergman, Rinman, Berkenhout, Black, and
several others. The great value of this invention,
in chemical and mineralogical inquiries, will ap-
pear from considering that the most intense de-
gree of heat may be obtained by it, with the ut-
most conveniency, in a few minutes, which can
$;carcely be obtained by means of a crucible in
many hours.

While new systems of arrangement and of lan-
guage i|i mineralogy, and new means of facilitat-
ing experiments in this science, have been pro-
posed by different philosophers during the period
under review, immense additions at the same
time have been made to the old catalogues of
mineral substances. Linnaeus described about ^five
hundred different species. Since that time so many
discoveries of new substances have been made,
that the number of species now known is between
seven and eight thousand. Seven new kinds of
tarih have been discovered within the century

Sect. 111.] Mineralogy. 1 99

tinder consideration. Among tliese arc AJagjiesia,
by lIofFman and Black ; Barytes, by Scheele and
Gahn ; StrontiteSy by Hope ; Silica, by Putt ;
Alumina, by Margraaf *; Adamanta, by Klaproth ;
and Jargonia, by the same great miiuTalogist.
Within this time, also, ten new metallic substances
have been discovered; viz. Cobalt, by Brandt, in
1733; Nickel, by Cronstedt, in 1751 ; Platina, by
Sch^ffer, in 1752; Manganese, by Scheele and
Gahn, in 1774; Tungsten, or Wolfram, by d'El-
huyart, in 1782; Molybdenum, by Hiehn, about
the same year; Uranium, by Klaproth, in 17^9;
Titanium, by the same philosopher, in 179-5; Tel-
lurium, or Sylvanite, also by the same, in 1797;
and Chromum, by Vauquelin, in 1798.— Beside
these, the discoveries belonging to almost every
class, order, and genus, in mineralogy, have been
^lore numerous than our limits admit of recounting.
It follows as a natural consequence, from what
has been stated, that collections of minerals have
been more numerous, and more complete, durnig
the last century, than ever before. Among those
who have formed these collections, it is not easy to
select such as are most worthy of notice. In gene-
ral, the great systematic writers, whose names ha\ e
been mentioned, are entitled to the highest praise
in this respect also. The best collection now on
earth, if we may rely on the judgement of Mr.
Kirwan, from which fOw will presume to di^scn^
is that made between the years 1782 and 17S7,

* It is not meant to be asserted thnt siliceous and ar^iUaceoi,^
earths were unknown previous to the time oi Pott and Margrant.
but that the discovery of their characters and properties, a. pure
cartlis, is to be attributed to thcbC mineralogists.

200 Natural History. [Cha?. III.

by professor Leske, of Leipsic, one of the earliest
and most eminent of the disciples of Werner, by
whose assistance it Avas arranged. After the death
of Leske, it was revised, corrected, and enlarged,
by Karsten, another disciple of Werner, and a mi-
neralogist of great judgement and learning. This
monument of skill and labour was, a few years
since, transferred to Ireland, where it has been fof
some time receiving those additions and improve^
ments from the hands of Mr. Kirwan, which his
Extensive acquaintarice with the subject, together
with his acuteness, zeal, and industry, render him
so capable of conferring.

In describing the present state of mineralogical
science, it is impossible to do better than to adopt
the words of the illustrious Irish academician,
whose name has been mentioned With so much
respect in the preceding paragraphs. Within a
few years, " precise lines of information have been
traced, even in the minuter subdivisions of the
science; the gross indications of the unassisted
senses, freed from their attendant fallaicies, have
been pressed into its service; the more refmed
chemical tests, still further perfected, have been
rendered more conclusive; many new species
brought to light ; the catalogue of the elementary
substances nearly completed; and the great art of
analysis, extended far beyond its former limits,
now nearly approaches the precision of an alge-
braic formula"*^."

The progress which was made in the art of ana-
lysing minerals^ in the course of the last thirty

* Kirwnn's Elcmciiis of Mincralovh — Pirfacc.

Sect. III.] Mineralog}}. 201

years of the eighteenth century, cannot be con-
templated without astonishment. To separate five
or six substances intimately combined together;
to exhibit each of them separately; to ascertain
the precise quantity of each ; and even to detect
the presence and the weiglit of substances which do
not approach y^th part of the compound ; would,
at no very remote period, have been considered a.s
a hopelessj if not an impossible task. Yet all this,
by means of the wonderful discoveries and im-
provements of MargrafF, Neumann, Schede, Berg-
man, Klaproth, Vauquelin, and others, can now bo
done with the most rigid accuracy*.

This science, like almost every other cultivated
in modern times, while its boundaries have been
extended, and its principles greatly improved, has
been rendered more subservient than Ibrmerly to
various important purposes of economy and art.
Instead of being considered, as it once was, a low
and trifling object of study, it has lately begun to
be viewed as dignified in its nature, and most in-
teresting in its relations. It is now regarded as a
valuable and indeed necessary handmaid to Medi-
cine, JgriaiUure, and a large portion of the wzfl-
mfactures, which su])ply the conveniences, com-
forts, or luxuries, of human life. Mineralogy has,
therefore, within a few years past, been cultivated
with great diligence and success by almost all the
nations in Europe, especially \n^ Germami and
;Siveden, where splendid mineral riches particularly
invited inquiry and application. Societies have
been formed for extending and improving the

* Thomson's Chanistry.

202 Natural History. [Chap. IIL

science ; travellers have explored foreign countries
for the same purpose; distinguished eminence in
this brancli of knowledge has been rewarded by
public esteem, and by civil honours; and the most
effectual methods used to direct general attention
to the subject.

The mineral treasures of America have been
hitherto but little explored. It were to be wish-
ed that some of its natives, who have leisure
and talents for the purpose, might be induced
to undertake this interesting task. That the
United States abound in Coaly Gypsum^ Mar-
ble, Metals y and other mineral riches, which would
abundantly reward the diligence of naturalists
in seeking for them, we have already had satisfac^
tory evidence. Professor Mitchill was commis-
sioned, several years ago, by the Agricultural
Society of New York, to travel through a consi-
derable part of the state, with a particular view
to mineralogical investigatian. The result of his
tour has been published*, and affords at once ho-
nourable testimony of his talents, and strong in-
citements to a further prosecution of the inquiries
wliich he instituted. It would be happy for the
interests of science in this new world, if siniilaar
undertakings, conducted with similar skill, could
be multiplied and extended. It is, indeed, de-
voutly to be wished that a kind Providence may
for ever conceal from our view all mines of tiie prc^
Clous metals, if there be such in the country f; but

* Sec a Sketch of tht Mineralogical Jlistonj of the State of Nei^
York in the Medical Repositori/, vols, i and iii.

t The most consklerahle mine of either of the precious metals
of \\hieh tlie author h;ia heard in the United btates,, is the aihxx:

Sect. IV.] Geology. 203

so many mines of more rral value to a nation liavo
been discovered, and profitably wroui^lil within
the last age, in the United States, that we may
safely wish for the extension and the more dili-
gent improyement of these discoveries.

SECTION IV.
GEOLOGY.

In the investigation of the natural history of the
Earth, little progress had been made prior to the
commencement of the eighteenth century. In-
deed, as Mineralogy is the alphabet, by the prin-
ciples and combinations of which the great vo-
lume of geological science must he formed, it is
plain, that, as long as the former remained in an
uncultivated state, the latter would receive but little
light or improvement. During the century under
consideration, geology has become an object of the
attention and inquiries of many distinguished phi-
losophers. The discoveries of chemists and niine-
ralogists, and the observations of intelligent travel-
lers, have all tended to facilitate these inquiries,

mine in the town of Mount-Pleasant, Westchester county, slate
of New York. This mine is near tlie margu) of the Hudson,
thirty-six miles above the city of New York, and on Isnd belong-
ing to William Street, esq. It was discovered about forty yearn
ago J and, for some years before the revolutionary war, was
wrought to tolerable advantage. The convulsions and derange-
ments attending that struggle suspended the operation, of the
company engaged in Uie business, and they have not suice been
resumed.

204 Natural Hisiorij. [Chap. III.

and to render them more enlightened and satisfac-
tory : and, although modern tidies have produced
many visionary theories, and crude conjectures on.
this subject, they have also given birth to some im^^
portant acquisitions, and much correct philosophy,j
wliich will be highly prized by all who study the
history and structure of our globe.

Towards the close of the seventeenth century,
three different Theories of the Earth were pro-
posed, by as many philosophers of Great Britain ;
of which, as they were among the first offered to
the world, and bear a relation to several of the
subsequent theories, it will be proper to take some
notice.

The first was the Telluris TJieoria Sacra^ of tlie
rev. Dr. Thomas Burnet. This celebrated theorist
was a man of genius and taste ; and his work, if it
do not command the assent of the philosophic
mind, will be found to display much learning, and
a very vigorous imagination. According to him,
the earth was first a fluid heterogeneous mass. The
heaviest parts descended and formed a solid body.
The waters took their station round this body, and
all lighter tluids rose above the water. Thus, be-
tween the coat of air, and that of water, a coat of
oily matter was interposed. But as the air was
then full of impurities, and contained great quan-
tities of earthy particles, these gradually subsided
and rested upon the stratum of oil, and composed
a crust of earth, mixed with oleaginous matter.

* This M'ork was first ]^ublished, in iGSO, in the Latin language.
It was afterwards translated, by the author^ and published in twu
parts, in 4tOj in l083 and l()CjO.

Sect. IV.] Geologi/. 00.-,

This crust was the first inhabitable part of the
earth; and was level and uniform, without nu)ni\^-
tains, seas, or other ine(|ualities. In this state it
remained about sixteen centuries, when tlie heat of
the sun, gradually drying the crust, produced, at
first, superiicial fissures or cracks; i)iit, in ])rocess
of time, these fissures became deeper, and increased
so much in their dimensions, that at last they en-
tirely penetrated the crust. Immediately the whole
crust split in pieces, and fell into the abyss of
waters which it had formerly surrounded. This
wonderful event was the universal Deluge. Tiiese
masses of indurated earthy and oily matter, in
falling into the abyss, carried along with them \ast
quantities of air, by the force of which they dashed
against each other, accumulated, and divided in so
irregular a manner, that great cavities, filled with
air, were left between them. The waters gradually
opened passages into these cavities, and in j)ro-
portion as the cavities were filled with water,- parts
of the crust began to discover themselves in the
.most elevated places. At last the waters appeared
.no where but in those extensive valleys which con-
tain the ocean. Thus our ocean is a part of the
ancient abyss ; the rest of it remains in the inter-
nal cavities, with which the sea lias still a commu-
nication. Islands and rocks are the small Irag-
ments, and continents the large masses, of the an-
tediluvian crust: and as the rupture and fall of
the mass were sudden and confused, the present
surface of the earth is full of corresponding conlii-
siou and irregularity '^.

•it Sullivan's View of Nature, vol. i, kticr o.

206 Natural History. [Chap. IlL

This " elegant romance" of Burnet was succeed-
ed by the work of his countryman, Mr. Woodward,
who, in \Qd5i published Essays towards a Natural
Historij of the Earthy and terrestrial bodies.
Though he possessed much more knowledge of
minerals than his predecessor, and on this account
had greatly the advantage of him, he produced a
work far less ingenious and interesting. He also
proceeded on the supposition of the Mosaic history
being true, and ascribed the present aspect of our
globe to the influence of the general deluge. He
supposed that all the substances of which the earth
is composed were once in a state of solution; that
this solution took place at the flood ; that on th6
gradual retiring of the waters the various sub^
stances held in solution, or suspended in them,
subsided in distinct strata, according to their spe-
cific gravities ; and that these are arranged hori^
zontally, one over the other, like the coats of an
onion. As this theory was soon found to contra-
dict some of the plainest and most unquestionable
facts which geologists observed, it has had few ad-
mirers, and its refutation has been usually consi-
dered as obvious and easy.

In 1696 Mr, William Whiston, a man of uncom-
mon acuteness, and of still greater learning, pub-
lished a New Theory of the Earth, from its original
to the consummation of all things. He supposed
the earth, in the beginning, to be an uninhabita-
ble Comet, subject to such alternate extremes of
heat and cold, that its matter, being sometimes
liquefied, and sometimes frozen, was in the form
of a chaos, or an abyss surrounded with utter dark-
ness. This chaos was the atmosphere of the comet.

S£CT. IV.] Geology, 20?

composed of heterogeneous materials, ha\ing its
centre occupied with a globular, Jiot, solid nucleus,
of about two thousand Ieag\ics diani(^t(>r. Such
was the condition of the earth before the period
described by Moses as the time of creation. Tiic
first day of the creation every material in this riich;
mass began to be arranged according to its speci-
fic gravity. The heavy fluids sank down, and left
to the earth}^ watery, and aerial substances, the
superior regions. Round the solid nucleus is placed
the heavy fluid, which descended first, and formed
the great abyss upon which the earth floats, as u
cork upon quicksilver. The great al)yss is formed
of two concentric circles ; the interior being the
heavy fliiid; and the superior, water ; upon which
last, the earth, or the crust we inhabit, is immedi-
ately formed. So that, according to this theorist,
the globe is composed of a number of coats or
shells, one within the other, of dilTercnt materials,
and of different densities. The air, the lightest
substance of all, surrounds the outer coat, and the
rays of the sun, making their way through the at-
mosphere, produced the light which Moses tells us
first obeyed the divine command. I'he hills and
valleys are formed by the mass of which they con-
sist pressing with greater or less weight upon the
inner coat of the earth ; those parts which are hea-
viest sinking lowest into the subjacent fluid, and
making valleys^ and those which are lightest rising
higher and forming mountains.

Such Mr. Whiston supposed to be the state of
the globe we inhabit before the Delude, Owing
to the superior heat, at that time, of the central
parts, which have been ever since cooling, tlxi

208 Natural History, [Ch;ip. III.

earth was more fruitful and populous anterior to
that event than, since. The greater vigour of
the genial principle was more friendly to animal
and vegetable life. But as all tJie advantages of
plenty and longevity which this circumstance pro-
duced, were productive only of moral evil, it pleased
God to testify his displeasure against sin, by bring-
ing a flood upon a guilty world. The flood vv:as
produced, as this theorist supposed, in the follow-
ing manner. A Cornet^ descending in the plane
of the ecliptic to its perihelion, made a near ap-
proach to the earth. The approximation of so
large a body raised such a strong tide, and pro-
duced such powerful commotion in the. abyss con-
cealed under the external crust, ♦that the latter was
broken, and the waters which had been before
pent up, burst forth with great violence, and, were
the principal means of producing the deluge. In
aid of this, he had recourse to another supposition,,
which ^vas, that the comet, while it passed so near
the earth as to produce these efl'ects by the force
of attraction, also involved our globe in its atmo-
sphere and tail for a considerable time, and depo-
sited vast quantities of vapours on its surface,,
'vvhich produced violent and long-continued rains j
and, fmally, that this vast body of waters was re-
moved by a mighty wind, whicli dried up a large
portion, and forced the rest into the abyss from
which it had been drawn, leaving only enough
to form the ocean and rivers which we now be-
liold.

The fanciful and untenable theories wliich have
been briefly stated, served little other purpose than
to amuse the curious, and excite to new, and, for

SeGt. IV.] Geology, 209

the most part, unsuccessful modes of speculation
on this interesting branch of natural history. Ac-
cordingly, the eighteenth century has teemed with
plans almost numberless, for sohing the pheno-
mena, and elucidating the internal structure and
history of the earth. These plans, to say nothing
of the impious nature and tendency of some of
them, have, generally, rather resembled pliiloso-
phical dreams, than the conceptions of waking and
sober reason. Their authors, in forming tliem, have
been too often guided by imagination more tlian
judgement; and have laboured rather to support a
favourite hypothesis, than to consult the voice of
authentic history^ or patiently to examine the ma-
terials and structure of the fabric which they un-
dertook to describe. It may not be improper to
take a brief review of some of the more conspicu-
ous, among the great number, which, at dilferent
periods of the century under consideration, and in
different parts of the world, have been received by
philosophers.

At an early period of the century, the celebrated
John Hutchinson, whose principles of philosophy
were mentioned in a preceding chapter, formed a the-
ory of the earth, which he professed to derive from
Scripture*. He supposed, that, when the earth was
first created, the terrestrial matter was entirely
dissolved in the aqueous, forming a thick, muddy,
chaotic mass -, that the figure of this mass was sphe-
rical, and on the outside of this sphere lay a body

* This theory was enlarged and commented upon by Mr. Cat-
cot, a follower of Hutchinson^ who, in ir0"8, publiahgd a voUimo
on the subject.

Vol. I. P

210 Natural HisLorij. [C^ap. III.

of f^-ross dark air; that within the sphere of earth
and water M^as an immense cavity, called by Moses
the deep ; that this internal cavity was filled with
air of a kind similar to that on the outside; that
on the creation of light the internal air received
elasticity sufficient to force its way through the ex-
ternal covering; that immediately on this, the wa-
ter descended, filled up the void, and left the earth
in a form similar to that which it bears at present;
that when it pleased God to destroy mankind by
a flood, he caused, by his own miraculous agency,
such a pressure of the atmosphere on the surface of
the earth, that a large portion of it was forced into
the internal cavity which it had formerly occu-
pied, and expelled the waters from it with great
violence, spreading them over the surface; that
the shell of the earth was by this means utterly
dissolved, and reduced to its original state of flu-
idity ; and that, after the divine purposes were an-
swered b}^ the deluge, the globe^ by a process si-
milar to that which at first took place, was restored
io the form >\ hich it now bears.

In the year 1740 the abbe Moro, of Italy, pub-
lished a theory of the earth, whicli he chiefly de-
riv(^d from the works of Ray, of the preceding
ceutnry. He supposed that the surface of the earth,
as we now behold it, and especially the mountain-
ous parts, arose originally from the bottom of th«
ocean. At first, according to him, ^hese mountains
contained neither strata of shells, nor any orga-
. nised fossils; but by means of subterranean con-
flagrations, earthquakes, and volcanoes, these sub-
stances were thrown up in confused heaps, after
which they successively subsided according tQ their

Sect. IV.] Gcologi/. on

Hifferent specific gra> ities, and thereby necessarily
disjposed themselves in dillrrent strata, lie also
maintained that these submarine eruptions, while
they threw up huge and irregular masses of matter,
also ingulfed marine plants and animals of every
kind, which subsided in like manner, and thus
formed new mountains, and new beds of stones,
sand, metals, and other minerals, intermingled uitli
tlie remains of vegetable and animal bodies, all
which remained under the sea till some new agi-
tation threw them above its surflice. He supposed
that the waters by which the earth was originally
overflown subsided by degrees, the dry land first
appearing in places adjacent to that where the first
man and animals were placed at the creation; that
the land extended itself gradually, a considerable
time elapsing before the waters had returned into
their proper bed, during which time the shell-fish,
multiplying in great abundance, were uni\ersa[iy
distributed by the w^aters of the sea; and that when
the bottom of the ocean was raised up by the earth-
quakes that accompanied the deluge, and formed
the mountains, wiiole beds of such shells were
thrown up, and distributed as we now behold
them.

About the year 1744 M. le Cat, a philosopher
of France, proposed a theory of the earth diiTcring
from all which had preceded it. According to liim,
in the beginning, the substance whence metals,
stones, earths, and other mineral bodies were to be
formed, was a soft mass, consisting of a kind of
mud. The earth was a globe, or regular spheroid,
and its surface was uniform and free from hills and
valleys. The sun and moon Were after wai^cfs created.

212 Natural History. [Chap. III.

The fluid which covered the mud became agitated
by the flux and reflux to which it was subjected
by attraction, and the mud was variously and vio*
lently moved- This agitation increasing, part of
the mud became exposed, and dried. Continents
were thus formed. The materials of the earth being
compact and solid, the sea continually excavated
its bed; and from the continual retreat of the sea>
and the excavation of the earth, this globe is
doomed to be at last so perfectly undermined as to
produce a confluence of the sea from hemisphere to
hemisphere. The earth becoming thus hollow, and
its shell being gradually extenuated, will at length
fall to pieces; a new chaos will be formed, the fa-
bric will be again revived, as at first; and a pe-
riodical dissolution and renovation will take place.
■ — Le Cat professed to believe the sacred scriptures,
and discovered an anxious desire to show that his
theory was consistent with them; but the best
judges among his contemporaries, and since that
period, have pronounced it equally inconsistent
with the structure and phenomena of our globe,
and with the Mosaic history.

About the year 17^0 appeared the Telliavied of
M. Maillet, a French writer of some note. He
taught, that the earth was once wholly covered
witli water, which, by means of strong currents,
raised in its bosom all those mountains which dif-
ferent countries bear on their surface ; that this
water has been ever since gradually diminishing^
and will continue to diminish until it shall be quite
absorbed ; that our globe, being then set on fire,
will become a sun, and have various planets re-
volving in its vortex, till its igneous particles bemg

Sect. IV.] (^<iolog\j. o\^

consumed, it will be extinguished; tliat then it
will roll through the immensity of space, without
any regular motion, till it is again covered with
watery particles, collected from other planets, when
it will fix in the vortex of a new sun, and again
go through the same course of motions and changes,
being supplied with fresh inhabitants, rcsemljling
those by which it is tenanted at present ; thnt the
earth has probably been undergoing revolutions
of this kind from all eternity, and will continue to
go through a succession of them without end. —
This atheistical and absurd theory, if it deseive
the name, not more hostile to revelation than to
all sound philosophy, seems to have gained l)uL
fktw adherents, and but little celebrity.

After M. Maillet, his countryman, tlie count
de BufTon, formed a new theory of the earth, which
has been mnch celebrated, and, notwithstanding
its inconsistency with revelation, and the visionary
absurdities which it involves, has gained many afl-
vocates and admirers. — According to tliis ingenious
theorist, a comet falling into the body of the sui)
with great force, struck from its surilice a large
mass of liquid fire. The comet communicated to
this fragment, thus driven olY from the sun, a \ io-
lent impulsive force, which it still retains. Tliis
fragment forms the globe we inhabit. Jt assumed
its present figure when in a fluid state. As the
heated mass gradually coolc^d, the vapours which
ijurrounded it condensed, fell down in the form of
water upon the surface, depositing at the same
time a slimy substance, mixed with sulphur and
salts, part of which was carried by the waters into
tUe perpendicular fissures of the strata, and pro-

214 Natural History, [Chap. Ill,

cjuced metals; the rest remaining on the surface,
and giving rise to vegetable mould, with more or
less of animal and vegetable particles. Thus the
interior parts of the globe were originally composed
pf vitrified matter, and they continue so at present.
Above these w^ere placed tliose bodies which the
fire had reduced to the smallest particles, as sands,
which are only portions of glass, and above these
pumice stones, and the dross of melted matter,
which gave rise to different clays. The whole was
covered with water to the depth of five or six
hundred feet. This^ water deposited a stratum
of mud, mixed with all those materials which are
capable of being sublimed or exhaled by fire, and
the air was formed of the most subtile vapours, which,
from their levity, rose above the w^aters.

Such w^as the condition of the earth, as Buffon
supposes, w^hen the tides, the winds, and the heat
of the sun, began to introduce changes on .its sur-
face. The diurnal motion of the earth, and that
of the tides, elevated the waters in the equatorial
regions, and necessarily transported thither great
quantities of slime, clay, and sand; and by thus
elevating these parts of the earth, sunk those under
the poles about tw^o leagues. The great inequalities
of the globe took place when it assumed its form
and consistence ; swellings and blisters arising, as
in the case of a block of glass or melted m?ctter. In
the act of cooling, it became furrowed, and vari-
ously irregular. The vitrescent matter of v;hich
the rock of the globe is composed, and all the nu-
clei of mountains were produced by the primitive
fire. Tlie waters have only formed the accessory
strata, which surround the nuclei horizontally, and

Sect. IV.] Geologtj. 01,5

in which are the relics of sliells, and other produc-
tions of the ocean. I'he whole snrface of the earth,
therefore, as y\c now behold it, was, at a period
long subsequent to its separation from the sun,
covered by an ocean; and the waters forming this
ocean probably remained for a succession of ages
on what are now inhabited continents. Hence the
remains of marine plants and animals to be found
in almost every part of the globe, on or near its
surface. M. IkifTon supposes, further, that, since
the period \\\\q\\ the primitive waters encircled the
earth, there have been repeated partial inundations,
in different places; and, in others, instances of land
formerly covered with the ocean being elevated
above it, and becoming inhabitable; and similar
events, he seems to suppose, may in future occur.
According to him, also, the earth, for many ages,
too intensely heated to admit the existence of ani-
mal life on its surface, first acquired at the poles a
more genial temperature. There, consequently,
must we look for the first abodes of man. To Green-
land or Iceland y to Spifzhergcn or Xova-ZembhTy
w^e must have recourse for the verdant bowers of
Eden. And, fmally, he contends tliat all the other
planets belonging to our system were stricken oil'
from the sun in the same manner with that which
we inhabit, and have probably undergone similar
changes, so far as their respective circumstances
admitted.

Such ar6 the outlines of a theoiy bold and plau-
sible, as might ha^ e been expected from tlie mind
of its author, but unsubstantial and deceptive. Its
manifest object is to exclude the agency of a Di-
vine Architect, and to represent a world begun

216 Natural History, [Chap, III.

and perfected merely by the operation of natural
undesigning causes. That it cannot be reconciled
with the sacred history, will appear evident on the
slightest inspection ; and that it involves the grossest
philosophical absurdities has been clearly shown
by succeeding geologists. It was embraced, how-
ever, by M. Bailly, of France, by the celebrated
Hollmann, of Goettingen, and others; and continues
to be respected and adopted by many to the pre-
sent time.

M. de BufTon's theory was warmly opposed,
soon after its publication, by Raspe, a geologist of
Germany*. He also opposed the theory of Moro,
before mentioned, though he considered it as ap-
proaching much nearer the truth than the inge-
nious fable of the French naturalist. He insisted,
that the opinion of continents and mountains hav-
ing been thrown up from the bottom of the ocean,
solely by submarine conflagrations and volcanoes,
^vas abundantly refuted by close observation. He
contended, likewise, that in veins of sand, marble,
chalk, and slate, there are found no indications of
a burning soil, but rather of a sediment disposed
by the agitation of the sea. Accordingly, he main-
tained, that the strata, of which the shell or surface
of the earth is composed, were originally formed
at the bottom of the sea, by the constant agitation
of the waters, and the continual production of
plants and shells; that the subterraneous explosions
and earthquakes, breaking through the bottom of
the sea, not only formed banks, hills, and sub-
marine mountains, of its broken parts, but also

* Specirneu Jlistnn's Natiiralis Glohi Tcrraquai.'^Autorc Rudol-
pho trico Kaspe. 8vo^ Leipiiic,, 17()3.

Sect. IV.] Gcologjj, 2 1 7

frequently raised up such laru^o portions of tli(» hcd
of the ocean, with its incumbent stnita, a.> to Ibnu
iolauds and (hy mountains. At sonir times, as lie
supposed, tiic presence of so large a hody of water
caused it to break throuiih the cavities made bv
previous eruptions, and at otlier times the \ iiiienco
of the subterraneous explosions was so great as to
remove mountains from one place to anothcM*; while
the heat of the internal hres causing tliesc e.\j)lo-
sions w^as so intense as to molt, calcine, or vitrify,
all adjacent substances.

In 177^j t)r. William AVorthingfon, of (»rcal
Britain, published a theory*, in which great Icaru*
ing and piety, and a considerable share of inge-
nuity, are combined. He maintained that the earth,
in its primitive state, Avas plain and nniform; and
that all mountains, and every thing irregular and
rugged in the surface of it, are the result of tJie
curse pronounced on the ground alter the fall ;
that the melancholy lapse of our fu'st parents \\iw
immediately followed by earthquakes, and e\XMy
species of convulsion, which produced these dread-
lul eflects in the surface of our earth; that the
antediluvian earth greatly abounded \\\x\\ water,
much more than at present, and that the greatest
quantity of it was collected about the poles; that
at first the poles of the earth Avere erect, and at
right angles with the plane of the equator; tiiat the
centre of the earth was then tlie centre of gravity;
that the deluge was produced by the centre of gra-
vity being removed twenty-three degrees and a half
nearer to one of the poles^ uhii h led to a cone-

* Scripture Theory of the Earth, bvn, 1773.

'21S Xalural His lor ij. [Cii ap. III.

sponding deviation of the poles fi'om their former
position, and thus threw the great body of water
accumulated round tliem on those parts of the
earth where little had existed before, and by these
means drowned them. This event, he supposed,
increased the irregularity of the earth's surface, and
produced many of those phenomena, which so
plainly establish the reality of the general deluge.

Another British theorist, of still more celebrated
name, published a new system of geology in 1778.
This v.as Mr. Whitehurst, a gentleman of rcspecr
tabic talents and information, and Vvhose theory
has attracted considerable attention*. ISIr. White-
hurst supposes, that not only this globe but the
v.hole of the planetary system was once in a state
of fluidity, and that the earth acquired its oblate
spheroidical form by revolving round its axis in
that state. In this fluid state, the component parts
of the earth were suspended in one general undi-r
videdmass, " without form and void." These parts
were endued with a variety of principles or laws
of elective attraction, though equally and univer-
sally governed by the same law of gravitation.
They were heterogeneous; and by their attraction
progressively formed a habitable world. As the
component parts of the chaos successively sepa-
rated, the sea universally prevailed over the earth;
and this would have continued to be the case had
it not been for the sun and moon, which were co-
eval with the earth, and l>y their attractive influ-
ence interfered with the regular subsiding of the
solid matter, which was going on. As the sepa-

* Ail Iixp/ir)/ vh'o the X)rigiiml State and Formation of the
Eurih, kc, by John Whiichurst, F.R.S. )77S.

Sect. IV.] Ceologj/. 019

ration of the solids and fluids increased, the former
were moved from i)laee to place, ^vill^()u( r(\:^nlH-
rity; and hence the sea hccame unequally ilccp.
These inequalities dail}^ becominp: greater, in ])ro-
cess of time dry land was formed, and divifh'd the
sea^ islands gradually apjjeared, like sand-hanks
above the water, and at length became firm, dr}-,
and fit for the reception of the animal and vege-
table kingdoms. He supposed that mountains and
continents were not primary productions of nature,
but of a very distant })eriod from the creation ; that
they are the eilects of subterranean fires and com-
motions, and were produced when the strata of the
oarth had acquired their greatest degree of firmness
and cohesion, and when the testaceous matter had
assumed a ston}^ hardness. And, finally, that the
marine shells found in various places, on and below
the surface of the earth, were for the most part \
generated, lived and died in the places in which
they are found; that they were not brought
from distant regions as some have supposed 3 and,
consecjuently, that the'se beds of shells, &c. were!
originally the bottom of the ocean.

Two or three years after the appearance of Mr.
Whitehurst's publication, M. de Luc, of Geneva,
dissatisfied with all the numerous theories which
had been proposed, oilered another, which has
occupied considerable attention in the scientific
world*. He supposes that the ocean once covered

•" L'Jitres Physiqites ct Morales stir VJJlsloire dc la Tcrre et de
PHumiuCf &c., by J. A. de Luc, 8vt), 5 torn. l/SO. This theory,
as to its principal outlines^ \v<is lir.st su^^g,.*.stcHi by .Mr, lidwjrd
King ; but was aftei\\\u\ls nmdi cxlcndcvl and improved by JNI.
«lc Luc.

220 Natural History. [Chap. IIL

our continents; that the bottom of the old oqean
uas full of mountains, which neither the waters,
nor any other cause known to us, formed, and
which he therefore calls primordial. These moun^
tains rose above the surface of the waters, and formed
islands. These islands, and the ancient continents^
were fruitful and well peopled, and the ancient sea
had tides, currents, and tempests, as the present
ocean. These powers acting upon the soft mat-
ters which are known to have formed the bottom
of the ancient ocean, produced accumulations of
calcareous substances, which, in process of time,
became more or less mixed with marine bodies.
The rivers, in the mean while, carried from the
land into the sea scattered remains of animal and
vegetable productions; the sea itself washed them
from its coasts into its bosom ; and these materials,
transported by currents, became a secondary soil
upon its primordial bottom. Fires and elastic fluids^
formed by fermentations, made various openings
in tlie bottom of the ocean, whence proceeded tor-
rents of liquid substances and lava, which gave rise
to the volcanic mountains observable on the surface
of our continents. The continents which existed
in a state of population and fertility, while the
sea covered those which we now inhabit, though
they did not form a solid mass, but \yqyq, pro,perly
.speaking, vaults, which covered immense ^a\'ernSj
maintained their elevation above the level of the
ocean by the strength of their pillars, which, being
of primordial matter, were solid and stable. But
the clianges wliich the subterranean fires produced
at the bottom of the ancient sea opened passages
for its waters into the interior of the earth; the

Sect. IV.] Ccologi/. 5291

fermentation produced by this irruption shook tli(^
pillars of the primitive earth, Avhich sinking into
its caverns, the old continents disaj)peared, and
their surface dcscendin<j^ below the level of the wa-'
ters, a general inundation ensued. This was the
general deluge. The sea now covered all the globe,
except the islands of its ancient bottom, which in*
creased in number and magnitude, until the weight
of the water, added to that of the superior vaults,
crushed the inferior ones, and deepened more and
more the new bed of the ocean; so that, at last,
by a motion rapid, but not violent, all the waters
retired from their former bed, and left our conti-
nents dry. Secondary mountains, and other irn--
gularities, were afterwards formed by volcanic com-
motions and maritime currents and convulsions.

This learned and ingenious theorist professes a
firm belief in revelation; and insists tiiat all the
principal lines in the Mosaic history are confirmed,
and none of them contradicted, by the most at-
tentive survey of the globe. It may well be que-
stioned, however, wliether some parts of his theory
can be reconciled with the sacred records; and they
are precisely those parts which it is most dilficult
to reconcile with reason and sound philosophy.

Next to the theory of M. de Luc appears that
of Mr. Milne, of Great Britain, which, though less
celebrated, is by no means unworthy of notice*.
This gentleman declares himself a warm friend to
jevelation, and professes to have formed a system
in strict conformity with the sacred history. In

* A Course of Physico-Thcologicnl Lectures on the State of th:
World, from the Creation to the Diluge, by Rob^nt Milne, A .M.

V„-

222 Nalural Hlstorij. [Chap. III.

some respects he agrees with Mr. Whitehurst; in
others, he adopts the opinions of M. de Luc; while,
with regard to a third class of his doctrines, he
claims to be original. He supposes that the earth,
innnediately after tlie fall, and in consequence of
the divine curse pronounced against it, miderwent
a total chansre, bv means of the elementary fire
lodged at that time near its centre; and that hence
arose the irregularities which no\v appear in the
earth's surface.

The theory of Milne was followed by that of Dr.
James Hutton, of Edinburgh, which has been much
more distinguished, and excited incomparably more
ii^ttention. Dr. Hutton thinks*, that all our rocks
and strata have been formed by subsidence under
the waters of a former ocean, from the decay of
a former earth, carried down to the sea by land
floods; that the strata at the bottom of the ocean
were brought into fusion by subterraneous iives^
and consolidated by subsequent congelation ; that
these strata were forced up, and made to form
islands and continents by similar agency; that the
shells and other exuvicti of animals, gradually col-
lected and incorporated with these strata, make
about a fourth part of our solid ground; and tliat
the foregoing operations, 17';::. the waste of old land,
the formation of new under the ocean, and tlie
elevation of the strata now forming there into
future dr}' land, are a progressive work of nature,

* Tlicoiy of the Earth ; or, an Invcsiigation of iht Laves ob-
sa-i'uhk in the Composition, Dissolution, and Restoration, of Lund
upon the Earth, by James Hutton, M.D. F.Il.S. E. This me-
moir is contained in the Transuction.^ of ihc Roj/al Sucitlj^f of Edin^
bur .ill, vol. i.

Sect. IV.] Ceolo^v, 003

\vhich always did, and always will go on, fijrmijig
world after world in pcrpetnal succx?ssion. Conse-
quently, according to this theory, the continents
"which we now inhabit mnst, in ])rocess of time,
be Avorn away and destroyed, and otiiers l>e forced
up to supply their place. The length of time to
be allowed for this successive destruction and re
production. Dr. Ilutton su})poses to be far greater
than is generally imagined. His system, therefore,
is to be arranged, of course, among those which
are hostile to the scicrcd histor}'; and the best
judges have pronounced it equally hostile to the
principles of probability, to the r<L"sults of the ablest
observations on the mineral kingdom, and to the
dictates of rational philosophy.

It has been suggested, that this doctrine of the
igniform origin of our globe appears to be drawn
from the theory of M.Builbn, with the dilltjrence
of perpetuall}^ renovating powers, having no deter-
nainate commencement, instead of a once slowly
forming and now^ gradually decaying principle.
Dr. Hutton, indeed, does not attribute the fusion
of terrestrial substances to the state in which this
planet issued from the sun, but to subterraneous
fires and furnaces, coeval with it, and still existing
undiminished*.

In 1790 appeared a new theory of the earth, by
Mr. John Williams, an English mineralogist of
respectable character, which, though it has not
acquired much celebrity, is entitled to a tran^'icnt
notice in the present -sketch f.

* Howard's Thow^hts en the Globe, &c.

f Natural History of th^ Mineral Kingdom, ScCv ^y John AVil-
liarns^ 2 vols 8vo^ i;oo.

224 KcUural Ilislory. [Chap. IIL

Mr. Williams Supposes, that the superficial parts
of the earth were, originally mixed with water into
a fluid or chaotic mass. All the regular strata
were formed by the flow of the tides successively
spreading out the deposited matters on a large ho-
rizontal plane. The granites and other stones^
^\ hieh he does not consider as stratified^ subsided
when the water was in some degree of rest, as at
tlie hi oiliest of the tides^ or where local obstruc-
tions produced stagnation. When the whole sur-
face was in a fluid state, the tides necessarily rose
to a prodigious height, several miles higher than
the tops of any of our mountains. The mountains
of granite, which are uniform throughout^ must
have subsided in one tide. The tides were highest^
and had tlieir resting places on the two opposite
parts of the globe, which are now the continents 5
and their direction, on different parts of the globe,
was such as we now find that of the strata to be.
lie maintained, further, that the interior body of
the earth was formed in the same manner^ prior to.
the superficial parts. From various causes, it was
full of inequalities. It contahied much Avater, both
in the composition of the not yet consolidated strata,^
and in separate cavities; so that when the super-
ficial strata were laid between the tides, and the
ocean began to retreat into its present bed, the
weight of these superincumbent strata forced out
tlic water imprisoned below them. These strata
tlicmselves, as yet soft and flexible, were, in many
cases, bent and broken; cracks were occasioned by
their contraction in drying, which cracks were in-
creased by the inclination of the strata in dilfcrent
'w'ays, and were widest at the top; and the whole

Sfey^T. IV.] Geology. 225

solid matter diminishing in bulk, as it became dry,
high tides still overflowed it, and poured extraneous
stony matter into the fissures. On these principles
he explains all the declivities, ruptures, interrup-
tions, and irregularities, which we now behold.
The larger grains and fragments found in the com-
position of our rocks, and all those bodies which
are of a similar structure, and not crystallised,
were once in distinct strata, though not now to be
found in that state. This he considers as one of
the many evidences which our earth every where
affords of the general deluge. By the high tides,
and violent agitation of the diluvian waters, the
primitive strata, which had never before felt any
rain, were loosened, torn asunder, and ground down
by attrition against each other, and all the super-
ficial parts of the earth reduced again to a chaos.
When the waters began to abate, the larger stony
particles and fragments subsided first, and formed
the compound rocks, and beds of sand; and the
finer and lighter sediment was spread, by the tides,
into strata of different consistency.

The next theory entitled to notice is that of M.
Delametherie, of France, which has been, of late,
very fashionable in that country, and produced con-
siderable discussion among naturalists*. He sup-
poses that the external crust of our globe was
formed in the l)Osom of the waters, from which it
emerged in a state not very different from its pre-
sent appearance. The crust, after its formation,
underwent a variety of small alterations, from local

* Theoric de la Ttrre, 8vo, 5 toni. Paris, 1797- This large
work embraces much extraneous matter. The fourth anl fitdi
volumes contain the author's theory.
Vol, I. . a

oo(5 Natural Ilistoiy. [Chap. III.

causes. Tiie waters surpassed the highest moun-
tains; in other words, they were at least three thou-
sand toiscs abo\ e their present level. All moun^
tains, valleys, and plains, were formed by crystal-
Usation amidst the Maters. The materials which
formed them w^ere truly dissolved; but as they
would require much more water for solution than
is now to be found, it is evident that most of the
waters of the primitive seas have disappeared.
He thinks, that these have chiefly retreated into the
bowels of the earth: that cavities were formed there
at the time of the crystallisation of the globe,
which were at hrst filled with elastic fluids; but
the A\'ater afterwards finding its way into them,
became lodged there: that some caverns have been
formed by subterraneous fires, but that the most
powerful cause of them has been the refrigeration
of our globe: and that, though the surface of
the earth has been brought to its present state
by the action of water, it may, at the first moment
of its formation, have undergone a very great de-
gree of heat, as happens to a comet passing near
the sun.

In the formation of this theory, AT. Delame-
therie discovered considerable ingenuity and great
learning. He can scarcely, however, be called an
oricrinal Avriter : Voi^t had held the doctrine of
the aqueous crystallisation of strata before him; andy
indeed, the greater part of his system is made up
of parts collected from diflcrent theorists. This
is generally considered as one of those theories
Avhich are hostile to revelation.

Of a very different character is the tlicory of Mr.
lIowar<l, a British geologist, ^^llO, about the same

Sect. IV.] Geology. o<27

time published his opinions on this subject*. This
gentleman is a firm believer in revelation, and his
theory is intended to be perfectly consistent with
the sacred histor3^

He supposes that the elements of all material
substances were originally in a confused mass, called
the abyss, without motion or animation; and that
the present order of things was gradually, and at
different intervals, drawn from it, by means of laws
impressed by the power of the Creator. The earth,
of which we now behold the ruins, was originally
constructed with its poles perpendicular to the
equator ; the centre of gravity was the centre of
the globe ; and the year consisted of three hundred
and sixty days. At that time, the irregularities of
the earth's surface being less considerable, and the
distribution of land and sea being more equal, the
atmosphere was more temperate and salubrious,
and, of course, the life of man was prolonged greatly
beyond its present limits. The termination of this
" golden age '^ might have been effected by the
proximity of a Comet condensing the vapours of
the atmosphere and attracting the subterraneous
waters, which, bursting through the exterior sur-
face, precipitated indiscriminate portions of the
primitive earth into the cavities below. The more
perfect consolidation of the globe in the southern
hemisphere changed the centre of gravity, wiiich
produced a proportionate deviation from the plane
of the equator. The ocean did not, at once, how-
ever, sink to its present level. The posterior ac-

* Thou<rhts on the Structure of the Globe, and the Scriptural

History of the Earth, and of Mankind, ^c, by Philip IIow .u\l,

<?sq. 4to, London, 1797-

Q 2

228 Natural History. [Chap. IIL

cession of walers from seas hitherto inland, may
have crushed down other inferior vauUs, and finally
settled its lowest degradations. As the land be-
came thus elevated above the bed of the ocean, the
cold became more intense, the vicissitudes of cli-
mate were more severely felt, and the life of man
suffered a proportionate abbreviation.

Mr. Howard was succeeded by M. P. Bertrand,
of France, who next proposed a theory, much less
philosophical, and in every respect unworthy of a
sober mind*. This wild and impious theorist con-
tends that water was the original substance of our
earth, but that this water, before motion and heat
were communicated to it, was a solid mass of ice.
Such was the condition of the globe we inhabit,
when one of th^ larger order of comets, after long-
wandering about, finally ended its career, and ful-
filled its destination, by striking this frozen mass,
breaking it in pieces^ and mixing its own materials
with those of the till then lethargic body. ' These
fragments acquired by this impulsion a common
projectile motion, in the same plane, and in the
same direction. The light, heat, and life, brought
by this energetic comet, mixing with the original
ic<.', formed new combinations, afforded causes of in-
ternal motion, and began, by these means, a new^ or-
der of things, wiiicli M. Bertrand calls vital and orga-
nic constitution, and which he su])poses to be diffe-
rent in e\ery planet, since the density is different.
The ice, by mc^ans of heat as a solvent, being re-
duced to primordial matter, all ancient combina-

* Noiivcaux Principes de Geologic, par P. Bertrand^ &c. 8vo.
V:irh, i;n8.

Sect. IV.] Ccolosiy. . 229

tions were destroyed, and room was given for new
combinations of a dirterent kind. The first result of
this regeneration was the production of calcareous'
earth, from which species every other kind of earth is
formed. Tins deposition of calcareous matter being
equal every where, produced a regular nucleus in
our globe, equally covered with water, and free
from valleys and mountains. In this situation, ac-
cording to our theorist, a new comet of high degree
approached near enough to our globe to influence
its destinies. By the force of its attraction it
changed and slackened both the annual and diurnal
motions of the planet, displaced the axis and the
equator, altered likewise the points at which the
spheroid was compressed or elevated; and by these
means displacing the waters, caused the emersion
of the iirst continents. The surfaces of these con-
tinents became unequal, from the change of level,
and from the sudden retreat of the waters. The
whole mass, however, was yet composed of calca-
reous matter. The first action of atmospherical
powers, and of solar rays, occasioned a sudden ir-
ruption of all the vital forces, so long suspended
and concentred. In this explosion of life every
particle of native soil was vklficd, and numerous
races of vegetables and animals were produced, in
such numbers, and of such sizes, t^at putrefaction
and fermentation ensued. Some meteoric pheno-
mena having set fne to this monstrous heap of pu-
trefied bodies, the horrid conflagration extended
every where, even under the sea, and was the cause
of most tremendous earthquakes, that broke all
the strata (which, till then, had been horizontal.

^30 Natural History. [Chap. III.

and threw them in every direction. The ashes of
this almost universal conflagration being the most
saline of the then existing substances, formed a
lixivium, which, filtering through the interstices of
the broken strata, produced the quartz and other
similar substances which now compose them.
Wherever this lixivium and quartzeous flux de*
posed large quantities of matter, granite was form-
ed; and, by a dilferent modification of the same
materials, other mineral bodies were composed.
This great conflagration occasioned hollows and
cavities of incalculable dimensions; which, being-
laid open by some violent shock, were filled by
v/aters of the ocean ; by which sudden retreat of
the watery element, large portions of the globe
were left dry, and formed new continents, while
])arts of the old continents fell into hollows and
disappeared. Beside our earth, which has under-
gone this series of revolutions, an indefinite nunv
ber of like cold lifeless masses exist, resting invi-
sible in darkness and inactivity, waiting for some
favourable circumstance, which may bring them
to light, life, and motion.

Such are the outlines of a theory which, though
exhibited and defended with some talents, may be
con.sidered as the most wild, and as involving the
most palpable opposition to every received prin-
ciple, that has yet been presented to the public.
Indeed, its unreasonableness and extravagance are
ho great, that it seems to have attracted but little
respectful attention among any class of philoso-
phors.

This theorist was succeeded by another of the

SiiCT.IV.] (Ecology, 2.S1

same name, but a much more sober and rational
inquirer. In 1799 M. L. Bertrand of Geneva,
published a work* which was intended to aceoinit
for the })henomena of the p^lobe we iuiiabit. This
gentleman supposes, witli Dr. Halley, that there is
a magnetic nucleus enclosed and suspended in a
hollow space in the centre of the earth. This
has a rotatory motion of its own, and an inclina-
tion of its magnetic axis to the axis of rotation,
thus causing an oscillatory motion in the magnetic
poles. While things were in this situation, he
supposes that a Comet of ordinary size and charac-
ter approached our earth, displaced the nucleus
from the centre, removed it toward one side, and
changed the centre of gravity of the earth. These
circumstances occasioned the derangement of the
seas, their removal to other parts of the globe, the
immersion of old and the emersion of new conti-
nents. This theorist is a disciple of M. de Saus-
suref ; and the principal design of his work seems
to have been to show the possibility of that sudden
retreat of the ocean which his n^aster believed and
taught, £ind to account for that event and the sub-
sequent elevatipn of the land wliicli before formed
jt-s bottom. — — c

The last person to be mentioned, as having ad- ^
ventured in this ample field of speculation anc^

* Renouvdlancns Fcriodlqucs, kc.j par L. BertraiKl, &:c., Svo,

1/99.

t jM. dc Saussure had promised to give a geological sy.^teni at
the end of his Travels over the Alps; but, after nuny years, he
contented himself witli inforiyiing the public, tlnU the result o\
his investigations induced him to believe, that the whole of our
^•ontihents had been formed under the sea, bad been arranged by
jts action, and were left dry by a pr.H'ipitate retreat of its waters.

032 Natural History. [Chap. III.

inquiry, is Mr. Kirvvan, whose name has been so
frequently and so respectfully mentioned in the
foregoing pages. This gentleman, with that learn-
ing which has enabled him to prosecute his nume-
rous investigations in so enhghtened a manner,
with that jndgement and penetration which render
Jiis inquiries so valuable, and with that spirit of
patient and accurate observation which is so in-
dispensably necessary to a successful developement
of this subject, has framed a theory of the earth,
which is perhaps the most rational and probable
extant*.

Mr. Kirwan believes that the superficial parts
of the globe were originally in a soft liquid state,
proceeding from solution in water heated at least
to ^'o^ and possibly much higher ; that this men-
struum held in solution all the different earths, — the
metallic, the semimetallic, the saline, and the in?
flammable substances ; that in this fluid it's solid
contents coalesced and crystallised, according to
the laws of elective attraction ; that these were
deposited in strata according to the predominant
proportion of the ingredients ; that by this crystal-
lisation of these immense masses a prodigious
quantity of heat must have been generated, and
increased by the decomposition of the water in?
terceptcd in the precipitated ferruginous particles,
and by the disengagement of inflammable air, even
to incandescence, — the oxygen uniting with the in-
flammable air, and bursting into flame ; that this
stupendous conflagration must have rent and split.

* Geological Essaj/s, hy Richard KirwaD, esq. F.R.S. 3cc. 8vo.

Sect. IV.] Geologj/. 233

to an unknown extent, the solid l;)asis on which
the chaotic Ihiid ,rcsted ; that from the heated cha-
. otic fluid must have been extricated the oxygen and
mephitk airs, which gradually formed the atmo-
sphere ; that from the union of oxygen with ignited
carbon proceeded the carbonic acid, the absorp-
tion of which, as the chaotic fluid cooled, occa-
sioned the crystallisation and deposition of calca-
reous earth. Mr. Kir wan also believes, that tlie
immense masses thus crystallised and deposited
formed the primitive mountains; that the forma-
tion of plains took place from the subsequent de-
position of matters less disposed to crystallise in
the intervals of distant mountains; that the level
of the ocean gradually subsided, leaving large and
elevated tracts of land uncovered ; that the a^ea-
tion of fishes was subsequent to the emersion of the
land ', that after this retreat of the sea, the earth
soon became covered with vegetables, and peopled
with animals, being in every respect fitted to re-
ceive them • that tlie gradual retreat of the waters
continued until a few centuries before the general
deluge; that this event was occasioned by a mira-
culous effusion of water both from the clouds and
from the great abyss, — the latter originating in and
proceeding from the great southern ocean belou-
the equator, and thence rushing on to the northern
hemisphere, spreading over the arctic region, and
descending again southward ; that during this ele-
mental conflict, the carbonic and bituminous mat-
ter ran into masses no longer suspensible in water,
and formed strata of coal; and that otlu'r sub-
stances, by the combination or dccomjjosition of
their respective materials, formed various other

03.4 Xatural Ilistorij. [Chap. IIL

kinds of mineral bodies, as basalik masses, calce^
denies, spars, SsC.

That the inequalitij of decUvify exhibited by the
sides or flanks of mountains, in every part of the
globe, had any regard to the points of the eompasSy
seems to have been fn'st remarked by the celebrat-
ed Swedish geologist, Tilas*: but he seems rather
to have directed his views to the elevation or de-
pression of the surface of Sweden, than to the bear-
ings of the declivities of mountains in general,
Bergman first discovered, that the declivities of the
flanks of mountains bear an invariable relation to
their different aspects. He found that, in moun-
tains extending from north to south, the western
flank is the steepest, and the eastern the gentlest ^
and that, in moimtains \\ hich run east and west,
the southern declivity is the steepest, and the
northern the gentlest. After Bergman, Buffoii
took notice of the generality of this phenomenon;
but his remark was confined to the eastern and
western sides of mountains extending from north
to south, having no reference to the north and
south sides of those which run east and west. The.
same fact was afterwards observed, in a general or
more partial manner, by Hermann, DclametheriCj^
Torstcr, Pallas, and several others.

'J'owards the close of the century. Air. Kirwan
directed his attention to this subject, and endea-
voured to assign the cause of this almost universal
allotment of unequal declivities to opposite points,,
and \\\\y the greatest are directed to the west and
south, and th(^ gentlest to the east and north. He.

•* Sec Memoirs of Stockholm for l/DO.

Sect. IV.] Geology, 23.5

supposes that this fact is connected with the origi
nal structure of our globe- that it proves that
mountains are not mere fortuitous eruptions (as
some, within a ic^w years past, have confidently
advanced) ; and that it furnishes a powerful argu-
ment in favour of the Mosaic account of the crea-
tion, deluge, &c*.

Beside the Theories of which an attempt has
been made to give a brief view, many others, less
distinguished, have been ollered to the world,
during the period under review. Among these it
would be improper to pass in silence the geolo-
gical systems of Scheuchzer, Pluche, Engel, Lulolf]",
Pyef, WalleriusJ, Bailly, Franklin §, Darwin 1|, and
several othei*s no less eminent. Some of these
gentlemen have adopted theories nearly agreeing
in their outlines with several of those which have
been stated -, and to attempt a further detail of
such as have any considerable claims to originality,
would be to present the reader with new vagaries
of imagination, rather than with sober inquiries of
philosophy.

But, although there has been in modern times
(as appears from the foregoing pages) a w^onderful
variety of fanciful productions, under the name of

* See Transactions of the lloynl Irish Academy, vol. vii.

f The Mosaic Theory of the Solar Systein, by Samuel Py^,
M. D. 4to. 1765.

X Mcditationes Physico-clicmicct dc Origine Mundi, Svo. Stock-
holm,. 1779.

§ Conjectures concerning the Formation of the Earth, in a letter
to the abbe Soulavie. See Americ. Philos. Trans, vol. ii'.

Ij See the Botanic Garden : Additional Notes to part i.

^236 Natural Historxj. [Chap. III.

geological theories, we are by no means to ima-
gine that httle has been usefully done in this de-^
partment of natural history. Amidst all the splen-
did rubbish with which it has been incumbered,
5ome precious treasures have been brouglit to light.
Amidst the speculations which have darkened coun-^
sel^ large additions have been made to our
knowledge of this important subject. These
may be briefly summed up in the following par-
ticulars.

The materials for the formation of a correct and
rational theory of the earth have been greatly aug-
:piented during the last age. Enlightened mine-
ralogists, practical miners, and patient chemical
experimenters, have been engaged, throughout the
^.-entury, in making accurate observations ; in visit-
ing foreign countries ; in exploring the bowels of
the eartli ; in comparing the strata of every portion
of the globe ; in examining their form, direction,
extension, and connexion ; in analysing their com-
ponent parts ; and in collecting a multitude of
facts, wliicli have all tended to throw light on the
€>rigin and history of our planet. By means of the
useful discoveries which these inquirers have made,
we are furnished with weapons for beating down
false theories, and with information enabling us to
pursue our investigations further, and with mare
advantage. " In this magnificent display of the
internal arrangement of the globe,'* says Mr. Kir-
wan, "many philosophical observers acquired distin-
guished eminence from tedious^ laborious, painful,
but successful exertions. Tilas^ Gmelin, Cronstedt,
Terber, Pallas, Charpentier, Born, Werner, Arduin,o^

Sect. IV.] Gsdlogjj, 237

de Luc, Saussure, and Dolomieu, arc names consc
crated to immortality *.'*

" So numerous, indeed," sajs the same respect-
able writer> " have been the more modern geolo-
gical researches, that, since the ol)scuration or ob-
literation of the primitive traditions, strano^e as it
may appear, no period has occurred so favourable
to the illustration of the original state of the globe,
as the present, though so far removed from it. At
no period has its surface been traversed in so many
different directions, or its shape and extent, under
its ditTerent modifications of earth and water, been
so nearly ascertained, and the relative density of
the whole so accurately determined ; its solid con-
stituent parts so exactly distinguished ; their mutual
relation, both as to position and composition, so
clearly traced, or pursued to such considerable
depths ', as within these last twentj^-five years.
Neither have the testimonies that relate to it been
ever so critically examined and carefully weighed,
nor, consequently, so well understood, as within
the latter half of the past century j."

DiiTiculties have been lately removed \vjiich
VI' ere once supposed, by some, to militate strongly
against the possibility/ of a general Ddluge. Eai'jy
geologists, for want of accurate information, sujj-
posed that all the w^aters of the globe were not
sufficient to cover the whole earth to sucli a depth

* Geological Easays. rnft-ice. Jt is j curious fact, that, while
some of these celebrated inquirers embraced geological principle*
unfriendly to reveiation, they have all brought to liglit liicts, and
given viev/s of the subject, whicli remarkably coiifuiti the sacred
history.

t Geological Jissay^, pp. 3, 4.

'238 Natural History. [Cha?. IIL

as the sacred historian describes. It was asserted
that tiie mean depth of the ocean did not exceed a
quarter of a mile, and that only half of the surface
of the globe was covered by it. On these data
Dr. KeiJ computed, that twenty-eight oceans would
be requisite to cover the whole earth to the height
o^ four on lies, which he judged to be that of the
higliest mountains 3 a quantity, which, at that
time, was utterly denied to exists But further
progress in mathematical and physical knowledge
has since shown^ that the different seas and oceans
contain at least forty-eight times as much water as
they were supposed to do, and much more than
enough for the extent ascribed to the deluge in the
sacred history*.

While difficulties which were supposed to ren-
der the deluge impossible have been removed by
the investigations of modern philosophers, many
facts haA e been, at the same time, brought to. light,
showing t\iQ probahilUy, and even certainty, of that
mighty inundation. In every valley and mountain,

- M. de la Place (whose mathcinatlcal and astronomical skill
"will not be questioned, and whom none will suspect of a disposi-
tion to press lacts unduly into the support of revelation) has de-
monstrated, by a strict application of the theory of tides, to the
iieight to which they are known to rise in the main ocean, that a
depth of water reaching only to half a league, or even to ti\)o or
three leagues, is utterly incompatible v»ith the Newtonian theory,
and that no depth less ihan/o/.-r leagues can possibly be reconciled
with the phenomena. It m ill be readily perceived tliat this is
much more than the Mosaic history requires. The extent of that
part of our globe w hich is covered by water is now known to be
far greater than JCeil supposed it 3 it being ascertained that nearly
two thirds of the surface of thei earth arc in tliis situation.—- Kir-
\wiu s Geological Es.sai/s, pp, 66. 0/.

Sect. IV.] <^^ology. 239

support for revelation has been found. Marine
shells have been discovered in situations so ele-
vated, and under circumstances so reniarkaljle, as
to prove that they were left there by a ilood ex-
tending over the whole globe ;. and what confirms
this conclusion is, that shells pecniiar to dillcrent
shores and climates very distant from each other
have been found in promiscuous heaps, plainly
showing that they could have been brought toge-
ther only by an extensive inundation. The bones
of elephants and of rhinoceroses have been found, in
a multitude of instances, far distant from the re-
gions in which they are found to live, and where,
from the nature of the climate, they could never
exist in the living state : and between the climates
wdiich they might have ii)liabited, and the places
in which they are now found, too many mountains
intervene to suppose them carried thither by any
other means than a general deluge*. Tiie most
patient and accurate examinations of detached
mineral substances, and of the strata of the globe,
which late inquirers have made, allbrd evcr\^ rea-
son to believe that the earth was for a conside-
rable time wiiolly overflowed with water. And, to
crown all, as voyagers and travellers have explored
new regions of the earth, they have found, Q\e.Yy
where^ the indications of geological phenome-ua
confirmed and supported by the notices of tradi-
tion. Accordingly, it is verv remarkablr \\vd\ a
great majority of modern theorists haxc cinlkniccd
the Neptunian doctrines; and even suchof thrn^ as
rejected the Mosaic account of the d< luLiC iiuve

* Kirwan's Gcoloqica! Essays, p. 54, et st.q.

540 Natural Jlisfory, [Chap. III.

been compelled to seek for other means of immerg^
ing the present continents in the ocean*.

Finally, the researches of modern geologists
have given abundant confirmation to the sacred
history, not only with respect to the general de-
luge, but also with regard to the age of the earth f.

* M. Bailly of France at fkst embraced the theory of the
earth proposed by Buftbn ; but finding the evidence arising from
the investigations of natural history, and from universal tradition,
so strongly to attest the reality of the ger)eral deluge, he abandon-
ed tliat delnsive theoiy, and took refuge ,in another system, in
which he recognises the deluge, and only contends for placing it
as far back as three thousand five hundred years before Christ.

f Sir William Hamilton and Mr. Ferber particularly applied
themselves to the study of volcanoes, without giving general
systems. They affirmed that the indications furnished by sub-
terraneous and volcanic phenomena, and particularly by the beds
of lava, announce the antiquity of tlie earth to be far greater than
the sacred histor}' represents it. But the}' did not advert to the
fact, that all lavas are not composed of the same substance. AH
have not undergone the same degree of vitrification, and of course
are more or less susceptible of decomposition. And even when
their composition is the ?.ame, much depends on tlie state m
\\ Inch they are emitted. When pom*ed from the crater in the
fermentation of boiliiu^" li(iuefaction, a .scoria (or dross) rises, like
broken waves, on the surface, and is easily pulverised by the air
and wcatlier. When the heat is less violent, or when the torrent
ii cooled in its course, an even and almost impenetrable surface
defies th.e influence of the atmosphere. These philosophers do
not recollect \.\vd\. I Icvcidaneum, the date of the destruction of which
is w ell known, is covered by nearly scrcnii/. feet of lava, interspersed
with ficzcn distinct seams of friable earth j and the whole covered
with good soil ; yet all tliis has been the midoubted production of
I'.-^sS tiian ci^luccii huxJrcd ycui;>. — Howard's Thoughts on the.
(Jhjhe.

In hke manner, count Ijorch, in his Letters on Sicilj/ and Malta,
professes to believe that ul^tna is at least eight thousand years old,
w hich lie infers from the beds of vegetable earth which he disco
vered betv/ecn different beds of lava. Yet M. Dolomieu, who

SjECT. IV.] Geology. llif

Early in the century, and indeed until \\itlii]i a
few years, several geologieal phenomena were con-
sidered, by superficial inquirers, as indicating that
the creation of the globe we inhabit was an event
much more remote than the sacred history repre-
sents it; and some theorists even went so fu' as to
profess a belief that it existed from eternity, 'i'liese
opinions were kept in countenance only as loni^ a^
geology was in its infancy. Every successive step
which has been lately taken in the improvement of
this science has served to show their fallacy. 1 he
investigations of the latest and most accurate phi-
losophers have afforded proof little sliort of demon-
stration, that the earth, at least in its present form;
cannot have existed longer than appears from the
Mosaic account ; the absolute falsehood of manv
positive assertions, and specious inferences, hostile
to the scripture chronology, has been evinced ; and
thence has arisen a new presumptive argument in
support of the aiitlienticity of that volume, whicli
contains the most ancient and the most precious
of all records.

has greatly distinguished himself by the acuteness and succtss ot
his geological inquiries, expressly tells us that such earth dots not
exist between the beds of lava of which the count speaks, and
thus destroys the foundation of his whole argument. But even if
vegetable earth were found in the circumstances supposed, no
conclusion relative to its age could faifly be deduced from this
fact_, as some lavas become fertile much sooner than oilier.-.
The chevalier Gioanni, in 17^7 > found lavas projected in l/Oo
in a state of vegetation ; while other lavas, known to be ujuch
more ancient, still remained barren. — Kirwan's Geological F.imys,
pp. J 04, 105,

Vol. I,

^4^i Natural History. [Chap. III>

SECTION V.

METEOROLOGY.

The natural history of the atmosphere began to
be cultivated as a science in the seventeenth cen-
tury. The ancients, for want of the necessary in-
.struments, Avere almost wholly unacquainted with
it ; but soon after the invention of the thermome-
ter and the barometer, the learned men of Europe
began to avail themselves of the manifest advan-
tages which these instruments gave them, in stu-
dying the origin, nature, and effects, of those
changes which take place in the atmosphere , espe-
cially with respect to heat and cold, motion and
rest, moisture and gravity. Still, however, from
the small number of the meteorological observa-
tions made by accurate philosophers -, from the
want of an extensive comparison of the results of
different observations; and especially from the
low state of those sciences most intimately con-
nected Vv'ith meteorology: little progress had been
made in this department of knowledge prior to
the commencement of the century under review.
yVnd though it must be acknowledged that this
subject is one of those which are still far from
])eing satisfactorily developed, yet so much has
been done, during the period under consideration,
to throw light upon it, and so many observations
and discoveries have been made either directly or
remotely relating to it, that it has, vvdthin a few
years, assumed an aspect more interesting, prac-

Sect. V.] Meteorology. 243

tical, and approaching to the form of a system,
than ever before.

The eighteenth century is distinguished by the
numerous and enhghtened experiments which were
made during this period to ascertain the ii)cight of
the atmosphere in different latitudes and situations.
For these we are principally indebted to M. Bou-
guer, M. Cassan, and M. Cotte, of France; and to
sir George Shuckburgh, lord Mulgrave, and Mr.
Kirwan, of Great Bi-itain and Ireland.

Though the experiments on the eudiometer
were mentioned undei' the head of Chemistry, and
in some respects belong to that department of
science, yet they also belong to Meteorology, and
have contributed to throw some light on this ob-
scure subject. These experiments, and the in-
quiries connected with them, belong exclusively to
the eighteenth century.

At the commencement of the eighteenth cen-
tury, the ascent of water in the atmosphere, in the
form of vapour, had been but little investigated,
and was very imperfectly understood. Nieuentyt
and others had taught that the particles of lire, by
adhering to those of water, made up vwleciiLe, or
small bodies specifically lighter than air. Dr. Hal-
ley supposed that by the action of heat the parti-
cles of water are formed into hollow spherules, filled
with a finer air, highly rarefied, of less specific gra-
vity than the atmosphere, and, of course, disposed
to rise in it. While Dr. Desagnliers thought that
the ascent of aqueous particles was owing to their
being converted into an elastic steam.

Such was the state of opinions with regard
to this fact, when Dr. Mauniton undertook the

R 2

244 Natural History. [Chap, III,

investigation of the subject, and proposed a
new theory. He held that evaporation is the
gracUial solution of zoater in air, and that the
former is suspended in the Jatter in the same
manner as salts, or other soluble substances, are
suspended in aqueous fluids*. The same doc-
trine, in substance, had been suggested before by
several philosophers; particularly by M. le Roy,
in 1751; by Dr. Franklin, in 1756; and by
Muschenbroeck, in 1769 f- ^^^^ though these, and
some others, had spoken of the solubility of water
in air, before Dr. Hamilton, yet he was the llrst
who treated the subject v.ith precision, or "who
applied it systematically to the explanation of
meteorological phenomena. This opinion was
afterwards adopted by Dr. Hut ton, and exhibit-
ed in his ingenious Theory of Rain J, and con-
tinued for a number of years to be the popular
doctrine.

In 1786, M. de Luc, of Geneva, published a
new theory on this subject §, which has been since
general!}^ considered as superseding the doctrine of
Hamilton and liutton. Observing that evapora-
tion takes place in vacuo, as well as in the open
air, M. de Luc rejected the opinion that vapour is

* Essaj/ on the Ascent of Vapours^ Sec This essay was first
read l)efore the Royal Society in 170\5, and was afterwards pub-
lished, w ith others, under the title of r/iilosophical Assays, by
Hugh Hamiltrm. D.D. IvU.S.

f Bishop Watson's Chemical Esstn/s, \o],\, p. 31/.

X Transactions of the Royal Society of Edinburgh, vol. i.

§ See Rechtrches sur les Modifications de I* Atmosphere, par J, A.
de Luc, 8vo, 2 vols, Gene\a, 1/72 ; and also Jdees sur la AJctco"
roLy^ie, a more full and bali.-fiicLory ^^ ork, by the same author^

irso.

Sect. V.] Meteorologi}. 245

the solution of water in air, aiul taught that this
effect is produced by tlie chemical combination, or
union, of the particles of heat with those of water.
Hence he accounted for the great loss of sensible
heat in every process of evaporation, according
to the celebrated doctrine of lattiit heat taught
by professor Black. He made a number of curi-
ous observations and experiments on this subject ;
by which he ascertained tiiat water, after its
ascent into the atmosphere, does not exist in a sen-
sibly hinnicl form; whence he concluded that it
passes into a form entirely dilTerent from itself, and
probably becomes air. This doctrine is evidently
founded on the mutual convertibility of water into
air, and the reverse, discovered by Cavendish and
some later chemists. The same theory, of the
combination of water with heat, was also embraced
by M. Lavoisier, and appears to be now the most
popular mode of interpreting the phenomenon in
question.

Beside forming and giving to the world this
ingenious theory of evaporation, INI. de Luc has
also rendered essential service to the science of
meteorology by his patient* and persevering ob-
servations on the comparative degrees of moisture
in the atmosphere in ddferent situations. On this
subject he has brought to light a nund)er of facts
equally new and interesting. His countryman, M.
de Saussure, has also laboured very successfully
in the same field of inquiry*; and though not al-
ways with an entire coincidence of opinion and
result, yet with sufficient agreement on most im-

* Essai sur rilj/Sf'^ffictrie, 4io. 1/83.

246 Natural History. [Chap. III.

portant points. There are, probably, no two indi-
viduals to whom the scientific world is more in-
debted for the minuteness, the accuracy, and the
success, of their meteorological investigations, than
to tliese philosophers of Geneva. *

All our knowledge of Atmospherical Electricity
is the product of the eighteenth century. To this
subject the attention of philosophers has been par-
ticularly drawn since the time of Dr. Franklin's
discovery that lightning and thunder are occasion-
ed by the agency of electricity.

The most complete set of experiments on this
part of meteorology were made by professor Bec-
caria, of Turin. lie found that the air is almost
always positively electrical, especially in the day-
time, and in dry weather ; that when dark or wet
weather clears up, the electricity is always nega-
tive ; and that low thick fogs, rising into dry air,
parry up a great deal of electric matter. He as-
certained that the mid-day electricity of days
equally dry is always proportional to the heat ;
that winds lessen the electricity of a clear day,
especially if damp; and that, for the most part,
when there is a clear sky, and little wind, a consi-
derable quantity of electricity arises after sun-set,
at dew-falling. Considerable light has been thrown
on the sources of atmospherical electricity, by the
experiments of M. de Saussure and other minera-
logists. Air is not only electrified by friction, like
other electric bodies, but the state of its electricity
is changed by various chemical operations which
often go on in the atmosphere. Evaporation seems*
in all cases to convey electric matter into the atmo-
.sphere ^ and de Saussure has ascertained, that the

Sect. V.] Meteorology, t47

quantity of electricity is as much increased when
water is decomposed as when water is dropped on
red-hot iron. On the other hand, when steam is
condensed into vesicular vapour, or into water, the
air becomes negatively electric. Mr. Canton has
ascertained that dry air, when heated, becomes ne-
gatively electric, and positively when cooled, even
when it is not permitted to expand or contract ;
and the contraction and expansion of air also oc-
casion changes in its electric state. It is discover-
ed, therefore, by these experiments, that there are
four sources of atmospheric electricity known ; vix.
1. Friction; 2. Evaporation; 3. Heat and Cold;
4. Expansion and Contraction ; not to mention the
electricity evolved by the melting, freezing, solu-
tion, &c., of various bodies in contact with the air*.
Closely connected with the doctrines which have
been taught on the subject of evaporation, are the
several theories of Bain to which modern times
have given birth. The phenomenon of vapour
becoming condensed, or of air in any manner pro-
ducing water, and falling in the form of rain, hall,
and snoiv, has long been considered a point of dif-
ficult solution among meteorologists. All the sup-
positions to account for this fact were for a con-
siderable time insufficient and unsatisfactory ; and
even now the subject is far from being fully unfold-
ed. At one time, the condensation and fall of va-
pour in different forms has been accounted for by
referring to the influence of electricity ; at another,
by considering water as held in solution in air,
^nd precipitated by streams of air of different tem-

* Thomson's Chemistn/,

548 Natural History, [Ghap. III.

)i(n'af iires being brought into contact or a state of
mixture; and, at a third, by supposing this event
to be produced by the conversion of oxygen and
hydrogen gases into water, according to the ex-
periments of Cavendish, Lavoisier, and others.
TJiese several opinions have been successively po-
pular in the course of the century, and will be
fouiid amply detailed in the writings of Hamilton,
Ilutton, dc Saussure, and de Luc, on this sub-
ject. But, after all, it must be acknowledged
that great difficulties attend every theory hitherto
formed with a view to solve this question: inso-
much that the greatest meteorologist of the age,
]\L de Luc, after making a more patient, accu-
rate, and thorough inquiry into the subject than.
V, as ever accomplished by any other man, seems
to be at a loss to furnish a satisfactory account
of the matter. He therefore contents himself with
concluding, that the air formed by the decompo-
sition and ascent of water becomes reconverted
into that fluid by some unknown cause, or by a
combination of causes, and falls in the form of
niin, hail, or snow, according to the circumstances
in which the reconversion takes place, or the state
of the regions through which it passes in its de-
scent.

Much light has been thrown, in the course of
the last century, on the varieties of temperature
in difierent seasons and latitudes. On this subject
Dr. Halley made some instructive observations.
_\ few years afterwards, M. de ISIairan, an in-
genious French meteorologist, by a series of ob-
servations and experiments, discovered that the
rigour of tlic winter's cold is tempered by the heat

Sect. V.] AIe/eoro!ogi/. 049

imparted to the atmospliere by the earth itself;
and thus explained by what means tlie winter's
cold is rendered so moderate as to make the colder
climates inhabitable. On the ground of this dis-
covery be calculated, with great sagacity, the
rnaximum and minimum of heat, in every latitude,
for the summer and winter solstices 3 and though
his calculations are not always found to coincide
with facts, yet they have proved highly instructive
and useful to subsequent inquirers. De Mairan
was followed by Mayer, the celebrated astro-
nomer of Goettingen, who, in a few pages, did
more to solve the difficulties that occurred on this
subject than any of his predecessors. Me first
pointed out to meteorologists the necessity of fol-
lowing the method long used by astronomers;
namely, of first finding the mean of certain large
periods, as years and months (gradually correcting
the errours that may be discovered), and afterwards
finding an equation whereby to' correct aberra-
tions arising from height and situation. He even
proceeded so far as to give an equation to correct
the effects of height, which in many cases approxi-
mates very nearly to the truth : but the equation
hy wiiich (knowing the mean annual temperature
of two latitudes) the mean annual temperature of
every other latitude, and even of the pole itself,
may be found, has been pronounced his most ini-
portant discovery *.

Mr. Kir\^•an has carried the discoveries and im-
provements of Mayer considerably further. By

* See An Estimate of the Temperature of diferent Latitudes, hr
BW.hard Kirwan, esq. F.R.S., ^'c.

250 Natural History, [Chap. III.

means of the equation formed by the philosopher
of Goettingen, but rendered much plainer and
more simple, he has calculated the mean annual
temperature of every degree of latitude between
the equator and the pole. He has also calculated
the mean monthly temperature of that part of the
ocean which lies between the eightieth degree of
northern and the forty-fifth of southern latitude,
extending westward as far as the Gulf Streamy
and to within a few leagues of the coast of Ame-
rica ; and for all that part of the Pacific Ocean
reaching from 45'^ north to 40° south latitude, and
from 20 '^ to %15^ east longitude. This immense
tract of ocean he calls the standard. From these
calculations he has deduced a number of important
principles of great practical utility, and which
place him among the most distinguished meteoro-
logists of the eighteenth century.

The origin, qualities, and laws of Winds have
been diligently studied during the period under
consideration, but not with the same success that
has attended inquiries into other branches of me-
teorology. No satisfactory theory has yet been
formed on this subject ; owing to the want of ob-
servations, sufficiently numerous, of the exact times
and places where they begin and cease to blow,
but chiefly to our imperfect knowledge of the
means by which great regions of air are either
suddenly produced or destroyed. The discoveries
of modern chemists evince that air is perpetually
subject to increase and diminution, from its com-
bination with other bodies or its evolution frorn
th'^m : and, therefore, that a just theory of winds,
whenever it shall be formed, will be found to rest

Sect, v.] Meteorology, 251

upon chemical principles, there is much reason to
believe. But though little has been done in ane-
mology, in the way of scientific reasoninof, much
has been accomplished, during the period under
review, in the way of patient observation, and the
establishment of numerous important facts. For
these we are chiefly indebted to Dr. llalley, M.
de la Caille, M. Prevost*, M. de la Cotte, Mr.
Daltonf, and several of the distinguished mcteoro-
legists before mentioned, — especially M. de Luc
and Mr. Kir wan. To these may be added Dr.
Franklin, Dr. Madison, Dr. Cutler, and several
other American gentlemen, who have made and
recorded valuable observations on the winds in
America f; and a long catalogue of modern navi-
gators and travellers, who have contributed rich
materials, brought from the most distant parts of
the globe, toward forming a systematic view of
anemology §.

Beside the great meteorologists whose names
have been already mentioned, very important ser-
vices have been rendered to this branch of natural
history by Bouguer, du Carla, Hales, Wargentin,
Mario tte, Reyer, Toaldo, Priestley, and many

* Siir les Limites des VoUs-AUzes.

f Meteorological Observations, 8vo, 1/93.

X For the observations of the above-named Amcricnn gen-
tlemen, and several others, see Franklin's Philosophical liters,
and the volumes of Transaction which have been pubJisiied by
die American Philosophical Society and the American Acadany of
Arts and Sciences.

§ For some ingenious remarks on anemology, see Botanic Gar^
den, Additional Notes.

QS2 Natural History, [Chap. IH,

others, to whom due honour is given by various
writers on the subject. The vohimes of viemolrs
published by the scientific academies, indifferent
parts of Europe, during the century under review,
contain rich treasures of meteorological informa-
tion, contributed by numerous hands.

Modern times have given birth to various in-
ventions for measuring the force and velocity of
winds. Among these, the most remarkable are the
Wind-gage, the Anemoscope, and the Ane7nometer ;
m the construction and improvement of which
Dr. Linn, Mr. Pickering, and others, have rendered
important service to meteorology. Numerous at-
tempts have also been made, during the period
imder review, to construct liygrometers, or instru-
ments for indicating the comparative states of the
atmosphere with respect to moisture and chnjness.
And though mucli imperfection is found to attend
every instrument hitherto devised for this pin-pose,
}ct gradual approximations have been made to-
ward those of a more perfect and useful kind.
Among these, Mr. Smeaton's hygrometer, ioxvciQ([ of
a hempen cord boiled in salt water ; M. de Saus-
sure's, made of human hair prepared by macera-
tion in alkaline ley; Mr. Coventry^'s, consisting
of dried paper ; and M. de Luc's, of ivory and
zvhalcbone ; deserve to be distinguished : especially
that formed of zohalehone by M. de Luc, which is
genera! {y considered as the most accurate and con-
venient hygrometer now in use.

That remarkable meteorological phenomenon
usually called tlic Aurora Borealis appeared Avith
pevuliar frequency in the course of the eightecntl^

Sect, V.] Melcorology* 253

century. Dr. Hallev tells us* that it was seen but
once in the seventeenth century, — rv:. in \Ch\ —
when it attracted considerable atlention, particu-
larly in France, where the celebrated (Jassendi
observed it, and gave it the name which it now
bears. After this there is no record of auy such
appearance until 1707, when a small one \\as seen.
But in 1716 an uncommonly brilliant one appciared,
which commanded universal attention, and was con-
sidered by the vulgar as a very portentous circum-
stance. Since that time these meteoric phenomena
have been so frequent and familiar, that they have
in a great measure ceased to attract attention or
to be recorded as remarkable events.

Modern philosophers have ascertained many
facts, with respect to the Aurora Bor calls ^ ^vhich
were of course unknown .to tho.re who h\ed in
the seventeenth century, and probably to all who
lived before them. It seems now to be generally
considered either as an electrical phenomenon, or
as produced by the combustion of injiammablc air
either wuth or without the intervention of the elec-
tric spark. For the observations which ha\ e been
made upon this kind of meteor, and the principles
with respect to it which appear to be established,
we are under particular obligations to Dr. Halley,
M. Mairan, signor Beccaria, Dr. Franklin, Dj\
F'orster, M. Gmelin, M. /Epinus, Dr. Hamilton
of Dublin, Mr. Canton, Dr. Blagden, Mr. Dalton,
and others. Ilie last-named gentleman is sup-
posed to have given the most satisfactory account
of the subject.

■^ Philosophical TranaacLions, X^.J-IT-

254 Natural History. [Chap. IIL

SECTION VI.

HYDROLOGY.

The natural history of Waters holds so important
a place among the objects of human knowledge,
that it has, in almost every age, attracted the at-
tention of those who loved to study nature : but
it is only within the century under review that
any thing on this subject deserving the name of
science, or a correct acquaintance with principles,
covdd be said to exist. The accessions to Hy-
drology in modern times have been very great.
The improvements in Chemistry, in Mineralogy,
and in many other sciences, have contributed much
to enlarge our knowledge in this department of
philosophy.

The comparative qualities of common -waters^
whether falling in rain^ or found in springs^ wells^
or lakes^ were observed and ascertained, during
the eighteenth century, with a degree of intel-
ligence and accuracy never before known. For
the experiments and inquiries which have led to
our knowledge on this subject, we are chiefly in-
debted to Bergman, Scheele, Carradori, Hassen-
fratz, and Guyton-Morveau.

The taste, specific gravity, and other properties
of sea water^ were also examined with new ac-
curac3% and with new results. For many en-
lightened experiments in tliis branch of hydro-
logy, we owe much to Sparrnian, Bergman, lord
Mulgrave, M. Pages, Mr. Biadh^ Dr. Watson, and
Mr. Kirwan.

Sect. VI.] Hydrology, t55

But among the discoveries and improvements of
thtj last age, which belong to this head, the most
important are the numerous and very useful inves-
tigations of Mineral WaUrs^ which were pursued
with great success during that period. It is
evident that our knowledge of the properties and
effects of mineral waters must in general keep
pace with the progress of chemical science; for
whicJi reason the early writers on thus subject were
in a great measure destitute of the best means of
pursuing their inquiries.

Mr. Boyle may be considered as tlie first person
wdio pointed out the method of examining mineral
w^aters. He first ascertained the existence of air
in water, and directed to a number of tests by-
means of which conjectures might be made con-
cerning the saline bodies which the water examin-
ed held in solution. He was soon followed hy du
Clos of France, by Hierne of Sweden, and by seve-
ral other philosophers in different parts of Europe,
who made considerable additions to the tests em-
ployed and the facts ascertained by Bo\'ie. In
1726 Boulduc pointed out a method of precipitat- .
ing sevei^l of the saline contents of water by means
of alcohol. But it was not till after the discovery
of carbonic acid by Dr. Black, that any great pro-
gress w^as made in ascertaining the composition of
mineral waters. That subtile acid, \Vhich is so
often contained in them, and which serves as a
ve\y powerful solvent to many of the eartiis, and
even of metallic bodies, had thwarted all the at-
tempts of former chemists to detect the composi-
tion of these liquids. Since the discovery of that
acid, the analysis of minerar waters has advanced

$.'>6 Natural History. [Chap. III.

with great rapidity; so that, at the present period,
this may be considered as one of the parts of che-
mical philosophy best understood.

The Dissertation on the Analysis of Mineral
Waters published by Bergman, in 1778, was con-
sidered as the first great work on this subject. No
general mode of analysing mineral waters was
known prior to this publication. The author, in
this admirable work, not only shed much new light
on the subject, but he also carried the investiga-
tion of it at once to a very high and honourable
degree of perfection. His method, with many ad-
ditions and improvements, has been generally
adopted by succeeding hydrologists.

About the same time with the publication of
Bergman's work, Messrs. Monnet and Cornette of
France, and Gioannetti of Italy, displayed in
their respective works considerable talents as
hydro-analysts, and gave much valuable informa-
tion to the world. These were followed by the
excellent treatises of Fourcroy on the waters of
E/igiu'c/i, of Klaprolh on the waters of Carlsbad^
and of Black on those of Iceland. In the experi-
ments of these distinguished philosophers new and
more accurate tests are exhibited, several im-
provements in the application of those before
known are comnuinicated, and methods unfolded
of determining with precision the separate quan-*
tities of inseparable substances.

Next appeared the publications of Dr. Pearson
on the waters ol' Buxton, of Dr. Garnett on the
^\ aters of Harroivgatc, of Mr. Lambe on those of
Lcniington Priors, of M. Breze on those of Fu,
and of M. Hasscnfratz on those of Pougucs. — ^To

SicT. VL] Hydrology. 2.57

these may be added the hydrological Inquiries of
Gren, Westrumb, and Kirwan, ^vhich are highly
valuable, — especially those of the last named gentle-
man, who, in a tract singularly comprehensive, and
abounding with instruction, has given a rich
amount of principle, experiment, and authority, on
this interesting subject*. By the labours of these
and many other philosophers, discoveries have
been made concerning the composition and medi-
cal powers of mineral waters, in almost every part
of the world, extremeiy useful to the interests both
of science and humanity.

* Essay on the Analysis of Mineral Waters, by Richard Kir-
wan, es^. F.R.S. &c. 8vo. I/99.

Vol. I.

25&

CHAPTER IV.

MEDICINE.

1 HE profession, whose department of knowledge
now comes mider consideration, occupies an immense
field of science, and by its number constitutes a
larcje class of the learned world. In addition to the
incentives of philanthropy and fame, which equally
actuate the exertions of others, physicians are com-
bined into a corps of observers and practical inqui-
rers by the nature of the employment and duties
they assume, and by the connexion which the usages
of society establish between their duties and emo-
lument. In discharging their professional labours,
they incessantly fmd observations and facts obtruded
on their attention; and by combining these into
hypotheses, theories, and systems, they only indulge
a favourite and almost irresistible propensity of the
human mind. Hence arises the vast mass of writings
which fill medical libraries, constantly accumulating,
and too numerous, extensive, and diversified, to come
within the comprehension of an individual inquirer.
Whoever duly considers these things will perceive
the necessity of resting satisfied on this occasion with
a transient retrospect. To attempt any minuteness
of detail would be to travel far beyond the limits
assigned to this work, and to engross the pages
which are destined to the examination of other
subjects. All that can be aimed at is briefly to no-
tice some of the more important revolutions and
improvements which distinguish the last age and

Chap. IV.] Medicine. 259

to commemorate a few of the illustrious names to
whom the praise of them is chiefly due*.

Within the period assigned for tliis review, the
state of medicine has been essentially cliangetl, and
has acquired a degree of extent, popular dissemina-
tion, and practical usefulness, unknown to precedino-
ages. The improvements in natural history and
chemistry, mentioned in the preceding chapters,
liave greatly contributed to this extension, and miiy
be considered as inexhaustible sources of materials cal-
culated for a similar extension in future times. The
more enlarged intercourse of mankind, the greater
facility of communicating opinions and discove-
ries fi'om one region to another, and the progress of
commercial arrangements, by which the choicest
productions of one country become the property of
every other^ may also be enumerated among tlie
causes of this advancement.

In no period so much as in the last century, and
in no science more than that which now engages
the reader's attention, have the advantages been
exhibited which arise from lord Bacon's plan of pur-
suing knowledge by observation, experiment, analy-
sis, and induction. Every department of medicine
bears witness of the efficacy of this process to remove
the rubbish of prejudice and errour, to present truth
in a simple form^ and to establish it upon a legiti-
mate foundation. A more precise, rigid, and logical
mode of philosophising has been generally substi-
tuted for the wild and visionary hypotheses which
disgraced the science of the preceding centuries.

* For many of the names, facts, and details, included in tlxis
chapter, the author is indebted to a medic?] friend.

S 2

260 Medicine, [Chap. IV.

To understand the history of medicine at any pe-
riod, it is necessary to trace the progress and mark
the affinities of all the sciences which are contempo-
rarily cultivated. Not only the reign of fashion, but
the peculiar acquirements and taste of individuals
are often to be considered in an estimate of their
medical principles. " La Philosophic," says M.
d'Alembert, " La Philosophic prend, pour ainsi dire,
*• la teinture des esprits ou elle se trouve, Chez un
'' metaphysicien, elle est ordinairement toute syst6-
" matique; chez un geometre, elle est souvent toute
"decalcul.'* The application of this remark, if
possible, is more eminently verified in respect to
medicine than to philosophy in general. This pro*
pensity of the human mind is productive both of
good and ill elfects. If it be easy to show example*
of injury sustained by the precipitancy of mathe-
maticians, chemists, and metaphysicians, in apply-
ing their doctrines to medical science, which can-
not indeed be reasonably doubted 5 it is equally easy
to prove that great benefit has arisen from iiuch
applications.

But notwithstanding the advantages and improve-
ments which the eighteenth century has bestowed
upon medicine, it must still be admitted that its pro-
gress has never equalled the sanguine expectations
formed by many. Although nearly coeval with the
existence of mankind, and demanding attention in
every stage and condition of human life, the art of
healing maintains a struggle with difficulties at
every step. Like all other knowledge derived from
observation and experience, that of medicine, though
continually progressive, is subject to perpetual re-
volution. This tardiness, therefore, in the career of

Sect. I.] Anatomy, 261

improvement, which all must admit aud deplore, will
excite no surprise in such as consider the mystery
which still envelopes the principle of life, the labour
of watching the operations of natnre, the number-
less fallacies which attend the endeavour to discri-
minate truth from falsehood, and the smallness of
the stock of genuine and undisputed facts which all
the observation and wisdom of ages have been able
-hitherto to collect.

There is no species of knowledge, relating to affairs
merely human, which more indispensably recpiires
steadiness of principles and harmony of opinion
than that now under consideration. There is none
in which speculation and action are more intimate-
ly related, where errour is of more immediate and
fatal consequence, or where a fluctuation of the mind
between opposite decisions is attended with more
embarrassment and distress. Yet medicine abounds
with schisms and controversies; and, in the present
imperfect state of knowledge, to hold doctrines and
adopt practices beset with the fewest errours, consti-
tutes the highest attainment within the reach of the
human mind. %

SECTION I.

ANATOMY.

This subject was pursued with so mucii diligence
soon after the restoration of learning in the fifteenth
and through the two succeeding centuries, as to leave
less than might be expected for the investigation of
modern anatomists. Leonardo da \'\\\c\ made great
progress in anatomical studies towards the close of

262 Medicijie. [Chap. IV.

the fifteenth century*. In the sixteenth century
flourished the immortal Vesalius, the founder of ra-
tional and systematic anatomy, whose works afford
surprising proofs of laborious and successful dissec-
tion. After him appeared Sylvius in France; Co-
lumbus, Fallopius, and Eustachius, in Italy j whose
discoveries and improvements were so numerous as
to give a deep impression of the zeal and enthusiasm
with which the knovrledge of the structure of the
human body was cultivated at that early period.

Soon after the time of the last mentioned writers,
the study of anatomy was gradually diffused over all
Europe. The principal impediment to its progress,
in that age, was the difficulty of obtaining human
subjects for dissection; the want of which frequent-
ly made it necessary to dissect the bodies of brutes.

With the dawn of the seventeenth century new
lights were shed upon anatomical inquiries from
every quarter. At this time Fabricius ab Aquapen-
dente, an eminent Italian teacher, published his
account of the valves in the veins ; which evidently
affected the established doctrine of all fonner ages,
tliat the veins carried the blood from the liver for
nourishment to all parts of the body. The detec-
tion of these valves may also justly be supposed to
have laid the foundation of the discovery of the cir-
culation of the blood.

For Dr. Harvey, the pupil of Fabricius, was re-
served the noble discovery of the circulation of the
blood soon afterwards. This was by far a more

* This was the first man who introduced the practice of making
anatomical drcmrngs. These drawings, preserved in a British
collection, excite astonishment at the depth and accuracy of his
kno\vledt2;e.

Sect. I.] Anatomy, 363

important step in the knowledge of animal bodies
than had ever been made before, and gave a new
spring to anatomical inquiries. In a few years after
Harvey's discovery, Asellius, an Italian physician,
found out the lacteals, or vessels which carry the
chyle from the intestines. And about the middle
of the seventeenth century, Pecquet, in France, was
so fortunate as to discover the thoracic duct, or com-
hion trunk of all the lacteals, which conveys the
chyle into the subclavian vein. At nearly the same
period, the practice of dissecting living animals
furnished the occasion of discovering the lymphatic
vessels. Rudbec, a young Swedish anatomist, was
the first to detect them; and, after him, Thomas
Bartholine, an anatomist of Denmark, who first ap-
peared as a writer on the subject.

Malpighi, an eminent Italian, made great progress
in anatomy soon after the period last mentioned.
He was the first who used magnifying glasses with
address to trace the early appearances in the forma-
tion of animals. He likewise improved anatomy
by many other observations on minute parts of the
body, by his microscopical labours, and by the dis-
section of animals. Between the middle and end of
the seventeenth century, anatomy was much impro-
ved by the diligence of Swammerdam, Van I lorn,
Steno, and de Graaf Professor Diemerbroeck, of
Utrecht, without much originality, compiled a work
which for many years was regarded among students
as a standard authority.

Towai'ds the close of the same century, Lewen-
hoeck obtained great celebrity by his im})rovement
on Malpighi's use of microscopes. Though many
of the supposed discoveries of this anatomist (parti

264 Medicine, [Chap. IV.

cularly his account of the composition of the red
globules of the blood, and of animalcula observed in
the semen) are now discredited, it must still be ad»
mitted that he advanced many steps in bringing to
light the more minute parts of the animal structure.
Nuck likewise soon afterwards added to the stock of
knowledge by his injections of the lymphatic glands.
I'he anatomical plates of Bidloo and Cowper, pub-
lished about this time, are also entitled to respectful
notice.

li\ the latter part of the seventeenth century
anatomy was greatly advanced by the invention of
injections, and the method of making what are
commonly called preparations. These two modern
artg have been. of great advantage in this science:
they have introduced not only an unexpected degree
of correctness, but an elegance in demonstrations
which formerly could not have been supposed to be
possible. Tliey began in Holland under Swammer-
dam and Ruysch, and were afterwards employed in
England by Cowper, St. Andre, and others. Ruysch
possessed a singular excellence in injections, which
has been supposed by many not to have been equal-
ed since, and which certainly has not been surpass-
ed. The anatomists of former ages had no other
knowledge of the blood-vessels than such as they
were able to obtain by laborious dissections, and
by pursuing the smaller branches of them, upon
favourable occasions, when they happened to be
more than commonly loaded with red blood : but
filling the vascular system with a bright-coloured
wax presents a distinct view of the large vessels, ren-
ders tlie smaller much more conspicuous, and makes
thousands of the very minute ones visible, which.

Sect. I.] Anatomij. 265

from their capillary size, their delicacy, and the
transparency of their contents, would be otherwise
imperceptible.

In this high state of advancement, anatomy stood
at the beginning of the century the progress and im-
provements of which it is the object of this work more
particularly to explore. -At that period, the Italian
and Dutch schools held an undoubted sui)eriority.
This superiority, however, has been since much
more equally divided among the British, French, and
German anatomists.

Early in the eighteenth century, anatomy was
improved by the writings of Ruysch in Holland,
and of Cowper, Keil, Douglas, Cheselden, and
others, in Great Britain. The works of Albinus,
Winslow, and the first Monro*, greatly contributed
to the same end, and are familiarly known to all
the cultivators of this science.

But the most memorable discovery that anatomy
can boast in the eighteenth century, is that of the ab-
sorbent system. It has been mentioned that Rudbec
and Bartholine became acquainted with the lympha-
tic vessels about the middle of the preceding century.
When they were first seen, and traced into the tho-
racic duct, it might have been supposed natural for
anatomists to suspect, that, as the lacteals absorbed
from the cavity of the intestines, the lymphatics, si-
milar in figure and structure, might possibly perform

* The family of Monro, in Edinburgh, has been long and
eminently distinguished in the annals of anaton;iy. Tiiree persons,
cf the name of Alexander Monro, have in succession adorned
the iijedical school of that city since the year 1720 ; of these, the
hst is yet alive, and ably supports tlie reputation of his illustriou*
predecessors.

^66 Medicine. [Chap. IV.

the same office with respect to other parts of the
body. Notwithstanding this, anatomists in general,
from repeated experiments, particularly such as
■were made by injections, were persuaded that these
lymphatic vessels did not arise from cavities, and
did not absorb, but were merely continuations of
the small arteries. It had indeed been supposed by
Dr. Glisson, who wrote in 1654, that they arose
from cavities, and that their use was to absorb. Dr.
Fredei'ick Hoflman had also very explicitly laid
down the doctrine of the lymphatic vessels being a
system of absorbents. These suggestions, however^
produced little effect. And it was reserved for Dr.
Hunter * of London, and Dr. Monro, the present
professor at Edinburgh, to prove that the lympha-
tics are absorbing vessels throughout tJie whole
body; that they are similar to the lacteals; that all
these, collectively taken, together with the thoracic
duct, constitute one great ajid general system, di^
spersed through the whole body for the purpose of
absorption; that their sole office is absorption; and,
finally, that they serve to take up and convey what-
ever is to enter the composition of the bloody or to be
again mixed with the blood, from the intestinal canal,
from the skin, and from all the internal cavities and
surfaces -f.

* William and John Hunter, also natives of North Britain, and
aften^'ards residents in London, hold a high place in the anatomi-
cal history of the eighteenth century. The former was born in
1/18, and died in l/b3 j the latter was born in 1728, and died
in 1793.

t A warm controversy, concerning the discovery of the true
use of the lymphatics, was carried on between Dr. Hunter and Dr.
Monro. The former asserts that he taught it in his lectures so
early as 17-16, and appeals tj3 his pupils for the truth of the asser-

Sect. I.] Anatovii/. 20?

The discovery of the absorbent system is justly
considered as the greatest that anatomy has sug<;cst-
ed since that of the circulation of the blood. The
advantages which arise from the knowledge of the
structure and office of this system of vessels, in esta-
bhshing physiological principles, and in ascertaining
the nature and treatment of diseases, are universally
admitted. Before the discovery of the lym])hatics
being a system of absorbents, it was impossible to
give a clear and consistent account of a great
number of phenomena which are now satisfactorily
unfolded. From this source much knowledge has
been obtained concerning the introduction and ef-
fects of poisons; and, aided by this light, physicians
are enabled to trace many diseases directly to their
causes, to explain the assemblage and succession of
symptoms, and to apply remedies with more prompt
and appropriate efficacy. On this account physicians
of learning and judgement have not been wanting,
who pronounce the solid and practical usefulness of
this discovery even to exceed that of the circulation
of the blood.

But whatever may be the comparative estimate
of the two discoveries in relation to one another, it
is plain that they arc both the most memorable

tion. The latter seems to have made the discoveiy in 1753 j and
in 1755 published an account of it in a thesis De Ttstibus in Variis
Animal ibus. Before the publication of this tJicsis, Dr. Black is
said to have informed the author that the same opinions concerning
the valvular lymphatics had been long entertained by Dr. Hunter.
In 1756 Dr. Monro attended Dr. Hunter's lectures in Lon-
don J heard the whole doctrine of the lymphatics very amply
explained J and in 1/57 reprinted his opinion at Berlin, witlv nit
taking notice of Di. Hunter's, who, in consequence, charges him
with plagiarism j and Uie charge is retorted by Dr. Monro.

0,6s Medicine. [Chap. IV;

that tlie annals of anatomy can boast. Under the
influence of this impression. Dr. Hunter declared,
in one of his lectures, that " in looking over the
whole progress of anatomy, from the time of Ari-
stotle to the present day, there have been only txvo
grand discoveries vi^ith regard to the physiology of
our bodies, — to wit, the vascular system^ or cirxvla-
Hon of the blood, and the absorbent system; — the
brain and nervous system having been knov/n long
before."

Notwithstanding, however, the weight of the
arguments adduced by Dr. Hunter, Dr. Monro,
and others, in support of this doctrine of the absor-
bent system, it has been opposed by writers of
great authority. The old opinion^ that the veins
perform the office of absorbents, was held by
Haller * and Meckel. Within a few years, Mr.
Humpage, in a work entitled " Physiological Re-
searches into the most important Parts - of the
Animal Economy, &c.," undertook to controvert
the prevailing doctrine on this subject. He en-
deavours to prove, conformably to the opinion of
the old anatomists, that the lacteals and the lym-
phatics constitute systems of vessels entirely separate
and distinct. He admits that the lacteals arise
from the internal surface of the alimentary canal,
terminate in the thoracic duct, and convey the chyle
into the blood : but he denies that the lymphatics
arise from cavities and surfaces, or that they termi-
nate in the thoracic duct ; and maintains, on the
contrary, that they originate from the heart and
arteries, that they serve to convey lymph from the

* Element. Physiolog. Corp. Human. I. 24, § 2, 3.

Sect. I.] Anatomij, 269

blood, pnd that they terminate on all surfaces and
cavities. He contends that the use of the lympha-
tic glands is for the separation of the lymph I'rum
the blood j and that the lymphatic vessels are ex-
cretory ducts to the lymphatic glands. For the im-
portant function of absorption he provides in tlie
following manner : he supposes that, aUhough the
lymphatic vessels convey fluids from the blood, they
also occasionally possess the power of absorption.
This office, he imagines, they perform after accom-
plishing their first purpose— that is to say, after
conveying the lymph to the various parts of the
body, they become mere empty tubes, and absorb
whatever is applied to any surface. According,
therefore, to the degree of inanition or repletion of
the lymphatic vessels, in his opinion, will the body
be more or less susceptible of the absorption of
any fluid applied to the skin or any other surface
or cavity.

These, however, and many other objections to
the generally received doctrine of the absorbent
system, have gained little credit among tlie most
respectable anatomists. The arguments by wliich
they are attempted to be supported have been
shown to be founded on injections unskilfully made,
on observations inaccurate, and conclusions altoge-
ther illogical.

In the oarly part of the controversy on this sub-
ject, it was urged, that, before the doctrine of the
lymphatics being a system of absorbents could
be established, it was necessary first to determine
whether this system is to be found in other animals
beside man and quadrupeds. Mr. Ilewson claimed
the merit of having proved the alTinnative of tliis

270 Medicine, [Chap. IV.

question, by discoveriag the lymphatic system in
birds, fishes, and amphibious animals *.

Since the time of Mr. Hewson, the anatomy of
the absorbent system has been greatly extended
and improved. The ramifications of it, in almost
every part of the body, have been traced by Mr.
Cruikshank, with great accuracy; and from his
dissections, figures have been made and published
which are deservedly held in high estimation. To
Mr. Sheldon, also, anatomists are much indebted^
for his illustration of this system. And Mascagni,
of Italy, has likewise bestowed great pains on
this subject f.

As a general system of anatomy^ the "Anatomi-
cal Exposition of the Structure of the Human Body,"
by professor Winslow, of the university of Paris,
though compiled and published early in the eigh-
teenth century, was, till near the close of it, regard-
ed as a standard work. This has, of late^ given
place to a more comprehensive and accurate com-
pilation, in three volumes, executed by Mr. Fyfe of
Edinburgh, under the direction of professor Monro.
Ileister's compendium, during a great portion of
the century, was held in high esteem. Dr. Simmons,
of London, has also lately obliged the world with
an excellent system of anatomy, in which the sub-
ject is treated with uncommon perspicuity and
elegance. Among treatises on anatomy in general,

* Philos. Trans, vols. Ixviii and Ixix.

•[ The work of Mascagni on the Lymphatics is considered bf
good judges, as by far the greatest work that has been published on
this subject, as one of the most valuable anatomical productions
of the age, and as a work thnt must immortalise the reputation.
of tiic author.

Sect. I.] Anatomy. 27 1

those presented to the world by Sabatler and
Plenck, within a few years, deserve to be particu-
larly mentioned. Mr. John Ikll, of Edinburgh,
has pubhshed two volumes of a system of anatomy,
which is considered as a very able work, so far as
it goes, and will probably be completed in a short
time. Mr. Charles Bell, of the same city, in u
work entitled "A System of Dissections," has done
much towards facilitating and familiarising the
study of anatomy, and displaying the appearances
of morbid parts of the body. And a very recent
*^ Compendium of Anatomy," by Mr. Fyfe above-
mentioned, illustrated by a large number of en-
gravings, is supposed to contain improvements, of
more or less value, on every preceding work of that
kind.

To the above may be added a variety of valuable
publications by professor Scarpa, of Pavia, wlio lias
well supported the reputation of the former Italian
schools of anatomy.

In particular departments of anatomy, much has
been done within the century to enrich the science,
\yhich ought not to be passed without special
notice.

The gravid iita-us is a subject which has attracted
much attention, and received considerable improve-
ment within this period. The works of Albinus,
Roejderer, and Jenty, have greatly enlarged tlie
knowledge of former anatomists on this point. But
Dr. Hunter's publication on the gravid uterus, to
which he had devoted a long time and unconnnpn
pains, far excelled every preceding work. Meckel,
and the second Monro, liave treated on the nerves
to considerable extent i Weitbi-ccht and Lebrron

jn^ Medicine. [Chap. IV.

the joints and fresh bones ; Soemmering and Monro
on the brain*; Porterfield, Haller, Zinn, andWris-
berg, on then/e; Cotiinnius, Meckel, jun.. Camper,
Scarpa f, and many others, on the ear. Walter is
celebrated for his description of the veins of the
head and neck, as well as very elegant plates of the
7ierves of the thorax and abdomen. Trew has ably
treated of the differences between the feet at and
adult vessels: Dr. Monro, jun., on the Bursa Mu-
cosa, &c.

The anatomists of the eighteenth century have
effected great improvements in the science, and
facilitated the communication of it to students, by
the number and correctness of their engravings.
Figures of the bones, in folio, have been published
by Cheselden, Albinus, Sue, and Trew, The muscks

* Mr. Soemmering thinks it probable that tlie soul is seated in
the fluid of the ventricles of the brain. He infers this from the
fact of tlie nerves of vision, hearing, taste, and smell, being all at
their origin in contact with and exposed to the action of tlie fluid
in the ^ entricles ; from the same taking place \^'ith regard to the
nerv-es of touch, originating from the fifth pair, the glosso-pharyn-
geal, those belonging to the organ of voice and the motions of the
eyes ; from tlie impossibility of finding a solid part of the brain
into which the terminations of all tlie nerves can be traced j from the
nerves of the finest senses~-v22. hearing and seeing — being most
extensively expanded and most directly in contact with this fluid ;
irom the preternatural increase of tliis fluid in the ven Uncles ot
ricketty children, which perhaps may be the cause of their micom-
Fnon acuteness of mind ; and, finally, from the fact, that no
animal possesses so capacious and so perfectly organised ventricles
as man, — they being in the other mammalia much smaller than in
man, still less in birds, least of all in fishes, and abiolutelj
wanting in insects.

t This great anatomist wrote ably, not only on the car, but also
on the nerves of the heart. His work oil tliis subject is said to bt
highly meritorious.

Sect. I.] Anatomi). 273

are exhibited by Cowper and Albinus with great
accuracy; by tlie latter particularly, in a style of
elegance which cannot easily be surpassed. 1 Jailer's
Iconcs, especially of the arteries, are much admired.
Anatomical figures of particular and smaller parts
of the body are without number, and many of them
possess great excellence. It will be suflicient to
mention a few ; such as those by Morgagni, Ruysch,
Valsalva, Sanctorini, Hcister, Vater, Cant, Zimmer-
mann, Walter, &c.

The vast work projected by Vicq-d'-Azyr, of
France, was soon terminated by his premature
death. He conceived the idea of representing ana-
tomically the whole animal kingdom, from man
down to the simplest hydra, of giving exact figures
of every form of living matter, and of consolidating
the immense plan into one great whole. Upon
the brain alone nineteen folio plates are employed,
of which several are coloured; these are executed
with admirable elegance. This universal system of
anatomy and physiology, both human and compa-
rative, was i>roposed to be executed in the same
splendid style. But he lived only to finish five
numbers. The design is apparently too extensive
to be accomplished within the period of a single
life.

In Great Britain, likev/ise, an extensive anatomi-
cal work has been undertaken by Mr. Andrew BqW,
entitled Anatomia Brifanuica, under the inspection
of Mr. Fyfe and Dr. Monro. It is designed to
compose a complete illustration, both general and
particular, of the human body, by a selection from
the best plates of all the greatest anatomists, a^ well
foreign as British, exhibiting the latest discoveries,
Vol. I. T

J274 Medicine. [Chap. IV.

and accompanied with copious explanations. The
■whole number of plates is to be upwards of three
hundred, in royal folio 3 of which a large proportion
is already published.

The art of injection and of making preparations^
which was before stated to have reached such a
point of excellence towards the close of the seven-
teenth century, has been very extensively and suc-
cessfully exercised during the eighteenth. The
modern practice of corroding the fleshy parts and
leaving the moulded wax entire, is so useful as well
as ornamental, that it reflects great credit on Dr.
NichoUs, the ingenious inventor. In the injection
of the lacteals and lymphatics, the late centiuy may
justly claim the credit of having made very conside-
rable progress.

Alorbid dissections form a new and interesting
aera in anatomy and medicine. Bonetus, near the
end of the seventeenth century, had published his
Sepulchre turn Anatonicum. Morgagni, in his in-
estimable work, " De Causis et Sedibus Morborujny'
has enriched morbid dissections with many valuable
additions, and has rendered them highly instructive
to the medical practitioner. Lieutaud and Haller
also greatly increased the stock of knowledge on
this point. ^lost of the distinguished anatomists,
indeed, liave contributed their exertions to im-
prove the principles of medicine, by directing their
dissections to this object. Lately Dr. Baillie^s pub-
lications.on morbid anatomy, illustrated by corre-
spondent engravings, do the highest honour to his
diligence, learniiig, and judgement.

Beside the discoveries and improvements ob-
tained from the dissection of human bodies, Compa-

Sect. I.] Anafomij. $75

rative Aiiatoniy or Zobtoim) has made great pro<^rcss
in the course of the eighteenth century. Many
advantages have arisen, and may be expected here-
after to arise, from this source. In addition to the
benefits resulting from a more enlarged acquaint-
ance with the properties and functions of animated
nature, vvliich often reflect hght on the human
economy, and are founded on the knowledge of
comparative anatomy, the veterinary art has lately
become so extensive and respectable as to require,
on its own account, a more minute examination of
the structure of many animals.

The most illustrious names among such as have
distinguished themselves in human anatomy are in
general precisely those who have done the most to
extend the limits of comparative anatomy in the
eighteenth century. To prove this, it will be sufli-
cient to recall the reader's attention to the writings
of Haller, Dr. and Mr. Hunter, the first and second
Monro, &c. The Essay on Comparative Anatomy
by the first Monro affords proof of the diligence
lie exercised on the subject. The thesis of the se-
cond Monro, " De Testibus in variis Animalibus^'*
abounds with evidence of deep, laborious, and suc-
cessful researches. And his work on Fishes, men-
tioned in the preceding chapter, has greatly con-
tributed to enlarge our acquaintance with the
structure and functions of that large class of animals.
Every anatomist is informed of the discoveries and
improvements made by Dr. and Mr. Hunter in
their numerous dissections of animals, and of the
principles and doctrines which these dissections
enabled them to establish. They were followed
by J»Ir. Hewson, Mr. Cruikshank, and many

T 2

576 Medicine, [Chap. IV*

others of distinguislied reputation, who were em-
ployed in the investigation of the absoi'bent sys-
tem. Daubenton and Vicq-d'-Az} r, the dissections
made mider the orders of the lloyal Academy of
Sciences of Paris, Spalhmzani of Italy, Camper
of Holland, the late extensive and systematic work
of Mons. Cuvier, w^hich exhibits the dawn of an
improved arrangement, and a great number of the
most eminent zoologists of the age, have strong
claims to be commemorated in a review of the com-
parative anatomists of the eighteenth century*.

In concluding this brief survey of the subject, it
may not be improper to remark, that far less re-
mained to be done in anatomy, at the commence-
ment of the late century, than in any of the other
branches of medicine. The leading principles of
the science had been chiefly ascertained and settled
by the industry and perseverance of preceding ages.
And the greater part of what was left to be accom-
plished consisted in a superior lulness, accuracy,
and minuteness of description, more elegance of
d«-hneation, more neatness and variety of prepa-
rations, and a progressive hnpro\ement in the arts
of dissection and demonstration. It is evident, that,
in all these respects, a considerable progress has
been made w ithin the period under review.

•* In adilltiun to tlie above-mentioned works and names, it may
not be improper to subjoin the following comparative anatomists,
selected from a great number. Fragments of the Curieux de la
Nafure; the collections of Blasius and Valentinij da Verney,
Collins, Stnbbs, Cijkinan, and Home, on quadniptds and birds ;
Charas, Roesel, and Fontana, on reptiles; Artedi, tlie Gouans,
and r.rou8.sonet, unjishes ; Reaumur, the Geoffroys, Bonnet, and
Ly(j!K't, on insects; and Kllis;, Donati, Trembley, Baker, Baster,
Bohadich, Forskal, Adanson, Mueller, Fallas, and Dicquemar(?,
on vjorm'^i zoophytes ^ dud polype.^ .

Sect. II.] Physiology. ^17

SECTION II.

niYSIOLOGY.

That department of physical science which treats
of the various properties and functions of living
bodies nuist be allowed to possess great import-
ance; and the review of its progress during a
hundred years of more industry and enterprise in
the pursuit of natural knowledge than the world
ever witnessed before, will be supposed to pre-
sent difficulties proportioned to the extent and
complexity of the subject.

To such as feel a genuine attachment to the
science of nature, few subjects present inquiries of
a more interesting and instructive kind. AVhen im-
pro\ ed as far as the state of the other contemporary
sciences will admit, it will be found to exhibit a
systematic result of all the experiments and obser-
vations, facts and principles, which serve to explain
and illustrate the ]3henomena of animated nature.
And when it shall reach that point of advancement
to which a cautious estimate of the powers of tlic
human mind may suppose it to proceed, it will
probably be enabled to diffuse lights and suggest
improvements far beyond the most sanguine ex-
pectations of the naturalists of the present day.
In zoology, botany, anatomy, and the theory and
practice of physic, these good ellects may be con-
fidently anticipated. . , . ,

As all li\ ing bodies are subjects of physiological
inquiry, and as by living bodies are here meant all

278 Medicine, . [Chap. IV".

those which are enabled, by a certain organised
structure, to grow and to propagate their kind, it
is plain that physiology must extend to the whole
of that organical economy in animals and plants
which the Author of Nature has contrived for the
preservation of the individual, and the continuance
and propagation of the species. But although it
is not intended, in this brief retrospect, wholly to
overlook the history of the doctrines of general
physiology for the late century, it may be proper
to apprise the reader that the objects of human
physiology will chiefly claim attention, This re-
stricted view of the subject is preferred on the
present occasion, not only on account of the re-
quisite brevity, but because the chief design of in-
troducing this sketch of the progress of physiology
is to consider it in subserviency to medical science,
and as preparatory to the remarks which are
to follow concerning the theory and practice of
physic.

At the close of the seventeenth century, phy-»
siology presented a chaos of the wildest and most
discordant principles. The extravagant notions of
the Galenists and chemists had indeed ceased to be
generally defended; but they were succeeded by
those of the mathematicians, which were nearly
as far removed from truth and nature. The dis-
covery of the circulation of the blood, in the be-
ginning of the seventeenth century, had given rise
to the introduction of mechanics into medical doc-
trines. And as that system of philosophy was
founded upon the general laws of nature, the ablest
physiologists of the day were easily induced to ap-
ply it to the human body; which was supposed to

Sect. II.] Phjslology, 979

difler only from the rest of the universe hi the
variety and complexness of ils machinery.

Bellini, of Florence, was the first who attracted
much attention by the introduction of matlieniatics
into physiology. Professor Horelli pursued the same
course of reasoning, and soon became one of its
most enthusiastic admirers. He employed it so
well in showing how the muscles act as cords, and
the bones as levers, that he thence undertook to
explain, with happy effect, the phenomena of stand-
ing, walking, leaping, flying, and swimming, in
ditferent animals*. Emboldened l)y the success
of his hrst attempt, he afterwards ventured to ex-
plain on the principles of mechanism all the in-
ternal motions and their proximate causes. On
the same ground he gave a minute account of the
pulsation of the heart, of the circulation of the
blood, of the office of the lungs, the kidneys and
the hver, of the nervous fluid and the semen, of ve-
getation, generation, nutrition, hunger, thirst, pain,
lassitude, and febrile heat. Y^y this ardent specu-
latist all nature was interpreted on mathematical
principles; for, except the mechanical, he \\as wd-
ling to admit no other secondary powers in nature.
He thought, with Plato, that the Deity nimself was
'dhvixys geovielrishig ; and was fully persuaded that
physical knowledge could only be acquired through
the medium of geometrical demonstrations and
forms.

With what eagerness and zeal Dr. Pitcairn
adopted mechanical physiology, and to what un-
reasonable extremes he was disposed to carry it, is

* See his ^vork, De Moiii AnimaUum.

580 Medicine. [Giiap. IV

sufficiently known. So attached was he to the geo-
metrical mode of demonstration, that he appeared
to consider it as the only species of evidence, ex-
cepting the senses, that deserved any reliance.

These opinions were warmly adopted and sup-
ported by the illustrious Boerhaave, who first ap-
peared as a public teacher about the beginning of
the eighteenth century. He exhibited the first suc-t
cessful example of combining physiology with ana-
tomy, reduced the former from a rude and chaotic
into a regular state, and conferred upon it that
systematic and elegant form which so greatly re-
commended it to the notice and admiration of the
world. But a more particular account of the opi-
nions of this distinguished physician will be given
under a succeeding head.

Baron Haller, the disciple of Boerhaave, pur-
sued the steps of his master, and far surpassed him
in his physiological career. He made a universal
collection of preceding discoveries in anatomy and
physiology, and digested them into order and me-
thod. He surveyed every part of the human body,
explained the various functions according to the
best lights which the state of science at that time
afforded, corrected the errours of preceding vyriters,
and, by a series of indefatigable labours, was ena-
Ijled to make very important additions to the ex-
isting stock of knowledge. In his great work, en-
titled Elcmenta Physiologice Corporis Hinnani, he
examined the opinions whicli had been recom-
mended, or at least advanced, by all tlie most ce-
lebrated authors. Nothing of importance, that had
been previously published, escaped his notice. The
most rapid sketch of the errours in physiology which

Sect. II.] Fhj/siologij, 281

he detected, of the new facts wliicli he added, of
the ingenious and profound views which he opened,
of the doubts he removed, and of the theories he
reformed and improved, would exceed the hmits as-
signed to this work*.

But the greatest of Ilaller's discoveries, and tliat
which forms an lera in tlie progress of physiology,
is the irritabilUij of tlie animal fibre. This irritable
or contractile power is tliat property hy which
muscles recede from stimuli, and become shorter
on being touched by them. It is a power inherent
in the muscular fibre, and essential to life. It is
so far independent of nerves, and so little con-
nected with feeling, which is the leading property
of nerves, that, upon stimulating any muscle by
touching it with caustic, or irritating it m ith a sliarp
point, or directing the electric spark through it,

* Baron Albert von Haller \vas boin at Berne, October 1 8,
17O8, and died in J//"/. He was unqnestionnbly one of the
greatest men of tJie age in which he Hved j being equally distin-
guished for the extent and variety of his learnin^-, the vigour and
comprehensiveness of his mind, the purity of his taste, and the
excellence of his moral and religious character. His great attain-
ments, and the uncommon powers which he dlspla) cd in almost
every kind of knowledge, and particularly in anatomy, physio-
logy, medicine, botany, and various branches of Natural History,
and also in classical and polite literature, are generally known.
He was not less distinguished as a friend to ihe religion of Christ.
He not only professed to believe in revelation, and to cherish a
warm attachment to theGospel, but, amidst his multiplied a\oca-
tions, he spent much time in studying the Scriptures, and the
evidences of tlicir divine origin 5 and entered the lists as their
avowed advocate and defender. His excellent letters to his
Daughter will long remain a monument at once of his regard to
religion, and of his paternal tidclily. See Henry's Memoirs of
Uallcr,

ogO| Medicine. [Chap. IV.

tlie muscle instantly contracts ; although the nerve
of that muscle be tied; although the nerve be cut
so as to separate the muscle entirely from all con-
nexion with the nervous svstem ; although the
muscle itself be separated from the body; and al-
though the animal upon v.hich it is performed have
lost all sense of feeling, and have been long to all
appearance dead. It is b^^ this irritable principle
that an incised muscle contracts so powerfully, aiid
that a divided artery shrinks and retires into the
flesh.

This important principle of irrifahilify, which
Ilallcr denominated Vis Ins it a, from its being an
inherent, independent, and permanent property of
the living fibre, was in a great measure unknown
to preceding physiologists. Boerhaave acknow-
ledged an active power in the heart, and a latent
principle of motion in the parts of it when divided;
but, nevertheless, he attributed this to the nerves,
though the communication with the brain had been
entirely cut off. The celebrated Dr. Whytt, of
Edinburgli, followed nearly the same path, with
only some difference in point of expression. About
the middle of the century now under consideration,
this physician was engaged in a controversy with
Ilaller on this subject. Whytt coiitended that all
the phenomena of irritability might be referred to
nervous influence, and rejected his antagonist's prin-
ciple of muscular action, as founded in errour, and
Tumecessary to explain the phenomena. On the con-
trary, to this Vis Nervosa of Whytt, though main-
tained with all the aid of ingenuity and learning, I lal-
ler, with much greater force and conclusiveness of
reasoning, persisted in opposing his doctrine of Vis

Sect. II.] Physiology. 283

Insita, as a primary, essential, and inherent quality
of the hving fibre, dependent on its original struc-
ture and organisation, and entirely independent of
the nerves. Not many years ago, professor Monro,
of Edinburgh, in his Observations on the Sh'iic-
ture and Functions of the Nervous System , renewed
the attempt, though it is conceived without suc-
cess, to invalidate the doctrine of Haller.

In pursuance of this interesting doctrine, Mailer
contemplates the living body under a fourfold di-
vision, into parts, 1. Irritable; 2. Inirritablc; 3.
Sensible; 4. Insensible. Among irritable parts he
ranks the heart, the muscles generally, the dia-
phragm, the oesophagus, the stomach, the intestines,
the gall-duct, the arteries, the absorbents, and the
bladder. Among inirritable parts he reckons the
lungs, the liver, the kidneys, the spleen, and the
nerves. Among sensible parts he enumerates the
brain, the spinal marrow, the nerves, the skin,
the internal membranes of the stomach, intestines,
and bladder, the ureters, the muscular flesli, and
the breasts. Among insensible parts he considers
the dura mater, the pia mater, the periosteum, the
peritongeum, the pleura, the pericardium, the omen-
tum, the cellular texture, the cuticle, the rete mu-
cosum, the fat, the tendons, the capsules and liga-
ments of the joints, the bones, the marrow, the
teeth, and the gums.

From this account, given by Haller, of the va-
rious parts which are united to form an animal
system, it results that the irritable and sensible por-
tions are comparatively iew and small ; that the
great mass of the body consists of inirritable and
insensible parts, which serve to combine, envelope.

584 Medicine. [Chap. YV.

and defend the former, and tlicreby to constitute
a moving perfect whole, adapted to assmne the ac-
tions of life, and to sustain the impression of sur-
rounding objects.

In this arduous inquirj'jVvhicli so long engaged
the mind of Haller, and w hich led to so many in-
teresting results, he was not condemned to the ne-
cessity bi labouring alone. The example of the
preceptor inspired many of his pupils with the same
spirit of exertion and enterprise. Zinn, Zim.mer-
man, Caldani, and several others, animated by a
liberal emulation, laboured with indefatigable di-
ligence to extend and improve the discoveries of
their illustrious master. Thus, by the combined
exertions of the teacher and his students, was the
philosophy of animal life more deeply investigated
than ever before, and eventually placed on a basis
almost entirely new.

The effects of Haller^s doctrine of irritahiliti) in
improving physiological and medical principles must
be obvious to the most superficial observer. It
will not be thought extravagant to say that he
seems to have laid the true foundation of the sci^
ence of medicine, if indeed such a foundation can
be said to be yet laid. From Haller, more than
from any single writer. Dr. Brown, and other mo-
dern sj^stematic reformers, who have done most to
improve medical principles, seem to have borrowed
the torch b}- which they were enabled to direct
their progress, and to explore the obscurities of
their route.

But notwithstanding Ilaller's felicity in accom-
phshing so much to aid the |)rogress of physiology,
he did not live to witness two of the most signal

Sect. II.] Plwsiologi). 585

improvements in tliat science which the eighteentfi
oentnry can boast. lie died in the year 1777, .just
about the time when a new and unexpected light
began to l)e shed upon the functions of respiration
and digestion.

The oflicc of the Luugs^'\\\\\c\\ is now of all the
animal functions tlie best understood and the most
susceptible of scientific illustration, was unknown
to Haller. lie supposed that the principal ob-
ject of respiration was to form the voice. That
such a man, possessed of all the knowledge of pre-
ceding and contemporary physiologists on this sub-
ject, should have acquiesced in this conchision, is
indeed matter of surprise ; but at the same time it
serves to fix tlie source, and to enhance the value
of this great discovery.

To modern cliemistry the praise of unfolding the
mystery of respiration is certainly due. The esta-
blishment of this truth alone is almost sufficient to
subvert the old and to erect a new system of phy-
siology. And if no other benefit than this had
arisen from all the brilliant discoveries which che-
mistry offers to the world, it would have sufficed
to rescue that science from neglect, and to assign
it an elevated rank among the objects of human
knowledge.

It is offen asserted, that much of the true office
of the lungs was known to the physiologists of tlie
seventeenth century. Even from much more an-
cient writers expressions sometimes escape which
show a tendency to just views of the sul)jt^ct; as, for
example, when air received in respiration is sup-
posed to 7)SiQX(ii\\Q pabulum 'dUy spiritus alimejitum,

28^ Medicine. [Cha?. IV.

&:c. But in the century just mentioned a much
nearer approximation to the truth was undoubtedly
made. Verheyen observed that those animals which
respire most have the warmest blood*. Lower de-
monstrated that the blood receives a new and a
brighter colour in passing through the lungs f,
Verheyen and Borelli both proved that the air lost
something by coming into contact with that organ J.
And the former remarked that this something is ab-
sorbed by the lungs; and is probably that which
maintams combustion, which qualifies the air to sup-
port animal life, and imparts to the blood the ver-
milion colour §. Towards the latter part of the
same century Dr. Hook and Dr. Mayow published
opinions concerning respiration, which approach
more nearly to the doctrine now generally received
than could be readily believed, if their writings
themselves did not bear witness. The former seems
to have been obscurely acquainted with oxygen and
its absorption in breathing. The latter, according
to the opinion of Dr. Beddocs||, '^ was acquainted
with the composition of tlie atmosphere, and per-
ceived the action of vital air in almost all the wide
extent of its influence. He carried on his investi-
gation of respiration from the diminution of the
air by the breathing of animals, to tho change it
produces in the blood during its passage through
the lungs. The office of the lungs, says Dr.Mayow,
is to separate from the air, and convey to tl\e blood
one of its constituent parts."

* Tract. Be u.su Rapiralionis. f Jh'nJ. X Ibid. § Ibid,
jj See i)r. Beddoes's Anali/sis of Dr. Aiuyow's Work,

Sect. II.] Physiulogy. 287

It is astonishing tliat sucli suggestions should
have been so littlo known and so little attended to
hy succeeding physiologists, Tliey seem to have
attracted but sHght regard at the time of their pu]>-
lication, and very soon afterwards to have been
completely forgotten. But after all it must be
admitted, that the superior light of modern disco-
veries, reflected on organs of eager discernment, is
alone sufficient to enable the reader of these anti-
quated writings to perceive, in the few truths they
contain, blended and buried under so much obscu-
rity, mistake, and errour, the true principles of re-
spiration.

There cannot be stronger proof of the fact, that
these obscure hints of the real use of respiration
were unknown or forgotten by succeeding physio-
logists, than may be found in the works of Ilal-
ler and Dr. AViiliam Hunter. The opinion of the
former of those great physiologists, concerning the
subserviency of respiration chiefly to the formation
of the voice has been already mentioned. Tlie
latter, in his introductory lecture, published in
1784, expresses himself as follows: — " licspiration
we cannot explain; VvC only know that it is in
fact essential and necessary to life.' Notwith-
standing this, wdien vrc see all the other parts of
the body, and their functions so well accounted fur,
we cannot doubt but that respiration will be so
likewise. And if ei'cr we should be iiappy enough
to fnid out clearly the object of this function, we
sliall, doubtless, as clearly see, that this organ is as
wisely contrived for an important oflice, as we now
see the purpose and importance of tlie heart and
vascular system; which, till the circulation of

iSS Medicine, [Chap. IV.

th.e blood was discovered, was wholly concealed
from us."

It will scarcely be necessary to add to what is
ah'cady stated concerning Hook and Mayow, that
Mr. Boyle and Dr. Hales were much engaged on
the same subject, and that the latter particularly
w^as greatly useful by his experiments and re
searches in pneumatic philosophy, which paved the
way for the brilliant uuprovements of his successors
in that inquiry.

The splendid progress of pneumatic chemistry
which ennobles the last twenty-six years of the
eighteenth century, has been detailed in another
place. The discovery of oxygen, and the analysis
of the atmosphere, are prominent points in that
progress ; and they likewise constitute the basis of
the principles which were afterwards so successfully
applied to explain the nature and objects of the
function of respiration.

It is universally known, that the merit of taking
the lead in the application of the principles of
pneumatic chemistry to explain the function of the
lungs is due to Dr. Priestley*. h\ the year 1774
he discovered the existence, and many of the pro-
perties, of oxiigen. JMr. Scheele made the same
discovery nearly at tlie same time. Not long after-
wards these two pliilosophers demonstrated that
the quant itj^ of oxygenous gas is diminished in
respiration. ]n 177^) Lavoisier proved that atmo-
spheric air is compounded of oxygen and azote,

* For a considerable portion of the fads detailed in several of
the following paragraphs on the subject at' respiration, the author
is indebted to a very respectable work, entitled A Si/.stem of Che-
m^iiry, by 'i'honias Thonj^un, M. D. 4 vols, i5\o, 1802.

Sect. II.] Physiology. 289

brought by means of caloric to the state of elastic
fluids. In the following year that eminent philo-
sopher discovered that a quantity of carbonic acid
gas is found in air after it has been respired for
some time, which did not previously exist in it.
Some time afterwards he found, by a variety of ex-
periments, that no animal can live in air totally
deprived of oxygen. This fact was soon confirmed
and extended by the experiments of many other
philosophers, who proved that even fishes, which
do not perceptibly respire, and frogs, which can
suspend their respiration at pleasure, speedily die
if the water in which they are placed become
destitute of oxygenous gas*.

By a further prosecution of observations and
experiments on this subject, it was not long after-
ivards satisfactorily establislicd, that certain re-
markable changes are produced by respiration not
only upon the air respired, but likewise upon the
blood exposed to this air. The most noted changes
observed to take place, in the air itself subjected to
respiration, are the following :— a part of the air
respired entirely disappears ; the rest becomes im-
pregnated with carbonic acid, and is loaded with
Water in the state of vapour. For the knowledge
of these changes effected in the air respired, and for
the numerous and laborious experiments from which
these conclusions were inferred, the world is chiclly
indebted to Priestley, Cigna, Lavoisier, MenzitSj
Seguin, and Davy.

Changes no less remarkable are found to be
produced in the blood exposed to the air in the

* Carradori^ Ann. dc Chim. xxi\, i;i.
Vol. I. U

1290 Medicine. [Chap, IV.

lungs. The principal of these are as follow : the
blood absorbs air ; it acquires a florid red colour,
and the chyle mixed with it undergoes such altera-
tion as to lose its colour and disappear; it emits
carbonic acid, and perhaps carbon itself; ar^d it
emits water, and perhaps hydrogen. The writers
who have principally signalised themselves in tra-
cing and making known these changes in the blood,
are Priestley, Cigna^ Fourcroy, Hassenfratz, Bed-
does, Watt, and, very lately, Mr. Davy.

The tiieories of this function, as deduced from
facts successively discovered^ have varied according
to the number of such facts, and the impressions
which they made on different minds. Dr. Priest-
ley, the first of the modern chemical philosophers,
as was before remarked, who attempted to investt-
gate the use of respiration, seems to have consider-
ed it, from some of his earliest experiments, chiefly
as an excretory process. He believed that the
blood, in passing through the lungs, gives out
phlogislon to the air, which, when expired, he' sup-
posed to be loaded with that substance, and, con-
sequently, that the main purpose of respiration is
to discharge phlogiston from the blood.

Soon after these conclusions had been formed
by Dr. Priestley, M. Lavoisier directed his efforts
to ascertain, with as much precision as possible,
the changes which the air undergoes in the process
of respiration. In order to explain this function
he framed a theory, which assumed, as its basis,
that all the changes produced on the air inspired
are produced in the lungs; and, of consequence,
that all the new compounds and substances detect-
<='d in the air expired, are formed in the lungs. It

Sect. II.] Physiology. 291

was a principle of this theory, that the blood ab-
^sorbs no air in the lungs; but that it di.sciiarges
hydrogen and carbon, which, combining with the
oxygen of the air inspired, form water and carl)onic
acid. This theory was adopted by la Place, Craw-
ford, Gren, and Girtanner, with some small modi-
fications, which it is unnecessary here to particu-
larise. Upon close inspection, it appears that this
theory of Lavoisier does not materially dilfer from
the original hypothesis of Dr. Priestley, viz. that
the object of respiration is to free the blood of
phlogiston. The diilerence consists chiefly in terms
and in detail. For if carbon and hydrogen be sub-
stituted for phlogiston, which is often necessary in
reconciling the statement of facts delivered by the
phlogistians and antiphlogistians, the two theories
will be found entirely to agree. M. Lavoisier did
little to establish his theory by proof. He only
attempted to prove that the amount of oxygen
absorbed in respiration exactly corresponds with
the quantity of it contained in the carbonic acid
and the w^ater emitted. But as this coincidence of
quantities cannot be proved, his theory is unsup-
ported, so far as the establishment of it depends
upon such coincidence.

Afterwards, when a greater number of facts and
illustrations of this sulject had been collected, a
different theory was offered by la Grange. Ac-
cording to him, the oxygen which disappears in
respiration combines with the blood in its passage
through the lungs, and at the moment of this com-
bination there is set loose from the blood a quan-
tity of carbonic acid gas and water in the form of
vapour, which are thrown out with the air es-

U2

ggl^ Medicine. [Chap. IV,

pired. This theory was adopted and illustrated
by M. Hasserifratz, who succeeded in proving
its superiority to that of Lavoisier and his associ-
ates. Tlie establishment of this theory depended
upon proving that the oxygenous portion of the
atmosphere alone is absorbed from the inspired air.
This was indeed the generally received opinion of
chemical philosophers for some time ; but as it has
lately been brought into question, and the contrary
asserted, it is proper to notice the variation of
theory which has thence been attempted to be
made.

Mr. Davy h^s endeavoured to prove that azote,
as well as oxygen, is partly absorbed by the lungs
in respiration. As the azote which disappears in
breathing is not to be found in the products of
respiration, it has been thence concluded that it
is absorbed by the blood. The experiments of
Mr. Davy led him to believe that atmospheric air
is absorbed by the blood in an undecomposed and
unaltered state ; that it is afterwards decomposed
in that fluid by the afhnity of the red particles for
its oxygen ; tliat the greater part of the aaote is
liberated without undergoing any change, and
again given out and mixed with the air in expira-
tion; but that a minute portion of it remains con-
densed in tlje serum and coagulable lymph, and
passes with them to the left ventricle of the heart.
A miimte examination and decision as to the cor-
rectness of these facts> will not be attempted in this
place. But admitting the facts to be justly stated,
the following changes will appear to be produced
by respiration. The blood in passing througli the
lungs absorbs a portion of air, and carries it along

Sect. II.] Physiology, 293

with it through the hlood vessels. In tlie course
of the circulation, this air is gradiinlly decomposed
by the blood, the oxygen and part of the azote
entering into new combinations, while at the same
time a portion of azote, of ear])onie acid and water,
15 evolved. On returning to the lungs, the blood
receives a fresh quantity of air, and at the same
time discharges the azotic gas, carbon ie acid gas,
and watery vapour which had been formed during
the circulation. This theory of respiration by Mr.
Davy is believed to be the latest of those deserving
especial notice which belong to the eighteenth
century*.

Beside the general theories of respiration wliich
have been just stated, it will be proper to mention
a few of the leading discoveries on this suljjeet,
and the authors to whom they respectively belong.

It was not till Dr. Priestley had discovered that
venous blood acquires a scarlet colour when brought
into contact with oxygen gas, and arterial blood a
purplish red colour when put in contaet \\\i\\ hy-
drogen gas ; or, in other words, that oxygen gas
instantly gives venous blood the colour of arterial,
and that hydrogen, on the contrary, gives arterial
blood the colour of venous 3 — it was not till the
accomplishment of this discovery that philosophers
began to attempt any explanation of the pheno-
mena of respiration.

To Dr. Priestley likewise belongs the merit of
that instructive experiment of enclosing blood in a
bladder, and exhibiting the passage of oxygen

* Researches Chcmk'al and Thilosophiail by Miiirpliry Davy,
6vo^ 1800^ p. 477^ c\-c.

294 Medicine. [Chap. IV.

through its moistened coats, by the florid colour
thence imparted to the blood, in order to demon- ^
strate the mode m which oxygen fmds its way
through the coats of the blood-vessels in the lungs.

Dr. Goodwin was the author of the celebrated
experiment, in which the action of the lungs is ex-
hibited by opening the chest of a living dog, and
exposing to view the motion of the lungs and heart*
In this experiment, the blood driven from the right
ventricle of the heart into the pulmonary artery
appears of a dark venous complexion ; but on its
return from the lungs, by the pulmonary veins, it is
changed to a bright vemiilion colour. He also de-
monstrated that the bright florid appearance of the
blood, derived from oxygen received in the lungs,
is absolutely necessary to enable it to stimulate
the left ventricle of the heart, in order to produce
the contraction which propels the blood into the
aorta. For whenever an intermission in the mo-
tion of the lungs denied the access of air, the blood
in the pulmonary veins returning to the heart was
of a dark purple colour, and was no longer sufli-
cient to excite the due contraction of that organ.

That respiration is the source of the temperature
of animals, or of what is commonly called animal
heat, is one of the results of the light recently
thrown on that function. Physiologists long ago
observed that animals which do not breathe have
a temperature little higher than the medium in
which they live. This is the case with flshes and
many insects. Man, quadrupeds, and birds, on
the contrary, have a temperature considerably
higher than the ordinary states of the atmosphere.
It may hv i)rovcd f hat the heat of all animals is pro-

.": ^cT. 11. J Ph/ysioLogy. 295

portional to the quantity of air tliey breathe in a
given time. These circumstances are suliicient to
establish the flicl, that the heat of animals rlcpunds
upon respiration. On tliis subject the phiJosophi-
cal world are under strong obligations to Dr. Black,
whose doctrine of latait heat offered the first hints
towards an explanation of the cause of tempera-
ture in breathing animals. It was observed, in a
preceding chapter, that the discoveries of this emi-
nent chemist place him in a liigh rank, and consti-
tute much of the foundation of that chemical phi-
losophy which is the boast of modern times, and
the source of numberless improvements in the arts
and sciences. He early perceived the light which
his doctrine of latent heat was calculated to shed on
the temperature of animals, and with great sagacity
availed himself of the advantage.

Dr. Black formed the following theory of animal
heat. He supposed part of the latent heat of the
air received into the lungs to become sensible ;
that the temperature of that organ and of the blood
passing through it is consequently raised ; and that
the blood thus heated communicates its tempera-
ture to the whole body. This opinion was plausi-
ble, but by no means free from objections; for, ad-
mitting the truth of it, the heat of the body ought
to be highest in the lungs, and thence gradually to
abate in proceeding to the extremities ; which is
not the fact. The author's attempts to support
this theory were so feeble as to induce the belief
that he himself considered it as untenable.

Lavoisier first announced, in 1777> that animal
heat was owing to tlie caloric disengaged from
oxygen gas during its decomposition and conden-

296 Medicine. [CfiAP. IV.

sation in the lungs. Dr. Crawford, in 1779^
adopted this opinion, and supported it by experi-
ments. They both believed that all the changes
produced by respiration are performed in the lungs j
and their theory differs but little in reality from
that of Dr. Black. They supposed the oxygen
gas of the atmosphere to combine in the lungs
with the hydrogen and carbon emitted by the
blood ; that, during this combination, the oxygen
gas sets free; a great quantity of caloric; and that
this caloric is not only sufficient to maintain the
temperature of the body, but also to carry off the
new formed water in the state of vapour, as well as
the carbonic^^cid, and to raise considerably the
temperature of the air expired. According to the
opinion, therefore, of these philosophers, the whole
of the caloric which supports the heat of the body
is extricated in the lungs. But on this hypothesis
the question will arise, how it happens that the
heat of each individual is maintained nearly the
same in every part of his body.^ To explain this.
Dr. Crawford endeavoured to prove, by well de-
vised experiments, that the capacities for contain-
ing caloric in arterial and venous blood are nearly
as 11.5 to 10; that is to say, if it require a quan-
tity of caloric, represented by 1 1 .5, to heat a pound
of arterial blood from zero to 30'', it will only re-
quire a quantity as 10 to heat a pound of venous
blood from zero to 30 ^

On these experiments the following conclusions
were formed. Oxj^gen gas is decomposed in the
hings in consequence of the affmity of the carbon
and hydrogen of the blood for oxygen being
greater than that of oxygen for caloric, or of the

^ECT. II.] Physiologjj. 297

carbon and hydrogen for tlie blood. In proportion
as the oxygen unites with tlie hydrogen and car-
bon, water and carbonic acid are formed; the ca-
loric combines with the venous blood, which, in
losing its carbon and hydrogen, becomi^s arterial,
and has its capacity for containing caloric immedi-
ately augmented. The blood, now become arterial,
in its circulation through the body, gradually ab-
sorbs carbon and hydrogen, repasses to the venous
state, and sets ivQQ a portion of caloric in ])ro-
portion as its capacity for containing it is dimi-
nished. According to this doctrine, therefore, the
almost uniform temperature in all parts of the body
is owing to the gradual and successive changes of
arterial blood to venous throughout the body, and
of venous to arterial in the lungs. It is also agree-
able to this doctrine to suppose that the higher
temperature of some parts of the body may be
caused by arterial blood absorbing more carbon
and hydrogen, or, in other words, becoming more
rapidly venous.

However ingenious this explanation deserves to
be regarded, it has not been deemed satisfactory.
The difference in specific caloric, admitting the
calculation to be accurate, is justly thought too
small to account for the great quantity of heat
which must be evolved. And if the opinion of
some be true, that the carbonic acid gas and water
emitted in expiration are not formed in the lungs,
but during the circulation, this doctrine nuist be
altogether untenable.

This defect in Dr. Crawford's hypothesis might
perhaps be remedied, if Mr. Davy's supposition
of air enterimr the blood and combining with it in

298 Medicine. [Chap. i.v\

the state of gas should be admitted. In this case
it is evident that the air at first would only set free
part of its caloric, and that the remainder must
gradually escape in the successive stages of the cir-
culation. In another mode, likewise, that defect
has been attempted to be remedied. It has been
alleged, that the evolution of caloric attends almost
all chemical combinations; that all animal fluids
which pass through capillary vessels and glands, for
the purposes of secretion, are subjected to such new
chemical combinations, as must incessantly give
out heat ; and that this glandular action thu,s ac-
counts for the more general and copious source of
animal temperature.

From the view of respiration now given, it re-
sults that the final causes of that function are these :

1. To complete the assimilation of the blood:

2. To produce and support animal heat : 3. To
impart a quality to the circulating fluid which
enables it to stimulate the left side of the heart.

After this account of respiration, vvliich, from
its great importance in the animal economy, has
been treated of more at large than was at first in-
tended, it is proper to proceed to the consideration
of Digeslion. This function in its full extent in-
cludes all the changes which aliment undergoes for
the formation of chyle, whether such changes are
elFected in the mouth, stomach, or small intes-
tines. But as it is the knowledge of the oflice of
the stomach which has received the most impor-
tant improvement within the period assigned for
this retrospect, and as the other parts of the pro-
cess, such as mastication, deglutition, the admix-
ture of saliva, &c., were tolerably well understood'

Sect. II.] Physiology, 299

before, it is obviously expedient to direct the chief
attention to the former branch of the subject.

Galen supposed heat to be the principal cause
of digestion, and this opinion so generally prevail-
ed for a long time that the term coction was used
by the greater part of physiologists instead of
digestion. But, though the effect of heat in assist-
ing and expediting digestion is universally admit-
ted, no person will now contend that it is the sole
cause.

During the eighteenth century, the theorists of
digestion have ascribed it either, sijigly, to fcr-
mentation^ mechanical action, or the operation of a
solvent in the stomach j or to the combined efl'ects
of two or all of these agents.

Dr. Boerhaave, dissatisfied with the opinions of
all who had gone before him on this subject, and
leaning "strongly to mechanical theory, admitted
fermentation as one cause of digestion, but princi-
pally ascribed to it trituration, pressure, and power-
ful quassation. The analogy of digestion, as per-
formed in certain birds, seems to have led him into
this doctrine. He had observed the ostrich to
swallow pieces of iron and glass, evidently for the
purpose of trituration, because the sound of grind-
ing was perceptible to those who listened. In tiie
^ranivorous birds he had noticed, in addition to
the crop furnished with salivary glands to macerate
and soften their food, a gizzard, or second sto-
mach, provided with strong muscles to triturate
the grain, and the eagerness with which they swal-
low gravel to assist the operation. Considering the
predominance of mathematical doctrines at thai
period, it is not wonderful that this great mechanic

300 Medicine, [Chap. IV,

ill medical science was desirous to explain diges-
tion on mechanical principles.

Early in the eighteenth century Mr. Cheselden
appears to have imbibed some correct notions on
this subject. He remarked, that in serpents, some
birds, and several kinds of fishes, digestion seemed
to l"3 performed by some unknown menstruum ; as
he frequently found in their stomachs animals so
totally digested, before their form was destroi/ed,
that their very bo7ies were rendered soft.

About the same time M. Reaumur instituted
a set of experiments concerning this function ;
and, by a number of clear and decisive facts, ex-
hibited in his excellent memoirs on this subject,
proved the existence and agency of a solvent in
the stomach.

About the year 1777> the abbe Spallanzani,
professor of natural history in the university of
Pavia*, began, by his numerous experiments and
diversified inquiries, to throw new light upon the
function of digestion. Having directed his inqui-
ries to a great number of animals, man, quadru-
peds, birds, fishes, and amphibia, he was led to
divide an extensive variety of stomachs, differing
from one another in many important points of
structure and functions, into three classes, the
muscular, inter mediate y and membraiious f.

* The abbe Lazarus Spallanzani,of Italy, was bom in the year
1729, and died in 1800. His researches and publications in seve-
ral branches of natural history, especially in animal and vegetable
physiology, place him among the most distinguished men of his
age. On the subject of Bigcslion, he is, perhaps, the highest
authority.

t Dissertations relative to the Natural JJiitojy of Ammah and
Vtgetabk's, vol. i.

Sect. II.] Physiologj/, 301

Among such as have muscular stomachs, he par-
ticularly examined common fowls, turkeys, ducks,
geese, pigeons, &c. In these, that organ is pro-
vided with very large and powerful muscles, ca})a-
ble of grinding down to powder the grains and
other aliment which they receive. 1 ie proved by
his experiments, that such muscular stomachs can
pulverise pieces of glass, and abrade and smooth
the rugged edges of the hardest su])stanees, even
of granite, without any injury to the animal. He
resorted to experiments to illustrate the force of
trituration in these stomachs, which a person of less
ardour in this kind of investigation, and more ten-
derness for the animal creation, would certainly
have spared. He caused a leaden ball, beset with
needles fixed in it, with the points outwards, to
be forced do\^Ti the throat of a turkey. He con-
trived to make another swallow a ball of a still
more formidable construction 5 for it was aniied
with small lancets, sharp at the points and edges,
instead of needles : both balls were covered with
paper to prevent the throat of the animal from
being hurt as they descended, but fixed so loosely
as to fall off in the stomach. The consequences
proved the force and ruggedness of these muscular
stomachs ; the needles and lancets were broken to
pieces and voided without wounding or injuring
the animal.

But notwithstanding such proofs of the strength
and activity of this kind of stomach, he ascer-
tained that the solvent po\^ ers of a gastric lupior
are combined even in these animals with the ope-
ration of gastric muscles to etVect the process of

302 ' Medicine, [Chap. IV.

digestion, and that they mutually assist each
other.

Spallanzani's next experiments were directed
to animals possessing what he called intermediate
stomachs ; such as are endowed with muscles less
thick and strong than the former, but more so
than the membranous stomachs. Among these he
examined and made experiments upon the raven,
the crow, the heron, and many other birds, which
have this intermediate structure of the organ in
question. It was found in these birds, as might
be expected, that digestion is performed by a more
equal combination, than in the former cases, of the
forces of muscular action and a gastric menstruum
secreted for the purpose.

These interesting experiments on digestion were
finished with those animals which have thin mem^
braneus stomachs. This class comprehends an im*-
mense number of species, as man, quadrupeds,^
fishes, reptiles, &p. No triturating power is pos-
sessed by the stomachs of this description ; for their
muscular fibres seem to exert little other effect
than that of propelling their contents through the
pylorus. In proof of this is alleged the well known
fact, that cherries and grapes are often received and
voided entire from the human alimentary canal.
The solvent power of the gastric liquor in these
animals was found almost solely to effect the dis-
solution of food, after the preparatory treatment
of mastication, and the admixture of saliva. To
prove the efficacy of this powerful agent in the
process of digestion, Spallanzani enclosed different
kindii of animal and vegetable food in linen bags.

Sect. II.] Physiology. 305

and in wooden tubes, perforated in such a manner
as to admit the entrance of the gastric juice ; these
he swallowed ]iimself,and, after a short interval, the
contents of them were found to he dissolved and
discharged. He satisfied himself that no tritura-
tion could take place by employing tubes so thin
and weak that the slightest pressure would have
crushed them to pieces; yet not one was ever
broken, nor could he ever perceive the snuillest de-
pression or fissure. Of the active solvent ]>o\vers
of this gastric fluid he gives many remarkable
proofs. In a dog it not only dissolved bones, but
was found to corrode the enamel of two dcntcs in-
cisor es taken from the jaw of a sheep. And, from
some experiments on himself, he observed it to be
sufficiently powerful to digest not only muscular
fibres and meml>ranes, but tendon, cartilage, and
even bone itself, when not of the hardest kind.

The conclusions arising from these experiments
of the professor of Pavia were, about the same time,
confirmed aiKl illustrated by others equally inge-
nious and interesting, undertaken by Dr. Edward
Stevens*. He prevailed on a person to swallow
little hollow spheres of silver, filled with food of
different kinds ; the sides of the spheres being per-
forated in various places, the gastric juice had ac-
cess to, and, of course, could act upon their con-
tents; and when voided, the food within them was
found to be dissolved, either partially or entirely,
according to the nature of it, and the time allowed
for its remaining in the stomach.

*-See his Inmigural Dissertation. publi.sl:^'d at Kdiiiburgh, m
the yeai' 1777-

504 Medicine. [Chap. IV^.

1 he celebrated Mr. John Hunter is to be always
enumerated among those who have improved our
knowledge on the subject of digestion. In addi-
tion to many other improvements, he endeavoured
to solve the question, how the stomach itself can
remain unhurt, while it encloses so penetrating
and active a solvent as the gastric juice, seeing
that it consists of materials similar to a large pro-
portion of our food ? He ascribes to the living
principle in animals the power which the stomach
possesses to resist that action of its gastric fluid
which penetrates and dissolves the aliment. In
confirmation of this, he observes that intestinal
worms can remain a considerable time unhurt in
the stomach, while they retain the principle of life ;
but as soon as they lose this, they are dissolved and
digested, like other substances. In like manner
he asserts, that while the stomach itself retains this
living principle, the gastric fluid cannot exert its
solvent powers on it; but when the person dies,
particularly in cases of violent and s]adden death,
that fluid immediately begins to corrode it, and
sometimes is found to have made its way entirely
througli the coats of the stomach into the cavity of
the abdomen*.

It seems therefore to result, from all the most
successful inquiries concerning digestion made
during the eighteenth century, that this function
is variously perlbrmed by mechanical action, or
chemical solution in different animals, according to
the structure of the stomach, and the nature of the
gastric secretion; and that in man, and many

* riiil. Trans, vol. Ixii, p. 44;.

Sect. II.] Physhlogi/. 305

other tribes of animals which possess asimiiar orga-
nization of this viscus, it is cilbcted by the solvent
operation of the gastric fhiid independently of tri-
turation.

Beside the points in physiology already noticed,
many others might be mentioned which have un-
doubtedly received much elucidation and improve-
Jiient in tlie course of tiie late century. The senses
of Vision and Hearing, which had previously de-
rived a great deal of light from the endeavours used
to investigate them, have been examined with still
more minuteness and success within the last hun-
dred years, and many new facts and princii>Ies con-
cerning them have been satisfactorily ascertained.
But the doctrines of Secretion and Nutrition, thouirh
so fundamental in a thorough acquaintance with
the animal economy, notwitlistanding all the dili-
gence and ingenuity bestowed on them by a mul-
titude of physiologists, have not been cultivated
with equal success, and indeed can scarcely be
said to be better understood at ' this time than
they were at the close of the seventeenth cen-
tury.

The celebrated doctrine of the vitalitj/ of the
blood, which Avas first distinctly taught in modern
times by Harvey, found a new and able advocate
in Mr. John Hunter, who maintained, in his lec-
tures, that the fluids as well as the solids were pos-
sessed of the principle of life. The arguments by
which he endeavoured to support this doctrine are
not only ingenious and forcible in themselves, but
they derive additional strength from the theory of
respiration, and the principles ol' pncunuitic che-
mistry, which are now generally received.
Vol. I. X "

306 Med feme. [CuatAV.

Within the period assigned to this retrospect,
the functions and laws of the Nervous System have
been investigated with the greatest zeal. Wilhs,
in tlie seventeenth century, had laid the foundation
of this improvement, by his accurate description
of the brain and nen^s. Vieussens, in his Neuro-
graphiay pursued the subject with much discern-
ment. Early in the eighteenth century Hoffmann
still further prosecuted this inquiry; and, at a
more advanced period of it. Dr. Cullen exerted
all his powers in the same course. The use made
by the two latter of the knowledge gained on this
subject, in constructing their medical theories, will
be mentioned more particularly uhder the succeed-
ing head.

Coinparative physiology has been cultivated with
j^reat ardour and success in the course of the cen-
tury now under contemplation. Haller, though
chiefly devoted to human physiology, did. not neg-
lect the instruction which may be derived from a
comparative view of the functions of man and
other animals. The Hunters, the Monroes, and
most of the other distinguished anatomists of thfe
late century^ laboured in this field with the utmost
zeal and assiduity. The great anatomical work
planned by Vicq-d'-Azyr, that was mentioned
\mder the preceding head, was principally designed
to deduce a body of physiological principles, which,
by comparison, might illustrate the functions of
the whole animal kingdom. The numerous com-
parative inquiries concerning animals of warm and
cold blood, and those which, in respect of the
fuiK'tion of generation, are distinguished into vi-
Tiparous and oviparous, liave already thrown much

Sect. II.] Physiologi), . ' S07

new and important light on this branch of knowledge,
and opened a train of investigation which here-
after will probably lead to still more interesting re-
sults. Mr. Blunienbach of Goettingen, whose phy-
siological labours deserve very high praise, has
greatly distinguished himself by his Specunen Phy-
siologitf t'oviparattc inter Animantia calidi Sangui-
nis Fivipara el Ovipa7'a*. The recent work of M
Cnvier, on comparative anatomy, furnishes an abun-
dance of the materials requisite for the extension
and the improvement of this part of science.

Within a few years the irritability of vegetable;?
has attracted much of the attention of physiologists;
and the interesting facts which it offers have been
naturally cojnbined with the great body of corre-
sponding facts presented b}^ the animal kingdom.
Such general views penetrate deeply into the eco-
nomy of nature; and the light they afford may be
clearly discerned in an estimate of the progress and
present state of medical opinions. To the account
before given of the labours of Haller, in the former
part of the century, to ascertain the fundamental
laws of the animal economy, it would be improper
not to add those lately undertaken for the same pur-
pose by the abbe Fontana. By a series of experi-
ments, in v/hicli accuracy and industry are eminently
conspicuous, the abbe has proved, beyond the pos-
sibihty of doubt, the existence of a principle in the
animal fibre, independent of nervous i:nergy, from
which result, on the application of certain exciting
powers, the various actions suited to the support of
animal life. This principle, which with Haller h<?

•'•^ ViJe Comment. Soc. PiOr. SlUth. Gotting. \^A. ix.

508 Medicine. [Chap. IV^

denominates irritability, has been since proved by
ii great variety of facts to be susceptible of two re-
markable changes in the living fibre, viz. increase
and diminution, depending upon the abstraction
or accumulation of stimulant powers. In support
of this general principle, which is supposed univer-
sally to belong to animated nature, the aid of many
facts, derived from the vegetable kingdom, has beeii
recently added. As the functions of the animal
economj', viz. sensation and voluntary motion, to
which I lie nerves seem alone to be necessary, are*
never satisfactorily observed in the vegetable king-
dom, it is presumed that the absence of nerves in this
kingdom can in no degree diminish the analogy
which is attempted to be established between these
two grand divisions of created nature. It is con-
tended by these physiologists, that there is a prin-
ciple of action common to both kingdoms, upon
which their respective functions chietly depend, and
which is believed to be governed by the same laws
as are laid down for the regulation of the irritability
of the animal fibre. By the term irritability, nothing
more is here meant than merely to express -a act ;
which fact is this, that certain parts of animals and
vegetables are possessed of a propertv', by which,
upon the application of a stimulus, the ends of a
straio-ht fibre approach nearer to each other, and
the diameter or area of a curved or circular one is
diniini.siicd.

For the facts respecting the functions of vegeta-
bles from which tiie above-mentioned principles
have been drawn, the world is indebted, among
many others, to Males, Grew, Duhamel, Bonnet,
J^ufton, Spallanzaui, des Fontaines, Gmelin, Ingen-

Sect. II.] Plnpiologt/. 509

hoiisz, Hunter, Broussoncl, Danvin, and man v of
tJie most distinguished disciples of the Lmn.can
school. And when the progress made by tliem in
vegetable physiology is considered in relation to the
discoveries obtaincvi by Haller and Fontuna in ani-
mal phj'siology, it will not appear surprising tliat
inferences and doctrines of the greatest interest
have recently been thence dedueeiJ. Tlie physio-
logical principles of Brown and Darwin, which now
occupy the attention of so large a portion of the
medical world, are conclusions resulting from that
great body of facts. But of these more particular
notice will be taken imder the next head.

Theories oiGenercuion have engaged mucli atten-
tion during the last century. Towards the close
of the preceding one^ Leuwenhoeck attracted notice
])V Jiis microscopical inquiries concerning the scmc?i
7nascuUnu7nj in which he believed that he saw nu-
merous animalcula, one of which was destined to
form the rudiments of the future embryo. I'liis
»su])posed discovery gave rise to a theory not yi:t
altogether exploded, according to whicli tJie womb
of the female only allbrds to the embryo a lodging,
iindthe requisite suppli-es of nourishment.

M. BuiTon endeavoured to prove that the female
holds n more important share in the process of
generation. He asserts that animalcula, or organic
particles, are to bo found in the semen of both sexes j
and he derives that of the female from the o\aria,
dcnving, at the same time, that any ovum exists'in
thooe parts. But in this he is connnonly suppctocJ
to he mistaken.

The opinion more generally adopted within a few
years is, that an impregnation of the o\um by (he

^10 Medicinf^\ [Chap. IV-

influence of the semen masculinum is essential ta
conception. The abbe Spallanzani has thrown
much light on this obscure subject; he labours to
prove, by a variety of experiments, that the animaK
cule exists entire in the female ovum, and that the
male semen is only necessary to vivify and put it hi
motion.

This part of physiology furnishes one among nu-
merous instances, in vi^hich modern improvements
in science serve to support and confirm religious
faith. It was mentioned, in the last chapter, that
toward the close of the seventeenth century, the
doctrine of equivocal generation began to be dis-r
carded by the ablest physiologists; still, however,
it continued to find some advocates long after the
beginning of the eighteenth. The atheistical ten-
dency of this doctrine is obvious; for, if a- single ani-
mal could be produced in this manner, what should
prevent the universe from having come into exist-
ence without an intelligent author? Accordingly,
this mode of accounting for the production of
animals was, in general, fondly embraced by those
who wished to exclude God from the creation and
government of the world. But all the experiments
and discoveries which were made on the subject of
generation, in the course of the century under review,
have served to discredit this doctrine ; so that it is
now considered, by the most eminent naturahsts, as
exploded. It is true, difficulties, or rather darkness
and doubt, still exist, particularly with respect to
tlie generation of one class of animals; but all mo-
dern experiments seem to concur with analogy in
showing, that the doctrine in question is imphilo-
3ophical and untenable. Indeed it may be assert-

Sect, III.] Theorij and Pradicc of Physic. 311

ed that every siiccesfiive step \n hieh has hccn taken
ill developing the strueture and functions oi' tiic
animal frame, and every new ray of li.i^ht that lias
been shed upon this interesting siil>j(x.'t, in modern
times, liave made more apparent the absurdity of
atheism, and furnished ne^v demonstration of tlic
43xistence and wisdom of the Great First Cause.

SECTION III.

THEORY AXD PKACTICE OF PHYSIC.

At the period of the revival of learning in tlie
fitleenth century the medical system of Galen was
restored, and began generally to prevail. Early in
the sixteenth century the famous Paracelsus laid
the foundation of a chemical system, which attract-
ed much notice, and excited a violent contest with
the followers of Galen. The efficacy of the remedies
employed by Paracelsus and his disciples, and the
bold and confident terms in which their virtues
were extolled, procured, with many, the reception
of his system, and for a long time supported its
popularity and fame. But the regular and syste-
matic physicians still generally maintained the
doctrines of Galen, and, by their superior learning,
were enabled to keep possession of the schools
of physic till the middle of the seventeenth
centur}'.

About this time the discovery of the circulation
of the blood began to be generally recei\eti, which,
together with that of the receptacle of the chyle, and
tl|e thoracic dad, gave a heavy blow to the Galenic

3b2 Medicine. [Chap. IV.

theory. In the destruction of this theory, the
operation of the revohition in philosophy, effected
by lord Bacon, deserves hkewise to be particularly
mentioned. His m(,Hhod of philosophising exhibited
the futility of the numberless hypotheses which are
found in the system of Galen, and excited a dispo-
sition to observe facts and make experiments.

At the beginning of the seventeenth century the
contest bet^\ een the Galenical and chemical physi-
cians was carried on with the utmost animosity and
indecorum. The influence of the writings of Gali-
leo, aided by the discovery of the circulation of the
blood, introduced mathematical reasoning into the
doctrines of medicine. The progress made about
this time in the knoM ledge of the organic structure
of animals, which was greatly facilitated bj an ac-
quaintance with the circulation of the blood, had
extended the application of mechanical philosophy
in order to explain the phenomena of the "animal
economy. The agency of the nerves or moving
])Owers of animals was at that time so little under-
stood, that physicians universally, whether Galenists,
chemists, or mathematicians, considered the state
and condition of the fluids as the cause of diseases,
and the medium of the operation of remedies.
Hence arose the Humoral Pathology^ which then
predominated in every system of opinions, however
diversified in other respects. While the followers
of Galen were daily losing ground from the circum-
stances which have just been stated, the chemists
gained some accession of strength from the doc-
trines of the humoral ])athology. Chemical reason-
ing was readily ado{)ted to explain the various
acrimonies which v, ere supposed to infest the cir-

Sect. III.] Theory and Practice of PJiyslc. 313

dilating mass, and thereby to irive orli^iu to diseases.
On this ground the use of stimulating, eordial, and
sudorific remedies became fasliionable through* uit
Europe in the latter half of the seventeenth centJi-
ly. This doctrine, which exhibits the last glinnncM-
ing of the chemical sect, attained its utmost heiglit,
and was taught and practised with the greatest ap-
plause, hv the celebrated Francis du Bois, more
known by his Latin name of Sylvius, professor of
medicine in the university of Leyden, who conti-
nued for many years the medical oracle of Europe,
and gave an eminent degree of eclat to the semi-
nary to which he belonged. With this physician
acidify formed the principal source of morbid afVee-
tions; and he extended and supported his doctrine
by every analogy that the learning of that period and
the utmost ingenuity could devise. Agents adapt-
ed to correct or expel this acrimony were exalted
into universal remedies, and supplied every inten-
tion of cure.

To .oppose the cardiac and alcxipharmic doc-
trines of the Sylvian school, which often consisted
in doing violence to nature, and could not fail,
when carried to extremes, of increasing the mischiefs
it was intended to remove, required the powers of
a great and original mind. For this purpose the
illustrious Sydenham was eminently suited. The
sagacity of this physician led him, hy an almost
seeming intuition, to discern and obey the dictates
of nature, and to atlbrd every proper assistance
without urging her to useless and liazardous ellbrts.
The effects of this revolution were innnediately seen
in the improved treatment of acute diseasc^s of every
class, when, instead of the fashionable ah^xipharmic

514 Medic inc. [Chap. IV.

remedies, intended to promote imaginary depura-
tions, by additional heat and increased stimulus, a
5"afer antiphlogisiic or cooling plan was adopted,
with a view to unload the oppressed habit, to reduce
excessive action, and to preservp the strength of
the system for the subsequent conflict.

Towards the close of the seventeenth century,
the application of mathematical reasoning to medi-
cal theory had attained its greatest height. Tlie
mathematicians were alike hostile to the Galenists
and chemists. With equal aversion they discarded
the qualities^ elements^ temper aments, concoctionSy
and crises of the Galenist ; and the Arclueus of Van
llelmont, the salts^ the sulphur, the mercury, the
acids, alkalies, effervescences, fermentations, ebulli-*
tionSy and deflagrations of the chemist. Instead of
such objects as these, the mathematical pathologists
endeavoured to direct the public attention to me-
chanical tensioji and relaxation, to true and spurious
plethora, to obstruction and error loci, to excessive
or deficient motion of the fluids, and to their lentor,
tenuity, or dissolution. Flushed with their success
in astronomical inquiries, and with their dominion
over the globe ^^'e inhabit, the mathematicians
confidently imagined they should fmd no difficul-
ty in subjecting the province of medicine to their
extensive empire. The chemists of that day had
little to urge against the claims of these invaders.
Their loose, visionary, and capricious doctrines
(for such was undoubtedly much of the chemistry
of that })eriod) could make no successful opposition
to the axioms, postulates, propositions, lemmas, pro^
blems, theorc/ns, demonstrations, corollaries, and
calculations, Avith which the mathematicians were

Sect. III.] Theory andPradkc of Phi/sic. 315

constantly armed when they entered inio contro-
versy. J3elliiii, of* Florence, as was formerly observ-
ed, was among thfc first medical writers who intro-
duced mechanical reasoning; and soon afterwards
the application of it was extended still liuiher by
profes.sor Borelli, wiio j^rosecnted the subject with
great learning and zeal. The laborious calculations
piade by these mathematicians of th(^ force exerted
by the heart in propelling the blood^, and by the
stomach in the digestion of food, are signal exam-
ples of the delusion which then occupied the luo.st
respectable minds. But no person at this period
seems to have proceeded farther in this course than
the celebrated Dr. Pitcairn, who, during some of
the last years of the seventeenth ceutiuy, held a
medical professorship in the university of Ley den.
He flattered himself that medical principles might
be supported by a clear train of mathematical
reasoning, which would defy the attacks of the so-
phist, and which would be exempt from the fluctu-
ations of opinion and prejudice. His works are
full of postulates, data, and demonstrations. And,
after a long parade of geometrical forms, he supposes
himself to have arrived at the nc plus uLlra of the
science of medicine f.

* BorelU believed that he made it clearly to appear, that the
force of the heart is equal to 180000 pounds weight; while Dr.
Keil's calculation reduces the pofwer of the left ventricle to/r«
ounces.

t Pictairn concludes his chrpler, De divUionc Morborum, thus
triumphantly : " Quapmptcrnon dubito mc .sohisse nohik probkma,
quod est, daU) morbo, invcnrc remvdinm, Jumquc opvs exi'Zi" Vide
Ekmtnta Mcdkimr Physko-Mnt/umntka, p. 177. The annaU of
science can scarcely furnish a more striking example of the delu-
tiion of enthusia'i-m, or the blindness of prejudice.

516 Medicine. [Chap. IV.

^J he mechauic theory of medicine is now so ob-
solete that even the most illiterate aftect to smil^
at the al)siirdities of that kind, which were often
nttered by learned men. But it should be remem-
bered, that, amidst all its extravagance, it was an
important step towards improvement ; and it will
certainly be rescued from contempt by the recol-
lection that it was once honoured with the crreat

o

names of Eorelli, Boerhaave, and Newton.

The Italian and Dutch schools, though hurried into
wild extremes by the rage of mathematical reasoning
which then prevailed, possessed an unrivalled cele-
brity at the end of the seventeenth century. The
history of medicine at that period particularly dwells
on the merits and services of many of their physi-
cians, and abundantly justifies their claim to di-
stinction.

Thus stood the theory of medicine at the be-
ginning of the eighteenth century. At that: auspi-
cious period, every part of science began to assume
a more correct and improved aspect ; and, from the
vasl^ and diversified labours of the preceding age, it
hi^d become more practicable to select and combine
the materials necessary to construct the theories of
medicine which were speedily to ap})ear. Accord-
ingly, xii-vy early in the century three new and
consirlerably different systems were presented to
the ^vorld in the writings of Stahl, Hoffmann, and
lioerliaave. And they are the more worthy of ex-
amination at the present time, as they not only
engrossed the attention of physicians during a great
part of the century, but as even now they are not
T^ithout induence upon principles and practice.
Notuiihstandine^ the seniority of Stahl and llofll

Sect. III. J Theory and Practice of Physic. S 1 7

maim by a few years, they were, as theorists of nie-
ilicine, strictly the contemporaries of Buerhaave.
It is judged expedient to begin with the latter in
this place, not only on account of the great impor-
tance and celebrity of his system, but because lii^
doctrines held a closer -.dliance with the predomi-
nant philosoi)hy of that period, and those of the two
Others with the succeeding theories.

Hermann Boerliaave began his career as a teacher
and a writer about the commencement of the eigh-
teenth century, in all respects he deserves to be
considered as one of the greatest men that ever
adorned the medical profession. He possessed a
vast range of erudition, and had cultivated the aux-
iliary branches ofmedicme with such assiduity, that
be particularly excelled in anatomy, chemistry, and
botany. No physician, since Galen, has so autho-
ritatively swayed the empire of opinion, nor been
more universally obeyed in the schools of ph\ sic.
Endowed by nature with a powerful, logical, and
s^'stematic mind, he seemed to be designed to clear
away the rubbish of errour and prejudice, with which
he foun^ medical learning overgrown ; to collect
knowledge from every source; and to present it to
the world embodied in that clear, consistent, elegant,
and luminous state of arrangement, which consti-
tutes him the parent of medical theory *.

* This great man was bom at a vilhigo n^ar lA^ydcn, in the
year i06S, juid died in 1/38. The sparu whicii hu- tilled in the
seieiititic world, for upwards of forty years, vas so great, that nu
one acqnainted with the history of the period in w liich he lived 'a
jgnorant of his immense learning, his singular talents, or liis nu-
merous and inestimable woik^. His moral and religious character
is as worthv of commenioration as his iuteilettuul endowuwiKs,

318 Medicine.: [Chap. IV.

In framing his system of physic, Boerhaave seems:
diligently to liave studied the writings of both an-
cient and modern physicians, from Hippocrates down
to Sydenham. Though extremely partial to the
mechanical principles of Bellini and Pictairn, he
appears to have endeavoured, as much as possible,
to divest himself of prejudice in favour of former
systems, and to make a candid and genuine selec-
tion of truth from every source. Beside availing^
himself of the experience of Hippocrates, and other
observers of nature in every age, he drew many of
his doctrines fi*om the chemical as Avell as mathe-
matical philosophy of the period in which he lived.

Boerhaave's Institutes, which is his theoretical
work, contain all the discoveries in anatoni}- and
physiology known at that time; and that system
likewise of pathology and therapeutics which he
thought proper to adopt. His Aphorisms, or prac-

** Some, ihoiigl: few," (says his great disciple Haller) ^*'\vill rival
him in erudition 3 his divine temper, kind to all, beneficent to foes
and adversaries, detracting from no man's merits, and binding by
favours his daily opponents, may perhaps never be paralleled." He
was at once a practical philosopher and an eminent Christian. No
one was ever less moved by the attacks of envy and malice j no
one ever bore with more firmness and resignation the evils of life.
Simplicity was the characteristic, of his manners. He was easy and
familiar in his converse ; perfectly free from parade of every kind;
grave imd xu])er in dc meanour, and yet di>.p().sed to pleasantry, and
occasionally indulging in good-humoured raillery. lie was almost
adored by his pupils, whose interests he regarded v/ith the kind-
ness of a parent, and wliom, when sick, he attended preferably tvj>
any other patients. Piety of the most amiable cast was wrought
In tlie very habit of his soul ; the perusal of the scriptures was one
of his habitkial and stated employments 3 and the business of every
day wiis precededby the devotiorial exercises of the closet. — General
Biograpftj/ by John Aikin, J\I. D. -and others, vol, ii.

Sect. III.] Theonj and Practice of Phijsic. 3 1 9

ticdl work, with all their imperfections, contain
perhaps more medical learning than any book ex-
tant of the same size.

The most prominent feature in the Boerhaaviun
system is the attempt to explain the phenomena
of the animal economy, whether in healtli or disease,
upon mechanical principles. Under the impres-
sion of such opinions he considered the body ehirfly
as an hydraulic machine, composed of a conic, elas-
tic, inflected canal, divided into similar less canals,
all proceeding fron the same trunk; which, beinpr at
last collected into a retiform contexture, nuitually
open into each other, and send olV two orders of
vessels, lymphatics and veins, the former terminat-
ing in different cavities, the latter in the heart;
that these tubes are destined for the conveyance of
the animal fluids, in the circulation of which he
<?upposed life to consist, and on the free and undis-
turbed motion of which he judged health to depend.
lie therefore believed obstruction to be the proxi-
mate cause of most diseases; and this obstruction
he supposed to be produced either by a constriction
of the vessels, or by a lentor in the blood.

In Boerhaave's doctrine of obstruct ioUy which is
fundamental in his system, he makes an important
use of Leuwenhoeck's supposed discoveries c:on-
cerning the blood. That, eminent microscopical
investigator had imagined that iio found each glo-
bule of red blood composed of six serous globules,
the serous of six lymphatic globules, the lym-
phatic of six other globules still fnier, and so on m
a similar progression till these particles were dnm-
nished down to the finest and most subtde of all,
namelv, the nervous fluid. According to l^o.r-

3:20 Medicine. [Chap. IV.

haave's opinion, the diameters of the vessels also
decreased in the same regular series, perfectly cor-
responding with the size of the globules. This
explains his frequent introduction of error loci in
his account of obstruction and inflammation. But
as the notions of Leuwenhoeck on this subject are
now generally exploded, so likewise must be the
inferences and doctrines grounded upon them.

It was taken for granted by Boerhaave and by
almost all preceding medical writers, that diseases
always arise either from some depravity of the fluids,
or some fault in the composition or cohesion of the
simple solids; and that wherever such disorders ex-
ist, they are always susceptible of a definite charac-
ter, and placed vrithin the reach of the senses. He
believed the fluids to be liable to contamination by
acid andx alkaline acrimony, and by other morbific
inatters variously constituted, and to be disordered
by lentor and excessive tenuity. The simple solid,
according to his doctrine, is subject to very frequent
chano-es of condition, from weakness and exces-
sive stiffness or elasticity, and from laxity and
rigidity.

Boerhaave supposed the proximate cause of fever
to consist in a lentor or viscidity prevailing in the
mass of blood, and stagnating in the extreme vessels.
To this he attributed the cold stage of fevers, and
all its consequences. It is true that he afterwards
introduced, though with some doubt and hesitation,
as an additional part of the proximate cause, an
inertia of that portion of the nervous fluid which
is destined to the heart. It was one of his positions,
that the morbid heat in fever, being a symptom
only, might therefore be disregarded.

Se'ct. III.] Theory and Practice of Phi/ sic. SHX

His doctrines of acid and allialinc acrimofii/, of
ftnnentation, and of morbific matter in the blood,
were evidently derived from the chemical theories
^vhich then prevailed. And from the mechanical
philosophy he borrowed his opinions concerning the
diseases of the sunple solid; concerning deficient
or excessive circulatory motion; concerning ob-
struction and error loci*; and concerning the laitor
and morbid tenuity of the fluids.

The objections which have been made to this
system are numerous and important. Though it
was exhibited by the illustrious author in a very
attractive and elegant form, and long possessed aa
unrivalled degree of reputation, yet it appears
that time and the great mass of improvements since
made in every department of medical knowledge
have effected its entire overthrow.

The leading defects in the Boerhaavian system
are too close an adherence to the humoral patholo-
gy, and a constant neglect of the moving powers of
the animal body. In his notions of various acrimo-
nies, and of Icntor, he yielded almost entirely to a
hypothetical mode of reasoning. In his considera-
tion of the diseases of the solids, he dwelt too much
on the changes of the simple inanimate solid, and too
little on those of the living or vital solid. Most of
the faults, however, of his theory are chargeable
rather on the time in which he lived, and on the
general imperfection of knowledge at that period,
compared with the present, than on any defects in
himself It is surprising that he considered his sy-
stem as having advanced so near to perfection ; for,

* Ey this phrase is meant the entrance of particles of the blood
into vessels the capacity of wiiich i, too small to transmit them.
\0L. I. ' Y

322 Medicine. {CnAr.IV.

though he lived almost forty years after he had
formed it, he seems to have made in all that time
but iGW corrections or additions which can be
thought to be of any moment.

The next medical theorist whose system demands
notice is George Ernest Stahl, professor of medi-
cine at Halle, in Saxony, who was so illustriously
distinguished for his improvements in chemistry,
mentioned in a former part of this work. For a
long time his was the prevailing system in Ger-
many; and the traces of it may be discerned in
many modern writings, which still maintain a high
degree of authority.

The fundamental principle of this system is, that
the rational soul of man presides over and governs
the whole economy of his body both in health and
sickness. In all ages physicians have supposed the
existence of a power or faculty in the animal eco-
nomy, by which it is enabled to resist injuries^ and
to correct and remove the diseases to which it is ex-
posed. This power by many of the ancients, w^as
vaguely termed nature, and, under the dcnomina*
tiori. of vis conservatrix ei medicatrix natura, has
been long celebrated in the schools of medicine.

Stahl explicitly founds his system on the principle
that this power of nature, so much spoken of, is no--
thing else than a faculty of the rational soul *. On

* It appears that physicians are by no means unanimous in
their mode of understanding the Stahlian tlieory. In proof of
this the follouing quotation is offered from a writer of high repu-
tation. " Stahl has been reproached for having ascribed too much
to the soul 5 but they who have done this, eitlier have never read
liis works, or did not understand them. The soul, according to
Staid, in a being purely materiiU ; or ratlier he adiuilfteu no i>uii\.

Sect. III.] llicorij and Practice of Fhj/sic. 3Q3

many occasions he iina«i:incs the soul to act inde-
pendemly of the state of the ]>ody; and that, with-
out any physical necessity arising from a particular
state, the soul, merely in consequence of its intelli-
gence, perceiving the aj)plication of noxious powers,
or the ap])r6ach of disease from any cause, imme-
diately excites such motions in the hody as are
suited to ob\ iate the hurtful or pernicious effects
which might otherwise take place. He sometimes
mentions two opposite princi})les or propensities in
the human frame; one constantly and unifonnly
tending to corruption and decay, the other to life
and health; the former founded on the elementarv
composition of the body, the latter depending im-
mediately on the energy of the mind or soul. B\
means of the nerves, the influence of the soul is ex-
tended to every part of the system ; and if their
action be impeded or deranged, disease is tlje un-
avoidable consequence. A plethora and lentor of tlu'
blood are therefore the proximate causes of disease,
as the energy of the mind i5 thereby diminished,
and its action on the body obstructed. Hence, to
lessen the quantit}', and to break down the Iciitor
of the blood, the soul exerts all its powers, and ex-
cites haemorrhages, sweats, diarrhoeas, fevers, and tlie
like. These efforts are sometimes hap])y and suc-
cessful; at otlier times they tail to answer tiie pur-
pose, and may oceasionall\' even do mischief, espe-
cially w^hen opposed by the imj^roper interference
of physicians, or by some internal, acGidental, or
organic, impediment.

only the vlfal principle of :\u organi'ed boJv.'* Zirtimermann on
Experience, vol. i, p. U"^

3i24 Medicine. [Chap. IV.

Such is tlie theory of health and disease which
Stahl dehvered to his pupils and readers, and which
he endeavoured to recommend and support by all
his great powers of learning and ingenuity. But, in
his ponderous volume on this subject, entitled The-
oria Medic a Vera, we look in vain for the logical
arrangement, the elegance and perspicuity, which
are constantly displayed in the writings of Boer-
haave. There were not wanting, however, in various
parts of Europe, especially in Germany, many fol-
lowers of Stahl, who thoroughly imbibed his princi-
ples, and pursued his practice in the treatment of
diseases. Among these, Juncker and Carl, particu-
larly the fonner, in his work entitled Conspectus
TlierapeicC Specialise have given a much better ac-
count of the doctrines and opinions of their pre-
ceptor than himself.

To many the Stahlian theory appears so fanci-
ful and absurd, that they can scarcely think it de-
serving of a serious refutation. But still, it has
been often thought there are such appearances of
intelligence and design in the operations of the
animal economy, that many eminent physicians
have been induced to countenance similar opinions.
Among these may be mentioned Nichols and
Mead, in England; Porterfield and Simson, in
Scotland; Gaubius *, in Holland; and perhaps
Wliytt, of the university of Edinburgh f .

■'^ Doiibts ha\ e bi'cn suggested whether Gaubius was really a
follower of Stahl. Dr. Haller represents hinj as cautus vir, et in
rtclpicndis opinionihus dijficills. He is said, at any rate, never to
Iiavc openly avowed his adhercnee to the Stahlian system.

I Among those wlio embraced either the whole or a part of the
l^tahlijn doct/inc, Pual Joseph Barthex is entitled to respectful no-

Sect, in.] Theory and Practice of Physic. 3i2.'3

Of the writers who adopt the opinions of Stahl,
111 a greater or less de^^ree, Nichols and Gaubius
may be considered as two of those who deserve tlie
highest consideration *. Tlie consequences result-

ticc. His work De Principio Vitali Jloi/iinis, published in 1773,
and his Nova Doctrine dc rivutiontbu.s NuturiT JIumanw, j)ubhsht'J
ki 1774, both deserve to be commended as indications ot'acutcness
and ingenuity.

* In an elegant prelection by Dr. Nichols, which he published
under the title of Oratio dc Anhnu Mtdica, we find the following
visionary excesses ot Staltlianism. According to him, the '^oul at first
forms the body, and governs it ever afterwards. He ascribes it to the
prudence of the soul, that the stinai is not jKTfc»eted in males, till
tlie strength and vigour of the system are prepared for generation,
and he sees her sagacity in the slow and gradual eruption of the
small-pox, thereby dividing the force of the disease and greatly
lessening the danger. After violent pain or exhaustion by fatigue,
tiie soul hides herself in sleep, in order to recruit the body or to
r-ectify any disorder ; hence the inclination to sleep after child-birth ;
hence also the frequent sleeping of infants, whose anima is so cn-
"•rossed with attention to the vital motions as to mind little else.
When too much distracted and perplexed with external things, she
cTften neglects her internal duties ; and hence health is so much
impaired by fear, grief, love, and other violent passions. He also
accuses the soul of occasional fits of caprice and ill-humour, by
w hich she is led to disregard her office, and indulge herself in
freaks of petulance and perverseness. In fevers, the sudden failing
of the strength and pulse ought to be regarded, he tells us, us
signs of the soul's abandoniug the body in despair, and intending
soon to relinquish it. Nay, he sometimes imputes to her cow-
ardice and folly in sufiering the body to sink under diseases by no
means deadly in their own nature; in falling into undue akirui and
trepidation, thereby becoming unfit to discharge her office, and
being often precipitated into mischief and injury; and in deserting
her post in a moment of peril, when, were she always wiiie enough
to neglect things of inferior moment, and to attend solely to the
preservation of the body, she might not only prevent diseases, >r,
tar at leask as they proceed from internal causes, but might protract
the life of man to an indefinite period, it may be to a thousand
■^.ears l^Vide Oratio de Anima Mcdicn, pa-^sim.

3^6 Medicine. [Chap, IV,

ing from such doctrines may be discovered from
what appears in their writings. If it be thought
proper to admit such a capricious government of
the animal economy as these writers in some in^
stances maintain, it will follow that a rejection
of all the physical and mechanical reasoning which
is employed concerning the human body must
fake place.

Nor are the consequences of such doctrines coh-
fmed to reasoning and speculation. It appears
that Stahl and his followers, in the whole of their
practice, whatever may haye been asserted to the
contrar}^, were very much governed by their ge-
neral principles. Trusting to the wisdom and con-
stant attention of nature, they proposed the art of
curing diseases by expectation. As practitioners,
therefore, they seem to have been cautious, inde-
cisive, and timid, in the extreme; they adopted, for
the most part, only very feeble, inert, and frivolous
remedies; and they strenuously opposed the use
of some of those which are most eincaciou"^ and the
most deserving of confidence.

It would be doing injustice, however, to the
Stahlian practitioners not to acknowledge that they
greatly enriched medical science by their incessant
and unwearied observation of the history and phe-
nomena of diseases, and were instrumental in di-
recting the attention of physicians to those salu-
tary efforts of nature, which cannot be too accu-
j ately understood, or too dihgently })ursucd in the
treatment of diseases.

Frederick Hoffmann is tlie last of the three illus-
trious systematists whose different theories of me-
dicine were disclosed to the world in the beginning

Sect. 111.] Thconj and Practice of Physic. 32?

of the eighteenth eeutury*. lie was the eollea.i^ie
and ri\al of Stahl in the university of Ilallc, and
a most learned and voluminous writer. For more
tljan fifty years he llonrished as a practitioner and
author, enjoyed a splendid reputation, and added
greatly to tlie mass of medical science.

lIofTmann had the discernment early to perceive
the errour of those who sufferetl themselves to he
led away by the hyi)0thetical doctrines of the hu-
moral pathologij, and the otiicr wild opinions then
prevailing among the chemical and mechanical theo-
rists. He set himself to cultivate and improve
what Boerhaave had neglectt^l. He diligently un-
dertook to explore the functions and diseases of the
oieri'ous system, and wisely concluded that noxious
causes much more generally affect the solid moiiug
poivcrs than the fluids of tiie animal body. He ad-
mitted indeed into his system some portion of the
mechanical,Cartesian,and chemical doctrines which
had previously prevailed; but these did not blind
him to the light which he derived from the patho-
logy of the nervous system. According to him,
atom) and spasm are the great sources of disease ;
and he proceeded so far as to maintain that all m-

- Frederick Hoffmann ^vas born at Magdeburg in the year
xmo. The principal circumstances much known in the lite ot
rhisiHustrious physician are, that he travelled mto England and
Holland, where he became acquainted witli Robert Boyle and
Paul Hermann ; that he never received any professional tees bemg
supported by his annual stipend j Uiat he cured tiic emperor
ClKU-lcsVI, and Frederick \ kin- of Prussia, of inveterate d.sca!^-s j
and that he had a very accurate and extensive knowledge, tor that
day, of rtie nature and virtues of mineral waters. Hotlmann sur-
vived his setli yeari and his works were printed at (nueva. in
/ix volumes folio, iu 1 740.

3'2S Medicine. [Chap. IV,

ternal disorders are to be ascribed to some preter-
natural affection of the living solid*.

Hoffmann's pathology of fever deservedly excited
great attention. Though he undertook, like many
of his predecessors, to inquire into the intentions
of nature, he certainly contemplated her process in
fever with more sagacity; and, rejecting chemical
and mechanical analogies on this subject, endea-
voured to discover the cause of fever in the pecu-
liar nature and affections of the vital motions. He
supposed the noxious cause producing fever (in
the language of the schools, the remote cause) to
operate first on the living solids, producing a ge-
neral spasm of the nervous and fibrous system, be-
ginning in the external parts, and proceeding to-
wards the centre. In consequence of this, a con-
traction of the vessels of the extremities must of
course take place, impelling the circulating fluids
in an increased ratio on the heart and lungs;
which stimulating these organs to increased action,
the fluids are thereby repelled towards the extre-
mities, and thus the phenomena of fever are pro-
duced. There are, therefore, according to Hoff-
mann, two distinct sets of motions in fever 5 the first,
from the extremities towards the centre, arising im-
mediately from the spasm, and accompanied by a
small pulse, anxiety, and oppression; the second,
from the centre towards the surface, which is the
effort of nature to resolve the spasm, and indicated
by a full strong pulse and increased heat. The
lirst of these sets of motions is baneful, and som^T

* Vide Fred. Hoffmann. Opera Omnia Phi/sico-Medicit, vol, i,
M(d. Rat. Syntaii. toin. iiJ, § I, cap. iv^ p. J08. Geneva edition.

Sect. III.] Theory and Practice of Physic. ^l\\

times fatal; the second is medicinal and salntarv.
By thtsc views of the nature of fever, he sujj|)osfs,
the physician ought to be directed in counteracting
the morbid actions, and in assisting tiie sanative
process of nature*.

The general pathological doctrines of lIofTmann
undoubtedly contain a great deal of truth, and form
a distinguished aera in the history of medical the-
ory. Tiiough his opinions on the sul)ject of fever,
however impro\'ed by a succeeding theorist, must
be supposed to be rapidly falling into disrepute;
still they evince deep and Just views of the animal
economy, and much observation of the nature ^nd
phenomena of diseases.

The originality of HolTmann's scheme of patJKj-
iogy has been brought into question; and nobody
can doubt that he received many important hints
from preceding writers. Van Helmont seems to have
been the first who turned his attention to the nervous
system with any discernment. Some, indeed, have
gone so far as to pronounce him the author of the
spasmodic theory of f ever ; but whatever intimations
he may be supposed to have given of febrile spasm
in different parts of his huge indigested \vork, they
are surely too crude and indistinct to be considered
in the light of a theory of fever. Dr. Willis, in the
latter part of the seventeenth centuiy, had also laid
some foundation for this doctrine, in his Palhologia
Cerebri ct Nervorum; and Baglivi, in tlie begin-
ning of the eighteenth, had improved it still further
in his Specimen dc Fibra Motrici el Morl)osaf.

•^- IIofTmann. Oft Omn. vol. i, torn, ii, p. 10.
j Dr. I'cniai- ot >r;inrlu'strr, in thcprefacto hi> .Mtuficul Ilis-
rc'/ii's ami R»jhxliom: iiuikcs the following rcinaik : " Tijc avsci-

550 Medicine, {Chap, IV.

The theory of diseases last stated formed tlie
ground-work of a system which was adopted and
taught for many years, with great celebrity, by the
learned Dr. Culien of Edinburgh *. He assumed the
genera] principle of Hollmann, that the phenomena
of health and disease can only be explained by re-
ferring them to the state and affections of the pri-
mary moving powers of the animal economy. He
endeavoured to extend the application and uses of
this principle as far as possible, and for this pur-
pose he- expunged certain hypothetical doctrines of
the humoral pathology which Hoffmann had suf-
fered to remain j and to depreciate the Mtlue of
his system.

According to the hypothesis embraced by Dr.
Cullen, the bra hi, with all its ramifications and de-
pendencies combined to form the nervous system, is
the primary organ of the human body, the different
conditions of which constitute the various states of
health and disease. In pursuance of this hypo-
thesis, the circulation of the blood, instead of being
the principal of the vital functions, as in the Boer-

tion of a spasfnodic state of the extreme vessels in the cold stage
offerers, commonly ascribed to Dr. Iloffmann, was first naade by
Dr. Pien>, in his comprehensive treatise De Febrt."

* Dr. William Cullen was born in Lanarkshire, in the west of
Scotland, December 11, 1/12. He was chosen one of the me-
dical protessors in tlie university of Edinburgh in 1756^ and died
in that city in l/.qo, in the 77th year of his age. The various
publications of this distinguished physician are so well known,
that it is nn!iccessary to dwell on their merits. Of these, his
Noxologia Mt'thodica, his First Lines of the Practice of Pli^s/c,
and his Materia Medica, arc the most valuable. — See an elo-
quent and interesting luulogiuia upon Dr. Callcn, pronounced
liefore the College jof Physicians of Philadelphia^ by Dr. llui,h,
bvo, 1790.

Sect. III.] Thcorj/ and Praciinf of Pin/sic. 331

haaviaii doctrine, occupies only a s<'con(lary cle-
grce of importance in tiie anini;il economy. Dr.
Cullen supposed it to be evident that tlie nervous
power, in the whole as well as in the several parts
of tlie nervous system, and particularly in the
brain, which unites tiie several parts, and forms
them into a whole, is at dillerent times in ditlerent
degrees of mobility and force. To these dilferent
states he applies the terms of cxcUcmtnt and col-
lapse. To that state in which the mobility and
force are suilicient for the ordinary exercise of the
functions, or ^vhere these states are any way ]-)re-
ternaturally increased, he gives the name of crcite-
ment; and to that state in which the mobility and
ibrce are not sufficient for the ordinary exercise
of the functions, or when they are diminished from
tlie state in which they had been before, he gives
the name of collapse*.

Dr. Cullen's opinions concerning the nature of
fever have excited much attention and controversy
in the medical world. lie delivers an account of
them in the following ivords : "Upon the whole,
our doctrine of fever is explicitly this. The remote
causes are certain sedative powers appUed to the
nervous system, which, diminishing the energy of
the brain, thereby produce a dc-bility in the whole
of the functions, and pnrticularly in the action of
the extreme vessels. Such, however, is, at the
same time, the nature of the animal economy, that
this debility i)roves an indircct stimulus to the san-
guiferous system ; whence, by the intervention of
^he cold stage, and spasm connected with it, the

* See his histitutes of Midkinc, § 12u to 13:';.

332 Medicine. [Chap. IV.

action of tlie heart and larger arteries is increased,
and continues so till it has had the effect of restor-
ing the energy of the brain, of extending this energy
to the extreme vessels, of restoring therefore their
action, and thereby especially overcoming the
spasm affecting them ; upon the removing of which,
the excretion of sweat, and other marks of the re-
laxation of excretories, take place*."

As Hoffmann's theory of fever evidently produced
that of Cullen, it is proper to ascertain the points
of variance between them. According to Hoffmann,
the first effect of the remote cause of fever is the
spasm, producing a reaction, as has already been
stated in the account given of his doctrine. Cullen
introduced a previous link into the chain of effects:
he contended that the first effect of the noxious
power (the remote cause) was a general debility,
consisting in a diminution of the energy of the
brain. To this debility he attributes the spasm,
and to the spasm the reaction of the heart and ar-
teries; which reaction continuing till the spasm is
n^solved, removes the debility and the disease. Ac-
cording to Hoffmann, the spasm belongs to the class
of motions MJiicli he pronomices to be baneful;
\\\i\ Cullen presumes it to be salutary, and there-
iore ascribes it, in the language of the schools, to
the vis medico I rix natuvcv.

Dr. Cullen's theory of fever was received with
great applause, and, for a considerable time, main-
tained its ascendancy, especially in the British do-
minions and in the I'nited States. Few, however,
at the present da}', seem to consider it as tenable.

* Vh'i^t Lines of ihc Practice of Th^sic, vol. \, p. 55.

Sect. III.] Theory and Praclkc of Physic. 33.^

The author has not iDidertaken to explain in what
manner the debihty in the w hoU^ of tlie hnietions
proves an indirect stimulus to the sanguiferous sy-
stem 3 nor how this stimulus operates in exciting
the cold stage and spasm, I'he coexistence of
atony and spasm in the same vessels is regarded by
many as an insuperable diihcult}\ No explana-
tion is offered of the mode in which the action of
the heart and larger arteries is augmented by the
intervention of the cold stage and spasm. The pro-
cess by which this augmentation restores the energy
of the brain, and extends such energy to the ex-
treme vessels, is also left entirely in the dark. His
introduction of the vis medicatrix naturu: is liable
to almost all the objections of the aniina mtdicu of
Stahl, and must be considered as no better than a
confession of ignorance. In all these respects,
and many others, this celebrated doctrine rests
on hypothetical ground. This will appear the
more surprising, as the learned author professed
to disclaim all those hypothetical opinions which
go to the formation of theories ; and seems to
have been persuaded that his doctrine of fever
was only an induction from a generalisation of
facts.

It would be injustice, how^ever, to Dr. Cullen,
not to subjoin that his merits are extensive and
universally acknowledged. He was a diligent and
faithful collector of facts. His works often contain*
admirable descriptions and sagacious discrinnna-
tions of diseases. His great excellence seems to
have consisted in methodical arrangement. But
it is commonly remarked, and apjiarently with
truth, that he was much more successful in d m*>-

354 Medicine. [Chap. IV.

lishing the systems of others than in erecting his
own.

l>;e next system which demands attention, in
the order of time, is that of Dr. John Brown of
Edinburgh*. This original, eccentric, nnfortnnate
man framed a physiological and pathological theory,
which, amidst great erronrs, inconsistencies, and
contradictions, contains many vigorous conceptions,
of truth and nature, and some which it is probable
the improvements of future times will serve much
further to elucidate and confirm.

Brown assumed, as the foundation of his system,
the existence of an unknown principle, on which,
when acted upon by stimuli, all the phenomena of
life, health, and disease, depend, and which he de~
nominated excitability. This excitability he be-
lieved to vary in different animals, and in the same
anim.al at ditferent times. As it is more intense,-
the animal is more susceptible of the action of ex~
citing powers. Exciting powers, or stimuli, may
be referred to two classes ; either external, as heat,
food, wine, poisons, contagions, the blood, secreted
fluids, and air; or interna], such as the functions of
the body itself, muscular motion, thought, emotion,
and passion. Excitability produces no effect, or

* Dr. John Brown was born in the village of Dunse, in Scot-
land, in ihe year I7«'5. His parents were in very Immble life:.
and through his whole career he maintained a struggle with po-
verty. He began to teach medicine by public lectures in Edin-
burgh, about the year 1777 •' he removed to London in l78Ci,
where he died in 1783, in the 53d year of his age. Pie v. as un-
doubtedly a man of great and original genius, and ^of considerable
ac(|uiremeht,s, but tlie unfortunate victim of folly and intempe-
rance. His Ehmenta MediciiKV were first pubhshed by him id
Latin, and afterwards trani>lated 1 y the author into English.

S^cT, IIL] Theory mid Practice of Physic. 3S^

rather docs not exist, unless exeiting powers arc
applied; for, if tlioy be entirely witlidrawii, deatli
as certainly ensues as when excitability is coiismned
hy the excessive application of ihein ; life is there-
fore a forced slate. Excitement may be in just
measnre, or too great, or too small. St imuH ap|)ned
in due proportion produce that just (le,i;ree of ex-
citement wliich constitutes the «tate of health. If
the stimuli be diiiiinished below the healthy pro-,
portion, he supposed the excitability to a/:eumu-
late; if increcLsed beyond this proportion, to be
expended; and on these opposite states he at-
tempted to found a theory of diseases, denominat-
hig the ibrmer direct, the latter indirect debilitv.
Diseases he divided into tv.o classes, slJttnic and
astJienic, or such as arise from increased and from
diminished excitement. He believed no aq-ent on
the living body could properly receive the title of
scdatiie; and insisted that every ])o\ver tiiat acts
on such a body is stimulant, or produces excite-
ment by expending excitabilit\\ Whatever powers
therefore may be employed, and however they may
vary from sucii as are habitually applied to produce
due excitement, they can onlv' weaken the system,
by urging it into too much motion, or saiVering it
to sink into languor. He is supposed to have in-
cluded both the nervous and muscular powers un-
der tlie term of excitability ; yet he did not con-
sider the excitability as a pro}>erty residing in and
depending upon the mechanism of particular parts,
but as a iniiform undivided property, pcrvatling
the whole system, which cannot be affected in any
one part without being atfected in a siuiilar nianuer
in every other.

336 Medicine. [Chap. IV,

Dr. Brown supposes the proximate cause of
fever to consist in debility, which may be either
direct or indirect, according to the nature of the
noxious powers previously applied to the system.
Hence he makes two divisions of fevers : 1st. Those
which depend on direct debihty, such as intermit-
tent fevers, typhus, &c. 2d. Those ^^'hich depend
on indirect debility, such as mahgnant fever, con-
fluent small-pox, plague, &c. Having therefore
assigned to fever its place in his series of descend-
ing excitement, he neglected particularly to in-
quire into its symptoms, or to enlarge on its treat-
ment. Thus debility, which was the first link in
the chain of Dr. Cullen, formed, according to the
theory of Dr. Brown, the essence of fever. He
altogether denied the existence of spasm ; he ridi-
culed reaction and the vis medicatrix natura; ; and
he wholly overlooked the phenomena of morbid
association and morbid heat.

In a word, the basis of Dr. Brown's system
seems to be this ; in every state of the body, ex-
cept that of perfect health, there always exists
either too strong or too weak an excitement.
Hence there can be only two species of disease,
two methods of treatment, and two kinds of medi-
cinal agents.

In framing his system. Brown seems to have
combined the irritability and sensibility of Haller
to form his excitability ; and to that eminent phy-
siologist he w^as probably more indebted for the
first hints of his doctrine, and especially for the
facts on which it is founded, than to any preceding
writer. His general principles are supposed more
correctlv to suit the condition of the animal eco-

Sect. III.] Theory and Practice of Physic. 337

nomy in health than in disease. The fundamental
position, that excitabihty is accumulated and ex-
pended in the inverse ratio of the stimulation, ap-
pears to be confirmed by many i\ic[^ conct-rning
the application of heat and the taking m of food,
during the healthy states of the body, or when it
is only affected by cold or hunger. Whether it
equally hold good in the state of disease is more
liable to doubt. He was acquainted with only
one mode of action of the living principle, that
which has been described by a succeeding theorist
under the name of irritation ; while he was wliolly
regardless of the influence of sensation, volition,
and association. He neglected, or was ignorant
of most of the important relations which the doc-
trines of modern chemistry bear to the animal
economy, and to the composition of animal mat-
ter. These, however, comprise only a small por-
tion of the criticisms to which this system is ex-
posed.

But with all these, and many more faults, it
cannot be denied that the praise of genius and ori-
ginality in an eminent degree belongs to Dr.
Brown. The simplicity^ comprehensiveness, and
consistency, as well as novelty, of his system, gave
it a very seducing appearance, and contributed
greatly to its prevalence. One of the greatest ex-
cellences of it, as applied not only to the practice
of physic, but to the general conduct and preserva-
tion of health, is, that it impresses on the mind a
sense of the impropriety and danger of suddenly
going from one extreme of excitement to ano-
ther*.

* See Brown's Elements, passim.
Vol. I. ^

338 Medicine, [Cha?. IV.

Near the close of the eighteenth century, a new
medical theory was presented to the world by Dr.
Erasmus Darwin, in his celebrated work which he
entitled Zobnomia^,

According to this theory, there is, in every part
of the animal system, a living principle, which is
termed Sensorial Fowei\ which is considered as
the immediate cause of all its motions, and is sup-
posed to be secreted in the brain and spinal mar-
row. This sensorial power is capable of being
acted upon in four different ways, or it possesses,
in other words, four different faculties or modes
of action, which, in their passive state, are deno-
minated irritability, sensibility, voluntarity, and
associability ; and in their active state, or during
exertion, they are termed irritation, sensation, voli-
tion, and association. The faculty termed irrita-
tion is exerted, and produces fibrous motions, in
consequence of the stimulus of external bodies
acting on any part of the system where sensorial
power resides. That of sensation is exerted in
consequence of the stimulus of pleasure or pain,
occasioned by fibrous motions originally produced
by the sensorial power of irritation. That of vo-
lition is exerted in consequence of the stimulus of

'^ Dr. Erasmus Darwin was a native of Nottinghamshire,
where he was born, December 12, 1/31. He was educated at
the university of Cambridge, and graduated Bachelor of MedU
cine in that institution in 1755, and soon afterwards commenced
the practice of physic at Litchfield, where he long resided in the
honourable, useful, and profitable practice of his profession. His
first great work, tlie Botanic Garden, was published in 1/89^
the Zomomia in I794j hh Phytologia in 1799? ^^^^ ^^is Temple of
Nature a short time after his death, which took place on the 18th
of April, 1802.

Sect. III.] Theor}/ aiid Practice of Phijsic. S3C;

desire or aversion, occasioned by fibrous motions,
which liad been previously i)rodu(( d by tbe senso-
rial power of sensation. That of association is at
first eixerted in consequence of tlie stinuihis of
fibrous motions, previously occasioned by irrita-
tion, sensation, or volition.

Having thus stated the various modes of action
of the sensorial power. Dr. Darwin proceeds to de-
liver the other fundamental principles of his theory.

During the application of any of the above-men-
tioned stimuli, the sensorial power becomes ex-
hausted; on the contraiy, while any of them an*
withdrawn, it becomes accumulated.

In order to illustrate and establisli his important
doctrine of association. Dr. Darwin asserts that
there are various circles of associate motions in the
animal system, which may take their names Ironi
that faculty of the sensorial power by which they
are introduced. Those circles, for example, which
are introduced by an irritative motion, may be
termed irritative associate motions ; and, in like
manner, the sensitive and voluntary associate mo-
tions are produced and denominated. All these
several circles of motions act upon one another by
means of the sensorial power of association.; they
may be affected by other sensorial motions, such
as those of irritation, sensation, and volition ; and
they may be considered as compounded, each one*
of smaller circles ; as, for instance, tiie great circle
of irritative associate motions may be sup|)ose(l to
be made up of smaller circles of the same kind.

Conformably to this scheme of association, tin
introductory link of any circle of associate motions
may have its action increased, diniiiiislied, or ^u^-

Z 2

S 40 Medicine, [Chap. IV.

tained in the natural degree. The first may take
place either in consequence of excess of sensorial
power, the stimuli being in their accustomed de-
gree ; or in consequence of excess of stimuli, the
sensorial power being in its natural degree ; or in
consequence of excess of both. The second may
arise either from want of sensorial power, the
stimulus being in its usual degree -, or, from sub-
duction of stimuli, the sensorial power being in its
natural quantity ; or from want of sensorial power
and subduction of stimuli. The third takes place,
when both the sensorial power and the stimuli are
in proper degree. In some cases, the .morbidly in-
creased, as well as the morbidly diminished, actions
of the mtroductory link of a circle of associate mo-
tions are followed by similar actions of the other
links ; at other times, by contrary actions : in the
former case there is direct, in the latter reverse,
sympathy. The morbidly diminished actions aris-
ing from subduction of stimuli are sooner relieved
than such as are occasioned by want of sensorial
power. The morbidly increased actions which
arise from excess of sensorial power are more vio-
lent than those which are produced by excess of
stimuli. Hence inilammatory diseases are com-
monly preceded by subduction of stimuli, and con-
«3quent accumulation of sensorial power. But
when excess of sensorial ])ower is acted upon by
excess o^ stimuli, the exertion which follows is
far greater and more destructive. Hence the mor-
tiiicatiou of frozen limbs Vvhen brought near the
fire.

According to Dr. Darwin, all those parts which
arc subjected, during health, to perpetual action, as

Sect. III.] llieory and Practice of Pin/sic. 341

the heart arid arteries, aceumulate sensorial power
faster, when impeded, than those which are sub-
jected only to intermitted action. M'hen stimuli
which are usually applied to any particular j^art of
the system, are withdrawn, an accimiulation of sen-
sorial power takes place there, proportioned to tli(;
subduction of those stimuli and to tlic state of that
part.

The exertion of any part of the system, Dr.
Darwin believes, may be proper, or greater, or
smaller than it ought to be. All diseases, there-
fore, originate in the exuberance, deficiency, or
retrograde action, of the faculties of the sensorium,
as their proximate cause ; and consist in the dis-
ordered motions of the fibres of the body, as the
proximate effect of the exertions of those disorder-
ed faculties. Hence, in conformity vv itii the prin-
ciples before mentioned, health, inflannnation, and
the various degrees of exhaustion of sensorial
power, or torpor from accumulation of sensorial
power, will be found to ensue.

After premising these general principles, and
deducing from them many important doctrines
concerning the sound and diseased states of the
animal system. Dr. Darwin proceeds to offer his
theory of fever, which, whatever may have been
the remote cause of it, he supposes to consist in the
increase or diminution of direct or reverse associated
viotions. It commences in a particular organ, oc-
cupies one or more disordered tribes or trains ot
associate motions, and is more or less compli-
cated according to the number of such disordered
tribes.

Dr. Darwin's doctrine of fever may thcrelbre be

342 Medicine, [Chap. IV.

considered as follows. When the torpor of any
part of the • system (owing to deficient irritation,
occasioned either by the subdiiction of the natural
stimuli, and consequent accumulation of sensorial
power, or by the application of powerful stimuli,
and consequent exhaustion of the same living prin-
ciple) is such as to occasix)n diminished action of
that part, the following effects will take place :
the next link of the tribe of associate motions fails
also into a torpor, from defect of excitement of
the sensorial power of association; and so the sub-
sequent one, till a general torpor affects the system.
This constitutes the cold paroxysm of fever. This
general torpor remains till the accumulation of the
sensorial power of association is formed, which
overbalances that defect of excitement of associa-
tion ; and then tlie torpor ceases, and the hot fit of
fever is produced. When the torpor of the part
first affected is occasioned by the subduction of
the natural stimuli, this is likewise thrown into in-
creased action during the hot fit. But if it arise
from exhaustion of sensorial power, the part re-
mains in a torpid state during the hot fit. The
torpor induced by the subduction of natu;'al sti-
muli, as it is overcome at the end of the cold fit,
always gives rise to fevers of strong pulse ; since,
in such case, all the parts of the system have their
actions increased during the hot fit. The torpor
arising from the exhaustion of sensorial power pro-
duces various ctfects, according to the part in which
it takes place. AVhen seated in the stomach, it
always produces continued fever, with weak pulse.
In this case, in consequence of the torpid state of
the stomach, the arterial system likewise falls into

Sect. III.] Theory and Practice of Physic. 343

torpor, from defect of the excitement of associii-
tion; therefore an accumuUitiou of the sensorial
power of association takes place in the arterial
system. But this accumulation is so great, owing
to the interrupted actions of the stomach, cate-
nated with those of the arterial system, that it
affects the next link of the associate train, that is,
the capillaries of the skin, with increased energy.
Hence these last, in this kind of fever, are per-
petually exerted with great increase of action.
When torpor affects the secerning vessels of the
brain, it produces fever with arterial dehility. In
this case, the secretion of sensorial power being
more or less impaired, languid actions of every
part of the system must be the consequence. In
fevers from this cause, the action of th« capillaries
is diminished with that of all the rest of the system.
Hence the heat of the body does not rise above
the natural standard, and sometimes it is even
lower throughout the course of the disease j a phe-
nomenon which serves to direct the attention to
this cause. When torpor, from exhaustion of sen-
sorial power, affects other parts of the system sym-
pathetically associated with the stomach, such as
the liver, spleen, &;c., the stomach falls into torpor,
from defect of the power of association ; and, in like
manner, the arterial system ; till a general torj)or
is formed, which constitutes the cold fit. During
this cold fit, an accumulation of the associative
sensorial power takes place in the stomacii, ai'terial
system, &c., which more than compensates this de-
fect of excitement in the sensorial power of asso-
ciation ; consequently all these parts are thrown
into increased action. This constitutes the but ht;

544 Medicine, [Chap. IV.

which, according to the degree of accumulation of
the sensorial power of association, and the force of
stimuli applied to it, will produce various effects.
Hence various kinds of intermittent fevers. Or these
increased actions may be in such degree as to pro-
duce sensation, and thereby occasion inflammatory
fevers: or, lastly, such increased actions may, in
consequence of their violence, produce a smaller,
4Dr greater, or complete exhaustion of sensorial
power in some part essential to life. Hence various
kinds of continued fevers with arterial debility, or
even death.

On this extensive scale of sympathy and associa-
tion, Dr. Darwin endeavours to account for a great
number of the phenomena of diseases, and espe-
cially for those of fever. From the same doctrine
he deduces the indications of cure, and explains
the operations of the remedies by which these indi-
cations are fulfilled*.

The extensive and accurate observations of the
laws of organic life, the sagacious conjectures and
profound reflexions, which abound in the Zoonomia,
must be greatly admired. The most competent
judges seem to concur in pronouncing it the ablest
medical work of the eighteenth century. In col-
lecting and arranging the facts belonging to animal

* The number of compartments which belong to the system of
medical philosophy delivered in Zoonomia, the cycles and epi'
cycles, and the variety and intricacy of the relations they bear to
each other, render it difficult to comprise, within a short compass,
such an abstract as can do justice to the ingenuity and learning of
the celebrated r.uthor. If this attempt should be found unsuc-
cessful, tlie difficulty of con>bining clearness and brevity in
sketches of such a kind ought not to. be forgotten.

Sect. III.] Theorxj and Practice of Physic. 345

life, and unfolding the inflncncc of morbid associa-
tion, which involves the essence of diseases, the
author undoubtedly excels all preceding \Miters.
Still, however, his work must be allowed to lalx)ur
under great faults and radical deficiencies*. In
many instances he gives the rein to his imagina-
tion, and suffers fanciful speculations to usurj) tli(>
place of facts and legitimate reasoning. I lis doc-
trine of the retrograde action of the absorbents, of
which he makes such frequent and important use,
in a great many various states of disease, may l)e
mentioned as one of those which seem to want
confirmation. And there is reason, indeed, to ap-
prehend that errours still more fundamental and
essential have crept into this vast plan for binding
together the scattered facts of medical knowledge,
and converging into one point of view tlie laws of
animated nature. That interesting doctrine, com-
mon to Dr. Brown and Dr. Darwin, that all the
phenomena of life are to be explained on tlie prin-
ciple of the excitability or sensorial power being
accumulated and expanded in the inverse ratio of
stimulation f, however elegantly it may admit of

* The atheistical tendency of his speculations can scarcely be
doubted j and his crude and visionary philosophy of mind w'lW not
stand the test of sober inquiry. This, however, is not the place
to enter into a discussion of these errours.

t The originality of some of the leading doctrines delivered by
Dr. Darwin has been called in question. He himself recognises
the coincidence of some of his opinions with those of Dr. Brown ;
but contends that he arrived at his conclusions on those .-ubjecij
by a different train of reasoning from that of the Scottish theorist.
He also declares, and asserts tliat his friends arc able to attest the
fact, that the greater part of his work had lain by him twenty yr,irt
before its pubhcation. These iacls evidently preclude Uic pro«

546 Medicine. [Chap. IV,

illnstration by the use of heat, light, and food, after
coldness, darkness, and hunger, seems to fail in its
application to many morbid states of the system.
It a})pears, on the contrary, often to happen that
excitement and excitability are increased at the
5ame time, and perhaps still oftener that they are
diminished and wasted together*. The radical
defect in every inquiry of this kind is our unao
quaintance with the nature of the vital principle,
a defect which \\\(t scantiness and imperfection of
all human knowledge does not seem likely speedily
to supph^

In a review of the systematic arrangements of
medical knowledge which have been undertaken
in the course of the eighteenth century, it would
be improper to pass w^ithout notice the learned
and laborious work of M. Lieutaud, first physician
to the monarch of France, published nearly fifty
years ago, under the title of Synopsis Universce
Medicina, This singular work was attempted on
the plan of collecting all the facts that experience
has taught, without any reasoning concerning their
causes. But the total want of method, perhaps
the unavoidable result of the plan, continually in-
troduced such confusion as to render this perform-

bability of his being muchj if at all, indebted to Dr. Brown. Dr.

Hnrtley seems to have been the first who, clearly and with effect,
employed the principle of associutlori to account for the pheno-
mena of the animal economy. (See Observations on Man). It is
iVbt improbable that Dr. Darwin was indebted to him for some
hints in forming his great work.

* The author is aware that Dr. Darwin's theory makes provi-
sion to meet tliis difficulty and to explain it > but v/hether tlie-
explanation be sufficiently satisfactory, remains to be decided.

Sect. III.] Theory and Practice of Physic. 347

aiice much less uistructivc and useful than might
have been expected.

It may also appear improper to omit some no-
tice of a theory of fevers, formed by the late sir
John Pringle, which, from its i)eculiar charaeter,
has been denominated the putrid theory. Having
been long conversant with the malignant diseases
of camps and military hospitals, that respeetaljle
physician adopted the notion of miasmata and con-
tagions operating like a ferment on the animal
fluids, and thereby producing putrid fevers. This
doctrine of fevers, however, is regarded as so
vague and improbable that few have been induced
to adopt it.

Among living authors, many have been so justly
distinguished for their efforts to improve the theory
and treatment of diseases, that it would be inex-
cusable to omit their names in this retrospect.
The learned and excellent Dr. Rush stands in
the first rank of medical theorists in the United
States. His doctrine of the proximate cause of
fiver is the result of a long, vigilant, and enlight^
ened attention to the phenomena of febrile dis-
eases, and to the various plans of cure which his
extensive learning enabled him to survey. The
pathology of the blood-vessels, which had been
too much neglected by preceding theorists, seems
to have employed a principal share of his atten-
tion in framing his doctrine of fevers ; which makes
their proximate cause consist of a convuisiou in the
sanguiferous, but more particularly in the arterial,
system. In conformity to this opinion, his deci-
sive and energetic treatment of febrile diseases is
chieflv directed to the reduction of excessive and

348 Medicine. [Cha?. IV..

the liberation of oppressed action, by depletion, and
other analogous means; or to the support of feeble
action by appropriate stimulants; and afterwards
to the transfer of remaining morbid action, of
whatever kind, from the vascular system to parts
less essential to life*.

The inquiries concerning the nature and consti-
tution of pestilential fluids, which have been pro-
secuted with great learning and ingenuity by Dr.
Mitchill, so radically concern many of the lead-
ing doctrines of diseases, that they may justly be
said to embrace a new theory. His doctrine, as
was before mentioned, is this, that the acid oiTspring
of putrefaction, composed of oxygen and azote
(which latter he denominates septon) chemically
united, forms the febrile poison the ravages of which'
are often so fatally experienced ; and that alkaline
and calcareous substances aiford the best means of
extinguishing its virulence. The evidence he ad-
duces to maintain this doctrine, drawn from an-
cient as well as modern authorities, and from facts
observed in all parts of the globe, does equal honour
to his diligence and erudition.

In Germany there are several eminent physi-
cians who lately have published systems of medi-
cal doctrines, which are said considerably to differ
from all preceding ones, and which attract much
ntt^ntion in that enlightened part of Europe.
Among these, the names of Reil, Roschlaub, and
Hufeland deserve particularly to be mentioned ;
but the confmement of their opinions to the Ger-
man language prevents them from being sufti-

* Medical Inquiries (jliuI Obsch-ations, vol. iv.

Sect. III.] Theori) a?id Practice ofPlnjsic. 349

ciently known to give any account of them in tla:>
review.

Within a few years, Dr. lleich, of that country,
has presented to the pubhc a new theory of fcvtrs,
which seems, however, to have attracted l)ut little
attention, and it is believed is now failing into
neglect. His fundamental doctrine is, that fevers
are produced by destruction of the equilibrium bo
tween oxygen and the other principles which eutcr
into the composition of the animal body; and that
fevers may be most speedily cured by introducing
and restoring equally, to all parts of the body,
such a quantity of oxygen as is necessary to re-
establish the equilibrium between the ditferent con-
stituent parts. And hence he infers that aci(L«,
especially the mineral acids, and particularly tlie
muriatic acid, are better adapted than any other
remedies to the cure of fevers.

Among the improvements which occurred to-
wards the close of the eighteenth century, Pneu-
matic MedicLJW holds a distinguished rank. I'he
knowledge of the gases in the last quarter of the
century assumed a regular and scientific form;
and the analysis of the atmosphere by Scheele and
Lavoisier, at that period, gave a new aspect to
many doctrines of the animal economy, both in its
healthy and diseased state. When the comi)osition
of the atmosphere, its intluence in the function of
. respiration, and the constitution of animal matter,
were ascertained, it was natural to suppose that
many of the gases received into the hini^s in breath-
ing might become powerful remediLis. M. Four«
croy took the lead in this incpiiry, and was soon
assisted by the exertions of Lr. Girtanncr. Dr.

350 Medicine, [Chap. W.

Beddoes was the first who introduced the pneu-
matic practice into Great Brttain, where it appears
to have been more assiduously cultivated, and ap-
])lied to a greater variety of medical purposes, thai>
in any other country. The names of Davy, Thorn-
ton, and Townshend, are also to be mentioned
among the most enterprising cultivators and im
provers of this practice. The sanguine expecta-
tions of those who first proposed this mode of ap-
plying remedies seem hitherto scarcely to have been
answered ; but how far industry and ingenuity may
hereafter vary and improve the practice must be
left to the decision of time.

The methodical arrangement of diseases, called
Nosology, had its birth in the eighteenth century.
This consists in a systematic distribution of dis-
eases into classes, orders, genera, and species, on
the plan of natural history. This scheme of ar-
rangement was first conceived by Sydenham, and
afterwards by Baglivi, towards the close of the
seventeenth century. For the first actual attempt
the world is indebted to Francois Boissier de Sau-
vages, an eminent professor of medicine at Mont-
pellier, who published his laborious work in the
early part of the eighteenth century. After Sau-
vages, this subject was cidtivated by Linnaeus, to
whose genius for arrangement every branch of
natural history is so greatly indebted ; by Rodoi-
l)hMS Augustus Vogel, of Goettingen; by John
Baptist Sagar, of Iglaw, in Moravia; by Dr. Cul-
leii, of Edinburgh; by Dr. Macbride, of Dublin;
and by Dr. Darwin, in his Zoonomia; beside
some others of inferior" note. For some time past,
tlie iniluence of Nosology has been evidently on

Sect. III.] Tlieory and Practice of Physic. 3 J 1

the decline. The ever-varying furnis of diseases
are so dissimilar to the steady and lixod character
of the objects belonging to the tliree kingdoms of
natm-e, that it is diflicuit to accoinit for \\\v. con-
fidence and zeal v^ith uhich tiiis subject lias Wcw
cultivated by some disthiguislied naim s. It can-
not, however, be denied, that nosological in<|uiriu{s
have produced many good elfccts : tlicy doubtless
promote the discrimination of diseases ; and many
of the questions they involve are extremely in-
teresting to the practical physician. An undue
reliance upon nosology, and allowing it to substi-
tute names for realities, seem to have produced tlio
mischief which has thrown it into discredit.

, The cool regimen in fevers constitutes one of the
most universally acknowledged improvements in
the practice of physic of the eigliteenth centurv.
A revolution on this point was begun by the new
and interesting doctrines, which the sagacity of
Sydenham had enabled him to develop towards
the latter part of the preceding age. Every day's
additional experience gave some new confirmation
of this important practice. A further acquaint-
ance with the diseases of hot climates, where thti
pleasantness as well as the efficacy of coolness in
fevers had overcome the opposition both of theory
and prejudice, gave a deep blow to the alexiphar-
mic and heating system. The good effects of
coolness in the small-pox, and more especially in
the improved stages of the inoculation of that dl>-
ease, seem to have settled the detenni nation of
physicians to extend the same remedy to the treat-
ment of fevers. And the conviction since wrought
by experience and observation, both on the public

352 Medicine. [Chap. IV.

and medical mind, may now be said to have esta-
blished this improvement on the firmest basis.

It is remarkable, that, aUhough the use of cold
air and cold water had been recommended in ar-
dent fevers by Hippocrates, Galen, Celsus, and most
of the celebrated physicians of antiquity, as well as
by many eminent moderns, it was discountenanced
by Boerhaave and all the disciples of his school.
In his commentator Van Swieten, and in the writ-
ings of Pringle, Cleghorn, Lind, and even Cullen,
little is to be found in commendation of this sa-
lutary practice. It remained for the learned and
judicious Dr. Currie, of Liverpool, to extend the
cool regimen in fevers, by adding to the use of
cool air and cool drinks, the affusion of cold water
over the surface of the body, when in a very dry
and heated state. This remedy, the application
of which by long experience, he has been enabled
precisely to regulate and determine, may be confi-
dently pronounced to be one of the greatest of
modern improvements in the practice of physic*.
In the course of the century under review, some
particular diseases have been treated with more
success than in former periods. It may not be
improper to direct the attention of the reader to a
few of the most remarkable of these.

The triumph of medicine over the Small-pox has* '
been completed in the eighteenth century. This\|
scourge of the human race has exceeded all other
diseases in the number of its victims, and in the
frequency of deforaiity, blindness, and other dread-

* See Dr. Currie's Medical Reports on the Effects of Water, cold
QTid iiai-m, as a Remedy in Fever, and other Diseases.

%)s.cr. III.] Theo?y and Practice cf Physic. ^ 353

ful consequences inflicted on sucli as escaped witli
their Jives.

The practice of ijiocnlation has reduced this
frigiitful malady to sucli a degree of mildness and
S2iiety that it no longer excites the terrour of the
community*. The date of this interesting disco-
very is lost in the obscurity of tradition and imme-
morial usage. Traces of it may be found among
the traditions of many former ages in Great Britain,
particularly in Wales and the Ilighhmds of Scot-
land ; in Italy, France, Germany, Denmark, Sweden,
and some other parts of Europe; in Alrica and
Asia, particularly in Hindostan and China f ,

* See Additional Notes. (E E.)

f It is a remarkable fact, that, in all tlie countries above men-
tioned, there is satisfactory evidence of inoculati(jn for the small-
pox having been practised by the common people, for many years
before its introduction by the physicians of Great Britain ; and, in
«ome of themj as far back as tradition can be tiaced. It is also a
still more remarkable fact, that in JVaks/m the Highlands of ScvN
land, among the ignorant peasantry of Gennauj/, in the interior of
Africa, and in severai parts of tlie Asiatic continent, distant a3
they are from each other, differing widely as they do, in manners,
customs, laws, and religion, the art of communicating tliis dis-
ease by inoculation was designated by the singular phrase of buying
the small-pox ; because it was superbtitiously imagined tb.at, uiocu-
lation would not produce the proper effect, unless the person from
whom the variolous matter was taken received a piece of money,
or some article in exchange for it.— See Dr. Woodville's History
Cf Inoculation. ^'Rovf shall we account for so many different and
distant nations agreeing in so remarkable a phrase to ecipress ino-
culation, and agreeing also to connect with it such as'ii>eri>titiouj
ceremony ? How shall we account, fnrtlier, for this art being con-
fined chiefly to the common people, or the less civilised pjrt of
mankind, while tlie learned were ignorant of it ? May it not be
admitted as one proof of tlie ^reat antiquity of the practice, that
precisely that portion of the community, whose habits, in every

Vol. I. 2 ^

Sol Medicine, [Chap. IV,

But the eighteenth century may boast of the first
regular and satisfactory notices of this noble im-
proveftient, and of making it to be understood and
practised in an intelligent manner among all the
enlightened part of mankind. It is generally said
that the Circassians first inoculated their children in
order to rear them as slaves for the Turkish se-
raglio; and it was certainly first introduced into
Constantinople from Georgia, towards the end of
the preceding age. From Constantinople the Bri-.
tish nation received an account of the practice of
it by the celebrated lady M. W. Montague, who
caused the disease to be thus communicated to her
own children. In IT^l, inoculation was first regu-
larly adopted in England; and in the succeeding
year, the operation being performed upon some of
the children of the royal family, it soon began to
be in vogue. Objections both of a physical, moral,
and religious kind were urged against this new
practice, with great zeal and intemperance, by
many respectable persons of the medical and cle-
rical professions, as well as by others of inferioP'
character. These objections for some time excited
scruples in the minds of many well-disposed people,
and greatly retarded the progress of inoculation.
Having at length, however, surmounted these dif-
ficulties, tlie value of the discovery became every
day more highly rated, and before the middle of
the century might be considered as established upon
the firmest basis.

In the year 1721, and in the same month in
wiiich the daughter of lady Montague' was inocu-

i-ouiitry, are in general most simple, uniform, and stationary, were
f jun;l to reUiin a practice which the more polished had lost?

Sect. III.] Theory and Practice of Physic. 353

lated in England, this mode of communicating the
small-pox was introduced at Boston, in Massachu-
setts. Dr. Cotton Mather, one of the minister; of
that town, having observed, in a volume of the
Philosophical Transactions, printed in Ix>ndon, some
communications from Constantinople and Smyrna,
giving a favourable account of tiie practice, and the
small-pox beginning, about the same time, to spread
in the town, he recommended to the physicians of
his acquaintance to make trial of inoculation. They
all declined it except Dr. Boylston. He began with
his own children and servants. But the degree of
odium which he drew u})on himself by this measure
is scarcely credible. The i)hysicians in general
highly disapproved his conduct. Dr. Douglas*, one
of their number, who had received a regular me-
dical education in Scotland, his native country,
stood foremost in the ranks of opposition. He
wrote, declaimed, and employed all his inlluence
against the intrepid innovator. The medical gen-
tlemen were joined by the populace, who were so
much inflamed against what they esteemed a spe-
cies of murder, that Dr. Boylston was in danger of
his lifef, and Dr. Mather was scarcely less an ob-

* Dr. William Douglas is said to have been a man of learning
and talents. He published some small medical pieces, and ct»r-
responded with Dr. Colden of New York, who, in one ot'hxs
medical communications, speaks of him in terms of high respect.
He was also the author of the work entitled, A Su/iimarj/ of ihc
British Settlements in America, 2 vols, 8vo, London, 1/55. — He
was, however, conceited and arrogant, and behaved w ith great
disingenuousness in his opposition to Boylston.

t Dr. Boylston's house was attacked with so much \ iolence,
tliat he and his family did not consider themseh es sale in it. He
was assaulted in the streets, loaded with e\ery spwcics of abuse,
'J A i

35i5 Medicine. [Chap. IV,.

ject of popular indignation. But the ;;^reater pro-
.portion of tlie clergy of Boston embarked in sup^
port of the measure; they preached and wrote* in
favour of it, until, at length, their influence, greatly
confirmed by the success attending Dr. Boylston*s
practice, gradually overcame the opposition; and
near three hundred persons were soon after inocu-
lated in Boston and the neighbouring towns f.

A degree of the same prejudice and opposition,
which raged with so much violence in Boston, con-
tinued to be manifested not only there, but also in
many other places, for a considerable time after-
wards. But the practice gradually gained ground,
and became general in New-England; in a few
years it was adopted in New- York and Philadel-
phia; and in the year 1738 had reached Charleston,
in South-Carolina.

Till near the close of the century now under con-
sideration, the inoculation of the small-pox con-

and execrated as n murderer. Indeed, many sober pious people
were deliberately of opinion, when he commenced the practice of
inoculation, that, if any of his patients should die, he ought to b«
capitally punished. A bill was brought into the legislature for
prohibiting the practice, under severe penalties, and actually passed
the house of representatives 3 but ^some doubts existing in the
council, its progress was arrested, and it never became a law. — •
See Wwwh'm^ou ?, History nf Massachusetts, vol. ii, p. 247, &^c.

* The Nticspapers teemed with pieces on both sides of -this
interesting controversy ; and especially with some of a xery viru-
lent character, from the opponents of inoculation. The Courant,
a newspaper edited at tliat time by a brother of Dr. Benjamin
Franklin, took a decided part with Douglas and his coadjutors^
The young philosopher was tben an apprentice in tlie office, and
employed his opening talents in favour of the same deluded party.
JV/kS'. Letter of the Rev. Dr. Eliot to the Author.

t Hutchinson's Histvri/ of Muasckchusctts, vol, ii«

Sfxt» III.] Tliconj and Practice of Phi^sic. So7

tinned more and niorc^ to pre\'ail, and to become
the settled iiabit of all that ])oiiion of society who
were placed in easy circnmstanees, and possessed
the better degrees of intelligence. The advantages,
however, of this practice, notuithstaiuling all its
benefits to the individuals who employed it, were
supposed by many, on a general calculation of
human life, to be extremely problematical. Bv'
carrying the disease more fre(|uenlly and univer-
sally through cities and countries, it was i'ound that
the poorer classes of people, which constitute the
great mass of every nation, were much oftener exr
posed to casual infection; and that, on the whole,
the mortality of mankind from this disease was
thereby much augmented.

But such doubts and difficulties as these arising
in the mind of the philanthropist, and much of the
importance of the inoculation of the small-pox,
even to those who employed it, were removed by
the discovery of the inocidation of the Vaccine Dis-
ease, in the year 1798. This may perhaps l)e justly
considered as the most memorable imi)rovemenl
ever made in the practice of physic. By substi-
tuting a disease so much milder that it cannot fail
of being universally preferred, and one w liich at
the same time affords eifectual security against the
small-pox, the prospect is presented of speedily
exterminating the latter disease, and thereby closing
a great outlet of human life.

To Dr. Jenner, of Great Britain, the worl.i i^
indebted for this incomparable discovery, lor al-
though there has existed, perhajis from time im-
memorial, some popular knowledge of the vaccine
disease, and of the fact of its rendering the hunum

358 Medicine, [ChAp. IV.

system unsusceptible of the small-pox*, yet the
practice of inoculating it successively from one
'person to another as a substitute for the small-pox,
and the investigation of the principal circumstances
which ought to regulate that inoculation, in order
to confer upon it the greatest certainty and suc-
cess, seem undoubtedly to have originated with
that physician. Further investigations and disco-
veries have since been made, concerning the nature
and the inoculation of this disease, by other phy-
sicians, particularly by Drs. Pearson and Wood-
villc, and Mr. Ring, of London f. '

* For a number of years before Dr. Jenncr's discovery, it was
kno^vn to many, physicians as well as others, that a disease exist-
ed among the cattle in Great Britain, particularly in Gloucester-
shire, which it xnas said, among the common people, when com-
municated to the human subject, formed a defence against Small'
Pox. Dr. Barry tells us that this disease has been long known in
Ireland, under the name of Shinach : he gives instances of per-
sons who had passed through it Jifty years ago ; and mentions that
one woman, eight 1/ years of age, declares, tliat as long as she can
remember, the opinion prevailed, that people who had the Shi-
nach, or Cow-Pox, could not take tlie S)?iall-Pox; and that many,
at tliat early period, purposely exposed themselves to tlie former,
to avoid taking the latter. Traces have also been found of some
knowledge of this disease existing in other parts of Europe, among
the lower classes of people, a number of years before tlie publica-
tion of Dr. Jenner. — See Barry on Coiv-Pox.

t An institution for the purpose of preserving and communi-
cating the vaccine infection, and particularly for inoculating
the poor, has been formed in London since the publication of
Dr. Jenner's discovery. For this the public are principally
indebted to the enlightened and benevolent exertions of Dr.
Pearson. A similar institution has been more recently formed
in the city of New York. The first person who inoculated
with the vaccine virus, in the United States, was Dr. Waterhouse,
professor of the theory and practice of physic in the university
of Cambridge, Massachusetts,

Sect. III.] Theory and Practice of Physic. 3o9

All preceding ages, and a considerable jiortioii
of the eighteenth century, abound in accounts of*
the destructiveness of the Scurvy in ships on long
voyages, in armies, particularly in garrisons, as
well as in some regions of the high latitudes.
Towards the close of the period under examina-
tion, that dreadful disease has been disarmed of
all its violence, and seems now to be completely
reduced under the dominion of the healing art.
This revolution has been effected by procuring for
persons in the situations above mentioned more
comfortable shelter, clothing, and food. Fresh
meats substituted for salted, and vegetables plen-
tifully supplied, especially the vegetable acids,
may be considered among the principal means of
prevention and cure. The citric acid, in particu-
lar, has accomplished wonders in this disease ; and
the late discovery of crystallising it renders the
remedy conveniently portable to any distance, and
capable of preservation in all climates and seasons,
and for any length of time. 1 he eminent services
of Dr. Lind in improving our knowledge of this
disease can never be forgotten. The philosophic
and enterprising captain Cook was the first who
reduced the improvements in nautical medicine to
practice, in all their extent, and with complete
success*.

* In the first voyage for the establishment oi the East-India
company, out of four hundred and eighty men one hundred and
five died of scurv)/ before they reached the Cape of Good Hope.
Lord Anson, in his voyage round the world, lost, from ihe same
disorder, four-fifths of his original number. Those who have
read the narrative of his expedition, by Robins, will recollect the
dreadful picture w hich is diawn of tlie ravages of this disease ii*

560 Medicine. [Chap. IV,

Pestilential diseases are supposed to have greatly
abated in frequency and malignity in the course of
the eighteenth century. Tiiis observation, how-
ever, must be understood to be chiefly restricted
to those parts of the world which, during that
period, have been making progress in civilisation,
intelligence, and refinement. In many parts of
Asia and Africa, and in European Turkey, it is
probable that little abatement of the ravages of
such diseases has actually taken place. The de-
graded state of man in most of the Mohammedan
countries; the poverty, filth, and wretchedness,
which oppress the lower classes of people in their
crowded cities, and the inattention to cleanliness
and ventilation, even in the houses of the most
opulent, aided by the influence of their doctrine of
fatalism, seem to leave them little prospect of
emerging from their present condition into one
more respectable, and exempt from malignant dis-
eases. The contrast of health and disease, in the
Christian and Mohammedan world, while it aflbrds
to the pious mind a satisfactory confirmation of
his faith, furnishes also to the philosopher and phy-
sician an instructive lesson, with regard to the com-
parative influence of the respective principles and
institutions of Christianity and Mohammedanism.

the vessels under his command. Captain Cook, thirty years
alter Anson, with a company of one hundred and eighteen men,
performed a voyage of tliree years and eighteen days, tliroughout
all die climates, from 52 deg. north, to 72 deg. south, witli the
loss of only one man, who had been previously indisposed. — See
Dr. Ramsay's learned and interesting Revieio of the Improvements^
Proj^n-exs, and Slate of Medicine in, the Eightcciuh Century, &c.
pp. 29 and 30.

Sect. III.] Theory and Practice of PJnjsic. 5G I

The comparative mildness and infrequency of
pestilential diseases in Christian Europe, durin^i^
the late century, are probably owing to a combina-
tion of many causes. Much may ])e srifely ascribed
to improvements in the cleanliness and vcntiiation
of houses, in diet, in apparel, in habits, customs,
and all the modes of life. Cities, which are usually
the great nurseries of pestilence, are now less
crowded than in former ages. The comforts, de-
<:encie% and elegancies of life, from a variety of
causes, are now enjoyed by a greater portion of the
.community, and in a much higher degree than in
preceding times. To the same causes, also, may
be ascribed the almost entire banishment of that
loathsome disease the Leprosy, from tlie civilised
world, which has been in a great measure etfected
in the course of the last a^e.

The frequent and mortal prevalence of the pesti-
lential disease called Yellow Fever, in the cities,
and in some parts of the country, in the United
States, for the last ten years, forms a memorable
€vent in the medical history of this country, during
the century which is the subject of this retrospect.
The malignity and ravages of this epidemic impress^
.ed the public mind with the deepest apprehensions,
and undoubtedly gave a new impulse and vigour to
medical investigation. The origin of this disease
has been warmly contested in the United States,
in the West-Indies, and in Europe. AVliile many
maintain that it is produced by the exhalations of
putrefaction, whether such putrefaction be found in
the fdth of cities, of marshy grounds, or of vessels
f)i\ the water ; others, on the contrary, assert, that
it is always produced by contagion emitted from

S6'2 Medicine, [Chax*. IV.

tlie sick labouring under the disease, and successively
j)ropagated from one person to another. The lat-
ter opinion seems to be fast losing ground among
the better informed part of the medical profession^
and of the public; while the evidence in support of
tlie former is accumulated, and rendered more lu-
minous and irresistible, by the occurrences of every
epidemic season. Much light has been thrown on
the origin, course, precursors, and concomitant
circumstances of this, and of other pestilential dis-
eases, by Mr. Noah Webster, in his History of
Epidemics i an ingenious and learned work, in which
a rich and curious amount of information On this
subject is brought together and exhibited in a very
impressive manner. Though the author is no pfiy-
.sician, he has made a very valuable present to the
medical world, and has entered and pursued with
much ability a path of inquiry, which will proba-
bly conduct to very interesting and instructive con-
clusions. In the mean time, the modes of treating
yellow iii\QY have received great improvement dur-
ing the period under consideration. Those who
liave written on this disease with most reputation,
arc Dr. Rush of the United States, who has had
ample experience in the treatment of it*, and Drs,
Jackson and Chisholm, of Great Britain.

* The intrepidity and benevolence displayed by Dr. Rush, dur-
ing the several seasons in which pestilence has prevailed in Phila-
delphia, deserve the highest eulogium. This remark applies with
peculiar force to the season of 1793, when tlie yellow fever ap-
peared in that city, arra}x^d in greater terrour than ever before or
since in any part of the United States ; when the metliods of treat-
ment were comparatively little understood; when it was univer-
sally considered as a highly contagious disease; and when the.
fortitude and services of this distinguished physician, through the

Sect. III.] Theory and Practice of Physic. Vf^':^

The diseases of Camps^ Armies, and Military
Hospitals^ have attracted much attention, and the
treatment of them received great improvements in
tlie course of the late century. The means of pre-
venting diseases, in such situations, are much more
attended to than formerly; particularly ail circum-
stances which respect the sites of encampments,
the shelter, clothing, food, cleanliness, &c. of troops,
and the ventilation of tlic places in which they are
stationed. For many of these improvements the
public are indebted to sir John Pringle, Drs. Donald
Monro, Brocklesby, Hunter, and others, who have
written on the diseases of armies.

The means of preventing and curing the diseases
incident to Seamen have also been more diligently
and successfldly studied in the course of the last age
than ever before. For very enlightened inquiries
and useful publications on this subject we owe much
to Drs. Lind, Macbride, Clarke, Blane, and Trotter.

Modern times have also given rise to improved
modes of preserving the health, and promoting the
comfort, of persons conhned in Prisons, and other
close apartments. The honour due to the rev. Dr.
•Hales, and sir John Pringle, for their philosophic
inquiries and enterprising exertions to foruard this
branch of improvement, are generally known. But
to no individual that ever lived is the cause of hu-
manity more indebted for services of this kind than

whole course of the epidemic, were preeminently conspicuous.
If the admirers of moral heroism celebrate, as they justly do, the
conduct of the good bhliop of MarseiUcSy and of the benevolent
lord mayo'r of London, it is conceived that the lirmness and useful
exertions of Dr. Rush, in similar circumstances, arc in uo resj[X?ct
less worthy of their commemoration and praise.

S6i Medicine. [Chap. IV.

to the immortal Howard, whose long and painful
journeys, persevering labours, and successful plans
tor meliorating the condition of Prisoners, in every
part of the world, to which he could obtain access,
will ever form one of the most honourable pages in
the annals of human nature *.

The diseases of JVarni Climates are become better
understood, by the efforts of modern times to ex-
tend the range of geographical and commercial en-
terprise; and, from their bold and definite features*
much light has been thrown on the theory and treat-
ment of such as prevail in more temperate regions.
In fact, the whole of that important and interesting
field of inquiry which relates to the comparative
frequency and force of particular diseases, as they
appear in different regions of the earth, and in dif^
icrent states of society, had been but little explored
prior to the period Vvhich we are now considering,

Hie exertions rec'ently made to investigate the
nature and causes, and to lessen the fatality of Pz^/-
monary Consumptiony deserve a transient notice. If
such exertions have not yet produced all the beneficial
consequences which humanity could wish, there is
yet groimd to believe they have effected some good ;
and that no effort in such a cause will be finally

''^ In John Ho\\-ard the eighteenth century may boast of having
produced an unif^ne in the history of man. It would be unjust
to compare Jiim with any hero of benevolence, merely human,
Ix-fOi-e or since li;s time, for such a one never existed. It has
Ueen truly taid, that his plan for promoting the happiness of his
icilow creatures was ori<rinal ; and that it was as full of genius as
oi humanitj/. That it was. the religion of Christ which directed
and animated the exertions of this wonderful man, no one car)
doubt who is acquainted with his history and charrcter. He was
ijjom at }Ia:knoy iu 1720', nivl died in lygo.

Sect. TIL] Theori) and Practice of Physic. S6^

lost. Justice requires, whenever this subject is
mentioned, that the phihinthropic labours of Kush
and Beddoes should be duly appreciated. Simihir
exertions have also been made, and vv ith like con-
siderable success, to throw light on the nature and
cure o^ Scrofula, and the Diseases of the Mind, to
say nothing of many others equally worthy of notice.
Under this head it is proper to take some notice
of the successful attempts which ha^e been made,
during the eighteenth century, to enable the Deaf
and Dumb to speak. Deafness has, in all ages,
been considered such a total obstruction to speech,
and the knowledge of written language, that the
attempt to teach those who are destitute of the
sense of hearing, either to speak or read, has been
generally regarded as vain. One of the first teach-
ers of the deaf and dumb was Bonet, a priest, se-
cretary to the constable of Castile, in Spain, lie
undertook the tuition of his younger brother, who
had lost the sense of hearing at ten years of age;
and he published an account of his system in 1620,
at Madrid. Amman, a Swiss physician, was the
next systematic writer on this subject. He printed
at Amsterdam a treatise in Latin, about the year
1692, entitled Surdus Loquens. Dr. John Wallis,
a iQw years afterwards, suggested, in his Gram-
matica LingUiS Anglic ame, a plan for conveying
ideas to the minds of the deaf more distinctly than
by ordinary signs. He was followed \>y Holder,
Dalgarno, and Bulwer, each of whom devised a
plan, and made some progress in its execution.
There was, however, little done to any vahial)I(,^
purpose till the year 1764, when Mr. Thomas Braid-
wood, of Edinburgh, undertook thc' diliicult ta>k.

366 Medicine. [Chap. IV.

In that year he began with a single pupil, when^
his exertions being attended with complete success,
he was encouraged to extend his views, and after-
wards taught a considerable number to speak di-
stinctl}^ to read and write, and to understand arith-
metic, and the principles of morality and religion.
The same curious and highly interesting art has
also been practised on different plans, but with
great success, by Mr. Baker of London, by M. Hei-
necke of Leipsic; and by father Vanier, M. Per-
riere, and the abbe de I'Epee of Paris. The last
named gentleman has been more successful than
any other. He had instructed upwards of ojie thon^
sand deaf and dumb persons, before he was suc-
ceeded by his pupil M. Sicard*. A regular insti-
tution for this kind of instruction was established
in London, in 1792, under the care of Mr. Watson,
a pupil of Mr. Braid wood.

The late century has likewise made great pro-
gress in ascertaining the means of restormg the
suspended actions of life. Humane Societies for the
recovery of drowned persons, which began to be
instituted soon after the middle of the century,
have since been multiplied to such extent, that they
are to be found in most large sea-port towns.
Great exertions have been made to improve the
knowledge formerly possessed on this subject; and
the means now employed are much more rational
and successful than the rude and often pernicious
ones which used to be resorted to. Many efforts
have likewise been made to prevent the premature
interment of such as are only apparently dead; by

* Sec The Method of Educating the Deaf and Dumb, by the
abbe dc TEpee, translated from the French, Svo, ISOl.

Sect. III.] Theory and Practice of PliysJc. 36?

ivhich some valuable lives have been saved, and
more caution relative to this point impressed on
the community. The service rendered by many
physicians to the cause of humanity, by promoting
objects of this kind, deserves honourable connne-
moration. Of these perhaps i(i\Y are entitled to a
larger tribute of acknowledgement than Drs. Ilaues
and Lettsom, of London.

It vt^ould be easy to descend to a great variety
of particulars, in which the means of curing or mi-
tigating diseases have been radically improved
during the period under consideration; but the li-
mits of this retrospect forbid such details. It is
sufficient to remark, that a large portion of diseases,
however faithfully observed by preceding, and even
by the most ancient physicians, have, within this
period, been better understood, arranged, and dis-
criminated, than ever before ; and that remedies of
superior efficacy have been selected, their qualities,
virtues, and uses, more fully ascertained, and the
best mode of their application rendered more dc-
fmite and precise. The number of incurable dis-
eases, also, has been diminished, and the treatment
of many hazardous and violent ones so far improved,
as greatly to diminish their force and danger. The
recent doctrines of Association and SijmpatJnj in
morbid action, and the interesting practical doc-
trine which results from them, of the transfer of
morbid action from vital parts to such as are less,
essential to life, have unfolded a vast extent of me-
dical exertion and usefulness, which was nearly un-
known to the physicians of former centuries.

The practical writers on medicine, durin;,- thi»
i^ighteenth century, were very nuni'^rous ajid ns

^

6$ Medicine. [Chap. IV,

spectable. From so large a catalogue it is difficult
to select the few names of which the brevity of this?
review will allovv' the insertion. Beside a conside-
rable number of those mentioned in the foregoing
pages, Wintringham and Huxham, on epidemicaF
diseases, deserve a high place ^ Cleghorn, on the
diseases of Minorca; Hillary, Why tt, FothergilP,
Heberden, Lind, Jackson, Fordyce, and Chishalm,
do honour to the British nation. Among the French
Senac and Lieutaud, and among the Germans Storck
and von Haen hold the first rank; to say nothing of
many others, in almost every cultivated part of
Europe, who have obtained much distinction by
their practical writings on medicine.

SECTION IV.

SURGERY AND OBSTETRICS.

Tliat department of medicine which treats of dis-
eases to be cured or alleviated by the hand, by in-
struments, or by external applications, is denomi-

* Dr. Fothergill died in 1/80, in the (58th year of his age.
Distinguished as he was f6r his learning, the soUdity of his talents,
and the extent and success of his medical practice, he was ren-
dered still more conspicuous by the purity of his moral and reli-
gious character, and the ardour of liis philantliropy. His great in-
fluence was continually exerted for the increase of human hap-
piness. Of every institution within his reach, which had for its
object the advancement of useful knowledge, or the iilterest of
liumanity, he was a zealous and active promoter. Of public and
pri\ate charity he was an illustrious example j and we are informed
that a large number of those improvements, which have so much
contributed to the health of the city of London, either originated
from his counsels, or were effected, in a great measure, by his
influence.

Sect. IV.] Surge?y and Obstetrics. 3G9

^nated Surgery. At the close of the seventeenth
century this art had considerably emerged from the
low state in which all preceding ages had left it.
Many respectable writers had appeared in the
course of that century, whose exertions to improve
the practice of surgery, and to diifuse the knowledge
of such improvements, were attended with so much
success as to ren(]er the ])rogress of it compara-
tively rapid at the commencement of tlie eighteenth
century.

It will be easy to perceive that the nmnerous
improvements in other branches of medicine, which
are detailed in the preceding parts of this chapter,
must have greatly . advanced the progress of sur-
gery. Every step in the cultivation of anatomy
and the theory and practice of physic confers some
advantage on medical or operative surger}'. Tlie
improved state of the m.echanic arts has likewise
served to divest it of much of that useless machinery
with which it was formerly encumbered, to retain
only what appears to rest on the basis of experi-
ence, and to aid ingenuity in supplying many im-
portant deficiencies. Menee, the surgery of the
eighteenth century may not only boast a more in-
timate acquaintance with the structure and func-
tions of the human body, and with the fundamental
principles of diseases, but likewise a superior sim-
plicity, neat ness, ease, and expedition, in the per-
formance of operations.

Early in the century whicii forms the sul^ject of
this retrospect, Laurence Heister, professor of sur-
gery in the university of Helmstadt, published his
System of Surgery, m Inch continued till about fif-
teen years ago to be the onlv tohTublv <N>inpf(4«''

Vv^L. I. '•' li

3;0 Medicine. [Chap. IV.

system in possession of the public. This work com-
prised whatever the experience of former times had
approved as useful, and such observations and
precepts as the knowledge and experience of the
learned author himself enabled him to add. Some
other systematic arrangements of chirurgical know-
ledge were, indeed, attempted about the middle of
the century. Platner, professor of surgery at Leipsic,
published his Institutes of Surgery in the year 1745;
and Ludwig, of the same university, favoured the
world with a similar publication in 1767. But both
these works, though possessed of great merit, are
too compendious to give a clear and distinct ac-
count of the numerous topics of which they
treat.

In Great Britain, Mr. Cheselden was much di-
stinguished by his chirurgical eminence in the early
part of the century. He improved the lateral ope-
ration of Lithotomy y and devoted much attention to
the diseases of the Eyes. His pupil, Mr. Samuel
Sharpe, obtained soon afterwards a high reputation.
His Treatise on the Operations of Surgery, and his
Critical Inquiry, were deservedly considered as
performances of great value at that period. The
elder Monro, of the university of Edinburgh, de-
serves also to be mentioned among those who did
much to improve the practice of surgery about
that time. Towards the middle of the centu-
ry Dr. William Hunter began to acquire great
celebrity as an anatomist and surgeon, and was
joined not long afterwards by his brother, Mr. John
Hunter, who, as an operator, was still more di-
stinguished. To the exertions of these eminent men
the art is indebted for many valuable irnprovementSj

Sect. IV.] Surgery and Obstetrics. 37 1

both in theory and practice. After the middle of tlie
century Mr. Percival Pott began to take a high
station among British surgeons, added greatly to
the progress of the art, and published many excel-
lent writings, which are still in the highest esteem.
The present professor Monro, of Edinburgh, ha.s
enriched surgery by many important additions to
the preceding stock of knowledge, which greatly
increase the lustre of his reputation. Late in the
century, about the year 1788, Mr. Benjamin Bell,
of Edinburgh, completed his Sxjslem of Surgery,
which vv^as compiled with much learning and dili-
gence, and exhibited an advantageous view of the
progress and improvements in surgery up to that
period.

The particular improvements in surgery during
the late century are extremely important, and re-
flect great credit on the ingenuity and labours of
those by whom they were made; but they are like-
wise so numerous that only a iew of them can be
mentioned consistently with the necessary brevity
of this retrospect.

The means of putting a stop to Hcemorrhages
from the division of the larger blood-vessels have-
been much improved during the i)eriod under con-
sideration. The hrst notices of the instrument for
this purpose,- called the Tourniquet, originated in
the seventeenth century. It is amazing that so
simple an instrument, and so obvious a mean of
compressing arteries, should have remained unknown
till that period. Surgery must have been in a <le-
plorable state of rudeness and imbecility, when no
operation of importance could be umlcrtaken on

anv of the extremities but with the greatest d;iu-

2 B J

S70| Medicine. [Chap. IV.

ger of bleeding to death, and large wounds, other-
w'lse in no degree hazardous, must often have
proved mortal for the want of this simple contriv-
ance. The first attempts to construct it were very
rude and imperfect 3 and it was reserved for Mons.
Petit of Paris, by adding the screw, to render it
much more convenient and powerful in the com-
pression of arteries. xVnother interesting improve-
ment in securing arteries belongs to the late cen-
tury. Instead of the needle and ligature, which
were formerly used for this purpose after operations,
the tenaculum, ovfoj-ceps, is now employed, which
produces much less pain, and prevents many ill con-
sequences of the old method. The first application
of the needle and ligature to surgical purposes,
'w hich is ascribed to Ambrose Parey, of the sixteenth
century, was a great improvement. Since that
time many variations have taken place in the mode
of using them 3 and in the course of the eighteenth
century, the different kinds of sutures have been
still further improved in many important respects.

The treatment of diseases of the Head from ex-
ternal violence has been extremely improved within
the period of this retrospect. For this interesting
l^art of the progress of surgery the world is much
indebted to M. le Dran, Mr. Pott, Mr. Bromfield,
and others.

The various species of Hernicc are much better
understood within the last fifty years; and much of
the progress in this branch of surgery is due to the
acuteness and indefatigable labours of the late Mr.
l^ott. Tlie disease termed Hydrocele has also,
within the same period, been investigated with
iiiucli more success than ever before ; for which mnch

Sect. IV.] Surgery and Obstetrics. 573

is to be ascribed to Mr. Pott, Mr. Benjamin Bell,
and sir James Earle..

The interesting subject of Aneurisms has derived
great additional light from the researches of modern
anatomists and surgeons. Dr. William Hunter ex-
amined the phenomena of this disease with great
diligence and success. Tiie present treatment of
the popliteal aneurism, which forms a memorable
improvement in surgery, is to be ascribed to Mr.
John Hunter.

The lateral operation oi Lithotomy, which is now
generally preferred, owes much of its present im-
proved state to the labours of the surgeons of the
late century. Mr. Cheselden did a ffreat deal to
improve it in the first half of the century; and,
since liis time, much has been done by Pott, Brom-
field, Gooch, sir James Earle, and many others.
The Gorget, which is so important among the se-
veral instruments employed in this operation, was
tjie invention of Mr. Hawkins of London.

In the management of Fractures and Luxations
much advantage has been obtained, witliin the
last fifty years, by avoiding the constrained and un-
natural positions formerly imposed in such cases,
and generally placing the alYected limb in that
easy, relaxed, and bent position which the natural
inclination of the patient prompts him to assume.
By these means much pain is spared, and the straight-
ness and perfect recovery of the alfccted limbs ex-
ceedingly promot.Yl. 'i'he efforts of Mr. Pott in
effecting this salutary reform deserve wvy honour-
able mention.

The treatment o^Gnnshot Wounds is another point
on which the surgerv of the eighteenth ccntmy

57-4 Medicine. - [Chap. IV.

claims a great deal of improvement. This has been
effected chiefly by giving up the artificial and over-
officious management of former times,. by admit-
ting the operation of general principles, instead of
considering them as poisoned wounds, and by adopt-
ing the light, easy, and superficial dressings which
experience has been found to approve.

Much light, during the late century, has been
thrown on the various diseases of the Eyes, and
particularly on the Cataract. The same may be
observed of Fistula Lacrijmalis, and of Fistula in
Am. Among many others, Mr. Pott has largely
contributed to the elucidation of all these subjects,
and to the banishment of many prejudices and er-
rours concerning them, which fifty years ago ex-
isted in great force. To the same distinguished
practitioner surgery is indebted for a mode of treat-
mg Curvatures of the Spine, far more successful
than any previously known.

Lately Mr. Abernethy, of London, has suggested ,
a mode of treating Lumbar Abscess, which some-
times succeeds very happily, and often affords rea-
sonable grounds of hope in that deplorable disease.
And not long since, the theory and management
of Ulcers has been gradually improved by the per-
severing labours of many surgeons, among whom
it would be unjust not to mention Mr. Benjamin
Bell, Mr. Home, Tvlr. Baynton, Mr. Whately, and
xVL'. Nay lor. The subject of Wounds has recently
>>eeii treated with great ability and discernment by
Mr. John Bell, of Edinburgh, who deservedly sus-
tains a liigli rank among the surgeons of the Scot-
tish iuolropolis.

But \.\\L' greattr-st of all luiprovemcnts in surgery

Sect. IV.] Surgerij and Obstetrics. 315

which the eighteenth ceutitry can boast, consists in
the maxim o^ Saving Skin in all operations, and in
the universal doctrine and practice of Jdhesiony as
now received. This improvement is so simple and
so important that it is wonderful to find it re-
served for the surgeons of so late a period. Tlic
merit of this discovery does not seem to belong
exclusively to any individual. A share of it doubt-
less attaches to Mr. Alanson of Liverpool, and
several others who directed their inquiries to this
object about the same time. But to !Mr. John
Hunter more is certainly due than to any other
person. This improvement was first applied to
amputation^ then to the operation of the trepan^
next to the extirpation of scirrhous breasts, after-
wards to all the great operations, and, lastly, to all
recent wounds. In short, it would not be too
much to assert, that this doctrine and practice of
adhesion have done more to promote the progress of
surgery, within a lew years, than any discovery of
modern times, not excepting, perhaps, even that
of the circulation of the blood.

It remains to offer a few remarks concerning the
progress of Obstetrics in the late century. By this
term it is usual now to understand not only the
art of facilitating the birth of children, but that of
managing pregnant and puerperal women. During
the period of our retrospect, the improvements which
this art has received may justly ])e considered as
numerous and important, and fully equal to those
which are claimed in the other departments of me-
dicine.

Both the theory and practice of obstetrics have
assumed a much more regular and scientific form

37t) Medicine. [Chap. IV.

Avitliln the period in question. The anatomical
structure of the l)ocly, so far as it concerns this art,
was well understood in former ages. But the in-
tricate and interesting relations of one part to
another, their distances and their inclinations, both
with respect to each otlier, and to different parts of
the bod}^, as well as with regard to the foetus, form
a branch of inquiry on this subject which has been
prosecuted to advantage only in modern times.
Dr.Smellie, is supposed to deserve the praise of be-
ginning this improvement and pursuing it to con-
siderable extent*.

By the light of the eighteenth century, not only
many new truths have been brought into view, but
a multitude of errours, prejudices, and superstitious
opinions, which formerly misled the obstetrical art,
have been in a great measure banished f. Nature
has resumed it.s dominion, and is now followed as
the safest guide. Much of the officious and violent
interposition of former practitioners, to hasten or
control tlie natural process of parturition, has been

* Dr. Smellie is said to have been the first writer who consi-
dered the shape and size of tlie female pelvis as adapted to the
head of the I'oetusj to have abolished many superstitious no-"
tions, and erroneous customs, that prevailed in the management of
women in labour and of children; and to have had the satisfaction
of seeing most of iiis maxims adopted in the greater part of
Europe. — Ramsay's Kcvic-j:, p. l.'}.

■\ Van Swieten quotes several authors of reputation, who had
advised lying in women to keep their beds till the tenth or twelfth
day after parturition j and this was frequently done without chang-
ing their bed-linen. The children were also incased from head to
foot, so as to be totally deprived of the use of their limbs. ThesG
absurd and unnatural practices have, witluu the last half cenairy,
?^!i ;idd'CkA\\y ey.ploded. — Ihid.

Sect. IV.] S'urgciy and Obstetrics, .^377

found to be injaiious, and is now generally relin-
quislied. The modern instriunents, in comparison
of those employed by the ancients, arc few in lunn-
ber, simple in construction, and seldom resorted to.
The diseases of the pnerperal state have been
much better understood, discriminated, and treated,
within a few years, than in preceding times. The
late publications of Dr. Smellie, Dr. Manning, Dr,
llulme. Dr. Leak, Mr. White, Mr. Moss, Dr. Ha-
milton. Dr. Denman, Dr.Osborn, M. Baudelocque,
and many others, whose names are only excluded
by the brevity of our plan, have thrown much hght
on the subject of obstetrics, and do great credit
to their profession. The elegant plates of doctor
William Hunter, before mentioned, may also be
considered as a great acquisition to the theory and
practiceof this art.

ADDITIONAL NOTES.

Noie (A), page 18.— THE following compendious view of
the system of J. Hutchinson, esq., as it respects Natural Philo-
sophy, is extracted from a Letter to a Bishop, concerning some ini'
portant Discoveries in Philosophy and Theology, by the right ho-
nourable Duncan Forbes, president of the court of session in Scot-
land. As this gentleman appears to have been favourable to tlie
Hutch insonian philosophy, and had doubtless devoted much atten-
tion to it, he may be supposed by som(^ to give a more satisfac-
tory account of it than that whidi is exhibited in the page above
referred to.

'' The first thing that is met with in the books o{ Moses is ?.n
assertion tliat God created the heavens and the earth, which is
followed by a particular account of the order and manner of the
tbrmation of all that was created, till the work was perfected.
After wliich, God is said to have rested ; and our author asserts,
that it is also said, the perfect machine, then left to itself, carried
on all the operations in tliis system, by certain known laws of me-
chanism, explained by Moses, and tliroughout the Scriptures by
the other inspired penmen.

*' The sum of what our author avers to be the doctrine of the
Scriptures, on tliis head, is, that, beside the difl'erently formed
particles, of which this earth, and tlie several metals, minerals,
and other solid substances in it, and in the other solid orbs, are
composed, God at first created all that subtile fluid which now is,
and from tlie creation has been, in tlie condition of fire, light, or
air, and goes under the name of the heavens.

"The particles of this fluid (which our author calls atoms),
when they are single and uncompounded, are inconveivably mi-
nute, and su subtiic as to pervade the poix-s of all substances what-

380 Additional Kofef*

ever, whether sohd or fluid, without any great difficulty or re-
sistance ; when tiiey are pushed fon^'ard in straight lines by the
action of fire, or are reflected or refracted in straight lines, they
produce light, and are so called ; but when the interposition of
any opaque body hinders their progress in stiaight lines, they pass,
but cease to produce light.

'* These particles or atoms, which, when moving in straight
lines, produce light, and, if collected and put into another sort of
motion, would produce heat and fire, are, as our author insists,
when the force impelling them ceases to act with vigour, and
when their motion is retarded, so made, tliat they are apt to ad-
here in small masses or grains, which the author calls spirit or
air, and is of the same kind and texture witii that air which we
daily breathe, and wdiich we feel in wind when it blow^s.

" The sun, which our author places at the centre of this sy-
stem, is an orb included in a vast collection of this subtile matter
in the action of fire, which continually melts down all the air that
is brought into it by the powerful action of the firmament or ex-
pansion, hereafter to be explained, into the subtile matter just
mentioned j and with an immense force sends forth, in perpetual
streams of light, this same subtile matter, so melted doA^-n, to the
circumference of this system, which the author says is bounded,
as he avers the space comprehended within it is absolutely
full.

*' The matter thus melted down at the orb ©f the sun into
light must, as every thing is full, either stand still or make its way
outwards to the circumference ; being forced by the particles which
are concreted into air at the utmost extremities, and return
towards the sun, where, the fluid, being most subtile, gives least
resistance, and take up the place that the light left.

" And therefore this endless uninterrupted flux of matter from
tlie sun in light, in place of being an expense that should destroy
that orb (which our author takes to be an insupportable objection
to sir Isaac Newton's scheme) is the very means of preserving it»
and every thing else in this system, in its action and vigour, by
pressing back perpetual supplies of air to be melted down into
light, and thercb}- producing a continual circulation. These per-
petual fluxes or tides of matter outv.ards and inwards, in every
point, from the centre to the circumference, mechanically, and
necessarily, as our author insists, produce that constant gyration in
the eartii and the planets rn\ind their own centres, and round thu
sun • and he avers, though he has not yd thought fit to explain it^

Additional Notes. 381

<:hat the same prliicipl(>, with 'sonic circumstances arising from
*he situation and fluxes of light coming from the other orbs, will
account also for the motions of the moon.

'' Beside the rotation of the orbs, the autlior affirms that the
adverse motions of the light pushing towards the circumference,
and the air pushing towards the centre with immense force, form
a general expansion (as he translates the word rendered firma-
ment) which brings that stress or compressure on all bodies it
meets with, that binds together solids, keeps fluids as they were,
causes the variation of times and seasons, the raising of water, the
production of vegetables and animals, and, in short, produces all
the effects falsely ascribed to gravity or attraction j continues mo-
tion without the assistance of the unmechanical principle of
projection; produces, supplies, and supports vegetables, fruits,
and animals 3 in short, produces almost all the effects and phaeno-
mena in nature,"

Note (B),p, 10. — I have scarcely done justice to Parkhurst,
Home, and Jones, those truly learned, pious, and excellent di-
vines of the church of England, in representing them, without .
qualilication, as having adopted the philosophy of Hutchinson.
Though they all went a considerable length in embracing the opi-
nions of that singular man, yet they were none of them thorough
Ilittchinsoniam. Perhaps the most satisfactor}' information on tliis
subject may be obtained from the perusal of Mr. Jones's Memoirs
of ike Life, Studies, and Writings, of bishop Home.

The philosophical works of the rev. Mr. Jones desen-e to l)C
mentioned with great respect, in this class of writings which
belong to the eighteenth century. On a variety of subjects I am
far from agreeing with him in opinion ; but his learning, his in-
genuity, his love of tmth, and particularly the zeal and success
with which he shows the consistency between tme philosophy
;and revelation, entitle him to the veneration and gratitude of all
good men.

In representing both the knowledge and the admiration of
Hutchinson's voluminous writings, as having nearly disappeared
before the end of tlie century, it is possible that the flict is stated
rather too strongly. It is believed, however, that very few gentle-
men now living' in Great-Britain, who hold a respectable rank in
the scieutUic world, either embrace die opinions of Hutchinson,
or study his works.

It i;: not ea«y to account for the prejudice^ puteitjin'.d t>y

582 Additional Notes.

Hutchinson and his followers against the philosophy of Xewtofi,
as if it were hostile to revelation -, and, above all^ for the suspicion
indulged by him, that sir Isaac and Dr. Clarke had formed a de-
sign, " by introducing certain speculations, founded on their new
mode of philosophising, to undermine and overthrow the theology
of Scripture, and to bring in the heathen Jupiter, or the stoical
Anima Mimdi into the place of the true God/' 1 believe that
notliing was further from the minds of those great men, than to
represent matter 36 possessing inherent activit^j. If any who pro-
fess to be their followers be chargeable with fallhig into this errour,
none can be too severe upon the atheistical tenet. In the New-
tonian system, the attraction ascribed to all matter is not an in-
dependent principle or agent, but simply a fact, referred for its first
and continued existence to the immediate power of God. If
either class of philosophers be chargeable with going too far in at-
tempting to ascertain causes, and in ascribing agencies to material
objects^ it appears to me to be the Hutchinsonians.

Note (C), p. 22. — The learning and talents of father Bosca-
vich are universally acknowledged ^ and he is represented as
'** unstained in his morals, sincerely attached to the Christian re-
ligion, and exact in the performance of all Christian duties, as be-
came a catholic priest."- His publications on Mathematicsy Optics,
Astronomy i Hydrodynamics, &c., render him one of the most distin-
guished men of the age.

The friends of the 'Theory of Natural Philosophy laid be-
fore the public by this celebrated Italian speak of it in the
higliest term's and consider it as one of the noblest etforts of mo-
dern genius. It has been substantially adopted by Mr. Mitchel,
by Dr. Priestley, and by some other distinguished writers on the
physical sciences, who all regard it as relieving philosophy from
many pressing difficulties, and opening the way to much new and
important light. One groat objection to this system immediately
presents itself to the mmd, and has been forcibly urged against
It, viz. — If every particle of matter be strictly inextended, wherein
does it differ from that eiv; rationis, a mathematical point, xvithout
parts or magnitude ? or rather, wherein does it differ from a mere
point of space ? "Will not the adoption of this system conduct its
advocate a step further, and lay him under the necessity of denying
the Ttal existence of a material world, and of supposing that what
we call by that name is a mere system of attractions and repulsions^
without any substunct in which they can inhere ? It is proper to

Jddiilonal Koles: 383

observe, that Boscovich was aware of tliis obj^-ction, and answered
it by denying that extension is a necessary attribute of matter. But
is not this a pctitio pr/ncipii ? And if it be adniittcd, we may
well ask, wherein does matter, acconling to tliis philosoplun",
differ from spirit F

Leibnitz had taught before Boscovich, that the first principles of
matter are incxtcnded points. The princij^al dirtijrence between
the monads of the former, and the incxtcnded atoms of the latter,
lies in the qualities or forces witli which they are represented as
endowed. The attractive and repulsive powers of Boscovich differ
materially from the active and perceptive powers of Leibnitz,
which he considered as sufficient not only to actuate the monad
at a particular point of time, but also to produce all the changes
which it undergoes from the beginning to eternity.

Boscovich seems to have been the fii-st who rejected all im-
mediate contact between bodies, and their constituent parti-
cles. In this way he got rid of the diiBculty of supposing an <rx-
teiided substance to be made up of incxtcnded points. Leibnit^
by not resorting to the same bold doctrine, left tliis diilicalty ly*
ing in all its force against his system.

Note (Djf /). 20. — ^The following account of experiments on
the influence of electricity, in forwarding the germination and
growtli of plants, is extracted from the Botanic Garden, part i,
canto i, note.

'' The influence of electricity, in forwarding the germination
of plants and tlieir growth, seems to be pretty well established;
though M. Ingenhousz did not succeed in his experiments, and
thence doubts the success of others ; and though ^L Rouiand
from his new experiments believes, that neither positive nor nega-
tive electricity increases vegetation, both which philosophers had
previously been supporters of the contrary doctrine : for many
other naturalists have since repeated their experiments relati^•e to
this object, and tlieir new results have confirmed their former
ones. M. d'Ormoy, and the two Roziers, have found the same
success in numerous experiments which they have made in the
last two years 5 and M. Carmoy has shown, in a convincing man-
ner, that electricity accelerates germination.

*' M. d'Ormoy not only found various seeds to vegetate sooner,
and to grow taller, which were put upon his insulated table, and
supplied with electricity, but also, that silk-worms began to spin

384 Additional Notes,

much sooner which were kept electrified, than those of the same
hatch which were kept in the same place and manner, except that
they were not electrified. These ^^experiments of M. d'Ormoy
are detailed at lengtli in the Journal de Physique of Rozier, torn,
xxxv, p. 270.

*' M. Bartholon, who had before written a tract on this subject,
and proposed ingenious methods for applying electricity to agri-
culture and gardening, has also repeated a numerous set of expe-
riments ; and shows both that natural electricity, as well as the
artificial, increases the growth of plants, and the germination of
seeds ; and opposes M. Ingenhousz by very numerous and conclu-
sive facts. — Ibid. torn, xxxv, p. 401.

" Since, by the late discoveries or opinions of the chemists,
there is reason to believe that water is decomposed in the vessels
of vegetables 5 and that the hydrogen, or inflammable air, of
which it in part consists, contributes to the nourishment of the
plant, and to the production of its oils, resins, gums, sugar, &c. 5
and, lastly, as electricity decomposes water into these two airs,
termed oxygen and hydrogen, there is a powerful analogy to in-
duce us to believe that it accelerates or contributes to the growth
of vegetation, and, like heat, may possibly enter into combination
with many bodies, or form the basis of some yet unanalysed
acid."

For a number of years after the experiments of Mr. Maimbray,
and the abbe NoUet, by which it appeared that electricity had
been found to forward the germination and growth of vegetables,
there was no doubt entertained of the tnith of their doctrine. It
remained uncontradicted until Mr. Swankhardt published the
facts which he had learned from M. Ingenhousz. Since that
time the number of sceptics or opposers has increased 3 and it
seems to be now doubtful whether the first experimenters on this
subject were not mistaken. — M. Sennebier, in a late work, con-
cludes tliat the eftect of the electric fluid on vegetables is at least
dabious — Sec Physiologie Vegetate, 8:c. tom. iii, p. 399.

Kote (E), p. 29. — The principal advocates of the Franklinian
theory, viz. that all the phenomena of electricity may be accounted
for by the difterent states and operations of one liomogeneousjiidd,
are Canton, le Roy, Priestley, Henley, Beccaria, Cavallo, Mor-
gan, and several others. To the class of those who reject this
theory, and consider the agency of tivo elcclricjluids as necessarj*

Additional Xotes. S^!j

(.o be supposed, belong Symmer, Eeles, Cisjna, Adams, Ciithbcrt-
«on, Darwin, Brooke, and several oi\w\- distinguished writers on
4his subject.

Tiiose who adopt the opinion tliat there, are u.o clcctvic fluids,
are, however, by no nicans agreed among themselves. Some, as
Syiumer, Eeles, Adams, c\:c., believe in two fluids, which operate
on each other, and on other bodies, upon mediunical principles.
They suppose that these are two distinct, positive, and active
powers, which equally and strongly attract and condense each
other j .that they exist together in all bodies, in tlieir natural state,*
conjoined j but that their electric signs, or what we call electricity,
only become sensible in consequence of the separation of these
two powers. That, w^hile united, they are latent and invisible j
but when separated they become immediately visible and active.
These two fluids or powers are called Vitreous and Resinous elcc-
tiucities. — See Eeles's Philosophicai Essays, 1/7 ^> and Adams's
Lectures.

There are others who explain the phenomena of electricity
upon cheinical principles. They also belie\e in the existence of
two distinct and positive fluids J but instead of a mechanical o^q-
ration, they consider all their sensible elfects as arising from che-
mical affinity and union. The following tlieory of Dr. Darwin
may serve as a specimen of chemical electricity. — See Temple of
Nature, Additional Notes, p. 40\ 4to. Lond. 1803.

1. There are two kinds of electric ether, whieh exist either
separately or in combination. That wdiich is accumulated on the
surface of smooth glass, when rubbed with a cushion, is here
termed vitreous ether ; and that which is accumulated on the sur-
face of resin, or sealing-wax, w-hen rubbed in like manner, is here
termed resinous ether : and a combination of them, as in their
iisusl state, may be ternied neutral electric ethers.

2. Atmospheres of vitreous, or of reshious, or of neutral elec-
tricity, surround all separate bodies, are attracted by them, and
permeate those which are called conductors, as metallic, aqueous,
^nd carbonic substances ; but will not permeate those which are
called nonconductors, as air, glass, silk, resin, sulphur.

3. The particles of vitreous ether stiongly repel each other,
but attract the particles of resinous ether, and via: lersd. When
the two electric ethers unite, a chemical explosion occurs, in some
respects like that of gunpowder, light and hc^at are lil)erated, and
rend or fu-e the bodies which they occupy.

4. Glass holds within It, in combination, much resinous elec-
VoL. I. 2 C

3S6 Additional Notes.

trie ether, ■tt-Lich constitutes a part of it, and which more forclbijr
attracts vitreous electric ether from surrounding bodies, which
stands on it, mixed with a less proportion of resinous ether, like
an atmosphere, but cannot unite with the resinous ether com-
bTned v ith the glass. And resin, on the contrary', holds within
it, in combination, much vitreous electric ether, which constimtes a
part of it, and which more forcibly attracts resinous electric ethei
n-om surrounding bodies, which stands on it, mixed with a les3
proportion of vitreous ether, like an atmosphere, but cannot unite
with the vitreous ether which is combined with the resin.

5. Hence the nonconductors of electricity are of two kinds,
and opposite to each other j the one class the vitreous, the other
,the resinous. But the most perfect conductors, such as metal,
w'ater, and charcoal, having neither kind of electric ether cofubined
xvith them, though surroimdtd with both, suffer both kinds to pass
through tliem easily.

6. Great accumulation or condensation of the separate electric
ethers attract each other so strongly, that they will break a passage
throu'jch nonconducting; bodies. Hence trees and stone walls are
rent by lightning.

7. When artiricial or natural accumulations of these separate
ethers are in very small quantity or intensity, they pass slowly,
and with ditficulty, from one body to another, and require the
best conductors for this purpose. Whence many of the pheno-
mena of the Toi'pcdo, or Gyytmotus, and of Galvanism.

8. The electric ethers may be separately accumulated by the
contact of conductors with nonconductors — by vicinity of the
two ethers — ^by heat — and by decomposition.

9. When these two etJiers unite suddenly, and with explosion,
a liberation of light and heat takes place, as in all chemical explo-
sions. Accordingly it is said that a smdl is perceptible from elec-
tric sparks, and even a tnate, which must be supposed to arise
from new combinations or decompositions.

The theory founded on the principles above stated is supposed,
by those who adopt it, to solve many difficulties which can
scarcely be accounted for on the theory of Franklin. To say that
the former inode of accounting for the electrical phenomena will
prcjbably be found the true one, would be, in the present state of
oar kno\^ ledge, to pronounce rashly ; but if this subject should
ever be developed, it will probably be found that Electricity ought
to be considered as a branch of Chemistry ; that its phenomena re-
tail from the union of two substances, by the cJieiuical combina-

Additional N'oles. 387

lion ©f which explosion is produced, ntid light and heat are
liberated.

Dr. Gibbes also adopts a chc-inicil theory of electricity. He
supposes that oxygen gas is pn^duced by the union of positive
electricity with water; and hydrogen gas by the union of negntiic
electricity with water ; and that water, uniting in dift'ercnt pro-
portions with the two electricities, is the ponderable part of all the
elastic fluids. He asserts that, by the positive electricity, metals
are oxydated, and blue vegetable colours reddened ; and also that
the acidifying effect of electric commotions in the atmosphere, on
weak fermented liquors, is unquestionable. On the otlicr hand,
according to this writer^ by negative electricity the vegetable blue is
restored, and the oxydated metal revived.

These circumstances, among others, lead Dr. Gibbes to con-
clude, that when hydrogen gas is produced by the affusion of
water on red-hot metal, and the metal is at the same time oxy-
dated, a decomposition of j?re ratlier than ofii:ater has taken place -,
that the hot nietal has parted with negative electricity, which,
uniting with a small proportion of the water, has formed hydrogen
gas ; (hat a greater proportion of the water has united with ihe
positiv'e electricity, and entered, as oxygen gas, into combination
with the metal. When the two gasses are inflamed together
the spark attracts to itself, in due proportions, the two electrici-
ties contained in the two gasses, which unite with explosion,
and produce fire. The water with which they were before com-
bined is of course deposited.

The reason why inflammable substances bum in oxygen gas,
and not in hydrogen. Dr. Gibbes supposes to be that negative elec-
tricity greatly prevails in all inflammable substances. Neither of
the gasses can be inflamed separately, because fire depends on the
union of the two electricities ; and such union cannot be eflected
unless both are present in due proportion.

Dr. Gibbes supposes that the further illustration of the effects
of the two electricities as chemical agents will set aside some of
the leading doctrines of the Lavoisierian theory, and aftbrd an easy
solution of certain phenomena which that theory cannot explain.

It is a curious fact tliat Dr. Gibbes, in supposing that oxyi^cn ga«
is produced by the union of positive electricity with water, and that
hydrogen gas is produced by the union of negative electricity with
water, was anticipated by Dr. Priesiley.— Scu his Letter to 1):
Woodhouse, Sept. iG, 1901, in the Medical Rcp-^iitory, New
York, vol. v, p. loS.

:>. C 2

388 Additional Notes.

Note (F), p. 30. — Mr. ^pinus, of the imperial academy of
St. Petersburg, has attempted to class the phenomena of JS/t^cm-
citj/ and Magnetism in a mathematical method. In the course of
his work he gives some views of the subject which *are new, and
highly ingenious, and, as some good judges suppose, calculated to
surmount many difficulties, and to answer many questions which
occur in considering the Franklinian theory. — ^The leading princi-
ples of his plan are comprehended in the following propositions.

The phenomena of electricity ai'e produced by a fluid of pecu-
liar nature, and therefore called the Electric jiuid, having the fol-
lowing properties.

1,. Its particles repel each other with a force decreasing as tlie
distances increase.

2. Its particles attract the particles of some ingredients in all
other bodies, with a force decreasing, according to the same law,
witli an increase of distance J and this attraction is mutual.

3. The electric fluid is dispersed in the pores of other bodies,
and moves with various degrees of facility through the pores of
dilTcrent kinds of matter. In those bodies which we call Tzon-
electrics, such as water or metals, it moves without any perceiva-
ble obstruction j but in glass, resins, and all bodies called electrics,
it moves with very great difficulty, or is altogether immovable.

5. The phenomena of electricity are of two kinds: — 1. Such
as arise from tlie actual motion of the fluid from a body contain-
ing more, into one containing less of it. 2. Such as do not im-
mediately arise from this transference, but are instances of its at-
traction and repulsion.

These principles are applied at great length, and with a pleasing
degree of precision, by the ingenious theorist, to the Leydcn Phiul,
and to the various phenomena of electric attraction and repulsion.
It will be readily seen that iEpinus adopts, in substance, the
theor)-^ of Franklin ; of which, in some particulars, he presents
new and more satisfactory \iews than the American philosopher.
In the sixty-first volume of tlie Philosophical Transactions there is
a Dissertation, by the honourable Mr. Cavendish, on this subject,
wliich he considers as an extension and more accurate application
of T^pinus's thcor}'.

Xott' (G)yp. 33. — ^The Gymnotns Electricus is a native of thoi
river of Surinam, in South America. Those which were carried
to England about eight years ago were about three or lour feet
long, and gave an electric shock, by putting one linger on the

Additional Nofa^ ?m

bacV, nenr its hcad^ nnd another of tlu* opposite Imnd into iLf
water near its tail. In their native country they are said to ex-
ceed twenty feet in length, and kill any man who approaclies iheni
in a hostile manner. It is not only to escape its enemies that
this surprising power of the iish is useil, but iilso to take its prev ;
which it does by benumbing them, and then devourhig them \m' ■
fore they have time to recover, or by perfectly killing them at
once J for the quantity of the power seems to be determined by
tlie will of the animal j as it sometimes strikes a tibh twice before
it is sufficiently benumbed to be easily swallowed.

The organs productive of this wonderful accumuhlion of elec-
tric matter have been accurately dissected and described by Mr. .T.
Hunter, Fhilos. Trans, vol. Ixv. They are so di\ ided by nKinbranc*
as to compose a veiy extensive surface, and are supplied witli
many pairs of nerves, larger than any other nerves of the body :
but how so large a quantity is so qpiekly accunu\lated as to pro-
duce such amazing effects in a fluid ill adapted for the purpose,
is not yet satisfactorily explained. The Tcw7jtfr/t> possesses a simi-
lar power in a less degree, as was shown by Mr. Walbh : so does
another fish lately described by Mr. Paterson. — Phil. Tram, vol.
ixxxvi. Botanic Garden, part I, canto i, p. 12, note.

Note (H), page 36. — Four epochas may be observed in the.
history of Galvanism, each of them distinguished by the develop-
ment of important facts. The first M'as formed by the publica-
tion of the fundamental Galvanic fact, viz. the production of
muscular contraction by the application of metals to the nenes
and muscles of animals, and which was entirely limited to orga-
nised bodies. The second may be derived from the discovery of
the Galvanic influence in inorganic matter. The researches of
Fabroni, Dr. Ash, and Creve, exhibiting the i)eculiar action ot
metals in contact with each other upon water, demonstrated the
production of the Galvanic influence in combinations wholly com-
posed of inorganic matter, and thereby connected it witli the
general principles of ph}'sics. The third epocha in the history of
Galvanism is founded on the discovery of the means of accumu
lating this influence by the battcrj/ or pile of \o\tii, which paved
the way for a distinct exhibition of the analogy between C-rl-
vanism and conmion electricity. The fuurth arises from the dis-
covery of the chcmiccd agencies of Galvanism. In the pro.-ecutiori
of this last train of inquiry, the principal degree of praise is due
to the British experimenters ^ and, among the^e, chiefly to Messrs

390 Additional Notes,

Carlisle, Nicholson, Cruickshank, Haldane, Henrys aiid.mDre par-
ticularly to Mr. Dav}' and Dr. Wollaston.

Me&srs. Carlisle and Nicholson did much towards establishing
the electricity of the pile, by ascertaining that it is minus in the
silver end, and plus in the zinc end. They also demonstrated its
chemical action^ especially in the decomposition of water j a
highly interesting experiment, which has led to many very im^
portjnt results.

Mr. Cruickshank was the first discoverer of the Galvanic pro-
duction of alkali. In his experiments he supposed ammoniac to
be generated j while, according to those of some others, the alkali
produced was thought to be fixed. He likewise invented the
mode of placing the metals horizontally in a kind of trough,
which, in several respects, is much more convenient than the ap-
paratus of Volta. And he was the first who succeeded in charg-
ing the Leyden phial by means of the Galvanic pile.

jVIr. William Henry ascertained, by his experiments, that tlie
sulphuric and nitric acids may be decomposed by the operation
of the Galvanic influence ; but, in his attempts on the muriatic
acid, he only succeeded in decomposing the water adhering to it.
He also demonstrated that ap^imoniac may be decomposed in a
similar manner.

Colonel Haldane found that the effects of the apparatus of
Volta were suspended when it was immersed in water -, and that
this likewise was tlip case when it was confined in azotic gas, or .
placed under the vacuum of an air-pump. He observed that the
pile acted more powerfully when immersed in a given quantity of
oxygen gas, than in the same bulk of atmospherical air.

Dr. Wolla.ston has greatly contributed to enlarge our knowledge
of the nature and principles of Galvanism. He read an excellent
paper on this subject to the Royal Society, which appeared in
their Transactions iox i\\t year 1801. After stating a variety of
experiments most ingeniously devised, and cautiously as well as
accurately conducted, he advances his induction, from a great
number of distinct and luminous proofs, tliat the phenomena
of electricity and Galvanism are all results of the same principle.

But scarcely to any one in Great Britain is Galvanism more in-
debted for its extension and improvement than to Mr. Davy, of
the Royal Institution, Aniong many piher discoveries of less im-
portaiice^ which die rapidity of this sketch dues not allow to be
mentioned, he first ascertained the fitness oi charcoal, when used
with silver, as a conductor of tlie Gidvanic infiuence. He dis-

Additional Xotes. 591

co\ierecl tliat a pile may be construct«.>d with oiu* ni<*tal only, pro-
vided proper fluids of tlitleront kintls be appliod to its ditVerent
surfaces. And he found tliat a sinillar result takes place with
respect to charcoal alone, if a like diversity in tlie fluids applicl
to its different surt'aces be duly oteerved. Mr. Davy also disco-
vered that the energy of the pile is nearly in p-roportion to the
rapidity with which the zinc becomes oxydated ; and, consequently,
that the effects will be found to be most powerful when nitric
add is interposed between the metals. I'his seems to be one of
the first steps towards the true thecjry of the action of Voltas
pile.

Most of the improvements by the British philosophers above-
mentioned were communicated to the public In the course of the
year 1601 j a year very memorable for the number, variety, and
itnportance of tlie additions made to the stock of knowledge in
ihis science.

Roused by the success aini eclat of the British discoveries w hich
have been just detailed, the votaries of this science on the conti-
nent of Europe soon began to furnish their additional contribu-
tions.

Tromsdorff* found that gold leaf, and other metallic leaves, may
readily be subjected to combustion by being lixed to the zinc end
of the w ire of Volta's pile.

Fourcroy made the remarkable discovery, that the shock is
greater in proportion to the accumulation of the nnnthcr of plates
in the pile, and the combustion in proportion to the extent of their
surface.

Dr. van Marum, of Holland, and professor Piaft', of Kiel, suc-
ceeded in charging electrical batteries of 140 feet square, by a sin-
gle contact witli the pile of Volta, and proved that this pile is a true
excitatory apparatus of electricity. I'hey melted, by the electri-
city of this apparatus, a large portion of iron w ire, and evou wire of
platina. The communication of Dr. van Maium on this subject
to signor Volta (see Annates de Chijnie, torn. 40} is highly intc-
restin"-. He charged both single jars and large batteries by means
of the pile, and always found that they were charged to the same
degree of intensity with that which the pile itself indicated to the
electrometer. He found, also, that the shocks given by the battery,
when charged from powerful electrical machines, were not per-
ceptibly different from those given by batteries charged from tlie
pile. He found, further, that piles which consist of the same
number of plates, but of different diumetirrr, ^avc equal intensities.

^9^ Additional Notes,

and equal shocks -, but tliat those made of larger plates are con-
siderably more powerful in fusing metals.

Dr. Bostock's TJieory of Galvanism.

John Bostork, M. D, of Liverpool, has offered the follow^
iug Gahanic theory : — He thinks that the phenomena of the pile
of Volta may be all easiJy explained by admitting the truth of the
following po&iulatts.

1 . I'h.at the electric fluid is always generated or liberated when
a metal, or any oxydable substance, is united to oxygen.

2. Ihat the electric fluid has a strong attraction for hydro-
gen.

3. That when the electric fluid, in passing along a chain of
conductors, leaves an oxydable substance to be conveyed through
water, it unites itself to hydrogen, from which it is again disen-
gaged, when it returns to the oxydable conductor. -^

The first of these propositions Dr. Bostock considers as almost
proved by the experiments of Fabroni, Davy, and Wollaston. The
second and third have not been directly established by experiment,
but are viewed by Dr. Bostock as highly probable.

Dr. Bostock accounts for the operations carried on at the end of
the \\irc, in tlie interrupted circuit, as discovered by Nicholson,
in the fi)llowing manner.

As the current of the electric fluid appears to pass from the
zinc, or plus end of the apparatus, to tlie silver end, it is flrst pro-
per to ascertain the action which takes place at the zinc end of the
wire. This appears to be the disengagement of oxygen in a con-
centrated state, by which the wire itself, Miien oxydable, is cor-
roded 5 but which, when the wire is formed of a perfect metal, is
disengaged in the form of oxygen gas. This oxygen appears to be
derived from the derompositicm of the water in which the wire
terminates, in consequence of the attraction which the electric
fluid possesses for hydrogen, and its incapacity of passing through
M'ater without being united to this substance, according to the
second and third postulates. The electric fluid, thus united to hy-
drogen, is carried to the other point of the wire, where, upon en-
tering the oxydable conductor, it is disengaged in the form of hy-
drogen gas, if water be the medium of communication. If a so-
lution of metallic oxyd be employed, it unites with the oxyd, and
reduces it. The decern [position of water is, therefore, elTccted at
the zinc point ajone, though the different gases which com])ose it
are discng.;j^vd at each of the points : and the process will continue

AdiUthnal Notes. 393

even when the points tenninnte in two diflcMont portions of water,
as was discovered by Mr. Davy, provided that the glasses are
united by a conductor which is not oxydable.

To exphiin the operation ciirried on in tlie body of the pile
itself. Dr. Bostock says —

In the construction of the pile there arc two points which are
essential to its action; viz. 1. That the electric fluid be disen-
gaged ; and, 2. That it be confined and carried forw nrd in one
direction, so as to be concentrated in the end of the apparatus.
Tlie first object is evidently attained by the oxydation of the zinc,
or otlicr oxydable body employed. If both sides of the zinc were
oxydated, the electric fluid would, indeed, be liberated, but it
would be immediately dispersed, and its e/lects could not be ob-
served. As soon, however, as the electric matter is CAulved, it is
immediately atti'acted by the hydrogen ; v.hich is, at the same
time, necessarily generated in the fluid vshich oxydate.s the metal j
and it is by tliis means conveyed across the water to the silver
plate, when two metals are used, or, in other cases, simply to the
opposite surface of the oxydating substance. The electric fluid
then enters the silver plate, and, instantly passing on to the con-
tiguous zinc plate, arrives at a second oxydating surface. I'he
same series of e^'eTlts that have been described is here repeated, ex-
cept tliat the electric fluid being in some degree accumulated in
the metallic plate, is disengaged by the second oxydating surface
in larger quantit}', and in a more concentrated state than before.
By pursuing the same train of operations, it is easy to see how the
dectric matter will continue to be aceumulated in each successive
pair of plates, until, by sufficient repetition, it may be made
to exists in the zinc end of the pile, in auy assigned degree oi
force.

The analogy Ijetween Galvanic phenomena and mnny circum-
stances connected with muscular action, and other processes of
vitality, began, several }'ears ago, to make an impression on tlic
minds of many who engaged in tlie pursuit of tliis science. TJie
appearance of Galvanic action in living animals, such as the 7ar-
pedo, kc, was found strongly to corfirm tliis inipression. Or-
ganised beings contain all the substances necessary for the formation
of Galvanic arrangements ; and chetuical changes are conlinually
going on in different parts of the living body, which are probably
connected w itli variations in their states of electricity. I'licse cir-
,<Lwnstaaces^ together \s ilh the origiiial Galvanic fact of the j)ro-

g<)4 Jdditional Note^.

duction of muscular contraction when the influence was applied,
and tlie dependence of irritability, and even life, upon the oxyge-
nation of tlie blood, served to strengthen tht; anally.

These speculations seem to have been reduced almost to de-
monstration by some recent experiments. Professor Aldini, of
Bologna, is supposed to have decisively shown, that a vital attrac-
tion subsists between a nerve and muscle. The suspended sciatici
nerves of a frog, after detaching the spine, being brought near the
intercostal muscles of a dog, while the assistant who held the frog,
with his other hand, touched tlie muscles of the thigh of the dog
(thus forming a circle) j in tliis situation the suspended nerves
approached and came into contact with the muscle, as evidently
as a silken thread is attracted by sealing-wax. But a still more
important fact was that of exciting contractions by making a circle
of nerves and muscles, of different animals, without emplqying
any metallic exciter or conductor. IM. Circaud found that the
coagulum of blood recently drav%^n from a living animal is suscep^
tible of the Galvanic stimulus, as appeared from contractions
evidently e.xcited by the pile of Volta. And M. Garve formed
a kind of pile, by alternate pieces of muscle and brain, with
the intervenlion of pasteboard or cloth, which produced, in
some small degree, similar phenomena with those of the cora,T.
mon pile.

Jdentiiy of Electricily and Galvanism.

Tliere appears to be now no longer any doubt that the Galvanic
and electric fluids are the same, differing in the means of their ex.-
citement, and in the modes of their exhibition. Beside the evi-
dence arising from the celebrated experiment of van Marum, in
which a large electrical battery was charged by a single contact
witii the pile of Volta, as before stated, we find, among the Gal*
vanic phenomena, indications of the plus and i?unus, or the nega-
tive and positive operation, which holds so important a station
among the doctrines of electricity : we find also the electric spark,
and substantially die same results, on employing tlie Condenser of
electricity and the Electrometer. The interesting experiments of
Dr. WoUaston, before-mentioned, tend strongly to the establish-
ment of this point. He even found that, when common elec-
tricity is passed through water, by means of two very fine metallic
points, chemical changes are eflccted by it, similar to those oc-
casioned by tlic transmission of the Galvanic influence.

Additional Notes. 395

It is scarcely necessary to add, that tlic most able experimenters
on the subject of Galvanism are as unanimous in considering tlii»
fluid as an important cficmical agent. — '* Tliat a strong chemical
action takes place among the substances composing the pile of
-Volta is clearly proved, since one of tlic metals is always oxy dated,
and die sahne solution employed to moisten ihc paslcbo;ird i>> de-
composed 5 and that this action is intimately connected witli tJio
excitation of tlie electric energy-, is established by numeroas ex-
periments. The power of the apparatus ceasing when it is placed
in tlic exhausted receiver of tlie air-pump, or in a vessel lilJt-d
■with azotic or hydrogen gas, strongly illustrates tiiis point. When
it is considered, also, that the apparatus is more powerful in
oxygen gas than in the atmospheric air, and that in eitlier the
oxygen is consumed ; and that its powers are much increased when
the water in contact with the metal, holds in solution oxygen, ni-
trous gas, diluted nitric or muriatic acid, or any substance which
either affords oxygen with fiicillty, or promotes the oxydation of
the metal, the evidence of strong chemical action will be viewed
as still more unquestionable. The power of the Galvanic series
or column seems, indeed, to be proportioned to the oxydation of
tlie metal which composes it; and hencfe it may, with much pro-
bability, be concluded, that it is to this chemical action tliat the
excitation. of the Galvanic influence is owing."

Those who wish to see a more detailed account of tJie history
of Galvanism, especially of the numerous and verv^ interesting ex-
periments and discoveries made in this branch of phihKophy, in
,tlie years 1801 and 1802, will do well tc^ consult tlie Philns.
Trans, for 1801, Tilloch's Philos. Mag., and Nichol,>,on's Jountal
of Natural Philosuphy.

Note (I)y p. 37.— The theory of this celebrated pliilosopher
of St. Petersburg may be comprised in the following propo-
sitions.

1. There exists a substance in all magnetic bodies, which may
be called the magnetic iluid ; the particles of which repd each
other with a force decreasing as tlie distances increase.

2. The particles of mngnetic fluid attract and are attracted by
the particles of iron, with a force that varies according to the same
law.

3. The piirticles of iron repel each othar acoiJing to tlie i>aine
law.

396 Additional Notes.

4. The magnetic fluid moves, without any considerable ob-
struction, through the pores of iron and soft steel : but it is more
and more obstructed in its motion as the steel is* tempered harder j
and in hard tempered steel, and in the ores of iron, it is moved
with tJie greatest difficulty.

. 5. When tlie quantity of tlfis fluid contained in iron is such
that the accumulated attraction of a particle for all the iron ba-
Iriuces, or is equal to, the repulsion of all the fluid which the iron
contains, the quantity may be said to be the natural quantity of the
iron, which may then be said to be in its natural state.

6. The magnetic fluid may be abstracted from one end of a
magnetic bar, and constipated in the other, and on this depends
the exertion of its force. In other words, the condensation and
motion of the magnetic fluid are subject to the same laws (mu-
tatis piutandis), in the opinion of this philosopher, as the electric
fluid on the Franklinian theory, the motion and sensible signs of
which depend on thep/'j/s and minus states, or the deficiency cUid
redundancy of the same fluid in different bodies.

J^ote (K), p. 37- — '' As every piece of iron which was made
magnetical by the touch of a magnet became itself a magnet, many
attempts \\-ere made to improve these artificial magnets, but with-
out much success, till Servdngdon Savary, esq. made thenioi hardened
steel bars, which were so powerful, tlrat one of. them, weighing
three pounds avoirdupois, would lift another of the same weight.

" After this Dr. Gowin Knight made very successful experi-
ments on this subject, which, though he kept his method secret,
seems to have excited others to turn their attention to magnetism.
About this time the rev. Mr. Michel invented an equally efficaci-
ous and more expeditious way of making strong artificial magnets,
which he published in the end of the year 17^0, in which he ex-
])lained his method of what he called the Double Touch, and
whicli, since Dr. Knight's metliod has been known, appears to be
somewhat different from it.

" This method of rendering bars of hardened steel magnetical
consists in holding vertically two or more magnetic bars nearly
parallel to each other, with their opposite poles very near each
other (but, ne^•ertheless, separated to a small distance) : these are
to be slided over a line of bars, laid horizontally, a few times back-i
ward and forward.

'• \\hat Mr. Michel proposed by this method was, to include a

Additional Notes. 397

very small portion of the horizontal bars intcndi-d to be made nuig-
netical, between the joint forces of two or more bars already
raagnetical, and, by sliding tliem from end to end, every part ot
the line of bars became successively included ; and tlius bar>,
possessed of a very small degree of magnetism to begin \\ith,
would, in a very few times sliding backwards and forwards, make
the other ones much more magnetical than themselves, which
are then to be taken up and used to touch the former, which are
in succession to be laid down horizontally in a \mcr— Botanic
Garden, Tart I, Canto ii, 1. IQS, note.

Dr. Knight's method of making artificial magnets, referred to
by Dr. Darwin in the abvove-mentioned note, was as follows:
He reduced iron to a very subtle powder, made it into a paste with
oil, moulded the composition into pieces of a convenient form,
dried them before a moderate lire, and then imparted to them the
magnetic virtue, by placing them between the extreme ends of his
large magazine of artificial magnets, for a few seconds or more, as
he thought requisite.

After Michel, the manufactory of artificial magnets received
further improvements by JNlr. Canton, in I75(i, and by M. An-
theaume, in 1 7QO.

Note (L), p. 40.— Among other attempts to extend the bounds
of chemistry, it has been lately proposed to place the magnetic
fluid in the list of its subjects. Accordingly, several writers have
considered this fluid as a chemical agent, and explained its pheno-
mena on corresponding principles. Among these, ])r. Darwin, in
the Additional Notes to his Temple of Nature, proposes tlic follow-
ing hypothesis.

I. Magnetism coincides with electricity in so many important
points, that ihe existence of tico ma<^netic ethers, as well as of two
electric ones, becomes highly probable.

3. In a common bar of iron or steel, the two magnetic ethers
(which, for the greater ease of speaking, may be called arctic ether
and antarctic ether), exist intermixed, or in their mutral .tale : in
tliis state, like the two electric fluids, tliey are not cognizable by

the senses.

3 When these two magnetic ethers are separated from each
other, and the arctic ether is accumulated in one end of an iron
or steel bar, which is then called the north pole oi the magnei;
and the antarctic ether is accumulated in the other end of die bar,
which h then termed the south pole of tbo magnet, they becou^e

S9S Additional Notes,

tapable of atti-actin^ other pieces of iron or steely and are tlins
cognisable by experiments.

4. It seems probable that it is not the magnetic ether itself
which attracts or repels particles of iron j but that an attractive
and repulsive ether attends the magnetic ethers, as in the case of
the electric.

5. "While the two electric ethers, v/hen separated by nature or
art, combine, by chemical affinity, with explosion, emit light and
heat, and leave a residuum ,• the two magnetic ethers, after being;
separated in like manner, combine by chemical affinity, but
without explosion, and produce, by their union, a neutralised
fiuid.

Note (M), p. 43. — This great practical philosopher was bom,
about the year 1/53, at Woburn, a small town in Massachusetts,-
ten miles north of Boston. His parents were in humble life, and
his advantages, with resj>ect to education, were small. But he
was early distinguished as a lad of spirit and enterprise, and
discovered a fondness for knoN^ledge. After spending some time
Jn a retail store in Boston, where he was more fond of amusing
himself with a violin than of attending on customers, and preferred
making experiments with an electrical machine to either, he re-
turned to Woburn : here, however, he did not remain long. Ir>
1772 he attended professor Winthrop's lectures on experimental
philosophy, in Harvard college. He was not a matriculated stu-
dent; but, being regarded as an ingenious and promising young
man, was permitted to attend this part of tlie usual course of in-
fitmction, for which he manifested a particular predilection.

In 1772 or 177^) young Thompson went to New Hampshire,
and settled in a town called Rumford, at that time under the juris-
diction of Massachusetts, but afterwards, by a new territorial ar-
rangement, assigned to New Hampshire, and riow called Concord.
Here he married a widow, of the name of Rolfe, with whom he
received a large fortune. In 1775 he went to England; and,
soon after his arrival, was introduced to lord George Germaine, then
secretary of state, to whom he so far recommended himself as ta
be appointed one of the first clerks in his office. When his lord-
ship went put of office, he still exerted his influence in favour of
Mr. I'hcjmpson, and obtained for hihi a colonel's commission.
V. !th this commission, towards the close of the American war, he
came to New York, with the view of raising a regiment of loya-
lists 3 but the regiment was never completed 3 he was, however^

Additional Notes, 399

■still^ctive in the service of the king, and, soon after die peace of
1/83, he returried to EnMand.

D

Here tlie proofs of his activity, enterprise, and philosophic
Qcuteness, and particularly of his taste for improvements in mili-
tary attairs, were so numerous, tiiat he began to attract more
public attention than before, and oflers v. ere made to him of pre-
ferment in foreign senice. He at length accepted a flattering in-
vitation given to him by the reigning duke of Hnvaria^ and went
into his ser\ice in 17S4. By this prince he was made lieutenant-
general of horse, and soon rendered himself conspicuous by intro-
ducing a new system of order, discipline, and economy among the
troops mider his command. He remained a number of years in
Bavaria, where he was much distinguished by his successful exer-
tions to destroy mendicity, and to meliorate the condition of the
poor ; and by a variety of improvements highly favourable to ma-
nufactures, economy, and humanity. On leaving the scr\-ice of
the elector he was created a count ; his title being taken, by his
own choice, from the name of the town in America in which he
iiad for some time resided.

Count Rumford has chiefly resided, for a number of years past,
in Great Britain, where he has been so much celebrated for his
experiments, discoveries, and improvements in militar}', economi-
cal, and chemical science, that it is unnecessary to dwell on his
merits. Beside the new light which he threw on the subject of
gunnery J before mentioned, the friends of science and humanity are
indebted to him for improved methods of constructing chimnicx
and stoves; for important discoveries and improvements relative to
cookery and aliment; for curious and highly interesting experi-
ments on heat ; &c. In short, it seems to be generally agreed,
that he stands in the first class, if not at the head, of all the
practical, and particularly the economical philosc^ihers, now
living.

He was knighted by the king of Great Britain in 1/S4, and has
received many honourable tcstimoiiies of public and private re-
spect in that country. His only child, a daughter, now resides in
tlie town of Boston.

Note (N), p. 57. — " The expansive force of steam was known,
in some degree, to the ancients. Hero, of Alexandria, describe?
an application of it to produce a rotatory motion by the reaction of
oieam issuing from a sphere mounted upon an axis, through two
imall tubes bent into tangents, and issuing from tlic opposite sides

400 Addllioiial Note$,

of the equatorial diameter of the sphere ; the sphere was supplfetl
\vith steam by a pipe communicating with a pan of boiling water,
and entering tlie sphere at One of its poles.

" A French writer, about the year l(i30, describes a method of
raising water to the upper part ot" a house, by filling a chamber
with steam, and suffering it to condense of itself) but it seems to
have been mere theorj^, as his method was scarcely practicable as he
describes it. In 1655^ the marquis of Worcester mentions a me-
thod of raising water by lire, in his Century of Inventions ; but he
seems only to have availed himself of the expansive force, and not
to have known the advantages arising from condensing the steana
by an injection of cold water. This latter and most important im-
provement seems to have been made by capt. Savary^ some time
prior to the year lOQS, for in that year his patent, for the use of
that invention, was conhrmed by act of parliament. This gentle-
man appears to have been the first who reduced the machine to
practice, and exhibited it in a useful form. His metliod con-
sisted only in expelling the air from a vessel by steam ; condens-
ing the ste-am by an injection of cold water, which making a vr-
cuum, tlie pressure of the atmosphere forced the water to ascend
hito the steam- vessel through a pipe of 24 or 26 feet high; and, by
the admission of dense steam from the boiler, forcing the water in
the stcam-vesscl to ascend to the height desired. This construc-
tion was defective, because it required very strong vessels to resist
the force of the steam, and because an enormous quantity of steam
was condensed by coming into contact with the cold water in tlie
steam- vessel.

" About, or soon after that time, M. Papin attempted a steam-
engine on similar principles, but rather more defective in its
construction.

*' The ru'xt improvement was made ver)' soon afterwards by
Messrs. Xewcomcn and Cawley, of Dartmouth : it consisted in
employing for the steam- vessel a hollow cylinder, shut at bottom
and open at top, furnished with a piston sliding easily up and
down in it, and made tight by oakum or hemp, and covered
with water. This piston is suspended by chains from one end of
a beam, moveable upon an axis in the middle of its length : to the
other end of this beam are suspended the pump-rods.

"The danger of bursting the vessels was avoided in tliis ma-
chine ; as^ however high the water was to be raised, it was not
necessary to increase the density of the steam, but only to enlarge
the diameter of the cylinder.

Additional NolC^\ 401

. ^' Aiiotlier advaiUnge was, that the cylinder, not being nuule so
cold as in Savary's method, much le.s steam was lost in lillin;^ it
after each condensation. .

**The machine, however, still remained imperfect^ for the cold
water thrown into tlie cylinder accjuircd heat tVom the steam it
condensed, and being in a Vessel exhausted of air, it produccil
steam itself, which, in part, resisted the action of the atmosphere
on the piston } were this remedied by throwing in more cold
water, the destruction of stea n in the iicx.t filling of the cylinder
would be proportionably increased. It has, therefore, in practice,
been found advisable not to load these engines witli culumns of
water weighing more than seven pounds for each square inch cf
the area of the piston. The bulk of water, when converted int,o
steam, remained unknown, until Mr. J. Watt, then of Glasgow, in
17G4, determined it to be about 1800 times more rare than water.
It soon occurred to Mr. Watt, that a perfect engine w culd be that
in which no steam should be condensed in filling the cyhnder, and
in which the ^eam should be so perfectly cooled as to produce
neaily a perfect vacuum.

*' Mr. Watt having ascertained the degree of heat in which
water boiled in vacuo, and under progressive degrees of pressure,
and instructed by Dr. Black's discovery of latent heat, having cai-
culated the quantity of cold water necessary to condense certain
quantities of steam so far as to produce the exhaustion required,
he made a communication from tlie cylinder to a cold vessel pre-
viously exhausted of air and water, into which the steam rushed,
by its elasticity, and became immediately condensed. He tJien
adapted a cover to the cylinder, and admitted steam above tlie
piston to press it down instead of "air, and^^tead of applying wa-
ter, he used oil or grease to fill the pores of tho oakum. :.nd Lo
lubricate the cylinder.

" He next applied a pump to extract the injection water, il:e
condensed steam, and the air, from the condensing- vessel, eveiy
stroke of the enoine.

o

" To prevent the cooling of the cylinder by the contact of
the external air, he surrounded it with a case containing steam,
which he again protected by a covering of matters which conduct
heat slow ly.

" This construction presented an ea-y means of regulating the
power of the engine, for tlie steam being the acting po\\ er, as the
pipe which admits it from the boiler is more or le:,3 opened, a
greater or smaller qumtitv c:in enter du)!ng the time ui a if.oke.

Vol. I ' •l-^y

405 Additional Nofe^.

and, consequenUy, the engine can act with exactly the necessatr/
degree of energy.

" Ivlr. "Watt gained a patent for his engine in 1 7^8 j but the
further prosecution of his designs \^'as delayed by other avocations
till 1775, \vhen, hi conjunction with Mr. Boulton, of Soho, near
Birmingham^ numerous experiments were made, on a large scale^
by their united ingenuity, and great improvements added to the
machinery, and an act of parliament obtained for the prolongation
-of their patent for twenty-five years : they have, since that time,
drained many of the deep mines in Cornwall, v.hich, but for the
happy union of such genius, must immediately have ceased to
^^ ork. One of, these engines works a pump of eighteen inches
diameter, and upwards of a hundred fathom, or 6OO feet high, at
the rate of ten or t^^-clve strokes, of seven feet long each, in a
minute, and that with one fiftli part of the coals which a common
engine would have taken to do the same work. The power of
this engine may be easier comprehended, by saying, that it raised
a weight equal to 81000 pounds, eighty feet high, in a minute,
which is equal to the combined action of two hundred good
horses. In Newcomen's engine this would have requued a cylin-
der of ihe enormdus diameter of 120 inches, or ten feet; but as
rn this cno i«e of Mr. Watt and Mr. Boulton the steam acts, and a
vacuum is made, alternately abo\'e and below the piston, the
•power exerted is double to what the same cylinder "Vvould other-
ways produce, and is further augmented by an inequality in th«
length of the two ends of the lever.

** These gentlemen have also, by other contrivances, applied
their engines to the turning oi\mills for almost every purpose, of
\^hich that great pile of machinery, the Albion Mill, is a well-
known instance. Forges, slitting-mill^, and other great works,
are cri'cted where nature has furnished no mnning water, and fu-
lul-e times may boast that this grand ajid useful engine was in-
vented and perfected in our own countr}'." — Botanic Garden,
Part i. Additional JS'o/c XI.

jN'o/r CO)y p. 64. — It appears that Bollond was not the first per-
son who invented Jlchrmnatic glasses. As early as 1729, Chestei*
More ILill, esq., of Mort-HuU, m the county of Essex, as
appears by his papers, considering the different humours of the
eye, imagined they M-ere placed so as to correct the different
refrangibility of liglit. He tlien conceived, that if he could find
^ubsiiuices having such properties; as he supposed these huniDun

Additional Notes, 403

might possess, he should be enabled to construct nn ohjcct glass
that Mould show objects culourk'ss. After many experiments, ho
ImJ the good fortune to tind these properties in two ditferent
kinds of glass ; and by forming lenses made of such glass, and
making them disperse the rays of light in contrary directions, he
succeeded. About 1733 he completed several achromatic objLtt
glasses (though he did not give them this name), that bore an
aperture of more than two inches and a half, thou'^h tiie focal
length did not exceed twenty inches. One of tliesc glasses,
which, in 179O, was in possession of the rev. Mr. Smith, of
Charlotte-street, Rathbone Place, London, has been examined
by several gentlemen of eaiinence in tlie scientilic world, and
found to possess the properties of the present achromatic glasses.

•In the trial at Westminster-Hall, about the patent for making
achromatic telescopes, Mr. Hall was allowed to be the inventor ;
but lord Mansfield observed, *' that it was not the person who
locked up his invention in his scrutoire that ought to profit by a
patent for such invention, but he who brought it fortli for th«
benefit of the public."

That Mr. Ayscough, optician, on Ludgate-Hill, was in pos-
session of one of Mr. Hall's achromatic telescopes in 17•'5-^, is a
fact indisputable. — Gcnthman's Magazine, vol. Ix, part ii, for
1790, p. 890, 8:c.

Note (P), p. 75. — Since the close of the eightcentli century
tu:o neiv planets have been discovered. The first was discovered
January 1, 1801, by Mr. Piazzi, of Palermo, in Sicily. It is called
by the discoverer Ceres, but by his brother astronomers Viazzi.
The second was discovered on the 28th of March, 1802, by
Dr. Olbers, of Bremen, and is called by him Pallas, but others
give it the name of Others.

The planet Piazzi {or Ceres) revohes bet\\'een Mars and Ju-
piter. It is not, apparently, larger than a fixed star of the eighth
magnitude. The inclination of its orbit to the plane of the eclip-
tic is about 10 deg. 3t? min. 57 sec, and the time of its periodical
revolution is four years, seven months, and ten days.

The planet Olbtrs (or Pallas) also revolves in tiie wide space
between Mars and Jupiter. It differs very little in ai)pearance
^fi-om stars of the eighth magnitude. The inclination of its orbit
to the plane of the ecliptic is 35 deg., n \ery extraordinary' degree
of obliquity, which shows that the ZoJiac must be cons-iderably
enlarged, if we continue to distin^uiih by that name the /one tu

2 D i

404 Additional Notes.

the heavens in which all die planets perform their revolutions,
I'iie period of its revolution is four years, eight months, and three
days.

The orbits of these two planets are nearer together tlian those
of any others in our system. In its distance from the sun Piazxi
varies from 21 to -25, and Gibers from 2/ to 28, taking tlie distance
of the earth as the standard, and estimating it at 10.

Beside the discoverers, Herschell, de la Lande, Delambre,
and Burckhardt, have particularly distinguished tliemselves in
observing the phenomena, and in calculating tlie elements, of
these planets. — Mr. Herschell proposes to designate these celestial
bodies, for the present, by the term " Asteroids."

Note C'2), p. 79. — Catalogues of stars are of two kinds, either
aft collected into certain figures called Constellatiom, or according
to their rirrht ascensions, or, in other words, according to their
order in passing over the meridian.

The fust specimen of this latter kind of catalogue, that is, ac-
cording to the order of the right ascensipns, was tliat published by
de la Caille, in 1755. It contains the right ascensions and decli-
nations of 307 stars, adapted to the beginning of tlie year 175O.
In 1757 the same gre?t astronomer published his Astronomict Fun^
daintnta, containing a catalogue of the right ascensions and decli~
nations of 398 stars. And in 17^3, the year after his death, was
published the Cahim Australe Stellifcnim, also by the same autlior,
containing a catalogue of the places of 1942 stars.

In the yautical Ahnanack for 17/3 is given a catalogue of 38/
stars, in right ascension, declination, longitude, and latitude,
derived from the observations of the celebrated Dr. Bradley, astro-
nomer royal of Great Britain, and adapted to the beginning of the
year 176'0.

In J 775 was published a catalogue among the papers of the late
Tobias Mayer, containing the right ascensions and declinations of
C)i)S stars, which may be occulted by the moon and planets,
adjusted to the year \75(5.

At the end of the first volume of " Astronomical Observations
made at the Royal Observatory at Greenwich," published in
177<>, Dr. Maskelyne, the present astronomer royal, has given a
catnlo'jjue ol the places of 34 principal stars, in right ascension,
and north polar distance, adapted to the beginning of the
}far 1770.

In 1782, prof. Bode, of Berlin, published a very extensive cata-

Additional Notes. 40.0

logueof 5058 stars, collected from the observations of Fiainstead,
Bradley, Hevelius, Mayer, de la Caiilc, Messier, Moiinier, d'Ar-
quier> and other astronomers ; all adapted to the beginning of die
year 1780, and accompanied with a celestial atlas, or set of maps
of the constellations, engraved in a very delicate and beautiful
manner.

lb these may be added Dr. Herscheirs catrdogue of double
«tars, printed in the Philosophical Transactions for 1782 and 1/83 ;
Messier's nebula: and clusters of stars, publi.-;hed in the Connoissunce
dcs Temps for 1784 ; and Herschell's catalogue of the same kin*.l-,
given in tlie Philosophical Transactions for lysO.

Jn 1792, Dr. von Zach, of Gotha, annexed to his Tahula Moluinn
Solis a new catalogue of the principal fixed stars, from his own
observations, made in the years 178/, 1788, 1/8^, 171JO. This
catalogue contains the right ascensions and declinations of 381
principal stars, adapted to the beginning of the year 1 800.

But all these catalogues yield, both in extent and value, to
thaf of dc la Lande, whose diligence, skill, and pcr.-.everancc, in
this department of astronomical observation, do him the highe»i
honour. — Suppltmcnt to the Encyclopcedia.

: Na'e (R), p. 82. — Professor Testa, of Rome, has read to the
Academy of Religion there, a memoir written by him, in which he
proves, in the most evident manner, that the Zodiacs lately dis-
covered in Egypt have not that antiquity w hicli some pretend to
give them j and, consequently, that they pro\e nothing against tlio
chronology of uVIoses. He asserts that the Eg}'ptians were not
acquainted with the motion of the fixed stars in longitude, an(]
that Hipparchus was the first who discovered it. Ilipparchus,
the astronomer here alluded to, was a native of Xicea, and
flourished about the year I29 before Jesus C^hrist. Professor
Testa remarks also, that the Zodiac of Dendera is found in a
temple of Grecian architecture, which bears the name of Tiberius 3
that this temple not being two tiiousand }c'ars okl, the Zodiac
discovered in it cannot have existed abo\e four thousand j that in
these Zodiacs is seen the sign of Libra, a constellation absolutely
unknown to the ancient Egyptians. It appears, therefore, that a
certain class of" philosophers will not deri\c from the discovery of
these Zodiacs that advantage which they expected.

iNVe (S), p. 85. — It is asFcrted in the page hero quoted,
tiiat the celebrated instrument called tlie (juadrunt, which bear*

406 Additional Notes.

the name of JMr. Hadley, and which is generally ascribed to him
as the inventor, was really invented by Mr. Thomas Godfrey, of
rhiladelphin. It will be proper, in this place, to give the reader
some account of Mr. Godfrey, and of the evidence on which the
above, assertion was made.

llie fullest and most satisfactor)'- information on both these points,
which the author has been able to obtain, is presented in the fol-
lowing letters, extracted from the American MagazinCj for the
months of July and August, 1758. Two of tliese letters are
wTitten by James Logan, esq., the distinguished classic scholar
and botanist whose name has been mentioned in several parts of
this work. For furnishing him with accurate copies of these do-
cuments, the author is indebted to his friend Ebenezer Hazard,
esq., of Philadelphia, a gentleman who has been long distinguished
for his researches in various departments of American history,
and who has probably amassed a larger store of curious relics and
facts relating to tiiis extensive subject, than any other individual
in the United States.

From the American Magazine for July, 1758, p. 475. *
To the Proprietors, ^c.
Gentlemen,

All civilised states have thought it their honour to have men of
great ingenuity born or bred among tliem. Many cities of ancient
Greece had long and sharp contentions for the honour of Homer's
Jjirth-place. And in latter times volumes have been written in
Enrope, in disputing which city had tlie true claim to the inven-
tion of the art of printing. Nor is it to be wondered that man-
kind should be so generally eager in this respect, since nothing re^
dound.s more to the honour of any state than to have it said that
fnme science of general utility to mankind v/as invented or im-
proved by them. Nevertheless it often happens that the true au-
thor of many a useful invention, either by accident or fraud,
Icses the credit thereof, and from age to age it passes in the name
of another. 'I'hus it happened, heretofore, to Columbus and
many others 3 and thus also it happened to a native of Pliila-
ddplud.

Mr. Thomas Godfiey, it is well known to many of us here,
wiLs the real inventor of that ^ cry useful instrument called Had-
Jey's quadrant or octant. To him the merit is due, and to his
j)osterity the profit ought to belong. This will fully appear from
tlie three following genuine letters, which, I persuade myself,
you w'i'X tliink v. orthy of being recorded in your magazine, in

Additional Notc^. 407

order to restore, as far as possible, the credit of lliat iiiveiuion to
our city, and to the posterity of Mr. Godtiey. How he came to
be deprived of it may be made a question by some. I answer that
Mr. Godfrey sent tiie instrument to he tried at sea by an accjuaint-
ance of his, an ingenious navigator, in a voyage to Jamaica, who
showed it to a captain of a ship there just goiii;,' tor Ew^lntid, by
which means it came to tlie knuw ledge of IMr. Hadk-y, though,
perhaps, without his being told the nnme of the real inventor.
This fact is sutiiciently knov/n to many seamen and others yet
alive in thi^ city ; and established beyond doubt by the followhig
letters, written about that time. It is, therefore, submitted to
the world whether, after perusing the letters, they ought not, in
justice, to call that instrument, for tlie future, Godfrey's, and no;
Hadley's, quadrant.

To Dr. Edmuxd Halley *.
Esteemed Friend,

The discovery of the longitude having, of late years, employed
the thoughts of many, and the world now expecting, from tliy
great sagacity and industry, some advances towards it, far exceed-
ing all former attempts, from the motion of the moon, to the
ascertaining of which thy labours have so long and happily been
directed ; the following notice, I hope, will neitlier be tirought
unseasonable nor prove unacceptable. That the success of this
method depends on linding the moon's true phice for cnie meri-
dian by calculation, and for another by observation, I think is
generally allowed 3 the first of which being depended on from tliy
great genius, what remains is some certain method for observa-
tion, practicable on that uncertain element the sea. In order to
tliis, thy predecessor at Grcemoich, if I mistake not, for some
years published his calculations for the UK.on's future appulse to
the fixed stars, which would save all observation but tliat of a
glass J but these not often happening, and the moon often ha\ing
a considerable parallax, when they did, that project dropped.

For finding her place by taking her greater distances from stirs,
the fore-statf or cross-staff cannot be exact enough : and quadrants,
sextants, &c., with two telescopes, afe impracticable at sea.

Dr. Biester's late proposal for taking the ditference of riglit

* An Introductory paper winch I !»ave net transcribed, not tliinkJ;:g it im-
portant, mentions this letter as N° 435 in the >PWoj<>//j/.j/ 7'r^'/Ti..v//&//i, ard
f ntitlod an " Account of Mr. Thomas Godfrey 't Improvement of Davis's
Quadrant transfcirt-d to the Mariner's Bcnv. '

40S Addiiional Notes,

ascension between the moon and a star, if that should prove prac-
ticable with sufficient exactness, would undoubtedly answer the
intention of all that is to be expected from the moon, if her place
were taken on or near the meridian. But to keep the arch of
this instrument in the plane of the equator, and at the same time
view two objects of unetjual altitudes, and considerable distance
from each other, by the edges of two sights, with the necessary
accuracy, will not perhaps be so easy in practice as he would
have it believed.

I shall, therefore, here presume, from thy favour shown me in
England, in 1/24, to comnmnicate an invention that, whether it
answer the end or not, will be allowed, I believe, to deserve thy
regard. I have it thus :

A young man, born in this country, Thomas Godfrey by name,
by trade a glazier, who had no otlier education than to learn to
read and write, with a little common arithmetic, having, in his
apprenticeship with a very poor man of that trade, accidentally
met ;viih a mathematical book, took such a fancy to the study,
that, by the natural strengtli of his genius, without any instructor,
Jie soon made himself master of that, and of every other of the
kind he could bnrrov/ or procure m English; and finding there
was more to be had in Liiiin books, under all imaginable dis-
couragements, a})plied himself to the study of that language, till
he could pretty well understand an author on these subjects ;
after wliich, the 'first time I ever saw or heard of him to my
knowledge, he came to borrow sir Isaac Newton's Principia of
me. Inquiring of him hereupon who he was, I was indeed asto-
nished at his re(jue.';t ; but after a little discourse he soon became
v/clcome to that or any other book I had. This young man,
about eighteen months since, told me he had for soitie time been
riiinking of an instrument for taking the distances of stars by re-
iiecting speculums, which he believed might be of service at sea j
and not long after he showed me a common sea quadrant, to which
he had fitted two jjicces of looking-glass in such a manner as
brought two stars, at almost any distance, to coincide j tlie one
b)' a direct, the other by a reflecting ray, so that the e3'e could
t^ikt^ them both tc/^cther as joined in one, while a moving label or
index on the graduated ar(.'li marked exactly half their distance :
for 1 need not say that the variations of the angles of reflexion
irom two speculums are double to the angle of the inclination of.
their planes, and therefore give but half the angle or arch of the
tii.it;-4;t.«^*, v.hich is the only inconveniency that appears to me to

Aildilional No/e^.

409

attend this. But as it m:iy be made so simple, cnsy, and light.
Hi not to be much more unwieldy or uuniaiuiijeable, tiioiigli of
considerable length, tlian a single telescope ul" the same, that in-
conveniency will be abundantly compensated.

The description of it, as he proposes it, and has got one made,
is nearly thus, which he is v illing I should communicate to thee,
if possibly it may be of service.

To a straight ruler or piece of wood, AB, of about three mchea
m breadth, and from forty to forty-five in length (or of any other
that may be thought convenient), with a suitable thickness; an
arch or limb, AC, of about 30 degrees to the radius, KL, is to be
fixed. To the upper end of the piece AB, a piece, DD, is to b©
morticed, and in it the centre K taken, so that OP may be about
six inches, and the angle KOP about 40 degrees. On this centre
K, the ruler or ii.'dex KL is to move, having a liducial edge below

answerable to the central
point, to cut the graduations
on the limb. On the upj^er
end of this index a speculum
of silvered glass, or rather
metal, exactly plain, EF, of
about three inches in length
and two in height, is erected
perpendicular to the plane
of tlie index, and also nearly
at right angles with its sides,
the plane of the retlectiug
surface standing exactly over
tlie central point. At the
end B, of the piece AB, an-
other speculum of glass is
to be in the same manner
erected, which maybe some-
what less than the other,
with a square or oblong spot
in it unsilvered, tliat a star,
by a direct ray, may be seen
through it J and the back of
til is speculum should be
guarded witli a tlilu brass

y

J..

410 Additional Notes.

plate, \vith an aperture in it equal to the unsilvered part of
the glass 3 llie edge of the aperture toward H to be exactly-
straight, dividing between the silvered and unsilvered part of
the speculum, and standing in the line of the axis of the tele-
scope. This speculum is to be set at an angle of about 20
degrees, with the square of the piece AB, or at 110 degrees, with
the sides of it. Upon the piece AB, the telescope PQ is fixed,
of a good aperture and held, with the axis placed as above.
The limb is to be graduated by diagonals, or parallel circles, to
half degrees and half minutes, beginning from C, which are to be
numbered as whole ones. And if it be practicable to face wood
with brass without warping, the whole face should be so covered;
if not, then along tlie outward edge of the limb a narrow strip of
brass plate ma}- be let into the face of it, finely and equally in-
dented on the edge, to take a screw fitted to tliat tootliing to be
fixed on the moving index at L, as your instruments are made
that count by revolutions* and then, before this is used, it woiild
be proper to take the distance of the two objects first nearly by a
fore-staft^", and from thence accordingly to set the index. This
screw, at land, would be highly useful, but at sea it cannot be
wrought, while the instrument is directed by the same person ;
though, as the motion of the moon and variation of the angle is
but slow, it may be brought to exactness by several trials in the
intervals of direction. The instrument, as above described, will
not take an angle of much above 50 degrees, which, for the pur-
pose intended, may be fully sufficient. But if the speculum EF
be made to take oif and put on, and the end of the index at K be
so notched as to turn that speculum from its first perpendicu*
larity, to make an angle of about 25 degrees, it will then take
any distance to 100 degrees.

By this description it may be thought that tlie utmost ac-
curacy will be required in making the instrument : yet, of all that
ever liave been invented of so curious a kind, it will probably
be found to demand the least ^ for, provided the speculums are
good, on which the whole depends, if the first EF be set truly
over the centre, the limb well graduated, and the other speculum
be also set perpendicular, there can, I think, be no other errour
but what the instrument itself will easily rectify: for if it be di-
rected to one jitar, and that be taken, at tlie same time, botli by a
direct ray through the glass GH, and by a refiexion from EF,
both exactly coinciding at O, it is evident that then the specu-
hims are tx.ictly parallel. And if this falls not precisely wbcfw

Jddit tonal Notes. 411

the index cuts 0 degrees, if the variation be noted, this constantly
added or subti-acted, according as it tails, will fully rectify all
other errours. So in fixing the speculum £F to another angle, at
has been proposed, tlie like method may or must be taken, viz,
to observe two stars at the distance of about 45 or 50 degrees, by
the speculum, in its first situation, and thon tlie same stars by it
again in its second, and the diflerence of the intervention of the
index on the Hmb being noted, and constantly added to the arches
tiiken in the second situation, will give the true distance. This
method of observing one and the same star, in the first manner,
or two stars in the second, as has been mentioned, will nljo rectify
jerrours even in the speculums : for the line of the ray KO is in all
cases constantly tlie same , and, upon the whole, I may safely
say the instrument will be found much more certain in practice
than at first it may appear in theory, even to some good judges.
But I am now sensible 1 have trespassed in being so particular
•U'hen writing to Dr. Halleyj for I well know, that to a gentle-
man noted for his excellent talent of reading, apprehending, and
greatly improvmg, less wotild have been sufficient ; but as this
possibly may* be communicated by thee, 1 shall crave leave further
to add, that the use of the instrument is very easy, for if the
index be set so near the distance of the moon and htars, and the
limb so held as to cut the body of the moon, upon directing the
telescope to the star her image will, of course, be reflected on some
part of the speculum GH. There is no absolute necessity tlie
etar and moon should coincide exactly at the line limiting tlie
silvered and unsilvered part of the latter speculum ; for the trans-
parent part of that glass will often reflect on the moon's image
sufliciently for the telescope to take it, and if her limb in that and
the star exactly coincide near it, it may be sufficient, though the
nearer to that line the better. Now tlieir distance being found,
the tables that give the moon's place may be depended on for
her diameter and her latitude 3 Mhich last being known, there are
three sides of a triangle given to find the angle at tlie pole of tJie
ecliptic, which, compared with the star's longitude, determines
her place for that instant : for, in respect to her latitude when she
is sv/iftest in motion, when nearest her nodes, and w hen the in-
clination of the orbs is greatest (if these eould all happen toge-
ther), yet the vai-iation of her latitude, in the space ot one hour,
equal to 15 degrees of longitude on tiie earth, if a star be Uiken
fe^)me\\hat near the ecliptic, and not very near tlie moon, will not
alter the angle at the pole but a very few seconds. The neaniess

412 Additional Notes,

of the speculum GH is no disadvantage, because the rays comd
reflected in the same manner as they come direct. It may be
needless to add that, when practicable, the moon should be taken
■when near the meridian — or that the instrument will equally take
the distance of the sun from the moon, when visible, as she often
is, in the day-time; for which purpose there must be a place
made at M for a d^ikening glass, to be fixed there when neces-
sary, and the lele cope directed to tlie moon. Nor need 1 add,
that the same instrument will very well serve for taking the di-
stance of any two stars, a comet, &c., always taking the brightest
by reflection ; " all which is obvious. But I must further ob-
serve, with pleasure, that if we do not quite mistake in all that
has been said here, there is now a method found by it to obtain
what is equivalent to a bodily appulse of the moon to a fixed star,
or to the sun at any moment when visible, which, indeed, might
be wished 3 but if the longitude could ever be expected to be de-
termined by the motions of the moon (to which end J. Flam-
stead's, and thy more assiduous labours in observing her, have, I
suppose, been principally levelled), and this instmment be duly
made to answer what is proposed, as it may be framed light and
easily manageable, diou wilt then, with thy accurate tables, have
obtained the great desideratum, and all that can in this way be
had from our satellite. And if this method of discovering the
longitude by the moon is to meet with a reward, and this instru-
ment, which, for all that I have ever read or head of, is an inven-
tion altogether new, be made use of, in Uiat case 1 would recom-
mend the inventor to thy justice and notice. He now gets his own
and family's bread (for he is married) by the labour of his own hands
oaly, by that mean trade. He had begun to make tables of the moon,
on the very san:e principles with thine, till I lately put a copy of
those that have lain so many years printed, but not published,
wath W. Innys, into his hands, and tlien, highly approving them,
he desisted. We both wish \ery much to see thy tables com-
pleted, and ushered into the world by thy own hand. On the
receipt of this 1 shall hope for a line, with thy thoughts on it;
wliich, however they prove, will afl^brd a pleasure to

Thy frienil,
Pcwiti/hunla, May 25, 11?>2. , J. LOGAN.

From the American Mai^azine fcr An^vst, 1758, p. 528.

To the Jioj/al Sociefj/.
Gkntlemkn-,

As none are better able than the Royal Sociciij to i)rovc and

AcliUtional Xutes.

41,

judge whelher such inventions as are proposed for the advancing
useful knowledge will answer the pretensions of the imcnlors or
not J and as 1 have been made acquainted, though at so great a
distance, of the candour of your learned society in giving encou-
ragement to such as merit approbation, 1 iuive tl)crefore pre-
sumed to lay before the society the following, craving pardon for
my boldness.

Finding with what difficulty a tolerable observation of die sun it
taken by Davis's quadrant, and that in using it, unless the spot or
shade be brought truly in the line of tlie horizon-vane, the obser-
vation, when made, is good for nothing; to do which requires
much practice, and at best is but catching au observatiouj
and considering further the smallness of the ()0 deg. arch, and the
aptness of wood to cast, which makes often little better than guess-
work ^ J therefore applied my thoughts, upwards of two years, to
find a more certain instrument, and contrived the following im-
provementj as I think, in the make and use of the bow; r/x.

The quadrant is to be numbered from each end to 90 at the
ether, as in the figure. The sight and glass vanes are the same
with the common, excepting that the glass should be larger, and
1 think it would be better if ground to the segment of tJie cylin-
der. The horizon-vane should be like that of the figure tliereot ;
having three holes, IKL; one hole, I, to tit on the centre of tlie
quadrant. A; the otlier two, KL, to see the horizon through,
whose length across the vane may be one-eighth of the radius
AB, or more ; the horizon-vane should be a little hollowed, an-
swerable to the curvature of the circle DAK, or cylinder, wliose
semidiameter, AJT, is about seven-elevenths of AB, the radiu:, of
the quadrant.

In observing with thifj quadrant at sen, let the sight and glaM
vanes be kept nearly on the same numbers, or at equal distances

41-4 Addilionat Notes.

from the ends of the arch, and then k will be sufficiently exact
to bring the spot and horizon in a right line, on any part of the
horizon-rane, by moving the vanes nearer together or flirther
apart, 4he middle of the horizon-vane being parallel to the hori-
zon, then the zenith distance will be the sum of the distances of
the vanes from the end of the quadrant arch. ' For, putting r =
the radius of the quadrant, a — the distance of the spot from the
middle of the horizon-vane, 5= the sine, and c = the cosine of
half the suns altitude, unity being radius, the sine of the errour

2 sua
will be nearly equal to c 4-4; x "rr" j ?-nd, tlierefore, when greatest

(which is when the zenith distance is 0000, or 47 degrees 45
minutes), of the distance of ^ of the radius of the quadrant from
tlie middle of the horizon-Vaue, it is but 1 '30^ I would advise
to bring the upper or lower edge of the spot, and not the middle
and horizon, on a right line, and then subtract or add sixteen
minutes for the sun's semidiameter from or to the zenith distance
given by the vane.

N. B. There should be an allowance for the obser\-er s height
above the surface of the sea, by subtracting four, five, or six mi-
nutes. A table of this kind would not be amiss on the back of
the quadrant.

There may be some graduations put on the staff, near the centre,,
to be cut by a plumb-line hung on a pin put into a small hole for
land observations. One of these quadrant-., being eighteen inches
and two feet radius, if well graduated, will be sufficient to take
tlie sun's zenith distance within two or three minutes.

Succeeding so well witli the sun, encouraged mc to take what
appeared a more difficult task, the finding some way to take the
altitude of the stars at sea (\\hen the horizon may be seen) belter
than by the fore-staff, which I concluded must be by bringing the
two objects, horizon and star, together. I first considered one re-
flexion ; but the faults of Davis's quadrant were here enlargc^d,
which is chiefly tlie flying of the objects from each other, by the
least motion of the instrument. I then examined what two re-
flexions would do, which perfectly answered my desire, being
equally useful in taking the distance of stars from each other,
and also from the moon, and I believe practicable at sea ; for I
found that when one star was made to coincide" by two reflex-
ions with another, the distance of these stars would be double
the inclination of the reflecting planes, as may be easily demon-
strated.

Additional Notes. 415

I see but one fault in this instmment, nnd that is, tliat lhre«
feet radius in this has a graduation no larger than a qij^drant ijf
eighteen inches radius. I hope Dr. Halley has received a more
fall account of this from J. Logan, esq., therefore I shall add no

more than that I am, gentlemtn.

Yours, iVc.
T. GODFREY.
Philadelphia, Nov. 9, 1734.

Page 529. Extracts from "A further Account of Thomas God-
frey's Improvcmait of Davis's Quadrant transferred to the Mari-
ners Boiv.'*

Being informed that this improvement, proposed by Thomas
Godfrey, of this place, for observing the sun's altitude at sea with
more ease and expedition than is practicable by the common in-
strument in use for that purpose, was last winter laid before tha
Koyal Scx:iety, in his own description of it, and that some gentle-
men wished to see the benefit intended by it more fully and
clearly explained, I, who have here the opportunity of knowing
the author's thoughts on such subjects, being persuaded, in my
judgement, that if the instrument, as he proposes it, be brought
into practice, it will in many cases be of great service to naviga-
tion, have therefore thouglit it proper to draw up a more full ac-
count of it than the author himself has given, with the advan-
tages attending it, which if approved of by better judgements, to
whom what 1 otfer is entirely submitted, it is hoped the use of it
will be recommended and further encouraged, as well as the au-
thor. The use of the improvement, witli its conveniences, a
also a description of it, are as follows.

[Then follows a repetition of the account of Godfrey's having
studied — what occurred to him about tlie importance of knowing
the latitude and longitude of a ship's place, &:c., which I do nut
transcribe, as it is long, and not to your purpose.

E. II.]

Pa^e 532.~Some masters of vessels who sail from hcnco ta
the West Indies liave got some of them* made, as well a.s they
can be done here, and have found so great an advantage in the
facility and in the ready use of them in those southerly latitudes,
that they reject all others. And it can scarce be doubted, but
when the in^iruraciit becon^es generally knu%vn, it may, uixm

* Goduey'j in«trument-w

416 Additional Notes,

the Royal Society's approbation, if the thing appears worthy o^
it, more universally obtain in practice. It is now four years
bince Thomas Godfrey hit on this improvement : for his account
of it, laid before the Society last winter, in which he mentioned
two years, was wrote- in 1/32] and in the same year, 1730^
after he was satisfied in this*, he applied himself to think of the
other, t'/z. the reflecting instrument by speculums for a h-lp in
tlie case of longitude, though it is also useful in taking alti-
tudes 3 and one of tlrese, as has been abundantly proved by the
maker, and those who had it with them, was taken to sea, and
there used in observing the latitude the winter of that year, and
brought back again to Philadelphia before the end of February
1731, and was in my keeping some months immediately after.

It was indeed unhappy, that, having it in my power, seeing
he had no acquaintance nor knowledge of persons in England,
1 transmitted not an account of it sooner f. But I had other
aifairs of more importance to me j and it was owing to an acci-
dent which gave me some uneasiness, viz. his attempting to pub-
lish some account.of it in print here, that I transmitted it at last,
in May 1732, to Dr. Halley, to M'hom I made no doubt but the
invention would appear entirely new^ ) and I must own I could
not but wonder tliat our good-will at least was never acknow-
ledged. This, on my part, was all the merit I had'to claim, nor
did I then, or now, assume any other in either of these instru-
ments. I only wished that the ingenious inventor himself might,
by some means, be taken notice of, in a manner that might be 0/
real advantage to him.

There needs not, I suppose, much more of a description of
the instrument than has been given. I shall only say that the
bow had best be an arch of about 100 deg. well graduated and
numbered both ways ; the radius 20 or 24 inches ; the cuiTe at
the centre to be one-tvvcntieth of the radius on each side, that is,
one-tenth of it in the whole ;' the radius of that curve -jV? P^rts?

* 'I'hat U, I suppose, being " saLisficd," that he had made a real 'impro'vi'
vient in the quadrant. ii. H»

f All these circumstances of Mr, Logan's complaint, and almost every
thing that follows to tlie enU, except the directions for making the instru-
ment, arc left out of the account J)ublishcd in the PhHosolih'ual Transactions^
•which strengthens the conjecture tliat justice has not been done to the ori-
ginal inventor.

Additional Notes, 41 7

of the radius of the instrument ; tlmt the glass for tlie solar vane
should not be less, but rather larger, than a silver shilling, vith \\%
vertex very exactly set ;^ and that the utmost care be Liken to
place the middle of the curve exactly perpendicular to the line or
radius of 45 deg., as the observer must also uikc care that the two
vanes on tlie limb be kept nearly equidistant from that dcgre?.
To which I shall only add, that it may be best to give the horizon-
tal vane only one aperture, not two. The rest, I suppose, may
be left to tlie workman. Thus, doubting I have already been too
prolix on the subject, to which nothing hut a sincere inclination
to promote any thing that might contribute to a public bencht,
and to do some justice to merit, could induce me, J shall only
request that what 1 have here offered may be construed by that
intention.

J. LOGAN.
Philadelphia, June 28, 1734.

P. S. [By the Editors of the AIa<razinc J] It is easy to see, by
a caretiil perusal of tliese two letters, and that in our last Maga-
zine, the progress of this invention, and how far Mr. Godfrey
ought to be considered as tlie inventor. It is our business to give
impartial accounts of facts and transcripts of authentic pa})crs.
The reader, after that, is to judge for himself For our own
part, we have no hesitation in pronouncing Mr. Godfrey the real
original inventor of this famous and useful instrument.

The following extract of a letter from Mr. Hazard, which ac-
companied the above documents, ought to be added, in justice
both to the Royal Society and to Mr. Godfrey.

*' Alderman Hillegas, of this city (Philadelphia), knew God-
frey. He says, he remembers to have heard, perhai)s fifty years
ago, that, as HadJey had obtained tlie patent, complete, justice
could not be done to Godfrey ; but that the Royal Society, think-
ing his ingenuity ought to be rewarded, eitlier subscribed for him
as individuals, or gave him out of their funds, af200 sterling :
and knowing his infirmity (for it seems he was apt to indulge in
intemperate drinking), they thought it better to send the amount
in household furniture than in cash, and, irUer alia, sent him a
clock J which the alderman remembers to ha>e seen."

Godfrey had a son, Thomas Godfrey, junior, who, in l/dj,
published a volume of Juvenile Poems. The young man is
Vol. I. 2 E

4 IS Additional Notes.

spoken of, by the writer of the preface, as possessing great natu-
ral endowments, with but little cultivation j and as deserving to
be ranl:ed, as well as his father, among the curiosities of Penn-
s}l\ania. — MS. Letter of the Rev. Dr. Elliot, qf BostoUj to the

Author.

It is worthy of notice, that the use of the quadrant in que-
stion was confined to the English nation until the year 1736,
when M. d'Apres de Mannevillette, the great maritime geo-
grapher, employed it on board a French ship 5 and on his return
to France, one of the earliest objects of his attention was to
state, in a public print, his high estimation of this curious in-
stmment. He thus had the honour of introducing to his coun-
trymen one of the most valuable inventions of the age.

Note (T), p. 101. — Dr. Priestley concluded from his experi-
ments, and it has been since generally believed by Ingenhousz,
Sennebier, and other vegetable physiologists, that vegetables, in
the course of their germination and growth, when exposed to
solar light, absorb azote and emit oxygen, and thus purify the
surrounding air. But, by a series of ingenious experiments
lately published, professor Woodhouse, of Philadelphia, has
drawn into question tlie truth of these conclusions. From the
result of these experiments, he contends that the germination of
seeds and the growth of plants do not purify atmospherical air 3
but that, whenever they appear to afford oxygen gas, it is by
devouring the coal of carbonic acid gas for food, and leaving its
oxygen in the form of pure air. He has also made experiments
on the effects produced by the leaves of plants in common air,
impregnated with carbonic acid gas, and exposed to solar light ,
in which cases the carbonic acid disappeared, and the oxygenous
gas increased. And from trials made with the fresh leaves of
many different plants, exposed to sunshine in pump-water, river-
water, and this latter charged with carbonic acid, he is confirmed
in the same conclusion. Dr. Woodhouse, therefore, denies that
vegetables either decompose water, emit oxygen, or absorb
azote, as has been some time commonly believed. — Nicholson?
Philos. Journal, 8vo. series, vol. ii. for July 1$02,

Note CU)y p. 1 II. — ^The important services of M. Lavoisier, in
forming tlie theory of the French academicians, and the intrinsic

Addllional Nolcs. 41 9

worth of his character, render it proper that some account .should
be given of him in this place.

Antony Laurenee Lavoisier was born al Paris, in the vcar
1743. He early discovered a taste for the study of the physical
sciences, and, for a considerable time, directed his attention to
most of them in succession, without discovering a preponderating
inclination for anyone in particular. This continued to be tiie
case till about tJie year 1770» when the important discoveries in
chemistry, by Black, Priestley, Scheele, and Cavendish, tired
his ambition, and directed his attention more particularly to < he-
mical philosophy, to which he almost exclusively attached him-
self during the remainder of his life.

It IS generally known that his experiments and discoveries
were among tlie principal means of establishing tliat revolution
in the theory and nomenclature of chemical science, \Nhich has
been, \\'ith great propriety, denominated tlie Lavoisieriun theory.
After numerous publications on different departments of che-
mistry, in the Memoirs of the Academy of Scieucc.t, and other
sclentilic journals, in which he successi^•ely treated of combus-
tion, the analysis of atmospheric air, the formation and fixation
of elastic fluids, the properties of heat, the composition of
acids, the decomposition and recomposition of uatcr, the dis-
.solution of metals, vegetation, &c., he at length combined his
philosophical views into a consistent body, which he publMied
in 1789, under the title of Elements of Chemistry ; a work u hich
has been pronounced one of the most elegant models of philoso-
phical arrangement, and of clear logical composition, that was
ever presented to the world.

He continued after this to pursue his favourite study with un-
abated diligence : his wealth enabled him to make experiments
on a great scale j his ardour, acuteness, and extended views,
enabled him to avail himself of every advantage ; and he conti-
nued to instruct his countrymen and the world, by tlic develope-
ment of new truths, or the recommendation of useful econo-
mical improvements, until the month of IMay l/p-i, when he
became an object of the malignant phrensy of Robespierre,
and suffered under the guillotine, in tlie fifty-first year <.f Ips
age.

Note (V)y p. 122.— Modern philosophers have discovered that
the influence of light on growing vegetablts is great and impor-
2 E 2

420 Additional Notes,

tant. Plants may be made to vegetate tolerably well in the dark j
but in this case their colour is always white, they have scarcely
any taste, and contain but a very small portion of combustible
matter. In a very short time, however, after their exposure to
light, their colour becomes green, their taste is rendered much
more intense, and the quantity of combustible matter is consi-
derably increased. — ^Thompson's Chemistry.

'' It has been found by Dr. Herschell (see Vhilos, Trans, for
1 800) that the rays of light differ in their power of illuminating
objects : for if an equal portion of each of these rays, one after
another, be made to illuminate a minute object, a printed pago
for instance, it will not be seen distinctly at the same distance
•when illuminated by each. We must stand nearest the object
when it is illuminated by the viokt. We see distinctly, at a
somewhat greater distance, when the object is illuminated by the
indigo ray; at a greater when by the bhw ; at a still greater
when by the deep green; and at the greatest distance of all
when by the lightest green or deepest yellow. We must stand
nearer when tlie object is illuminated by the orange ray ; and
still nearer when by the red. Thus it appears that the rays to-
wards the middle of the spectrum possess the greatest illumi-
nating power, andtliose at tlie extremity the least j and that the
illuminating power of tlie rays gradually :. diminishes from the
middle of the spectrum towards its extremities." — Ihid.

Note (W), p. 131. — In Fahrenheit's thermometer the freezing
point is fixed at 32 deg. and the boiling point at 212 deg. In
Reaumur's, or rather de Luc's, the freezing point is O, and the
boiling point 80 deg. In Delisle's, the usual order of gradua-
tion is inverted, tlie freezing point being 150 deg. and the boil-
ing point 0. And, finally, in the thermometer of Celsius, tlie
point of freezing is marked 0, and that of boiling 100 deg. To
reduce the degrees of Reaumur to those of Fahrenheit, tlie fol-
lowing formula may be employed :-^^ — i--f-32=F. To reduce the

4
degrees of Celsius to those of Fahrenheit, the following is suffi-
cient : -1?_? -f 32=F. To reduce the degrees of Delisle,

5
\inder the boiling point, to those of Fahrenheit, say, 212 ~

«=F, To reduce those above the boiling point to Fahrenheit,

5

say, 2!2 + ^j^=:;F.
5

Additional Notes. 421

Note (X), p, 133. — The numerous eudiometers proposed by
different chemists may be reduced to five.

1. The first is that invented by Dr. Priestley, in wluJi /«i-
trous gas is mixed, over water, with the air tlie purity of whicJi
it is wished to ascertain. The diminution of the volume of this
mixture is proportioned to the quantity of oxygen contained in
the air, which is rapidly absorbed by the nitrous gas, and tlie
nitric acid thus formed is also rapidly absorbed by the water.
This eudiometer has received various modifications and improve-
ments by Falconer, Cavendish, and von Humboldt, but is
still liable to considerable anomaly and inaccuracy in its indi-
cations.

2. The second kind of eudiometer was proposed by Volta.
His method was to mix given proportions of the air to be exa-
mined, and hydrogen gas, in a graduated glass tubej to tire the
mixture by an electric spark 3 and to judge of the purity of the
air by the bulk of the residuum. But this furnishes a measure
eren less to be depended on than the preceding.

3. Scheele was the inventor of tlie third kind of eudiometer.
It is merely a graduated glass vessel, containing a given quan-
tity of air, exposed to a newly-prepared liquid alkaline or earthy
sulphuret, or to a mixture of iron filings and sulphur, formed
Into a paste with water. These substances absorb the whole of
the oxygen of the air, which converts a portion of the sulphur
into an acid. The oxygen contained in the air thus examined is
judged of by tlie diminution of bulk which tlie air has under-
gone. This method is simple, and as accurate as any otlier.
The only objection to which it is liable is the slowness. of the
process. But this objection has been removed by M. de Marti,
who has brought the eudiometer of Scheele to a great degree of
accuracy, by improving the apparatus, and, instead of iron
filings and sulphur, using the hj/droi^niated sulpliiircts only.

Guyton-Morveau employs sulphuret of poUii,h, and measures
the proportion of oxygen present by the quantity absorbed by
the sulphuret.

4. In the fourth kind of eudiometer, the abstraction of tl.e
oxygen of air is accomplished by means of phosphorus. This
eudiometer was first proposed by Achard. It was considerably
improved by Reboul, Seguin, Lavoisier, and, above all, by
Berthollel, who has rendered it equal in simplicity with the
eudiometer of de Marti, and scarcely inferior to it i.'i pre-
cision.

42^2 Additional Notes,

5. The fifth eudiometer has been lately proposed by Mr,
Davy. In this the substance used to absorb the oxygen from the
air is a solution of sulphat or muriat of iron in water, and im-
pregnated with nitrous gas. This eudiometer is simple, and its
indications nearly, if not quite, as accurate as those of the two
last mentioned. — Thompson's Chemistry.

Note (Y), p. 151. — M. Cuvier, of France, a member of the
National Institute, and a celebrated zoologist, has been for some
time engaged in a very extensive work upon the species of quadru-
peds, the bones of which have been found in the interior parts of tlie
earth. He has undertaken to settle the controversy concerning
tliese animal relics. He says, that the strata of every country
upon earth contain bones different from those of the animals
which now inhabit their surface : that, with the single exception
of ruminant animals, all the complete fossil bones which he has
seen, are different from those of quadrupeds now alive : that of
these he has been able to ascertain twenty-three species, all cer-
tainly unknown at this day j and which appear to have been en-
tirely destroyed, though their bones evince their existence in
former ages.

These species of creatures, the races of which are now extinct,
M. Cuvier divides into two classes — 1 . Those which have, been de-
termined by others j and, 2. Such as have been settled by him-
self. In the first he enumerates the following : 1 . The Siberian
unimul, which affords fossil ivory. 2. The mammoth, differing
from the former chiefly in the size and points of its grinders.
3. The long-headed rhinoceros. 4. That animal of the tardi-
grade family called megatherium and megalonyx. 5. An extinct
species of large bear. 6. Another species of the bear. 7. A
carnivorous anirnal, intermediate between tlie wolf and hysena.
8. A creature akin to the ?noose, the horns of which measure fourteen
feet from tip to tip. g. The great fossil tortoise. 10. The
Maestricht crocodile. 11. A sort of dragon. 12. An unknown
kind of reptile or cetaceous animal. — In the second class, the
chief of which have been discovered in France, M. Cuvier places
the following species: l.That animal the fce^A of which, ivhcn
impregnated iiith copper, form the occidental turquoise. 2. A
tapir, dlfl'ering from that of South America only in the form of
its grinders. 3. Another tapir, of a gigantic or elephantine
size. 4. A species of hippopotamos, about the size of a hog.
^y 6. 7f 8, i), 10. Six fossil skeletons of an unknown species.

Additional Notes, 423

between the rhinoceros and the tapir, from the planter quarries
in the neighbourhood of Paris, n. A species of crocodile, con-
siderably like that of the Ganges.

But these are not all which the earth contains : there arc parts
of skeletons of which M. Cuvier cannot speak with equal as-
surance ; but of which, however, enough is known to encou-
rage a hope that the list of zo6k)gical anticjuitics will be soon
lengthened. Of these, some resemble the bones— -1. Of the
tiger. 2. Of an hyaena, or sea-calf. 3. Of the fallow-deer.
And others of uncertain characters j as the petrified bones, 1 .
Near Verona. 2 and 3. Two sorts in the Rock of Gibraltar.
4. In tlie vicinity of Dax. 5. Near Orleans, G. Near Aix and
Cette. 7. In the islands of Dalmatia, &:c. And, 8. All other
uncertain bones found in the peat mosses of all ])arts of Europe
and Asia. In tlie course of a short time M Cuvier hoiKs to
determine the exact place in the system to which tlicse doubtful
species are to be referred.

M. Cuvier solicits information on these subjects from all parts
of the world. He wishes to procure the bones themselves, or
figures of them, or correct descriptions in words. — Medical
Repository.

The naturalists of France derived great advantages when Hol-
land fell into the power of their countrymen, from the opportu-
nities which were afforded them of inspecting the rich museum
of the stadtholder. M. Cuvier's attention was more particu-
larly directed to tw^o elephants' heads, which having examined
with some nicety, he found to exhibit characters that warrant
their being considered as belonging to two distir.ct species. One
of them from Ceylon, he remarked, differed from the other
(which came from the Cape) in respect not only to the general
contour of the forehead, but to the shape of tlie teeth, which
last he was at length induced, like Blumenbach and others, to
constitute the distinguishing characteristics of elephants in ge-
neral: and extending his inquiries to such as we know only by
their fossil exuvicc, he has furnished us with the following spe-
cific descriptions : viz.

*'yJElephas Capensis, f route convexa, lamcllis molarium Thorn-
hoidalihus.

E, Indicm, frontc plano-concaia, lamtUis violariim arcuatis
tindatis.

E. Mammontcus, maxilla ohtusiore, lamellis molar ii m tenuihus
rcctis.

424 Additional Note^.

E. Americanus, molarihus multi-cuspidihus, lamdlis post dc-
tritionem quadrilohatis .**

C. Cuvier, since the publication of his Memoir, has disco-
vered several new species of elephants, differing not only from
the fossil ones hitherto described, but from all living animah
with which we are acquainted. One of them is found in Peru,
and other countries, and comes nearest to the elephant of the
Ohio : another has been discovered in the strata of the Black
Mountain, in the department of IHerault : a third is found at
Comminges ; and fragments of the fourth abound in the vicinity
of Paris. — Mem. de V List. torn, ii, p. 22,

The origin of these fossil hones, especially of some, found in
peculiar circumstances, has employed the ingenuity of many emi-
nent naturalists, and been made the subject of much specula-
tion in later years. On the supposition, which has been
adopted by a considerable number of these inquirers^ that the
account of the general deluge given in the sacred writings is
false, the question is, indeed, of difficult solution. But, ad-
mitting the trutli of that account (and every mountain and val-
ley lifts up its voice to confirm it), the difficulty, in a- great mea-
sure, if not entirely, vanishes. Ix?t us suppose that the animals
the fossil exuvice of which are now found were inhabirtants of th«
antediluvian world, is it not evident that many of the facts ob-
served are precisely such as must necessarily have arisen from this
state of the case ?

The fossil remains of elephants have been discovered in va-
rious parts of the North-A7nerican continent, where none of this
genus of animals are now to be found in the living state. This
has been made a wonder. But how could it have been other-
wise ? If the flood destroyed all the inhabitants of the earth,
except those \^hich were preseiTcd in the ark ; and if tlie ark
rested, after the subsiding of the waters, on the eastern conti-
nent, as is generally supposed by biblical commentators j then no
animals, excepting those capable of making occasional and con-
siderable expeditions by iiater, or of living in frozen regions,
and by this means passing from the eastern to the western conti-
nent on the ice, could be expected to be found in the latter, ii>
any other than the fossil state. It is true, we find animals in
South America which appear, at present, only capable of inha-
biting warm regions ; but it is well known, that both animals
and vegetables have the faculty of accommodating themselves to
the climate in which tliey are placed, and of gradually chang-

Additional Notes. 4^25

ing their character. It is by no means improbable, tlierefore,
that the ancestors of the animals now living in South America
had once a northern constitution; that, after crossing the strait
between Asia and America, they gradually strayed further s<nitl» ;
and that, in process of time, their offspring acquired southern
habits and constitutions.

Nor is it by any means difficult to suppose, that these fossTl
exnvia; were deposited in Uie places where they are found, at
the subsidence of the waters of the general deluge. They liavc
been generally found in circumstances calculated long to preserve
them ; in strata of earth which tend to resist putrefaction, and
which may account for their remaining entire after so great a lapse
of time.

Note (Z)y p. 181. — At the close of the eighteenth century,
only five dissertations, it is believed, had been published by the
medical graduates of America on botanical subjects. Tliese are
respectfully noticed in the above-mentioned page. Since that
time, publications of this kind have considerably multiplied.
The learned and interesting lectures on botany, delivered by
professor Barton, of the university of Pennsylvania, and his en-
lightened zeal in pursuing this branch of science, have produced
a very sensible effect in recommending it to the attention of
tlie students in that seminary. In the course of the last three
years, tlie following dissertations on botanical subjects have been
added to the former small list.

1. On the Digitalis Purpurea, by John Moore, of Pennsylva-

nia.

2. On the Kalmi'i. J^atifolia and AngusiifoUa, by George Tliomas,

of Virginia.

3. On the Melia Azedarach, by Grafton Du\a], of :\Iary^

land.

4. On tlie Primus Virginiana, by Charles Morris, of \'iiginia.
$. On the Liriodendron Tulipifcra, by Patrick Rogers, oi he-

land.
Q. On the Magnolia Glaucn, by Thomas D. Price, of Virginia.

7. On the Spigdia Mari/landica, by Hedge Thompson, of New

Jersey.

8. On the Sanguinaria Canadensis, by William Downej', of

Maryland.
g. On the Bignonia Catalpa, by Robert Holmes, of Virginia.

436 Additional Notes,

10. On the Poly gala Senega, by Thomas Massie, of Virginia.

1 1 . On the Arbutus Uva Ujsi, and Pyrola U7nbeUatu and MacU"
lata, by John S. Mitchell, of Pennsylvania.

12. On the Cornus Florida, and Scricea, and the Cinch(ma Offi-
cinalis, by John M. Walker, of Virginia.

Some of these academic publications have great merit : they
afford conclusive evidence, that this department of Natural His-
tory is more studied in the middle and southern than in the east-
ern states. It will be observed, that the authors of all tlie dis-
sertations above mentioned reside to the south of New York^
excepting the student from Ireland.

Note (AA), p. 184. — ^Two gentlemen of this name have con-
tributed to our knowledge of American plants, viz. John and Wil-
liam Bartram, both natives of Pennsylvania. John Bartram, the
father, was born in the year 1701* and died in 1777- He was a
self-taught philosopher and botanist. He travelled much, in the
America?! colonies^ particularly to the southward and westward ;
discovered many new plants, and made large collections of our
indigenous vegetables. (See vol. iii, chap. 2Q of this work.)
He made several valuable communications to Peter Collinson,
on diflerent subjects in zoology, which were published in the
Philosophical Transactions, chiefly between the years 1/43 and
1749. Professor Barton is preparing for the press some account
of this distinguished man, who may justly be styled '' one of
the fathers of natural history in North America." — His son,
William Bartram, is still living, and advantageously known by
his Travels through North and South Carolina, Georgia, East and
West Florida, &c. He still cultivates the gar^^en established by
his father, and continues to devote himself 10 botanical inquiries
and delineations with great zeal, and in a manner both useful
and honourable to our country.

Note (BB), ibid. — The work of professor Barton, an-
nounced in the above-mentioned page, bears the following title :
Elements of Botani/, or Outlines of the Natural History of Vege-
tables, &c. Svo. 1803. Dr. Barton has the honour of being the
first American who gave to his country an elementary work on
Botany ; and if we may judge of the subsequent harvest by the
first fruits, it will be rich indeed. This work is illusti-ated by
thirty plates, and discovers, an extent of learning, an acutenesa

Additional Notes. 42?

and vigour of mind, and an elegance of taste, highly honourable
to the author. Dr, Barton adopts the scnial system, and a great
part oi the Linnaean nomenclature ; but is by no means a servile
follower of that illustrious naturalist. He thinks tlie sexual sy-
stem would sutler no injury by the total abolition of the ilvvcnth
class (Dodcc(uulvia) ; and though he dissents from the i)r<)-
posed alteration by Thunberg, yet he thinks, with Dr. J. E.
Smith, that the tivcntij-third Linnnean class (Polj/s^cunia) is unnatu-
ral, variable, and obscure, and ought to be entirely suppressed.

Of the thirti/ plaits which accompany this work, twenty-eight
have claims to more or less originality, and many of them arc
completely original. They are well executed j and most of the
subjects selected for delineation arc remarkable for their rarity,
their beauty, or some other peculiarity of character. Every part
of this work discovers that the author has not been contented
with compiling the facts and opinions of his predecessors, but
that he has accurately observed and thought for himself Ha
will, therefore, no doubt, be pronounced, by the best judges, to
have presehted his countrymen witli the most comprehensive,
instructive, and satisfactory work of this kind in the English
language f. ■

Note (CC), p. 18/. — Among the numerous and important
services rendered to botanical science, by means of accurate and
elegant drawings, and other moiles of exhibiting plants, the fol-
lowing more partiouUirly deserve notice.

It is a singular fact that physic is indebted for the most com-
plete set r^ 'Ayilres of the medicinal plants to the genius and in-
<iustry of Mrs. .'"v*.zabet"h Blackwell, a native of Scotland, who,
in 1739, published a splendid work under the following title — A
curious Herbaly containing five hundred Cuts of the most useful
Plants uhich are now used in the Practice of Physic, em^ravcd on
Folio Copperplates^ after Drnivings taken from the Life, 2 vols,
folio. This ingenious lady, afler she had comj)k'ted die draw-
ings, engraved them on copper, and coloured the prints with her
own Iiands. It ought to be mentioned, to the honour of Mrs.
Elackwell, that she undertook and went through this ingenious
labour for the purpose of procuring her husband'^ liberation tVoni
prison, where he was confined for debt, and from which she
extricated him in two years. — Pultoney's Sketches.

* I'his work has becQ republished in London, in an improved form.

4^8 Additional Notes.

*' Mrs. Delany has finished nine hundred and seventy ac-
curate and elegant representations of different vegetables,
with the parts of their flowers, fructification, &€., accord-
ing with the classification of Linnaeus, in what she terms paper"
vwsdic. She began this work at the age of 74, whsn her sight
would no longer serve her to paint, in which she much excelled.
Between tlie age of 74 and 82, at which time her eyes quite
failed her, she executed the curious Hortus Siccus above mentioned,
which I suppose contains a greater number of plants than were
ever before drawn from the life by any one person. Her method
consisted in placing the leaves of each plant, with the petals^ and
all the other parts of the flowers, on coloured paper, and cutting
them with scissors accurately to the natural size and tbrm, and
then pasting them on a dark ground 3 the effect of which is won-
derful, and their accuracy less liable to fallacy than drawings.
She is at this time (1/88) in her 89th year, with all the powers
of a fine understanding still unimpaired. I am informed that an-
otlier very ingenious lady, Mrs. North, is constmcting a similar
Hortus Siccus, or paper-garden, which she executes on a ground
of vellum, with such elegant taste and scientific accuracy, that it
cannot fail to become a work of inestimable value." — Botanic
Garden, part ii, canto ii, 1. 155.

Note (I)D),p. 18/. — ^The late royal government of France,
for the promotion of botanical science, was in the habit of esta-
blishing Botanical Gardens in various parts of her colonies,- and of
foreign countries. A piece of land of moderate fertility an^i ex-
tent, hired or purchased at the public expense. <%! "fd, in the
distant country where it was situate, as a hcs^ffor a botanist, a
repository for the seeds he might collect, and a nursery for the
plants he should cultivate. From establishments of this naLiue in
distant regions, rich treasures of botanical specimens and informa-
tion have been transmitted to France.

The late king of France provided two gardens of this kind in
the United States 5 one in Bergen county, in the state of New
Jersey, within eight or nine miles of the city of New York ; the
other in South Carolina. The botanist employed to superintend
these, and to perform all the duties of a botanical pensionary, was
M. Andrew Michaux, who has lately distinguished himself by his
Ilibloire dcs C/icncs dc I'Amcricjuc, &c. Paris, 1801, Folio.

The first person who conceived and carried into eftect Llie de-

AdcUtiojial Notes, 429

sign of a Botanic Garden for the reception and cultivation of
American vegetables, as well as exotics, was the celebrated John
Bartram, mentioned in a former note. His establisliment, though
small, and scarcely worthy of the name when compared with those
of Europe, was respectable, considering the situation of tlie pro-
prietor, and is now probably the best in our countiy. Those
formed and supported by the French government, though calcu-
lated to answer the purposes intended, were nlso far from being
regular or complete botanical gardens. Nothing that dcscncs thi*
character has yet been established in America. It is hoped the
plan now in execution by professor Hosack, of Columbia college,
will be fostered by the public, and succeed better than any
former attempts.

Note (EE), p. 353. — It has been made a question whetlier the
inoculation of the small-pox. ought to be considered as a blessing
or an evil to society. Some have supposed that its effect has been
to keep the disease more steadily alive, and more extensively dif-
fused} and thus, on the whole, that it has produced an injury
rather than a benefit. Professor Waterhouse, of Massachusetts,
in a late publication recommending the substitution of ^h^ low-
PoXy makes the following statement : — " No less than forty mil-
lions of people die of the small-pox eveiy century. The Eu-
ropeans have carried the small-pox over the globe. The Danes
carried it to Greenland, and the Spaniards to South America, where
one hundred tliousand perished witli it in the single province
of Quito. When the annual number of births in London was
sixteen thousand two hundred and ninety-one, the number who
liieJ with the small-pox was two thousand five hundred and
fifty-four, and still greater in some other large cities of Europe.
A greater munber have died of the small-pox since the introduc-
tion of its inoculation than before it, that practice being the
means of keeping it always in large cities,"

END OF VOL. I.

S. Hamilton, Printer, Shoe Lane, Fleet Street.

8 6869

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