ANIMAL CHEMISTRY,

ORGANIC CHEMISTRY

IN ITS APPLICATIONS TO

PHYSIOLOGY AND PATHOLOGY.

BY

JUSTUS LIEBIG, M.D., Pn.D.,F.R.S., M.R.I.A.

PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GIESSEN.

EDITED FROM THE AUTHOR S MANUSCRIPT,

BY WILLIAM GREGORY, M.D., F.R.S.E., M.R.I.A.

PROFESSOR OF MEDICINE AND CHEMISTRY IN THE UNIVERSITY
AND KING'S COLLEGE, ABERDEEN.

LONDON:
PRINTED FOR TAYLOR AND WALTON,

UPPER GOWER STREET.

1842.

Printed by J. L. Cox & SONS, 75, Great Queen Street,
Lincoln's-Inn Fields.

THE BRITISH ASSOCIATION

FOR THE

ADVANCEMENT OF SCIENCE.

AT the meeting of the British Association in
Glasgow, in 1840, I had the honour to present the
first part of a report on the then present state of
Organic Chemistry, in which I endeavoured to de-
velope the doctrines of this science in their bearing
on Agriculture and Physiology.

It affords me now much gratification to be able
to communicate to the meeting of the Association
for the present year the second part of my labours ;
in which I have attempted to trace the application
of Organic Chemistry to Animal Physiology and
Pathology.

In the present work an extensive series of phe-
nomena have been treated in their chemical rela-
tions; and although it would be presumptuous to
consider the questions here raised as being definitely
resolved, yet those who are familiar with chemistry

VI DEDICATION.

will perceive that the only method which can lead
to their final resolution, namely, the quantitative me-
thod, has been employed.

The formulae and equations in the second part,
therefore, although they are not to be viewed as
ascertained truths, and as furnishing a complete, or
the only explanation of the vital processes there
treated of, are yet true in this sense: that being
deduced from facts by logical induction, they must
stand as long as no new facts shall be opposed to
them.

When the chemist shews, for example, that the
elements of the bile, added to those of the urate
of ammonia, correspond exactly to those of blood,
he presents to us a fact which is independent of all
hypothesis. It remains for the physiologist to de-
termine, by experiment, whether the conclusions
drawn by the chemist from such a fact be accurate
or erroneous. And whether this question be an-
swered in the affirmative or in the negative, the fact
remains, and will some day find its true explana-
tion.

I have now to perform the agreeable duty of
expressing my sense of the services rendered to me
in the preparation of the English edition by my
friend Dr. Gregory. The distinguished station he
occupies as a chemist ; the regular education which

DEDICATION. Vll

he has received in the various branches of medicine ;
and his intimate acquaintance with the German
language — all these, taken together, are the best
securities that the translation is such as to convey
the exact sense of the original ; securities, such as
are not often united in the same individual.

It is my intention to follow this second part with
a third, the completion of which, however, cannot
be looked for before the lapse of two years. This
third part will contain an investigation of the food
of man and animals, the analysis of all articles of
diet, and the study of the changes which the raw
food undergoes in its preparation ; as, for example,
in fermentation (bread), baking, roasting, boiling, &c.
Already, it is true, many analyses have been made
for the proposed work ; but the number of objects
of investigation is exceedingly large, and in order
to determine with accuracy the absolute value of
seed, or of flour, or of a species of fodder, &c., as
food, the ultimate analysis alone is not sufficient ;
there are required comparative investigations, which
present very great difficulties.

DB. JUSTUS LIEBIG.

GlESSEN,

3rd June, 1842.

NOTE.

I would beg leave to refer the chemical as
well as the physiological reader particularly to the
analyses (in Note (27), Appendix) of the animal
tissues, which ought to have been referred to on
pages 43 and 126, and which at present are only
referred to in Note (7). Since the work was
printed, moreover, there has been added, at the end
of the Appendix, an interesting paper by Keller
(see page 325), confirming the very important ob-
servation of A. Ure, junior, as to the conversion of
benzoic acid into hippuric acid in the human body;
a fact which I perceive, by the Philosophical Maga-
zine for June, has also been confirmed by Mr. Gar-
rod, probably at an earlier period than by M. Keller.
The reader will perceive that this fact strengthens
materially the argument of the Author on the
action of remedies.

W. G.

PREFACE.

BY the application to Chemistry of the methods
which had for centuries been followed by philoso-
phers in ascertaining the causes of natural pheno-
mena in physics — by the observation of weight and
measure — LAVOISIER laid the foundation of a new
science, which, having been cultivated by a host of
distinguished men, has, in a singularly short period,
reached a high degree of perfection.

It was the investigation and determination of all
the conditions which are essential to an observation
or an experiment, and the discovery of the true
principles of scientific research, that protected
chemists from error, and conducted them, by a way
equally simple and secure, to discoveries which have
shed a brilliant light on those natural phenomena
which were previously the most obscure and incom-
prehensible.

The most useful applications to the arts, to
industry, and to all branches of knowledge related
to chemistry, sprung from the laws thus established ;
and this influence was not delayed till chemistry

X PREFACE.

had attained its highest perfection, but came into
action with each new observation.

All existing experience and observation in other
departments of science reacted, in like manner, on
the improvement and developement of chemistry ;
so that chemistry received from metallurgy and
from other industrial arts as much benefit as she
had conferred on them. While they simultaneously
increased in wealth, they mutually contributed to
the developement of each other.

After mineral chemistry had gradually attained
its present state of developement, the labours of
chemists took a new direction. From the study
of the constituent parts of vegetables and animals,
new and altered views have arisen ; and the present
work is an attempt to apply these views to physio-
logy and pathology.

In earlier times the attempt has been made, and
often with great success, to apply to the objects of
the medical art the views derived from an acquaint-
ance with chemical observations. Indeed, the great
physicians, who lived towards the end of the seven-
teenth century, were the founders of chemistry, and
in those days the only philosophers acquainted with
it. The phlogistic system was the dawn of a new
day; it was the victory of philosophy over the
rudest empiricism.

PREFACE. XI

With all its discoveries, modern chemistry has
performed but slender services to physiology and
pathology ; and we cannot be deceived as to the
cause of this failure, if we reflect that it was found
impossible to trace any sort of relation between the
observations made in inorganic chemistry, the know-
ledge of the characters of the elementary bodies and
of such of their compounds as could be formed in
the laboratory, on the one hand, and the living
body, with the characters of its constituents, on the
other.

Physiology took no share in the advancement of
chemistry, because for a long period she received
from the latter science no assistance in her own
developement. This state of matters has been
entirely changed within five-and-twenty years. But
during this period physiology has also acquired new
ways and methods of investigation within her own
province ; and it is only the exhaustion of these
sources of discovery which has enabled us to look
forward to a change in the direction of the labours
of physiologists. The time for such a change is now
at hand ; and a perseverance in the methods lately
followed in physiology would now, from the want,
which must soon be felt, of fresh points of departure
for researches, render physiology more extensive,
but neither more profound nor more solid.

Xll PREFACE.

No one will venture to maintain, that the know-
ledge of the forms and of the phenomena of motion
in organized beings is either unnecessary or unprofit-
able. On the contrary, this knowledge must be
considered as altogether indispensable to that of the
vital processes. But it embraces only one class of
the conditions necessary for the acquisition of that
knowledge, and is not of itself sufficient to enable
us to attain it.

The study of the uses and functions of the diffe-
rent organs, and of their mutual connection in the
animal body, was formerly the chief object of physi-
ological researches ; but lately this study has fallen
into the back-ground. The greater part of all the
modern discoveries has served to enrich comparative
anatomy far more than physiology.

These researches have yielded the most valuable
results in relation to the recognition of the dissimi-
lar forms and conditions to be found in the healthy
and in the diseased organism ; but they have
yielded no conclusions calculated to give us a more
profound insight into the essence of the vital pro-
cesses.

The most exact anatomical knowledge of the
structure of the tissues cannot teach us their uses ;
and from the microscopical examination of the most
minute reticulations of the vessels we can learn no

PREFACE. Xili

more as to their functions than we have learned
concerning vision from counting the surfaces on the
eye of the fly. The most beautiful and elevated
problem for the human intellect, the discovery of
the laws of vitality, cannot be resolved, nay, cannot
even be imagined, without an accurate knowledge
of chemical forces ; of those forces which do not act
at sensible distances ; which are manifested in the
same way as those ultimate causes by which the
vital phenomena are determined ; and which are
invariably found active, whenever dissimilar sub-
stances come into contact.

Physiology, even in the present day, still endea-
vours, but always after the fashion of the phlogistic
chemists (that is, by the qualitative method), to
apply chemical experience to the removal of diseased
conditions ; but with all these countless experi-
ments we are not one step nearer to the causes and
the essence of disease.

Without proposing well-defined questions, experi-
menters have placed blood, urine, and all the consti-
tuents of the healthy or diseased frame, in contact
with acids, alkalies, and all sorts of chemical re-
agents ; and have drawn, from observation of the
changes thus produced, conclusions as to their
behaviour in the body.

XIV PREFACE.

By pursuing this method, useful remedies or
modes of treatment might by accident be disco-
vered ; but a rational physiology cannot be founded
on mere re-actions, and the living body cannot be
viewed as a chemical laboratory.

In certain diseased conditions, in which the
blood acquires a viscid consistence, this state cannot
be permanently removed by a chemical action on
the fluid circulating in the blood-vessels. The
deposit of a sediment from the urine may, perhaps,
be prevented by alkalies, while their action has not
the remotest tendency to remove the cause of
disease. Again, when we observe, in typhus, inso-
luble salts of ammonia in the faeces, and a change
in the globules of the blood similar to that which
may be artificially produced by ammonia, we are
not, on that account, entitled to consider the pre-
sence of ammonia in the body as the cause, but
only as the effect of a cause.

Thus medicine, after the fashion of the Aristote-
lian philosophy, has formed certain conceptions in
regard to nutrition and sanguification ; articles of
diet have been divided into nutritious and non-
nutritious ; but these theories, being founded on
observations destitute of the conditions most essen-
tial to the drawing of just conclusions, could not be
received as expressions of the truth.

PREFACE. XV

How clear are now to us the relations of the
different articles of food to the objects which they
serve in the body, since organic chemistry has
applied to the investigation her quantitative method
of research !

When a lean goose, weighing 4 Ibs., gains, in
thirty-six days, during which it has been fed with
241bs. of maize, 51bs. in weight, and yields S^lbs. of
pure fat, this fat cannot have been contained in the
food, ready formed, because maize does not contain
the thousandth part of its weight of fat, or of any
substance resembling fat. And when a certain
number of bees, the weight of which is exactly
known, being fed with pure honey, devoid of wax,
yield one part of wax for every twenty parts of
honey consumed, without any change being percep-
tible in their health or in their weight, it is impossi-
ble any longer to entertain doubt as to the forma-
tion of fat from sugar in the animal body.

We must adopt the method which has thus led to
the discovery of the origin of fat, in the investiga-
tion of the origin and alteration of the secretions, as
well as in the study of all the other phenomena of
the animal body. From the moment that we begin
to look earnestly and conscientiously for the true
answers to our questions, that we take the trou-
ble, by means of weight and measure, to fix our

XVI PREFACE.

observations, and express them in the form of
equations, these answers are obtained without diffi-
culty.

However numerous our observations may be, yet,
if they only bear on one side of a question, they
will never enable us to penetrate the essence of a
natural phenomenon in its full significance. If we
are to derive any advantage from them, they must
be directed to a well-defined object ; and there
must be an organized connection between them.

Mechanical philosophers and chemists justly
ascribe to their methods of research the greater
part of the success which has attended their labours.
The result of every such investigation, if it bear in
any degree the stamp of perfection, may always be
given in few words ; but these few words are eter-
nal truths, to the discovery of which numberless
experiments and questions were essential. The
researches themselves, the laborious experiments
and complicated apparatus, are forgotten as soon as
the truth is ascertained. They were the ladders,
the shafts, the tools, which were indispensable to
enable us to attain to the rich vein of ore ; they
were the pillars and air passages which protected
the mine from water and from foul air.

Every chemical or physical investigation, how-
ever insignificant, which lays claim to attention,

PREFACE. XV11

must in the present day possess this character.
From a certain number of observations it must
enable us to draw some conclusion, whether it be
extended or limited.

The imperfection of the method or system of
research adopted by physiologists can alone explain
the fact, that for the last fifty years they have esta-
blished so few new and solid truths in regard to a
more profound knowledge of the functions of the
most important organs, of the spleen, of the liver,
and of the numerous glands of the body ; and the
limited acquaintance of physiologists with the me-
thods of research employed in chemistry will con-
tinue to be the chief impediment to the progress of
physiology, as well as a reproach which that science
cannot escape.

Before the time of Lavoisier, Scheele, and
Priestley, chemistry was not more closely related
to physics than she is now to physiology. At the
present day chemistry is so fused, as it were, into
physics, that it would be a difficult matter to draw
the line between them distinctly. The connection
between chemistry and physiology is the same, and
in another half-century it will be found impossible
to separate them.

Our questions and our experiments intersect in
numberless curved lines the straight line that leads
I

XVJii PREFACE.

to truth. It is the points of intersection that indi-
cate to us the true direction ; but, owing to the
imperfection of the human intellect, these curve
lines must be pursued. Observers in chemistry and
physics have the eye ever fixed on the object which
they seek to attain. One may succeed, for a space,
in following the direct line ; but all are prepared for
circuitous paths. Never doubting of the ultimate
success of their efforts, provided they exhibit con-
stancy and perseverance, their eagerness and cou-
rage are only exalted by difficulties.

Detached observations, without connection, are
points scattered over the plain, which do not allow
us to choose a decided path. For centuries chemis-
try presented nothing but these points, and sufficient
means were available to fill up the intervals be-
tween them. But permanent discoveries and real
progress were only made when chemists ceased to
make use of fancy to connect them.

My object in the present work has been to direct at-
tention to the points of intersection of chemistry with
physiology, and to point out those parts in which
the sciences become, as it were, mixed up together.
It contains a collection of problems, such as chemistry
at present requires to be resolved ; and a number
of conclusions drawn according to the rules of that
science from such observations as have been made.

PREFACE. Xix

These questions and problems will be resolved :
and we cannot doubt that we shall have in that case
a new physiology and a rational pathology. Our
sounding line, indeed, is not long enough to mea-
sure the depths of the sea, but is not on that
account less valuable to us : if it assist us, in the
mean time, to avoid rocks and shoals, its use is suf-
ficiently obvious. In the hands of the physiologist,
organic chemistry must become an intellectual
instrument, by means of which he will be enabled
to trace the causes of phenomena invisible to the
bodily sight ; and if among the results which I
have developed or indicated in this work, one alone
shall admit of a useful application, I shall consider
the object for which it was written as fully attained.
The path which has led to it will open up other
paths ; and this I consider as the most important
object to be gained.

JUSTUS LIEBIG.
Gi ESSEN, April, 1842.

CONTENTS.

PART I.

Vital force, vis vitse, or vitality page 1

Distinction between animal and vegetable life 2

Assimilation the result of chemical forces ... ... ... 4

Vitality independent of consciousness ... ... ... 6

Laws of the vital force ... ... ... ... ... 8

Conditions of animal life ... ... ... ... ... 9

Nutrition depends on chemical changes 11

Amount of oxygen inspired by an adult man 12

It combines with carbon and hydrogen in the body ... 13

The consumption of oxygen varies 15

Effect of heat on these variations 16

The mutual action of oxygen and carbon in the body is the

true source of animal heat 17

The amount of oxygen regulates that of food 20

Effects of climate on the appetite 23

The process of starvation 25

Cause of death in starvation and chronic diseases ... ... 27

Nerves and muscles not the source of animal body ... 29

Amount of animal heat 34

Nervous and vegetative life .38

Nutrition depends on the constituents of blood 40

Identity of organic composition in fibrine and albumen ... 41

Nutrition in the carnivora the most simple 44

In the herbivora, depends on the azotised products of vege-
tables ... .45

XX11 CONTENTS.

These products identical with the constituents of blood ... 47

The blood of animals is therefore formed by vegetables ... 48

Uses of the non-azotised ingredients of food 50

Changes of the food in the organism of carnivora 53

Carbon accumulates in the bile 58

Nitrogen in the urine 59

The carbon is consumed or burned 60

True function of the bile 62

Amount of bile secreted ... ... ... ... ... 64

Assimilation more energetic in the young animal 67

The butter, sugar, &c., of its food support respiration ... 68

The same is true of the class of herbivora 70

Waste of matter very rapid in carnivora 76

Importance of agriculture to population 77

Assimilation less energetic in the carnivora ... ... 80

Origin of fat in domesticated animals ... ... ... 81

Its formation is a source of oxygen ... ... ... ... 86

It is formed when oxygen is deficient, and is a source of

animal heat 88

Elements of nutrition and of respiration ... ... ... 96

Gelatine incapable of serving for nutrition, strictly so called 97

But it may serve to nourish the gelatinous tissues ... ... 98

PART II.

THE METAMORPHOSIS OF TISSUES.

Discovery of proteine ... ... ... ... ... 1 05

It is formed by vegetables alone 106

Theory of chymification 108

Use of the saliva 113

Source of the nitrogen exhaled from the lungs and skin ... 114

Composition of proteine 121

Composition of the animal tissues ... ... ... ... 1 25

Gelatine contains no proteine, although formed from it ... 128

The secretions contain all the elements of the blood .. 132

CONTENTS. XX1I1

Formula of blood and metamorphoses of bile ... ... 133

Metamorphoses of blood and flesh ... ... ... ... 136

The constituents of the urine derived from the metamor-
phosed tissues ... ... ... ... ... ... 138

Relation of blood or flesh and proteine to the secretions and

excretions 140

Formation of gelatine ... ... ... ... ... 142

Origin of bile in the carnivora 144

Origin of bile in the herbivora ... ... ... ...147

Origin of hippuric acid ... ... ... ... ... 150

Formation of the chief secretions and excretions 152

Soda essential to the bile 154

Relation of urine to bile 155

Relation of starch to bile ... ... ... ... ...157

Uses of common salt. .. ... ... ... ... ... 162

Certain remedies take a share in the vital transformations ... 1 70

Chief qualities of the blood 171

Modus operandi of organic remedies 174

All organic poisons contain nitrogen 177

Theine identical with caffeine 179

Relation of theine and caffeine to bile ... 1 80

Theory of their action 181

Theory of the action of the vegetable alkalies ... ... 182

Composition and origin of nervous matter ... ... ... 184

It is related to that of the vegetable alkalies 185

Theory of the action of the latter 188

Phosphorus seems essential to nervous matter 190

PART III.

1 . The phenomena of motion in the animal organism ... 195

2. The same subject, with particular reference to the waste

and supply or change of matter 233

3. Theory of disease 254

4. Theory of respiration 265

XXIV CONTENTS.

APPENDIX.

Containing the analytical evidence referred to in the sections
in which are described the chemical processes of respira-
tion, nutrition, and the metamorphosis of tissues ... 279

On the conversion of benzoic acid into hippuric acid in the
human body, by W. Keller 325

INDEX

ORGANIC CHEMISTRY

APPLIED TO

PHYSIOLOGY AND PATHOLOGY.

I. IN the animal ovum, as well as in the seed of
a plant, we recognize a certain remarkable force, the
source of growth, or increase in the mass, and of re-
production, or of supply of the matter consumed ; a
force in a state of rest. By the action of external in-
fluences, by impregnation, by the presence of air and
moisture, the condition of static equilibrium of this
force is disturbed ; entering into a state of motion or
activity, it exhibits itself in the production of a series
of forms, which, although occasionally bounded by
right lines, are yet widely distinct from geometrical
forms, such as we observe in crystallised minerals.
This force is called the vital force, vis mice or vitality.

The increase of mass in a plant is determined by
the occurrence of a decomposition which takes place
in certain parts of the plant under the influence of
light and heat.

In the vital process, as it goes on in vegetables,
it is exclusively inorganic matter which undergoes
this decomposition ; and if, with the most distin-

2 VEGETABLE AND

guished mineralogists, we consider atmospherical
air and certain other gases as minerals, it may be
said that the vital process in vegetables accom-
plishes the transformation of mineral substances into
an organism endued with life ; that the mineral be-
comes part of an organ possessing vital force.

The increase of mass in a living plant implies that
certain component parts of its nourishment become
component parts of the plant ; and a comparison of
the chemical composition of the plant with that of
its nourishment makes known to us, with positive
certainty, which of the component parts of the latter
have been assimilated, and which have been rejected.

The observations of vegetable physiologists and
the researches of chemists have mutually contri-
buted to establish the fact, that the growth and
developement of vegetables depend on the elimi-
nation of oxygen, which is separated from the other
component parts of their nourishment.

In contradistinction to vegetable life, the life of
animals exhibits itself in the continual absorption
of the oxygen of the air, and its combination with
certain component parts of the animal body.

While no part of an organised being can serve as
food to vegetables, until, by the processes of putre-
faction and decay, it has assumed the form of
inorganic matter, the animal organism requires,
for its support and developement, highly organised
atoms. The food of all animals, in all circum-
stances, consists of parts of organisms.

ANIMAL LIFE. 3

Animals are distinguished from vegetables by the
faculty of locomotion, and, in general, by the posses-
sion of senses.

The existence and activity of these distinguishing
faculties depend on certain instruments which are
never found in vegetables. Comparative anatomy
shews, that the phenomena of motion and sensation
depend on certain kinds of apparatus, which have
no other relation to each other than this, that they
meet in a common centre. The substance of the
spinal marrow, the nerves, and the brain, is in its
composition, and in its chemical characters, essen-
tially distinct from that of which cellular substance,
membranes, muscles, and skin are composed.

Every thing in the animal organism, to which
the name of motion can be applied, proceeds from
the nervous apparatus. The phenomena of motion
in vegetables, the circulation of the sap, for example,
observed in many of the characeae, and the closing of
flowers and leaves, depend on physical and mechani-
cal causes. A plant is destitute of nerves. Heat
and light are the remote causes of motion in
vegetables; but in animals we recognize in the
nervous apparatus a source of power, capable of
renewing itself at every moment of their existence.

While the assimilation of food in vegetables,
and the whole process of their formation, are depen-
dant on certain external influences which produce
motion, the developement of the animal organism
is, to a certain extent, independent of these external

B2

4 ASSIMILATION THE RESULT

influences, just because the animal body can pro-
duce within itself that source of motion which is
indispensable to the vital process.

Assimilation, or the process of formation and
growth — in other words, the passage of matter from
a state of motion to that of rest — goes on in the
same way in animals and in vegetables. In both,
the same cause determines the increase of mass.
This constitutes the true vegetative life, which is
carried on without consciousness.

The activity of vegetative life manifests itself,
in vegetables, with the aid of external influences ;
in animals, by means of influences produced within
their organism. Digestion, circulation, secretion,
are no doubt under the influence of the nervous
system ; but the force which gives to the germ, the
leaf, and the radical fibres of the vegetable the
same wonderful properties, is the same as that
residing in the secreting membranes and glands of
animals, and which enables every animal organ to
perform its own proper function. It is only the
source of motion that differs in the twro great classes
of organised beings.

While the organs of the vital motions are never
wanting in the lowest orders of animals, as in the im-
pregnated germ of the ovum, in which they are deve-
loped first of all, we find, in the higher orders of ani-
mals, peculiar organs of feeling and sensation, of con-
sciousness and of a higher intellectual existence.

Pathology informs us that the true vegetative life

OF CHEMICAL FORCES. 5

is in no way dependant on the presence of this
apparatus ; that the process of nutrition proceeds
in those parts of the body where the nerves of
sensation and voluntary motion are paralysed, ex-
actly in the same way as in other parts where
these nerves are in the normal condition ; and, on
the other hand, that the most energetic volition is
incapable of exerting any influence on the contrac-
tions of the heart, on the motion of the intestines,
or on the processes of secretion.

The higher phenomena of mental existence can-
not, in the present state of science, be referred
to their proximate, and still less to their ultimate
causes. We only know of them, that they exist ;
we ascribe them to an immaterial agency, and that,
in so far as its manifestations are connected with
matter, an agency entirely distinct from the vital
force, with which it has nothing in common.

It cannot be denied that this peculiar force ex-
ercises a certain influence on the activity of vege-
tative life, just as other immaterial agents, such
as Light, Heat, Electricity, and Magnetism do ; but
this influence is not of a determinative kind, and
manifests itself only as an acceleration, a retarding,
or a disturbance of the process of vegetative life.
In a manner exactly analogous, the vegetative life
reacts on the conscious mental existence.

There are thus two forces which are found in
activity together ; but consciousness and intellect
may be absent in animals as they are in living

6 VITALITY INDEPENDENT

vegetables, without their vitality being otherwise
affected than by the want of a peculiar source of
increased energy or of disturbance. Except in
regard to this, all the vital chemical processes go
on precisely in the same way in man and in the
lower animals.

The efforts of philosophers, constantly renewed,
to penetrate the relations of the soul to animal life,
have all along retarded the progress of physiology.
In this attempt men left the province of philoso-
phical research for that of fancy ; physiologists, car-
ried away by imagination, were far from being
acquainted with the laws of purely animal life.
None of them had a clear conception of the process
of developement and nutrition, or of the true
cause of death. They professed to explain the
most obscure psychological phenomena, and yet
they were unable to say what fever is, and in what
way quinine acts in curing it.

For the purpose of investigating the laws of vital
motion in the animal body, only one condition,
namely, the knowledge of the apparatus which
serves for its production, was ascertained ; but the
substance of the organs, the changes which food
undergoes in the living body, its transformation
into portions of organs, and its re-conversion into
lifeless compounds, the share which the atmosphere
takes in the processes of vitality ; all these founda-
tions for future conclusions were still wanting.

What lias the soul, what have consciousness and

OF CONSCIOUSNESS AND INTELLECT. 7

intellect to do with the developement of the human
fetus, or the fetus in a fowl's egg? not more,
surely, than with the developement of the seeds of
a plant. Let us first endeavour to refer to their
ultimate causes those phenomena of life which are
not psychological ; and let us beware of drawing
conclusions before we have a groundwork. We
know exactly the mechanism of the eye; but
neither anatomy nor chemistry will ever explain
how the rays of light act on consciousness, so as to
produce vision. Natural science has fixed limits
which cannot be passed ; and it must always be
borne in mind that, with all our discoveries, we
shall never know what light, electricity, and mag-
netism are in their essence, because, even of those
things which are material, the human intellect has
only conceptions. We can ascertain, however, the
laws which regulate their motion and rest, because
these are manifested in phenomena. In like man-
ner, the laws of vitality, and of all that disturbs,
promotes, or alters it, may certainly be discovered,
although we shall never learn what life is. Thus
the discovery of the laws of gravitation and of the
planetary motions led to an entirely new concep-
tion of the cause of these phenomena. This con-
ception could not have been formed in all its clear-
ness without a knowledge of the phenomena out
of which it was evolved ; for, considered by itself,
gravity, like light to one born blind, is a mere
word, devoid of meaning.

8 LAWS OF THE

The modern science of physiology has left the
track of Aristotle. To the eternal advantage of
science, and to the benefit of mankind, it no longer
invents a horror vacui, a quinta essentia, in order to
furnish credulous hearers with solutions and expla-
nations of phenomena, whose true connection with
others, whose ultimate cause is still unknown.

If we assume that all the phenomena exhibited
by the organism of plants and animals are to be
ascribed to a peculiar cause, different in its manifes-
tations from all other causes which produce motion
or change of condition ; if, therefore, we regard the
vital force as an independent force, then, in the
phenomena of organic life, as in all other pheno-
mena ascribed to the action of forces, we have
the statics, that is, the state of equilibrium deter-
mined by a resistance, and the dynamics, of the vital
force.

All the parts of the animal body are produced
from a peculiar fluid, circulating in its organism, by
virtue of an influence residing in every cell, in every
organ, or part of an organ. Physiology teaches that
all parts of the body were originally blood ; or that
at least they were brought to the growing organs by
means of this fluid.

The most ordinary experience further shews,
that at each moment of life, in the animal organ-
ism, a continued change of matter, more or less
accelerated, is going on ; that a part of the structure
is transformed into unorganised matter, loses its

VITAL FORCE. 9

condition of life, and must be again renewed. Phy-
siology has sufficiently decisive grounds for the
opinion, that every motion, every manifestation of
force, is the result of a transformation of the struc-
ture or of its substance ; that every conception,
every mental affection, is followed by changes in the
chemical nature of the secreted fluids ; that every
thought, every sensation, is accompanied by a change
in the composition of the substance of the brain.

In order to keep up the phenomena of life in
animals, certain matters are required, parts of organ-
isms, which we call nourishment. In consequence
of a series of alterations, they serve either for the
increase of the mass (nutrition}, or for the supply of
the matter consumed (reproduction), or, finally, for
the production of force.

II. If the first condition of animal life be the
assimilation of what is commonly called nourish-
ment, the second is a continual absorption of oxygen
from the atmosphere.

Viewed as an object of scientific research, animal
life exhibits itself in a series of phenomena, the
connection and recurrence of which are determined
by the changes which the food and • the oxygen
absorbed from the atmosphere undergo in the organ-
ism under the influence of the vital force.

All vital activity arises from the mutual action
of the oxygen of the atmosphere and the elements
of the food.

10 NUTRITION AND REPRODUCTION

In the processes of nutrition and reproduction,
we perceive the passage of matter from the state of
motion to that of rest (static equilibrium) ; under
the influence of the nervous system, this matter
enters again into a state of motion. The ultimate
causes of these different conditions of the vital force
are chemical forces.

The cause of the state of rest is a resistance,
determined by a force of attraction (combination),
which acts between the smallest particles of matter,
and is manifested only when these are in actual
contact, or at infinitely small distances.

To this peculiar kind of attraction we may of
course apply different names ; but the chemist calls
it affinity.

The cause of the state of motion is to be found
in a series of changes which the food undergoes in
the organism, and these are the results of processes
of decomposition, to which either the food itself, or
the structures formed from it, or parts of organs,
are subjected.

The distinguishing character of vegetable life is a
continued passage of matter from the state of mo-
tion to that of static equilibrium. While a plant
lives, we cannot perceive any cessation in its growth ;
110 part of an organ in the plant diminishes in size.
If decomposition occur, it is the result of assimila-
tion. A plant produces within itself no cause of
motion ; no part of its structure, from any influence
residing in its organism, loses its state of vitality,

DEPEND ON CHEMICAL CHANGES. 11

and is converted into unorganised, amorphous com-
pounds ; in a word, no waste occurs in vegetables.
Waste, in the animal body, is a change in the state
or in the composition of some of its parts, and
consequently is the result of chemical actions.

The influence of poisons and of remedial agents
on the living animal body evidently shews that the
chemical decompositions and combinations in the
body, which manifest themselves in the phenomena
of vitality, may be increased in intensity by chemical
forces of analogous character, and retarded or put
an end to by those of opposite character ; and that
we are enabled to exercise an influence on every
part of an organ by means of substances possessing
a well-defined chemical action.

As, in the closed galvanic circuit, in consequence
of certain changes which an inorganic body, a metal,
undergoes when placed in contact with an acid, a
certain something becomes cognizable by our senses,
which we call a current of electricity ; so, in the
animal body, in consequence of transformations and
changes undergone by matter previously constituting
a part of the organism, certain phenomena of motion
and activity are perceived, and these we call life, or
vitality.

The electrical current manifests itself in certain
phenomena of attraction and repulsion, which it
excites in other bodies naturally motionless, and by
the phenomena of the formation and decomposition
of chemical compounds, which occur everywhere,

12 OXYGEN REQUIRED

when the resistance is not sufficient to arrest the
current.

It is from this point of view, and from no other,
that chemistry ought to contemplate the phenomena
of life. Wonders surround us on every side. The
formation of a crystal, of an octahedron, is not less in-
comprehensible than the production of a leaf or of a
muscular fibre ; and the production of vermilion from
mercury and sulphur is as much an enigma as the
formation of an eye from the substance of the blood.

The first conditions of animal life are nutritious
matters and oxygen, introduced into the system.

At every moment of his life man is taking oxygen
into his system, by means of the organs of respira-
tion ; no pause is observable while life continues.

The observations of physiologists have shewn that
the body of an adult man, supplied with sufficient
food, has neither increased nor diminished in weight
at the end of twenty-four hours ; yet the quantity
of oxygen taken into the system during this period
is very considerable.

According to the experiments of Lavoisier, an
adult man takes into his system, from the atmo-
sphere, in one year, 746 Ibs., according to Menzies,
837 Ibs. of oxygen ; yet we find his weight, at the
beginning and end of the year, either quite the
same, or differing, one way or the other, by at most
a few pounds. (1)*

What, it may be asked, has become of the enor-

* The Numbers refer to the Appendix.

AS WELL AS FOOD. 13

mous weight of oxygen thus introduced, in the
course of a year into the human system ?

This question may be answered satisfactorily : no
part of this oxygen remains in the system ; but it is
given out again in the form of a compound of carbon
or of hydrogen.

The carbon and hydrogen of certain parts of the
body have entered into combination with the oxygen
introduced through the lungs and through the skin,
and have been given out in the forms of carbonic
acid gas and the vapour of water.

At every moment, with every expiration, certain
quantities of its elements separate from the animal
organism, after having entered into combination,
within the body, with the oxygen of the atmosphere.

If we assume, with Lavoisier and Seguin, in
order to obtain a foundation for our calculation,
that an adult man receives into his system daily
321 oz. (46,037 cubic inches =15,661 grains, French
weight) of oxygen, and that the weight of the whole
mass of his blood, of which 80 per cent, is water, is
24 Ibs.; it then appears, from the known composi-
tion of the blood, that, in order to convert the
whole of its carbon and hydrogen into carbonic acid
and water, 64,103 grains of oxygen are required.
This quantity will be taken into the system of an
adult in four days five hours. (2)

Whether this oxygen enters into combination
with the elements of the blood, or with other parts
of the body containing carbon and hydrogen, in

14 OXYGEN COMBINES WITH

either case the conclusion is inevitable, that the
body of a man, who daily takes into the system
32J oz. of oxygen, must receive daily in the shape
of nourishment, as much carbon and hydrogen as
would suffice to supply 24 Ibs. of blood with these
elements ; it being presupposed that the weight of
the body remains unchanged, and that it retains its
normal condition as to health.

This supply is furnished in the food.

From the accurate determination of the quantity
of carbon daily taken into the system in the food,
as well as of that proportion of it which passes out
of the body in the faeces and urine, unburned, that
is, in some form in which it is not combined with
oxygen, it appears that an adult, taking moderate
exercise, consumes 13'9 oz. of carbon daily. (3)

These 13-is oz. of carbon escape through the skin
and lungs as carbonic acid gas.

For conversion into carbonic acid gas, 13^ oz.
of carbon require 37 oz. of oxygen.

According to the analyses of Boussingault (Ann.
de Ch. et de Ph. LXXI. p. 136) a horse consumes
in twenty-four hours 97J oz. of carbon, a milch
cow 69 A oz. The quantities of carbon here men-
tioned are those given off from the bodies of these
animals in the form of carbonic acid ; and it appears
from them that the horse consumes, in converting
carbon into carbonic acid, 13 Ibs. 3J oz. in twenty-
four hours, and the milch cow 11 Ibs. 10J oz. of
oxygen in the same time. (4)

THE CARBON OF THE FOOD. 15

Since no part of the oxygen taken into the sys-
tem is again given off in any other form but that
of a compound of carbon or hydrogen ; since fur-
ther, the carbon and hydrogen given off are re-
placed by carbon and hydrogen supplied in the
food, it is clear that the amount of nourishment
required by the animal body must be in a direct
ratio to the quantity of oxygen taken into the
system.

Two animals, which in equal times take up by
means of the lungs and skin unequal quantities of
oxygen, consume quantities of the same nourish-
ment which are unequal in the same ratio.

The consumption of oxygen in equal times may
be expressed by the number of respirations; it is
clear that, in the same individual, the quantity of
nourishment required must vary with the force and
number of the respirations.

A child, in whom the organs of respiration are
naturally very active, requires food oftener than an
adult, and bears hunger less easily. A bird, deprived
of food, dies on the third day, while a serpent,
with its sluggish respiration, can live without food
three months and longer.

The number of respirations is smaller in a state
of rest than during exercise or work. The quan-
tity of food necessary in both conditions must vary
in the same ratio.

An excess of food is incompatible with deficiency
in respired oxygen, that is, with deficient exercise ;

16 EFFECT OF HEAT ON THE

just as violent exercise, which implies an increased
supply of food, is incompatible with weak diges-
tive organs. In either case the health suffers.

But the quantity of oxygen inspired is also af-
fected by the temperature and density of the atmos-
phere.

The capacity of the chest in an animal is a con-
stant quantity. At every respiration a quantity of
air enters, the volume of which may be considered as
uniform ; but its weight, and consequently that of the
oxygen it contains, is not constant. Air is expanded
by heat, and contracted by cold, and therefore equal
volumes of hot and cold air contain unequal weights
of oxygen. In summer, moreover, atmospherical
air contains aqueous vapour, while in winter it is
dry ; the space occupied by vapour in the warm air
is filled up by air itself in winter ; that is, it con-
tains, for the same volume, more oxygen in winter
than in summer.

In summer and in winter, at the pole and at the
equator, we respire an equal volume of air ; the cold
air is warmed during respiration, and acquires the
temperature of the body. To introduce into the
lungs a given volume of oxygen, less expenditure of
force is necessary in winter than in summer ; and for
the same expenditure of force, more oxygen is in-
spired in winter.

It is obvious, that in an equal number of respira-
tions we consume more oxygen at the level of the
sea than on a mountain. The quantity both of

AMOUNT OF OXYGEN ABSORBED. 17

oxygen inspired and of carbonic acid expired, must
therefore vary with the height of the barometer.

The oxygen taken into the system is given out
again in the same forms, whether in summer or
in winter; hence we expire more carbon in cold
weather, and when the barometer is high, than we
do in warm weather ; and we must consume more
or less carbon in our food in the same proportion ;
in Sweden more than in Sicily ; and in our more
temperate climate a full eighth more in winter
than in summer.

Even when we consume equal weights of food in
cold and warm countries, infinite wisdom has so
arranged, that the articles of food in different cli-
mates are most unequal in the proportion of carbon
they contain. The fruits on which the natives of
the south prefer to feed do not in the fresh state
contain more than 12 per cent, of carbon, while the
bacon and train oil used by the inhabitants of the
arctic regions contain from 66 to 8t) per cent, of
carbon.

It is no difficult matter, in warm climates, to
study moderation in eating, and men can bear hun-
ger for a long time under the equator ; but cold
and hunger united very soon exhaust the body.

The mutual action between the elements of the
food and the oxygen conveyed by the circulation
of the blood to every part of the body is THE SOURCE

OF ANIMAL HEAT.

18 SOURCE OF ANIMAL

III. All living creatures, whose existence depends
on the absorption of oxygen, possess within them-
selves a source of heat independent of surrounding
objects.

This truth applies to all animals, and extends,
besides, to the germination of seeds, to the flower-
ing of plants, and to the maturation of fruits.

It is only in those parts of the body to which
arterial blood, and with it the oxygen absorbed in
respiration, is conveyed, that heat is produced. Hair,
wool, or feathers do not possess an elevated tempe-
rature.

This high temperature of the animal body, or, as
it may be called, disengagement of heat, is uniformly
and under all circumstances the result of the combi-
nation of a combustible substance with oxygen.

In whatever way carbon may combine with
oxygen, the act of combination cannot take place
without the disengagement of heat. It is a matter
of indifference whether the combination take place
rapidly or slowly, at a high or at a low tempera-
ture; the amount of heat liberated is a constant
quantity.

The carbon of the food, which is converted into
carbonic acid within the body, must give out ex-
actly as much heat as if it had been directly burnt
in the air or in oxygen gas ; the only difference is,
that the amount of heat produced is diffused over
unequal times. In oxygen, the combustion is more
rapid, and the heat more intense ; in air it is slower,

HEAT. RESPIRATION. 19

the temperature is not so high, but it continues
longer.

It is obvious that the amount of heat liberated
must increase or diminish with the quantity of
oxygen introduced in equal times by respiration.
Those animals which respire frequently, and conse-
quently consume much oxygen, possess a higher
temperature than others, which, with a body of
equal size to be heated, take into the system less
oxygen. The temperature of a child (102°) is
higher than that of an adult (99-5°). That of birds
(104° to 105-4°) is higher than that of quadrupeds
(98-5° to 100-4°) or than that of fishes or amphibia,
whose proper temperature is from 2*7° to 3*6° higher
than that of the medium in which they live. All
animals, strictly speaking, are warm-blooded ; but
in those only which possess lungs is the temperature
of the body quite independent of the surrounding
medium. (5)

The most trustworthy observations prove that in
all climates, in the temperate zones as well as at
the equator or the poles, the temperature of the
body in man, and in what are commonly called warm-
blooded animals, is invariably the same ; yet how dif-
ferent are the circumstances under which they live !

The animal body is a heated mass, which bears the
same relation to surrounding objects as any other
heated mass. It receives heat when the surround-
ing objects are hotter, it loses heat when they are
colder than itself.

c 2

20 UNIFORM TEMPERATURE

We know that the rapidity of cooling increases
with the difference between the temperature of the
heated body and that of the surrounding medium ;
that is, the colder the surrounding medium the
shorter the time required for the cooling of the
heated body.

How unequal, then, must be the loss of heat in a
man at Palermo, where the external temperature
is nearly equal to that of the body, and in the polar
regions, where the external temperature is from 70°
to 90° lower.

Yet, notwithstanding this extremely unequal loss
of heat, experience has shewn that the blood of the
inhabitant of the arctic circle has a temperature as
high as that of the native of the south, who lives in
so different a medium.

This fact, when its true significance is perceived,
proves that the heat given off to the surrounding
medium is restored within the body with great
rapidity. This compensation takes place more ra-
pidly in winter than in summer, at the pole than at
the equator.

Now, in different climates the quantity of oxygen
introduced into the system of respiration, as has
been already shewn, varies according to the tempe-
rature of the external air ; the quantity of inspired
oxygen increases with the loss of heat by external
cooling, and the quantity of carbon or hydrogen
necessary to combine with this oxygen must be
increased in the same ratio.

OF THE ANIMAL BODY. 21

It is evident that the supply of the heat lost by
cooling is effected by the mutual action of the
elements of the food and the inspired oxygen, which
combine together. To make use of a familiar, but
not on that account a less just illustration, the
animal body acts, in this respect, as a furnace
which we supply with fuel. It signifies nothing
what intermediate forms food may assume, what
changes it may undergo in the body, the last
change is uniformly the conversion of its carbon
into carbonic acid, and of its hydrogen into water ;
the unassimilated nitrogen of the food, along with
the unburned or unoxidised carbon, is expelled in
the urine or in the solid excrements. In order to
keep up in the furnace a constant temperature, we
must vary the supply of fuel according to the exter-
nal temperature, that is, according to the supply of
oxygen.

In the animal body the food is the fuel ; with a
proper supply of oxygen we obtain the heat given
out during its oxidation or combustion. In winter,
when we take exercise in a cold atmosphere, and
when consequently the amount of inspired oxygen
increases, the necessity for food containing carbon
and hydrogen increases in the same ratio ; and by
gratifying the appetite thus excited, we obtain the
most efficient protection against the most piercing
cold. A starving man is soon frozen to death ; and
every one knows that the animals of prey in the arctic
regions far exceed in voracity those of the torrid zone.

22 THE AMOUNT OF OXYGEN

In cold and temperate climates, the air, which
incessantly strives to consume the body, urges man
to laborious efforts in order to furnish the means of
resistance to its action, while, in hot climates, the
necessity of labour to provide food is far less urgent.

Our clothing is merely an equivalent for a certain
amount of food. The more warmly we are clothed
the less urgent becomes the appetite for food, be-
cause the loss of heat by cooling, and consequently
the amount of heat to be supplied by the food, is
diminished.

If we were to go naked, like certain savage
tribes, or if in hunting or fishing we were exposed
to the same degree of cold as the Samoyedes, we
should be able with ease to consume 10 Ibs. of flesh,
and perhaps a dozen of tallow candles into the bar-
gain, daily, as warmly clad travellers have related
with astonishment of these people. We should then
also be able to take the same quantity of brandy or
train oil without bad effects, because the carbon and
hydrogen of these substances would only suffice to
keep up the equilibrium between the external tem-
perature and that of our bodies.

According to the preceding expositions, the quan-
tity of food is regulated by the number of respira-
tions, by the temperature of the air, and by the
amount of heat given off to the surrounding me-
dium.

No isolated fact, apparently opposed to this state-
ment, can affect the truth of this natural law.

REGULATES THAT OF FOOD. 23

Without temporary or permanent injury to health,
the Neapolitan cannot take more carbon and hydro-
gen in the shape of food than he expires as carbonic
acid and water ; and the Esquimaux cannot expire
more carbon and hydrogen than he takes into the
system as food, unless in a state of disease or of
starvation. Let us examine these states a little
more closely.

The Englishman in Jamaica sees with regret the
disappearance of his appetite, previously a source of
frequently recurring enjoyment ; and he succeeds,
by the use of cayenne pepper and the most powerful
stimulants, in enabling himself to take as much food
as he was accustomed to eat at home. But the
whole of the carbon thus introduced into the system
is not consumed ; the temperature of the air is too
high, and the oppressive heat does not allow him to
increase the number of respirations by active exer-
cise, and thus to proportion the waste to the amount
of food taken; disease of some kind, therefore, ensues.

On the other hand, England sends her sick, whose
diseased digestive organs have in a greater or less
degree lost the power of bringing the food into that
state in which it is best adapted for oxidation,
and therefore furnish less resistance to the oxidis-
ing agency of the atmosphere than is required in
their native climate, to southern regions, where the
amount of inspired oxygen is diminished in so great
a proportion ; and the result, an improvement in the
health, is obvious. The diseased organs of digestion

24 HYDROGEN CONTRIBUTES

have sufficient power to place the diminished amount
of food in equilibrium with the inspired oxygen ; in
the colder climate, the organs of respiration them-
selves would have been consumed in furnishing the
necessary resistance to the action of the atmospheric
oxygen.

In our climate, hepatic diseases, or those arising
from excess of carbon, prevail in summer ; in winter,
pulmonic diseases, or those arising from excess of
oxygen, are more frequent.

The cooling of the body, by whatever cause it
may be produced, increases the amount of food
necessary. The mere exposure to the open air, in
a carriage or on the deck of a ship, by increasing
radiation and vaporization, increases the loss of heat,
and compels us to eat more than usual. The same
is true of those who are accustomed to drink large
quantities of cold water, which is given off at the
temperature of the body, 96'5°. It increases the
appetite, and persons of weak constitution find it
necessary, by continued exercise, to supply to the
system the oxygen required to restore the heat
abstracted by the cold water. Loud and long con-
tinued speaking, the crying of infants, moist air, all
exert a decided and appreciable influence on the
amount of food which is taken.

IV. In the foregoing pages, it has been assumed
that it is especially carbon and hydrogen which, by
combining with oxygen, serve to produce animal

TO THE ANIMAL HEAT. 25

heat. In fact, observation proves that the hydrogen
of the food plays a not less important part than
the carbon.

The whole process of respiration appears most
clearly developed, when we consider the state of
a man, or other animal, totally deprived of food.

The first effect of starvation is the disappearance
of fat, and this fat cannot be traced either in the
urine or in the scanty faeces. Its carbon and hydro-
gen have been given off through the skin and lungs
in the form of oxidised products ; it is obvious that
they have served to support respiration.

In the case of a starving man, 32^ oz. of oxygen
enter the system daily, and are given out again in
combination with a part of his body. Currie men-
tions the case of an individual who was unable to
swallow, and whose body lost 100 Ibs. in weight
during a month ; and, according to Martell (Trans.
Linn. Soc., vol. xi. p. 411), a fat pig, overwhelmed
in a slip of earth, lived 160 days without food, and
was found to have diminished in weight, in that
time, more than 120 Ibs. The whole history of
hybernating animals, and the well-established facts
of the periodical accumulation, in various animals,
of fat, which, at other periods, entirely disappears,
prove that the oxygen, in the respiratory process,
consumes, without exception, all such substances as
are capable of entering into combination with it.
It combines with whatever is presented to it ; and
the deficiency of hydrogen is the only reason why

26 EFFECTS OF STARVATION.

carbonic acid is the chief product ; for, at the tem-
perature of the body, the affinity of hydrogen for
oxygen far surpasses that of carbon for the same
element.

We know, in fact, that the graminivora expire a
volume of carbonic acid equal to that of the oxygen
inspired, while the carnivora, the only class of
animals whose food contains fat, inspire more oxy-
gen than is equal in volume to the carbonic acid
expired. Exact experiments have shewn, that in
many cases only half the volume of oxygen is ex-
pired in the form of carbonic acid. These observa-
tions cannot be gainsaid, and are far more convinc-
ing than those arbitrary and artificially produced
phenomena, sometimes called experiments ; experi-
ments which, made as too often they are, without
regard to the necessary and natural conditions, pos-
sess no value, and may be entirely dispensed with ;
especially when, as in the present case, nature
affords the opportunity for observation, and when
we make a rational use of that opportunity.

In the progress of starvation, however, it is not
only the fat which disappears, but also, by degrees,
all such of the solids as are capable of being dis-
solved. In the wasted bodies of those who have
suffered starvation, the muscles are shrunk and
unnaturally soft, and have lost their contractility ;
all those parts of the body which were capable of
entering into the state of motion have served to
protect the remainder of the frame from the

DEATH CAUSED BY RESPIRATION. 27

destructive influence of the atmosphere. Towards
the end, the particles of the brain begin to undergo
the process of oxidation, and delirium, mania, and
death close the scene ; that is to say, all resistance
to the oxidising power of the atmospheric oxygen
ceases, and the chemical process of eremacausis, or
decay, commences, in which every part of the body,
the bones excepted, enters into combination with
oxygen.

The time which is required to cause death by
starvation depends on the amount of fat in the
body, on the degree of exercise, as in labour or ex-
ertion of any kind, on the temperature of the air,
and finally, on the presence or absence of water.
Through the skin and lungs there escapes a certain
quantity of water, and as the presence of water is
essential to the continuance of the vital motions, its
dissipation hastens death. Cases have occurred, in
which a full supply of water being accessible to the
sufferer, death has not occurred till after the lapse
of twenty days. In one case, life was sustained in
this way for the period of sixty days.

In all chronic diseases death is produced by the
same cause, namely, the chemical action of the atmo-
sphere. When those substances are wanting, whose
function in the organism is to support the process
of respiration ; when the diseased organs are inca-
pable of performing their proper function of produc-
ing these substances ; when they have lost the power
of transforming the food into that shape in which it

28 RESPIRATION TENDS TO

may, by entering into combination with the oxygen
of the air, protect the system from its influence, then,
the substance of the organs themselves, the fat of
the body, the substance of the muscles, the nerves,
and the brain, are unavoidably consumed.*

The true cause of death in these cases is the respi-
ratory process, that is, the action of the atmosphere.

A deficiency of food, and a want of power to con-
vert the food into a part of the organism, are both,
equally, a want of resistance ; and this is the nega-
tive cause of the cessation of the vital process. The
flame is extinguished, because the oil is consumed ;
and it is the oxygen of the air which has consumed it.

In many diseases substances are produced which
are incapable of assimilation. By the mere depriva-
tion of food, these substances are removed from the
body without leaving a trace behind ; their elements
have entered into combination with the oxygen of
the air.

From the first moment that the function of the
lungs or of the skin is interrupted or disturbed,
compounds, rich in carbon, appear in the urine,
which acquires a brown colour. Over the whole
surface of the body oxygen is absorbed, and combines
with all the substances which offer no resistance to
it. In those parts of the body where the access of

* For an account of what really takes place in this process, I
refer to the considerations on the means by which the change of
matter is effected in the body of the carnivora, which will be found
further on.

CONSUME THE BODY. 29

oxygen is impeded ; for example, in the arm-pits, or
in the soles of the feet, peculiar compounds are given
out, recognisable by their appearance, or by their
odour. These compounds contain much carbon.

Respiration is the falling weight, the bent spring,
which keeps the clock in motion; the inspirations
and expirations are the strokes of the pendulum
which regulate it. In our ordinary time-pieces, we
know with mathematical accuracy the effect pro-
duced on their rate of going, by changes in the
length of the pendulum, or in the external tempe-
rature. Few, however, have a clear conception of
the influence of air and temperature on the health
of the human body ; and yet the research into the
conditions necessary to keep it in the normal state,
is not more difficult than in the case of a clock.

V. The want of a just conception of force and
effect, and of the connection of natural phenomena,
has led chemists to attribute a part of the heat gene-
rated in the animal body to the action of the ner-
vous system. If this view exclude chemical action,
or changes in the arrangement of the elementary
particles, as a condition of nervous agency, it means
nothing else than to derive the presence of motion,
the manifestation of a force, from nothing. But no
force, no power can come of nothing.

No one will seriously deny the share which the
nervous apparatus has in the respiratory process ;
for no change of condition can occur in the body

30 NERVES AND MUSCLES

without the nerves ; they are essential to all vital
motions. Under their influence, the viscera produce
those compounds, which, while they protect the orga-
nism from the action of the oxygen of the atmo-
sphere, give rise to animal heat; and when the
nerves cease to perform their functions, the whole
process of the action of oxygen must assume another
form. When the pons Varolii is cut through in the
dog, or when a stunning blow is inflicted on the
back of the head, the animal continues to respire for
some time, often more rapidly than in the normal
state; the frequency of the pulse at first rather
increases than diminishes, yet the animal cools as
rapidly as if sudden death had occurred. Exactly
similar observations have been made on the cutting
of the spinal cord, and of the par vagum. The
respiratory motions continue for a time, but the
oxygen does not meet with those substances with
which, in the normal state, it would have combined ;
because the paralyzed viscera will no longer furnish
them. The singular idea that the nerves produce
animal heat, has obviously arisen from the notion
that the inspired oxygen combines with carbon, in
the blood itself; in which case the temperature of
the body, in the above experiments, certainly, ought
not to have sunk. But, as we shall afterwards see,
there cannot be a more erroneous conception than
this.

As by the division of the pneumogastric nerves
the motion of the stomach and the secretion of the

NOT THE SOURCE OF ANIMAL HEAT. 31

gastric juice are arrested, and an immediate check is
thus given to the process of digestion, so the paraly-
sis of the organs of vital motion in the abdominal
viscera affects the process of respiration. These
processes (ye most intimately connected ; and every
disturbance of the nervous system or of the nerves of
digestion re-acts visibly on the process of respiration.

The observation has been made, that heat is pro-
duced by the contraction of the muscles, just as in a
piece of caoutchouc, which, when rapidly drawn out,
forcibly contracts again, with disengagement of heat.
Some have gone so far as to ascribe a part of the
animal heat to the mechanical motions of the body,
as if these motions could exist without an expendi-
ture of force consumed in producing them ; how
then, we may ask, is this force produced ?

By the combustion of carbon, by the solution of
a metal in an acid, by the combination of the two
electricities, positive and negative, by the absorption
of light, and even by the rubbing of two solid bodies
together with a certain degree of rapidity, heat may
be produced.

By a number of causes, in appearance entirely dis-
tinct, we can thus produce one and the same effect.
In combustion and in the production of galvanic
electricity w^e have a change of condition in material
particles ; when heat is produced by the absorption
of light or by friction, we have the conversion of one
kind of motion into another, which affects our senses
differently. In all such cases we have a something

32 TRUE SOURCE OF

given, which merely takes another form ; in all we
have a force and its effect. By means of the fire
which heats the boiler of a steam-engine we can
produce every kind of motion, and by a certain
amount of motion we can produce fire. *

When we rub a piece of sugar briskly on an iron
grater, it undergoes, at the surfaces of contact, the
same change as if exposed to heat ; and two pieces
of ice, when rubbed together, melt at the point of
contact.

Let us remember that the most distinguished
authorities in physics consider the phenomena of
heat as phenomena of motion, because the very
conception of the creation of matter, even though
imponderable, is absolutely irreconcilable with its
production by mechanical causes, such as friction or
motion.

But, admitting all the influence which electric or
magnetic disturbances in the animal body can have
on the functions of its organs, still the ultimate
cause of all these forces is a change of condition in
material particles, which may be expressed by the con-
version, within a certain time, of the elements of the
food into oxidised products. Such of these elements
as do not undergo this process of slow combustion,
are given off unburned or incombustible in the ex-
crements. *

Now, it is absolutely impossible that a given
amount of carbon or hydrogen, whatever different
forms they may assume in the progress of the com-

ANIMAL HEAT. 33

bustion, can produce more heat than if directly
burned in atmospheric air or in oxygen gas.

When we kindle a fire under a steam-engine, and
employ the power obtained to produce heat by
friction, it is impossible that the heat thus obtained
can ever be greater than that which was required
to heat the boiler ; and if we use the galvanic cur-
rent to produce heat, the amount of heat obtained
is never, in any circumstances, greater than we
might have by the combustion of the zinc which
has been dissolved in the acid.

The contraction of muscles produces heat ; but
the force necessary for the contraction has mani-
fested itself through the organs of motion, in which
it has been excited by chemical changes. The ul-
timate cause of the heat produced is therefore to
be found in these chemical changes.

By dissolving a metal in an acid, we produce an
electrical current ; this current, if passed through a
wire, converts the wire into a magnet, by means of
which many different effects may be produced. The
cause of these phenomena is magnetism ; the cause
of the magnetic phenomena is to be found in the
electrical current; and the ultimate cause of the
electrical current is found to be a chemical change,
a chemical action.

There* are various causes by which force or motion

may be produced. A bent spring, a current of

air, the fall of water, fire applied to a boiler, the

solution of a metal in an acid, — all these different

D

34 GREAT AMOUNT

causes of motion may be made to produce the
same effect. But in the animal body we recognize
as the ultimate cause of all force only one cause,
the chemical action which the elements of the food
and the oxygen of the air mutually exercise on each
other. The only known ultimate cause of vital
force, either in animals or in plants, is a chemical
process. If this be prevented, the phenomena of
life do not manifest themselves, or they cease to be
recognizable by our senses. If the chemical action
be impeded, the vital phenomena must take new
forms.

According to the experiments of Despretz, 1 oz.
of carbon evolves, during its combustion, as much
heat as would raise the temperature of 105 oz. of
water at 32° to 167°, that is, by 135 degrees ; in all,
therefore, 105 times 135°=14207 degrees of heat.
Consequently, the 13'9 oz. of carbon which are daily
converted into carbonic acid in the body of an
adult, evolve 13-9xl4207°=197477'3 degrees of
heat. This amount of heat is sufficient to raise the
temperature of 1 oz. of water by that number of
degrees, or from 32° to 197509-3° ; or to cause
136-8 Ibs. of water at 32° to boil ; or to heat 370 Ibs.
of water to 98-3° (the temperature of the human
body) ; or to convert into vapour 24 Ibs. of water
at 98-3°.

If we now assume that the quantity of water
vaporized through the skin and lungs in 24 hours
amounts to 48 oz. (3 Ibs.), then there will remain,

OF ANIMAL HEAT. 35

after deducting the necessary amount of heat,
146380-4 degrees of heat, which are dissipated by
radiation, by heating the expired air, and in the ex-
crenientitious matters.

In this calculation, no account has been taken of
the heat evolved by the hydrogen of the food, during
its conversion into water by oxidation within the
body. But if we consider that the specific heat of
the bones, of fat, and of the organs generally, is far
less than that of water, and that consequently they
require, in order to be heated to 98-3°, much less
heat than an equal weight of water, no doubt can
be entertained, that when all the concomitant cir-
cumstances are included in the calculation, the heat
evolved in the process of combustion, to which the
food is subjected in the body, is amply sufficient to
explain the constant temperature of the body, as
well as the evaporation from the skin and lungs.

VI. All experiments hitherto made on the quan-
tity of oxygen which an animal consumes in a given
time, and also the conclusions deduced from them
as to the origin of animal heat, are destitute of
practical value in regard to this question, since we
have seen that the quantity of oxygen consumed
varies according to the temperature and density of
the air, according to the degree of motion, labour,
or exercise, to the amount and quality of the food,
to the comparative warmth of the clothing, and also
according to the time within which the food is taken.
Prisoners in the Bridewell at Marienschloss (a prison

D2

36 AMOUNT OF OXYGEN

where labour is enforced), do not consume more than
10-5 oz. of carbon daily; those in the House of
Arrest at Giessen, who are deprived of all exercise,
consume only 8*5 oz. ; (6) and in a family well known
to me, consisting of nine individuals, five adults, and
four children of different ages, the average daily
consumption of carbon for each, is not more than
9'5 oz. of carbon.* We may safely assume, as an ap-
proximation, that the quantities of oxygen consumed
in these different cases are in the ratio of these
numbers ; but where the food contains meat, fat, and
wine, the proportions are altered by reason of the
hydrogen in these kinds of food which is oxidised,
and which, in being converted into water, evolves
much more heat for equal weights.

The attempts to ascertain the amount of heat
evolved in an animal for a given consumption of
oxygen have been equally unsatisfactory. Animals
have been allowed to respire in close chambers sur-
rounded with cold water ; the increase of tempera-
ture in the water has been measured by the ther-
mometer, and the quantity of oxygen consumed has
been calculated from the analysis of the air before

* In this family, the monthly consumption was 151 Ibs. of
brown bread, 70 Ibs. white bread, 132 Ibs. meat, 19 Ibs. sugar,
15-9 Ibs. butter, 57 maass (about 24 gallons) of milk ; the carbon of
the potatoes and other vegetables, of the poultry, game, and wine
consumed, having been reckoned as equal to that contained in
the excrementitious matters, the carbon of the above articles was
considered as being converted into carbonic acid.

CONSUMED BY ANIMALS. 37

and after the experiment. In experiments thus
conducted, it has been found that the animal lost
about TV more heat than corresponded to the oxygen
consumed ; and had the windpipe of the animal been
tied, the strange result would have been obtained of
a rise in the temperature of the water without any
consumption of oxygen. The animal was at the
temperature of 98° or 99°, and the water, in the
experiments of Despretz, was at 47'5°. Such ex-
periments consequently prove, that when a great
difference exists between the temperature of the
animal body and that of the surrounding medium,
and when no motion is allowed, more heat is given
off than corresponds to the oxygen consumed. In
equal times, with free and unimpeded motion, a
much larger quantity of oxygen would be consumed
without a perceptible increase in the amount of
heat lost. The cause of these phenomena is obvious.
They appear naturally both in man and animals at
certain seasons of the year, and we say in such cases
that we are freezing, or experience the sensation of
cold. It is plain, that if we were to clothe a man
in a metallic dress, and tie up his hands and feet,
the loss of heat, for the same consumption of oxygen,
would be far greater than if we were to wrap him
up in fur and woollen cloth. Nay, in the latter
case, we should see him begin to perspire, and warm
water would exude, in drops, through the finest
pores of his skin.

If to these considerations we add, that decisive

38 NERVOUS AND

experiments are on record, in which animals were
made to respire in an unnatural position, as for
example, lying on the back, with the limbs tied so
as to preclude motion, and that the temperature of
their bodies was found to sink in a degree appreci-
able by the thermometer, we can hardly be at a
loss what value we ought to attach to the conclu-
sions drawn from such experiments as those above
described.

These experiments and the conclusions deduced
from them, in short, are incapable of furnishing the
smallest support to the opinion that there exists, in
the animal body, any other unknown source of heat,
besides the mutual chemical action between the ele-
ments of the food and the oxygen of the air. The ex-
istence of the latter cannot be doubted or denied, and
it is amply sufficient to explain all the phenomena.

VII. If we designate the production of force, the
phenomena of motion in the animal body as nervous
life, and the resistance, the condition of static equi-
librium, as vegetative life; it is obvious that in all
classes of animals the latter, namely, vegetative life,
prevails over the former, nervous life, in the earlier
stages of existence.

The passage or change of matter from a state of
motion to a state of rest appears in an increase of
the mass, and in the supply of waste; while the
motion itself, or the production of force, appears in
the shape of waste of matter.

VEGETATIVE LIFE. 39

In a young animal, the waste is less than the
increase ; and the female retains, up to a certain
age, this peculiar condition of a more intense vege-
tative life. This condition does not cease in the
female as in the male, with the complete develope-
ment of all the organs of the body.

The female in the lower animals, is, at certain
seasons, capable of reproduction of the species. The
vegetative life in her organism is rendered more in-
tense by certain external conditions, such as tempe-
rature, food, &c. ; the organism produces more than is
wasted, and the result is the capacity of reproduction.

In the human species, the female organism is
independent of those external causes which increase
the intensity of vegetative life. When the organ-
ism is fully developed, it is at all times capable of
reproduction of the species ; and infinite wisdom
has given to the female body the power, up to a cer-
tain age, of producing all parts of its organisation in
greater quantity than is required to supply the daily
waste.

This excess of production can be shewn to contain
all the elements of a new organism, it is constantly
accumulating, and is periodically expelled from the
body, until it is expended in reproduction. This
periodical discharge ceases when the ovum has been
impregnated, and from this time every drop of the
superabundant blood goes to produce an organism
like that of the mother.

Exercise and labour cause a diminution in the

40 NUTRITION DEPENDS ON THE

quantity of the menstrual discharge ; and when it is
suppressed in consequence of disease, the vegetative
life is manifested in a morbid production of fat.
When the equilibrium between the vegetative and
nervous life is disturbed in the male, when, as in
eunuchs, the intensity of the latter is diminished,
the predominance of the former is shewn in the
same form, in an increased deposit of fat.

VIII. If we hold, that increase of mass in the
animal body, the developement of its organs, and
the supply of waste, — that all this is dependant on
the blood, that is, on the ingredients of the blood,
then only those substances can properly be called
nutritious or considered as food which are capable
of conversion into blood. To determine, therefore,
what substances are capable of affording nourish-
ment, it is only necessary to ascertain the composi-
tion of the food, and to compare it with that of the
ingredients of the blood.

Two substances require especial consideration as
the chief ingredients of the blood ; one of these
separates immediately from the blood when with-
drawn from the circulation. It is well known that
in this case blood coagulates, and separates into a
yellowish liquid, the serum of the blood, and a gela-
tinous mass, which adheres to a rod or stick in soft,
elastic fibres, when coagulating blood is briskly
stirred. This is the fibrine of the blood, which is
identical in all its properties with muscular fibre,

CONSTITUENTS OF BLOOD. 41

when the latter is purified from all foreign mat-
ters.

The second principal ingredient of the blood is
contained in the serum, and gives to this liquid all
the properties of the white of eggs, with which it is
identical. When heated, it coagulates into a white
elastic mass, and the coagulating substance is
called albumen.

Fibrine and albumen, the chief ingredients of
blood, contain, in all, seven chemical elements,
among which nitrogen, phosphorus, and sulphur are
found. They contain also the earth of bones. The
serum retains in solution sea salt and other salts of
potash and soda, in which the acids are carbonic,
phosphoric, and sulphuric acids. The globules of the
blood contain fibrine and albumen, along with a red
colouring matter, in which iron is a constant ele-
ment. Besides these, the blood contains certain
fatty bodies in small quantity, which differ from
ordinary fats in several of their properties.

Chemical analysis has led to the remarkable re-
sult, that fibrine and albumen contain the same
organic elements united in the same proportion, so
that two analyses, the one of fibrine and the other
of albumen, do not differ more than two analyses of
fibrine or two of albumen respectively do, in the
composition of 100 parts.

In these two ingredients of blood the particles
are arranged in a different order, as is shewn by the
difference of their external properties ; but in die-

42 IDENTITY OF ANIMAL

mical composition, in the ultimate proportion of the
organic elements, they are identical.

This conclusion has lately been beautifully con-
firmed by a distinguished physiologist (Denis), who
has succeeded in converting fibrine into albumen,
that is, in giving it the solubility, and coagulability
by heat, which characterize the white of egg.

Fibrine and albumen, besides having the same
composition, agree also in this, that both dissolve in
concentrated muriatic acid, yielding a solution of an
intense purple colour. This solution, whether made
with fibrine or albumen, has the very same re-actions
with all substances yet tried.

Both albumen and fibrine, in the process of nutri-
tion, are capable of being converted into muscular
fibre, and muscular fibre is capable of being recon-
verted into blood. These facts have long been esta-
blished by physiologists, and chemistry has merely
proved that these metamorphoses can be accom-
plished under the influence of a certain force, with-
out the aid of a third substance, or of its elements,
and without the addition of any foreign element, or
the separation of any element previously present in
these substances.

If we now compare the composition of all organ-
ised parts with that of fibrine and albumen, the fol-
lowing relations present themselves : —

All parts of the animal body which have a decided
shape, which form parts of organs, contain nitrogen.
No part of an organ which possesses motion and life

FIBRINE AND ALBUMEN. 43

is destitute of nitrogen ; all of them contain likewise
carbon and the elements of water, the latter,
however, in no case in the proportion to form
water.

The chief ingredients of the blood contain nearly
17 per cent, of nitrogen, and no part of an organ
contains less than 17 per cent, of nitrogen. (7)

The most convincing experiments and observa-
tions have proved that the animal body is absolutely
incapable of producing an elementary body, such as
carbon or nitrogen, out of substances which do not
contain it ; and it obviously follows, that all kinds
of food fit for the production either of blood, or of
cellular tissue, membranes, skin, hair, muscular fibre,
&c., must contain a certain amount of nitrogen,
because that element is essential to the composition
of the above-named organs ; because the organs can-
not create it from the other elements presented to
them ; and, finally, because no nitrogen is absorbed
from the atmosphere in the vital process.

The substance of the brain and nerves contains a
large quantity of albumen, and, in addition to this,
two peculiar fatty acids, distinguished from other fats
by containing phosphorus (phosphoric acid ?). One of
these contains nitrogen (Fremy).

Finally, water and common fat are those ingre-
dients of the body which are destitute of nitrogen.
Both are amorphous or unorganised, and only so far
take part in the vital process as that their presence
is required for the due performance of the vital

44 NUTRITION OF GRAMINIVORA.

functions. The inorganic constituents of the body
are, iron, lime, magnesia, common salt, and the alka-
lies.

IX. The nutritive process in the carnivora is seen
in its simplest form. This class of animals lives on
the blood and flesh of the graminivora ; but this
blood and flesh is, in all its properties, identical with
their own. Neither chemical nor physiological dif-
ferences can be discovered.

The nutriment of carnivorous animals is derived
originally from blood ; in their stomach it becomes
dissolved, and capable of reaching all other parts
of the body ; in its passage it is again converted into
blood, and from this blood are reproduced all those
parts of their organisation which have undergone
change or metamorphosis.

With the exception of hoofs, hair, feathers, and
the earth of bones, every part of the food of carni-
vorous animals is capable of assimilation.

In a chemical sense, therefore, it may be said that
a carnivorous animal, in supporting the vital pro-
cess, consumes itself. That which serves for its
nutrition is identical with those parts of its organ-
isation which are to be renewed.

The process of nutrition in graminivorous animals
appears at first sight altogether different. Their
digestive organs are less simple, and their food con-
sists of vegetables, the great mass of which contains
but little nitrogen.

VEGETABLE FIBRINE. 45

From what substances, it may be asked, is the
blood formed, by means of which their organs are
developed ? This question may be answered with
certainty.

Chemical researches have shewn, that all such
parts of vegetables as can afford nutriment to ani-
mals contain certain constituents which are rich in
nitrogen ; and the most ordinary experience proves
that animals require for their support and nutrition
less of these parts of plants in proportion as they
abound in the nitrogenised constituents. Animals
cannot be fed on matters destitute of these nitro-
genised constituents.

These important products of vegetation are espe-
cially abundant in the seeds of the different kinds
of grain, and of pease, beans, and lentils ; in the
roots and the juices of what are commonly called
vegetables. They exist, however, in all plants,
without exception, and in every part of plants in
larger or smaller quantity.

These nitrogenised forms of nutriment in the
vegetable kingdom may be reduced to three sub-
stances, which are easily distinguished by their ex-
ternal characters. Two of them are soluble in
water, the third is insoluble.

When the newly-expressed juices of vegetables
are allowed to stand, a separation takes place in a
few minutes. A gelatinous precipitate, commonly
of a green tinge, is deposited, and this, when acted
on by liquids which remove the colouring matter,

46 VEGETABLE FIBRINE,

leaves a greyish white substance, well known to
druggists as the deposit from vegetable juices. This
is one of the nitrogenised compounds which serves
for the nutrition of animals, and has been named
vegetable fibrine. The juice of grapes is especially
rich in this constituent, but it is most abundant in
the seeds of wheat, and of the cerealia generally.
It may be obtained from wheat flour by a mechan-
ical operation, and in a state of tolerable purity;
it is then called gluten, but the glutinous property
belongs, not to vegetable fibrine, but to a foreign
substance, present in small quantity, which is not
found in the other cerealia.

The method by which it is obtained sufficiently
proves that it is insoluble in water ; although we
cannot doubt that it was originally dissolved in the
vegetable juice, from which it afterwards separated,
exactly as fibrine does from blood.

The second nitrogenised compound remains dis-
solved in the juice after the separation of the fibrine.
It does not separate from the juice at the ordinary
temperature, but is instantly coagulated when the
liquid containing it is heated to the boiling point.

When the clarified juice of nutritious vegetables,
such as cauliflower, asparagus, mangel wurzel, or
turnips, is made to boil, a coagulum is formed, which
it is absolutely impossible to distinguish from the
substance which separates as a coagulum, when
the serum of blood or the white of an egg, di-
luted with water, are heated to the boiling point.

ALBUMEN, AND CASEINE. 47

This is vegetable albumen. It is found in the great-
est abundance in certain seeds, in nuts, almonds,
and others, in which the starch of the graminese is
replaced by oil.

The third nitrogenised constituent of the vegeta-
ble food of animals is vegetable caseine. It is chiefly
found in the seeds of pease, beans, lentils, and
similar leguminous seeds. Like vegetable albumen,
it is soluble in water, but differs from it in this, that
its solution is not coagulated by heat. When the
solution is heated or evaporated, a skin forms on its
surface, and the addition of an acid causes a coagu-
lum, just as in animal milk.

These three nitrogenised compounds, vegetable
fibrine, albumen, and caseine, are the true nitro-
genised constituents of the food of graminivorous
animals ; all other nitrogenised compounds, occur-
ring in plants, are either rejected by animals, as in
the case of the characteristic principles of poisonous
and medicinal plants, or else they occur in the food
in such very small proportion, that they cannot
possibly contribute to the increase of mass in the
animal body.

The chemical analysis of these three substances
has led to the very interesting result that they con-
tain the same organic elements, united in the same
proportion by weight; and, what is still more re-
markable, that they are identical in composition
with the chief constituents of blood, animal fibrine,
and albumen. They all three dissolve in concen-

48 IDENTITY OF ANIMAL WITH

trated muriatic acid with the same deep purple
colour, and even in their physical characters, animal
fibrine and albumen are in no respect different from
vegetable fibrine and albumen. It is especially to
be noticed, that by the phrase, identity of composi-
tion, we do not here imply mere similarity, but that
even in regard to the presence and relative amount
of sulphur, phosphorus, and phosphate of lime, no
difference can be observed. (8)

How beautifully and admirably simple, with the
aid of these discoveries, appears the process of nu-
trition in animals, the formation of their organs,
in which vitality chiefly resides ! Those vegetable
principles, wrhich in animals are used to form blood,
contain the chief constituents of blood, fibrine and
albumen, ready formed, as far as regards their
composition. All plants, besides, contain a certain
quantity of iron, which re-appears in the colouring
matter of the blood. Vegetable fibrine and animal
fibrine, vegetable albumen and animal albumen,
hardly differ, even in form ; if these principles be
wanting in the food, the nutrition of the animal is
arrested ; and when they are present, the gramini-
vorous animal obtains in its food the very same
principles on the presence of which the nutrition of
the carnivora entirely depends.

Vegetables produce in their organism the blood
of all animals, for the carnivora, in consuming the
blood and flesh of the graminivora, consume, strictly
speaking, only the vegetable principles which have

VEGETABLE FIBRINE, &c. 49

served for the nutrition of the latter. Vegetable
fibrine and albumen take the same form in the
stomach of the graminivorous animal as animal
fibrine and albumen do in that of the carnivorous
animal.

From what has been said, it follows that the de-
velopement of the animal organism and its growth
are dependant on the reception of certain principles
identical with the chief constituents of blood.

In this sense we may say that the animal organ-
ism gives to blood only its form ; that it is incapable
of creating blood out of other substances which do
not already contain the chief constituents of that
fluid. We cannot, indeed, maintain that the animal
organism has no power to form other compounds,
for we know that it is capable of producing an
extensive series of compounds, differing in composi-
tion from the chief constituents of blood ; but these
last, which form the starting point of the series, it
cannot produce.

The animal organism is a higher kind of vege-
table, the developement of which begins with those
substances, with the production of which the life of
an ordinary vegetable ends. As soon as the latter
has borne seed, it dies, or a period of its life comes
to a termination.

In that endless series of compounds, which begins

with carbonic acid, ammonia, and water, the sources

of the nutrition of vegetables, and includes the

most complex constituents of the animal brain,

E

50 USES OF THE STARCH,

there is no blank, no interruption. The first sub-
stance capable of affording nutriment to animals is
the last product of the creative energy of vege-
tables.

The substance of cellular tissue and of mem-
branes, of the brain and nerves, these the vegetable
cannot produce.

The seemingly miraculous in the productive
agency of vegetables disappears in a great degree,
when we reflect that the production of the consti-
tuents of blood cannot appear more surprising than
the occurrence of the fat of beef and mutton in
cocoa beans, of human fat in olive oil, of the prin-
cipal ingredient of butter in palm oil, and of horse
fat and train oil in certain oily seeds.

X. While the preceding considerations leave lit-
tle or no doubt as to the way in which the increase
of mass in an animal, that is, its growth, is carried
on, there is yet to be resolved a most important
question, namely, that of the function performed in
the animal system by substances containing no nitro-
gen, such as sugar, starch, gum, pectine, &c.

The most extensive class of animals, the grami-
nivora, cannot live without these substances ; their
food must contain a certain amount of one or more
of them, and if these compounds are not supplied,
death quickly ensues.

This important inquiry extends also to the consti-
tuents of the food of carnivorous animals in the ear-

SUGAR, &c. IN THE FOOD. 51

liest periods of life ; for this food also contains sub-
stances, which are not necessary for their support in
the adult state.

The nutrition of the young of carnivora is obvi-
ously accomplished by means similar to those by
which the graminivora are nourished ; their develope-
ment is dependant on the supply of a fluid, which
the body of the mother secretes in the shape of
milk.

Milk contains only one nitrogenised constituent,
known under the name of caserne ; besides this, its
chief ingredients are butter (fat), and sugar of milk.

The blood of the young animal, its muscular fibre,
cellular tissue, nervous matter, and bones, must have
derived their origin from the nitrogenised constitu-
ent of milk, the caseine ; for butter and sugar of
milk contain no nitrogen.

Now, the analysis of caseine has led to the result,
which, after the details given in the last section, can
hardly excite surprise, that this substance also is
identical in composition with the chief constituents
of blood, fibrine and albumen. Nay, more, a com-
parison of its properties with those of vegetable ca-
seine has shewn that these two substances are iden-
tical in all their properties ; insomuch, that certain
plants, such as peas, beans, and lentils, are capable
of producing the same substance which is formed
from the blood of the mother, and employed in
yielding the blood of the young animal. (9)

The young animal, therefore, receives, in the form
E 2

52 ANIMAL AND VEGETABLE

of caseine, which is distinguished from fibrine and
albumen by its great solubility, and by not coagu-
lating when heated, the chief constituent of the mo-
ther's blood. To convert caseine into blood no fo-
reign substance is required, and in the conversion
of the mother's blood into caseine, no elements of
the constituents of the blood have been separated.
When chemically examined, caseine is found to
contain a much larger proportion of the earth of
bones than blood does, and that in a very soluble
form, capable of reaching every part of the body.
Thus, even in the earliest period of its life, the de-
velopement of the organs, in which vitality resides,
is, in the carnivorous animal, dependant on the sup-
ply of a substance, identical in organic composition
with the chief constituents of its blood.

What, then, is the use of the butter and the su-
gar of milk ? How does it happen that these sub-
stances are indispensable to life ?

Butter and sugar of milk contain no fixed bases,
no soda or potash. Sugar of milk has a composition
closely allied to that of the other kinds of sugar, of
starch, and of gum ; all of them contain carbon and
the elements of water, the latter precisely in the
proportion to form water.

There is added, therefore, by means of these com-
pounds, to the nitrogenised constituents of food, a
certain amount of carbon, or, as in the case of but-
ter, of carbon and hydrogen ; that is, an excess of
elements, which cannot possibly be employed in the

CASEINE IDENTICAL. 53

production of blood, because the nitrogenised sub-
stances contained in the food already contain exactly
the amount of carbon which is required for the pro-
duction of fibrine and albumen.

The following considerations will shew that hardly
a doubt can be entertained, that this excess of car-
bon alone, or of carbon and hydrogen, is expended
in the production of animal heat, and serves to pro-
tect the organism from the action of the atmospheric
oxygen.

XI. In order to obtain a clearer insight into the
nature of the nutritive process in both the great
classes of animals, let us first consider the changes
which the food of the carnivora undergoes in their
organism.

If we give to an adult serpent, or boa constrictor,
a goat, a rabbit, or a bird, we find that the hair,
hoofs, horns, feathers, or bones of these animals, are
expelled from the body apparently unchanged. They
have retained their natural form and aspect, but
have become brittle, because of all their component
parts they have lost only that one which was capable
of solution, namely, the gelatine. Faeces, properly
so called, do not occur in serpents any more than in
carnivorous birds.

We find, moreover, that, when the serpent has
regained its original weight, every other part of its
prey, the flesh, the blood, the brain, and nerves, in
short, every thing, has disappeared.

54 NUTRITION OF CARNIVORA.

The only excrement, strictly speaking, is a sub-
stance expelled by the urinary passage. When dry,
it is pure white, like chalk ; it contains much nitro-
gen, and a small quantity of carbonate and phos-
phate of lime mixed with the mass.

This excrement is urate of ammonia, a chemical
compound, in which the nitrogen bears to the carbon
the same proportion as in bicarbonate of ammonia.
For every equivalent of nitrogen it contains two
equivalents of carbon.

But muscular fibre, blood, membranes, and skin,
contain four times as much carbon for the same
amount of nitrogen, or eight equivalents to one ; and
if we add to this the carbon of the fat and nervous
substance, it is obvious that the serpent has con-
sumed, for every equivalent of nitrogen, much more
than eight equivalents of carbon.

If now we assume that the urate of ammonia con-
tains all the nitrogen of the animal consumed, then
at least six equivalents of carbon, which were in
combination with this nitrogen, must have been
given out in a different form from the two equiva-
lents which are found in the urate of ammonia.

Now we know, with perfect certainty, that this
carbon has been given out through the skin and
lungs, which could only take place in the form of an
oxidised product.

The excrements of a buzzard which had been fed
with beef, when taken out of the rectum, consisted,
according to L. Gmelin and Tiedemann, of urate of

USES OF CARBON IN THEIR FOOD. 55

ammonia. In like manner, the faeces in lions and
tigers are scanty and dry, consisting chiefly of bone
earth, with mere traces of compounds containing
carbon ; but their urine contains, not urate of am-
monia, but urea, a compound in which carbon and
nitrogen are to each other in the same ratio as in
neutral carbonate of ammonia.

Assuming that their food (flesh, &c.) contains
carbon and nitrogen in the ratio of eight equivalents
to one, we find these elements in their urine in the
ratio of one equivalent to one ; a smaller proportion
of carbon, therefore, than in serpents, in which res-
piration is so much less active.

The whole of the carbon and hydrogen which the
food of these animals contained, beyond the amount
which we find in their excrements, has disappeared,
in the process of respiration, as carbonic acid and
water.

Had the animal food been burned in a furnace,
the change produced in it would only have differed
in the form of combination assumed by the nitrogen
from that which it underwent in the body of the
animal. The nitrogen would have appeared, with
part of the carbon and hydrogen, as carbonate of
ammonia, while the rest of the carbon and hydrogen
would have formed carbonic acid and water. The
incombustible parts would have taken the form of
ashes, and any part of the carbon unconsumed from
a deficiency of oxygen would have appeared as
soot, or lamp-black. Now the solid excrements are

56 FOOD OF CARNIVORA

nothing else than the incombustible, or imperfectly
burned, parts of the food.

In the preceding pages it has been assumed that
the elements of the food are converted by the oxy-
gen absorbed in the lungs into oxidised products ;
the carbon into carbonic acid, the hydrogen into
water, and the nitrogen into a compound con-
taining the same elements as carbonate of am-
monia.

This is only true in appearance ; the body, no
doubt, after a certain time, acquires its original
weight. The amount of carbon, and of the other
elements, is not found to be increased — exactly as
much carbon, hydrogen, and nitrogen has been given
out as was supplied in the food ; but nothing is more
certain than that the carbon, hydrogen, and nitro-
gen given out, although equal in amount to what
is supplied in that form, do not directly proceed
from the food.

It would be utterly irrational to suppose that the
necessity of taking food, or the satisfying the appe-
tite, had no other object than the production of
urea, uric acid, carbonic acid, and other excremen-
titious matters — of substances which the system
expels, and consequently applies to no useful pur-
pose in the economy.

In the adult animal, the food serves to restore
the waste of matter; certain parts of its organs
have lost the state of vitality, have been expelled
from the substance of the organs, and have been

IDENTICAL WITH THEIR BODIES. 57

metamorphosed into new combinations, which are
amorphous and unorganised.

The food of the carnivora is at once converted
into blood ; out of the newly-formed blood those
parts of organs which have undergone metamor-
phoses are reproduced. The carbon and nitrogen of
the food thus become constituent parts of organs.

Exactly as much carbon and nitrogen is supplied
to the organs by the blood, that is, ultimately, by
the food, as they have lost by the transformations
attending the exercise of their functions.

What then, it may be asked, becomes of the new
compounds produced by the transformations of the
organs, of the muscles, of the membranes and cel-
lular tissue of the nerves and brain ?

These new compounds cannot, owing to their
solubility, remain in the situation where they are
formed, for a well-known force, namely the circu-
lation of the blood, opposes itself to this.

By the expansion of the heart, an organ in which
two systems of tubes meet, which are ramified in a
most minute network of vessels through all parts of
the body, there is produced a vacuum, the imme-
diate effect of which is, that all fluids which can
penetrate into these vessels are urged with great
force towards one side of the heart by the external
pressure of the atmosphere. This motion is power-
fully assisted by the contraction of the heart, alter-
nating with its expansion, and caused by a force
independent of the atmospheric pressure.

58 CARBON IS ACCUMULATED

In a word, the heart is a forcing pump, which
sends arterial blood into all parts of the body ; and
also a suction pump, by means of which all fluids
of whatever kind, as soon as they enter the absorbent
vessels which communicate with the veins, are drawn
towards the heart. This suction, arising from the
vacuum caused by the expansion of the heart, is a
purely mechanical act, which extends, as above
stated, to fluids of every kind, to saline solutions,
poisons, &c. It is obvious, therefore, that by the
forcible entrance of arterial blood into the capillary
vessels, the fluids contained in these, in other words,
the soluble compounds formed by the transforma-
tions of organised parts, must be compelled to move
towards the heart.

These compounds cannot be employed for the
reproduction of those tissues from which they are
derived. They pass through the absorbent and
lymphatic vessels into the veins, where their accu-
mulation would speedily put a stop to the nutritive
process, were it not that this accumulation is pre-
vented by two contrivances adapted expressly to
this purpose, and which may be compared to filtering
machines.

The venous blood, before reaching the heart, is
made to pass through the liver ; the arterial blood,
on the other hand, passes through the kidneys ; and
these organs separate from both all substances in-
capable of contributing to nutrition.

Those new compounds which contain the nitrogen

IN THE BILE. 59

of the transformed organs are collected in the uri-
nary bladder, and being utterly incapable of any
further application in the system, are expelled from
the body.

Those, again, which contain the carbon of the
transformed tissues, are collected in the gall-bladder
in the form of a compound of soda, the bile., which is
miscible with water in every proportion, and which,
passing into the duodenum, mixes with the chyme.
All those parts of the bile which, during the diges-
tive process, do not lose their solubility, return
during that process into the circulation in a state of
extreme division. The soda of the bile, and those
highly carbonised portions which are not precipitated
by a weak acid (together making T^ths of the solid
contents of the bile), retain the capacity of resorp-
tion by the absorbents of the small and large intes-
tines; nay, this capacity has been directly proved
by the administration of enemata containing bile,
the whole of the bile disappearing with the injected
fluid in the rectum.

Thus we know with certainty, that the nitrogen-
ised compounds, produced by the metamorphosis of
organised tissues, after being separated from the
arterial blood by means of the kidneys are expelled
from the body as utterly incapable of further altera-
tion ; while the compounds rich in carbon, derived
from the same source, return into the system of
carnivorous animals.

The food of the carm'vora is identical with the

60 THE CARBON OF THE BILE

chief constituents of their bodies, and hence the
metamorphoses which their organs undergo must be
the same as those which, under the influence of the
vital force, take place in the matters which consti-
tute their food.

The flesh and blood consumed as food yield their
carbon for the support of the respiratory process,
while its nitrogen appears as uric acid, ammonia,
or urea. But previously to these final changes, the
dead flesh and blood become living flesh and blood,
and it is, strictly speaking, the carbon of the com-
pounds formed in the metamorphoses of living tis-
sues that serves for the production of animal heat.

The food of the carnivora is converted into blood,
which is destined for the reproduction of organised
tissues ; and by means of the circulation a current
of oxygen is conveyed to every part of the body.
The globules of the blood, which in themselves
can be shewn to take no share in the nutritive
process, serve to transport the oxygen, which they
give up in their passage through the capillary
vessels. Here the current of oxygen meets with
the compounds produced by the transformation of
the tissues, and combines with their carbon to form
carbonic acid, with their hydrogen to form water.
Every portion of these substances which escapes this
process of oxidation is sent back into the circulation
in the form of the bile, which by degrees completely
disappears.

In the carnivora the bile contains the carbon of

UNDERGOES COMBUSTION. 61

the metamorphosed tissues ; this carbon disappears
in the animal body, and the bile likewise disappears
in the vital process. Its carbon and hydrogen are
given out through the skin and lungs as carbonic
acid and water; and hence it is obvious that the
elements of the bile serve for respiration and
for the production of animal heat. Every part of
the food of carnivorous animals is capable of
forming blood ; their excrements, excluding the
urine, contain only inorganic substances, such as
phosphate of lime ; and the small quantity of organic
matter which is found mixed with these is derived
from excretions, the use of which is to promote
their passage through the intestines, such as mucus.
These excrements contain no bile and no soda ; for
water extracts from them no trace of any substance
resembling bile, and yet bile is very soluble in
water, and mixes with it in every proportion.

Physiologists can entertain no doubt as to the
origin of the constituent parts of the urine and of
the bile. When, from deprivation of food, the
stomach contracts itself so as to resemble a portion
of intestine, the gall-bladder, for want of the motion
which the full stomach gives to it, cannot pour out
the bile it contains ; hence in animals starved to
death we find the gall-bladder distended and full.
The secretion of bile and of urine goes on during
the winter sleep of hybernating animals ; and we
know that the urine of dogs, fed for three weeks
exclusively on pure sugar, contains as much of the

62 USES OF THE URINE,

most highly nitrogenised constituent, urea, as in the
normal condition. (Marchaud. Erdmaun's Journal
fur praktische Chemie, XIV. p. 495.)

Differences in the quantity of urea secreted in
these and similar experiments are explained by the
condition of the animal in regard to the amount
of the natural motions permitted. Every motion
increases the amount of organised tissue which
undergoes metamorphosis. Thus, after a walk, the
secretion of urine in man is invariably increased.

The urine of the mammalia, of birds, and of
amphibia, contains uric acid or urea ; and the ex-
crements of the mollusca, and of insects, as of can-
tharides and of the butterfly of the silkworm, con-
tain urate of ammonia. This constant occurrence of
one or two nitrogenised compounds in the excre-
tions of animals, while so great a difference exists
in their food, clearly proves that these compounds
proceed from one and the same source.

As little doubt can be entertained in regard to
the function of the bile in the vital process. When
we consider, that the acetate of potash, given in
enema, or simply as a bath for the feet, renders the
urine strongly alkaline (Rehberger in Tiedemann's
Zeitschrift fiir Physiologie, II. 149), and that the
change which the acetic acid here undergoes cannot
be conceived without the addition of oxygen, it is
obvious, that the soluble constituents of the bile,
prone to change in a high degree as we know them
to be, and which, as already stated, cannot be em-

AND OF THE BILE. 63

ployed in the production of blood, must, when re-
turned through the intestines into the circulation, in
like manner yield to the influence of the oxygen
which they meet. The bile is a compound of soda,
the elements of which, with the exception of the
soda, disappear in the body of a carnivorous animal.

In the opinion of many of the most distinguished
physiologists, the bile is intended solely to be ex-
creted ; and nothing is more certain, than that a
substance containing so very small a proportion of
nitrogen can have no share in the process of nutri-
tion or reproduction of organised tissue. But
quantitative physiology must at once and decidedly
reject the opinion, that the bile serves no purpose
in the economy, and is incapable of further change.

No part of any organised structure contains soda ;
only in the serum of the blood, in the fat of the
brain, and in the bile, do we meet with that alkali.
When the compounds of soda in the blood are con-
verted into muscular fibre, membrane, or cellular
tissue, the soda they contain must enter into new
combinations. The blood which is transformed into
organised tissue gives up its soda to the compounds
formed by the metamorphoses of the previously
existing tissues. In the bile we find one of these
compounds of soda.

Were the bile intended merely for excretion, we
should find it, more or less altered, and also the
soda it contains, in the solid excrements. But,
with the exception of common salt, and of sulphate

64 AMOUNT OF BILE SECRETED.

of soda, which occur in all the animal fluids, only
mere traces of soda are to be found in the faeces.
The soda of the bile, therefore, at all events, must
have returned from the intestinal canal into the
organism, and the same must be true of the organic
matters which were in combination with it.

According to the observations of physiologists, a
man secretes daily from 17 to 24 oz. of bile ; a
large dog, 36 oz. ; a horse, 37 Ibs.-^Burdach's Phy-
siologic, V. p. 260.) But the faeces of a man do
not on an average weigh more than 5^ oz.; and
those of a horse 28-^ Ibs., of which 21 Ibs. are water,
and 7J Ibs. dry faeces. (Boussingault.) The latter
yield to alcohol only ^ih part of their weight of
soluble matter.

If we assume the bile to contain 90 per cent, of
water, a horse secretes daily 592 oz. of bile, con-
taining 59'2 oz. of solid matter ; while 7Jlbs. or
120 oz. of dried excrement yield only 6oz. of mat-
ter soluble in alco*hol, which might possibly be
bile. But this matter is not bile ; when the alco-
hol is dissipated by evaporation, there remains a
soft, unctuous mass, altogether insoluble in water,
and which, when incinerated, leaves no alkaline
ashes, no soda. (10)

During the digestive process, therefore, the soda
of the bile, and, along with it, all the soluble parts
of that fluid, are returned into the circulation. This
soda re-appears in the newly-formed blood, and,
finally, we find it in the urine in the form of phos-

IN MAN AND ANIMALS. 65

phate, carbonate, and hippurate of soda. Berzelius
found in 1,000 parts of fresh human faeces only nine
parts of a substance similar to bile ; 5 ounces, there-
fore, would contain only 21 grains of dried bile,
equivalent to 210 grains of fresh bile. But a man se-
cretes daily from 9,640 to 11,520 grains of fluid bile,
that is, from 45 to 56 times as much as can be detect-
ed in the matters discharged by the intestinal canal.
Whatever opinion we may entertain of the accu-
racy of the physiological experiments, in regard to
the quantity of bile secreted by the different classes
of animals ; thus much is certain, that even the max-
imum of the supposed secretion, in man and in the
horse, does not contain as much carbon as is given
out in respiration. With all the fat which is mixed
with it, or enters into its composition, dried bile
does not contain more than 69 per cent, of carbon.
Consequently, if a horse secretes 37 Ibs. of bile, this
quantity will contain only 40 ounces of carbon.
But the horse expires daily nearly twice as much in
the form of carbonic acid. A precisely similar pro-
portion holds good in man.

Along with the matter destined for the formation
or reproduction of organs, the circulation conveys
oxygen to all parts of the body. Now, into what-
ever combination the oxygen may enter in the
blood, it must be held as certain, that such of the
constituents of blood as are employed for reproduc-
tion, are not materially altered by it. In muscular
fibre we find fibririe, with all the properties it had
F

66 THE CARBON OF THE FOOD

in venous blood ; the albumen in the blood does not
combine with oxygen. The oxygen may possibly
serve to convert into the gaseous state some unknown
constituent of the blood; but those well-known
constituents, which are employed in reproduction,
cannot be destined to support the respiratory process;
none of their properties can justify such an opinion.

Without attempting in this place to exhaust the
whole question of the share taken by the bile in the
vital -operations, it follows, as has been observed,
from the simple comparison of those parts of the
food of the carnivora which are capable of assimila-
tion, with the ultimate products into which it is con-
verted, that all the carbon of the food, except that
portion which is found in the urine, is given out as
carbonic acid.

But this carbon was ultimately derived from the
substance of the metamorphosed tissues ; and this
being admitted, the question of the necessity of sub-
stances containing much carbon and no nitrogen in
the food of the young of the carnivora, and in that
of the graminivora, is resolved in a strikingly simple
manner.

XII. It cannot be disputed, that in an adult carni-
vorous animal, which neither gains nor loses weight,
perceptibly, from day to day, its nourishment, the
waste of organised tissue, and its consumption of
oxygen, stand to each other in a well-defined and
fixed relation.

SUPPORTS RESPIRATION. 67

The carbon of the carbonic acid given off, with
that of the urine ; the nitrogen of the urine, and the
hydrogen given off as ammonia and water ; these
elements, taken together, must be exactly equal in
weight to the carbon, nitrogen, and hydrogen of the
metamorphosed tissues, and since these last are ex-
actly replaced by the food, to the carbon, nitrogen,
and hydrogen of the food. Were this not the case,
the weight of the animal could not possibly remain
unchanged.

But, in the young of the carnivora, the weight
does not remain unchanged ; on the contrary, it in-
creases from day to day by an appreciable quantity.

This fact presupposes, that the assimilative pro-
cess in the young animal is more energetic, more
intense, than the process of transformation in the
existing tissues. Tf both processes were equally ac-
tive, the weight of the body could not increase ;
and were the waste by transformation greater, the
weight of the body would decrease.

Now, the circulation in the young animal is not
weaker, but, on the contrary, more rapid ; the res-
pirations are more frequent; and, for equal bulks, the
consumption of oxygen must be greater rather than
smaller in the young than in the adult animal.
But, since the metamorphosis of organised parts
goes on more slowly, there would ensue a deficiency
of those substances, the carbon and hydrogen of
which are adapted for combination with Oxygen ;
because, in the carnivora it is the new compounds,
F 2

DO BUTTER, SUGAR, STARCH, &c.

produced by the metamorphosis of organised parts,
which nature has destined to furnish the necessary
resistance to the action of the oxygen, and to pro-
duce animal heat. What is wanting for these pur-
poses an infinite wisdom has supplied to the young
animal in its natural food.

The carbon and hydrogen of butter, and the car-
bon of the sugar of milk, no part of either of which
can yield blood, fibrine, or albumen, are destined
for the support of the respiratory process, at an age
when a greater resistance is opposed to the meta-
morphosis of existing organisms ; or, in other words,
to the production of compounds, which in the adult
state are produced in quantity amply sufficient for
the purpose of respiration.

The young animal receives the constituents of its
blood in the caseine of the milk. A metamorphosis
of existing organs goes on, for bile and urine are
secreted ; the matter of the metamorphosed parts is
given off in the form of urine, of carbonic acid, and
of water ; but the butter and sugar of milk also
disappear ; they cannot be detected in the faeces.

The butter and sugar of milk are given out in the
form of carbonic acid and water, and their conver-
sion into oxidised products furnishes the clearest
proof that far more oxygen is absorbed than is re-
quired to convert the carbon and hydrogen of the
metamorphosed tissues into carbonic acid and water.

The change and metamorphosis of organised tis-
sues going on in the vital process in the young

CONSUMED IN RESPIRATION. 69

animal, consequently yield, in a given time, much
less carbon and hydrogen in the form adapted for
the respiratory process than corresponds to the
oxygen taken up in the lungs. The substance of
its organised parts would undergo a more rapid con-
sumption, and would necessarily yield to the action
of the oxygen, were not the deficiency of carbon
and hydrogen supplied from another source.

The continued increase of mass, or growth, and
the free and unimpeded developement of the organs
in the young animal, are dependent on the presence
of foreign substances, which, in the nutritive pro-
cess, have no other function than to protect the
newly-formed organs from the action of the oxygen;
It is the elements of these substances which unite
with the oxygen ; the organs themselves could not
do so without being consumed; that is, growth, or in-
crease of mass in the body, the consumption of oxy-
gen remaining the same, would be utterly impossible.

The preceding considerations leave no doubt as
to the purpose for which Nature has added to the
food of the young of carnivorous mammalia sub-
stances devoid of nitrogen, which their organism
cannot employ for nutrition, strictly so called, that
is, for the production of blood; substances which
may be entirely dispensed with in their nourishment
in the adult state. In the young of carnivorous
birds, the want of all motion is an obvious cause of
diminished waste in the organised parts ; hencer
milk is not provided for them.

70 PROPERTIES OF STARCH.

The nutritive process in the carnivora thus pre-
sents itself in two distinct forms ; one of which we
again meet with in the graminivora.

XIII. In the class of graminivorous animals, we
observe, that during their whole life, their existence
depends on the supply of substances having a com-
position identical with that of sugar of milk, or
closely resembling it. Every thing that they con-
sume as food contains a certain quantity of starch,
or gum,, or sugar, mixed with other matters.

The most abundant and widely-extended of the
substances of this class is amylon or starch ; it
occurs in roots, seeds, and stalks, and even in wood,
deposited in the form of roundish or oval globules,
which differ from each other in size alone, being
identical in chemical composition. (11) In the same
plant, in the pea, for example, we find starch, the
globules of which differ in size. Those in the
expressed juice of the stalks have a diameter of
from Tib to 1777 of an inch, while those in the seed
are three or four times larger. The globules in
arrow-root and in potato starch are distinguished
by their large size ; those of rice and of wheat are
remarkably small.

It is well known that starch may be converted
into sugar by very different means. This change
occurs in the process of germination, as in malting,
and it is easily accomplished by the action of acids.
The metamorphosis of starch into sugar depends

EASILY CONVERTED INTO SUGAR. 71

simply, as is proved by analysis, on the addition of the
elements of water. (12) All the carbon of the starch
is found in the sugar ; none of its elements have been
separated, and, except the elements of water, no
foreign element has been added to it in this trans-
formation.

In many, especially in pulpy fruits, which when
unripe are sour and rough to the taste, but when
ripe are sweet, as, for example, in apples and pears,
the sugar is produced from the starch which the un-
ripe fruit contains.

If we rub unripe apples or pears on a grater to a
pulp, and wash this with cold water on a fine sieve,
the turbid liquid which passes through deposits a
very fine flour of starch, of which not even a trace
can be detected in the ripe fruit. Many varieties
become sweet while yet on the tree ; these are the
summer or early apples and pears. Others, again,
become sweet only after having been kept for a cer-
tain period after gathering. The after-ripening, as
this change is called, is a purely chemical process,
entirely independent of the vitality of the plant.
When vegetation ceases, the fruit is capable of re-
producing the species, that is, the kernel, stone, or
true seed is fully ripe, but the fleshy covering from
this period is subjected to the action of the atmo-
sphere. Like all substances in a state of erema-
causis, or decay, it absorbs oxygen, and gives off a
certain quantity of carbonic acid gas.

In the same way as the starch in putrefying paste,

72 SUGAR OF MILK, GUM, &c.

in which it is in contact with decaying gluten, is con-
verted into sugar, the starch in the above-named
fruits, in a state of decay, or eremacausis, is trans-
formed into grape sugar. The more starch the un-
ripe fruit contains, the sweeter does it become when
ripe.

A close connection thus exists between sugar and
starch. By means of a variety of chemical actions,
which exert no other influence on the elements of
starch than that of changing the direction of their
mutual attraction, we can convert starch into sugar,
but it is always grape sugar.

Sugar of milk in many respects resembles
starch ; (13) it is, by itself, incapable of the vinous
fermentation, but it acquires the property of resolv-
ing itself into alcohol and carbonic acid when it is
exposed to heat in contact wTith a substance in the
state of fermentation (such as putrefying cheese
in milk). In this case, it is first converted into
grape sugar; and it undergoes the same transfor-
mation, when it is kept in contact with acids —
with sulphuric acid, for example — at the ordinary
temperature.

Gum has the same composition in 100 parts as
cane sugar. (14) It is distinguished from the different
varieties of sugar by its not possessing the property
of being resolved into alcohol and carbonic acid by
the process of putrefaction. When placed in con-
tact with fermenting s'ubstances, it undergoes no
appreciable change, whence we may conclude, with

COMPARED WITH STARCH. 73

some degree of probability, that its elements, in
the peculiar arrangement according to which they
are united, are held together with a stronger force
than the elements of the different kinds of sugar.

There is, however, a certain relation between
gum and sugar of milk, since both of them, when
treated with nitric acid, yield the same oxidised pro-
duct, namely, mucic acid, which cannot, under the
same circumstances, be formed from any of the other
kinds of sugar.

In order to shew more distinctly the similarity of
composition in these different substances, which per-
form so important a. part in the nutritive process of
the graminivora, let us represent one equivalent of
carbon by C (= 75'8), and one equivalent of water
by aqua (= 112'4), we shall then have for the com-
position of these substances the following expres-
sions : —

Starch = 12 C + 10 aqua.

Cane Sugar... = 12 C + 10 aqua+1 aqua.

Gum = 12 C+10 aqua+1 aqua.

Sugar of milk = 12 C + 10 aqua + 2 aqua.
Grape Sugar = 12 C + 10 aqua + 4 aqua.

For the same number of equivalents of carbon,
starch contains 10 equivalents, cane-sugar and gum
11 equivalents, sugar of milk 12 equivalents, and
grape-sugar 14 equivalents, of water, or the ele-
ments of water.

74 GRAMINIVORA REQUIRE

XIV. In these different substances, some one of
which is never wanting in the food of the gramni-
vora, there is added to the nitrogenised constituents
of this food, to the vegetable albumen, fibrine, and
caseine, from which their blood is formed, strictly
speaking, only a certain excess of carbon, which the
animal organism cannot possibly employ to produce
fibrine or albumen, because the nitrogenised consti-
tuents of the food already contain the carbon neces-
sary for the production of blood, and because the
blood in the body of the carnivora is formed without
the aid of this excess of carbon.

The function performed in the vital process of
the graminivora by these substances (sugar, gum,
&c.) is indicated in a very clear and convincing
manner, when we take into consideration the very
small relative amount of the carbon which these
animals consume in the nitrogenised constituents of
their food, which bears no proportion whatever to
the oxygen absorbed through the skin and lungs.

A horse, for example, can be kept in perfectly
good condition, if he obtain as food 15 Ibs. of hay
and 4J Ibs. of oats, daily. If we now calculate the
whole amount of nitrogen in these matters, as ascer-
tained by analysis (1-5 per cent, in the hay, 2'2 per
cent, in the oats), (15) in the form of blood, that is, as
fibrine and albumen, with the due proportion of water
in blood (80 per cent.), the horse receives daily no
more than 4^ oz. of nitrogen, corresponding to about
8 Ibs. of blood. But along with this nitrogen, that is,

MUCH CARBON. 75

combined with it in the form of fibrine or albumen,
the animal receives only about 14J oz. of carbon.
Only about 8 oz. of this can be employed to support
respiration, for with the nitrogen expelled in the
urine there are combined, in the form of urea, 3 oz.,
and in the form of hippuric acid, 3J oz., of carbon.

Without going further into the calculation, it will
readily be admitted, that the volume of air inspired
and expired by a horse, the quantity of oxygen con-
sumed, and, as a necessary consequence, the amount
of carbonic acid given out by the animal, is much
greater than in the respiratory process in man. But
an adult man consumes daily about 14 oz. of carbon,
and the determination of Boussingault, according to
which a horse expires 79 oz. daily, cannot be very
far from the truth.

In the nitrogenised constituents of his food, there-
fore, the horse receives rather less than the fifth part
of the carbon which his organism requires for the
support of the respiratory process ; and we see that
the wisdom of the Creator has added to his food
the £ths which are wanting, in various forms, as,
starch, sugar, &c. with which the animal must be
supplied, or his organism will be destroyed by the
action of the oxygen.

It is obvious, that in the system of the gramini-
vora, whose food contains so small a proportion, re-
latively, of the constituents of blood, the process of
metamorphosis in existing tissues, and consequently
their restoration or reproduction, must go on far less

76 WASTE OF ORGANISED TISSUES

rapidly than in the carnivora. Were this not the
case, a vegetation a thousand times more luxuriant
than the actual one would not suffice for their
nourishment. Sugar, gum, and starch, would no
longer be necessary to support life in these animals,
because, in that case, the products of the waste, or
metamorphosis of the organised tissues, would con-
tain enough of carbon to support the respiratory
process.

Man, when confined to animal food, requires for
his support and nourishment extensive sources of
food, even more widely extended than the lion and
tiger, because, when he has the opportunity, he kills
without eating.

A nation of hunters, on a limited space, is utterly
incapable of increasing its numbers beyond a certain
point, which is soon attained. The carbon neces-
sary for respiration must be obtained from the ani-
mals, of which only a limited number can live -on
the space supposed. These animals collect from
plants the constituents of their organs and of their
blood, and yield them, in turn, to the savages who
live by the chase alone. They, again, receive this
food unaccompanied by those compounds, destitute
of nitrogen, which, during the life of the animals,
served to support the respiratory process. In such
men, confined to an animal diet, it is the carbon of
the flesh and of the blood which must take the place
of starch and sugar.

But 15 Ibs. of flesh contain not more carbon than

VERY RAPID IN CARNIVORA. 77

41bs. of starch, (16) and while the savage with one ani-
mal and an equal weight of starch could maintain life
and health for a certain number of days, he would
be compelled, if confined to flesh, in order to pro-
cure the carbon necessary for respiration, during the
same time, to consume five such animals.

It is easy to see, from these considerations, how
close the connection is between agriculture and the
multiplication of the human species. The cultivation
of our crops has ultimately no other object than the
production of a maximum of those substances which
are adapted for assimilation and respiration, in the
smallest possible space. Grain and other nutritious
vegetables yield us, not only in starch, sugar, and
gum, the carbon which protects our organs from the
action of oxygen, and produces in the organism the
heat which is essential to life, but also in the form
of vegetable fibrine, albumen, and caseine, our
blood, from which the other parts of our body are
developed.

Man, when confined to animal food, respires, like
the carnivora, at the expense of the matters pro-
duced by the metamorphosis of organised tissues ;
and, just as the lion, tiger, hyaena, in the cages of a
menagerie, are compelled to accelerate the waste of
the organised tissues by incessant motion, in order to
furnish the matter necessary for respiration, so, the
savage, for the very same object, is forced to make
the most laborious exertions, and go through a vast
amount of muscular exercise. He is compelled to

78 PHOSPHATES ABOUND IN

consume force merely in order to supply matter for
respiration.

Cultivation is the economy of force. Science
teaches us the simplest means of obtaining the
greatest effect with the smallest expenditure of
power, and with given means to produce a maxi-
mum of force. The unprofitable exertion of power,
the waste of force in agriculture, in other branches
of industry, in science, or in social economy, is
characteristic of the savage state, or of the want of
cultivation.

XV. A comparison of the urine of the carnivora
with that of the graminivora shews very clearly, that
the process of metamorphosis in the tissues is differ-
ent, both in form and in rapidity, in the two classes
of animals.

The urine of carnivorous animals is acid, and
contains alkaline bases united with uric, phosphoric,
and sulphuric acids. We know perfectly the source
of the two latter acids. All the tissues, with the
exception of cellular tissue and membrane, contain
phosphoric acid and sulphur, which latter element
is converted into sulphuric acid by the oxygen of
the arterial blood. In the various fluids of the
body there are only traces of phosphates or sul-
phates, except in the urine, where both are found
in abundance. It is plain that they are derived
from the metamorphosed tissues ; they enter into
the venous blood in the form of soluble salts, and

THE URINE OF CARNIVORA. 79

are separated from it in its passage through the
kidneys.

The urine of the graminivora is alkaline ; it con-
tains alkaline carbonates in abundance, and so small
a portion of alkaline phosphates as to have been
overlooked by most observers.

The deficiency or absence of alkaline phosphates
in the urine of the graminivora, obviously indicates
the slowness with which the tissues in this class of
animals are metamorphosed ; for if we assume that
a horse consumes a quantity of vegetable fibrine
and albumen corresponding to the amount of nitro-
gen in his daily food (about 4J oz.), and that the
quantity of tissue metamorphosed is equal to that
newly formed, then the quantity of phosphoric acid
which on these suppositions would exist in the urine
is not so small as not to be easily detected by
analysis in the daily secretion of urine(31bs. accord-
ing to Boussingault) ; for it would amount to 0*8 per
cent* But, as above stated* most observers have
been unable to detect phosphoric acid in the urine
of the horse.

Hence it is obvious, that the phosphoric acid,
which in consequence of the metamorphosis of
tissues is produced in the form of soluble alkaline
phosphates, must re-enter the circulation in this class
of animals. It is there employed in forming brain
and nervous matter, to which it is essential, and also,
no doubt, in contributing to the supply of the earthy
part of the bones. It is probable, however, that

80 ASSIMILATION IN CAKNIVORA.

the greater part of the earth of bones is obtained by
the direct assimilation of phosphate of lime, while
the soluble phosphates are better adapted for the
production of nervous matter.

In the graminivora, therefore, whose food con-
tains so small a proportion of phosphorus or of
phosphates, the organism collects all the soluble
phosphates produced by the metamorphosis of tis-
sues, and employs them for the developement of the
bones and of the phosphorised constituents of the
brain ; the organs of excretion do not separate these
salts from the blood. The phosphoric acid which,
by the change of matter, is separated in the uncom-
bined state, is not expelled from the body as phos-
phate of soda ; but we find it in the solid excre-
ments in the form of insoluble earthy phosphates.

XVI. If we now compare the capacity for in-
crease of mass, the assimilative power in the grami-
nivora and carnivora, the commonest observations
indicate a very marked difference.

A spider, which sucks with extreme voracity the
blood of the first fly, is not disturbed or excited by
a second or third. A cat will eat the first, and per-
haps the second mouse presented to her, but even
if she kills a third, she does not devour it. Exactly
similar observations have been made in regard to
lions and tigers, which only devour their prey when
urged by hunger. Carnivorous animals, indeed, re-
quire less food for their mere support, because their

LESS ENERGETIC THAN IN HERBIVORA. 81

skin is destitute of perspiratory pores, and because
they consequently lose, for equal bulks, much less
heat than graminivorous animals, which are com-
pelled to restore the lost heat by means of food
adapted for respiration.

How different is the energy and intensity of
vegetative life in the graminivora. A cow, or a
sheep, in the meadow, eats, almost without interrup-
tion, as long as the sun is above the horizon. Their
system possesses the power of converting into or-
ganised tissues all the food they devour beyond the
quantity required for merely supplying the waste of
their bodies.

All the excess of blood produced is converted
into cellular and muscular tissue ; the graminivorous
animal becomes fleshy and plump, while the flesh
of the carnivorous animal is always tough and
sinewy.

If we consider the case of a stag, a roe-deer,
or a hare, animals which consume the same food as
cattle and sheep, it is evident that, when well sup-
plied with food, their growth in size, their fattening,
must depend on the quantity of vegetable albumen,
fibrine, or caseine, which they consume. With free
and unimpeded motion and exercise, enough of
oxygen is absorbed to consume the carbon of the
gum, sugar, starch, and of all similar soluble consti-
tuents of their food.

But all this is very differently arranged in our
domestic animals, when, with an abundant supply

G

82 ORIGIN OF FAT IN

of food, we check the processes of cooling and ex-
halation, as we do when we feed them in stables,
where free motion is impossible.

The stall-fed animal eats, and reposes merely for
digestion. It devours in the shape of nitrogenised
compounds far more food than is required for repro-
duction, or the supply of waste alone ; and at the
same time it eats far more of substances devoid of
nitrogen than is necessary merely to support res-
piration and to keep up animal heat. Want of
exercise and diminished cooling are equivalent to a
deficient supply of oxygen ; for when these circum-
stances occur, the animal absorbs much less oxygen
than is required to con vert .into carbonic acid the
carbon of the substances destined for respiration.
Only a small part of the excess of carbon thus occa-
sioned is expelled from the body in the horse and
ox, in the form of hippuric acid ; and all the remain-
der is employed in the production of a substance
which, in the normal state, only occurs in small
quantity as a constituent of the nerves and brain.
This substance is fat.

In the normal condition, as to exercise and labour,
the urine of the horse and ox contains benzoic acid
(with 14 equivalents of carbon); but as soon as the
animal is kept quiet in the stable, the urine contains
hippuric acid (with 18 equivalents of carbon).

The flesh of wild animals is devoid of fat ; while
that of stall-fed animals is covered with that sub-
stance. When the fattened animal is allowed to

DOMESTICATED ANIMALS. 83

move more freely in the air, or compelled to draw
heavy burdens, the fat again disappears.

It is evident, therefore, that the formation of fat
in the animal body is the result of a want of due
proportion between the food taken into the stomach
and the oxygen absorbed by the lungs and the skin.

A pig, when fed with highly nitrogenised food,
becomes full of flesh ; when fed with potatoes
(starch) it acquires little flesh, but a thick layer of
fat. The milk of a cow, when stall-fed, is very rich
in butter, but in the meadow is found to contain
more caseine, and in the same proportion less butter
and sugar of milk. In the human female, beer and
farinaceous diet increase the proportion of butter
in the milk ; an animal diet yields less milk, but it
is richer in caseine.

If we reflect, that in the entire class of carnivora,
the food of which contains no substance devoid of
nitrogen except fat, the production of fat in the body
is utterly insignificant ; that even in these animals,
as in dogs and cats, it increases as soon as they live
on a mixed diet; and that we can increase the forma-
tion of fat in other domestic animals at pleasure, but
only by means of food containing no nitrogen ; we
can hardly entertain a doubt that such food, in its
various forms of starch, sugar, &c., is closely con-
nected with the production of fat.

In the natural course of scientific research, we
draw conclusions from the food in regard to the
tissues or substances formed from it ; from the ni-

84 ORIGIN OF FAT IN

trogenised constituents of plants we draw certain
inferences as to the nitrogenised constituents of the
blood ; and it is quite in accordance with this, the
natural method, that we should seek to establish the
relations of those parts of our food which are devoid
of nitrogen and those parts of the body which con-
tain none of that element. It is impossible to over-
look the very intimate connection between them.

If we compare the composition of sugar of milk,
of starch, and of the other varieties of sugar, with
that of mutton and beef suet and of human fat, we
find that in all of them the proportion of carbon to
hydrogen is the same, and that they only differ in
that of oxygen.

According to the analyses of Chevreul, mutton
fat, human fat, and hog's lard contain 79 per cent,
of carbon to 11*1, 11 '4, and 11 -7 per cent, of hy-
drogen respectively. (16)

Starch contains 44*91 carbon to 6'11 hydrogen
Gum and sugar 42-58 to 6'37 ditto. (17)

It is obvious that these numbers, representing
the relative proportions of carbon and hydrogen in
starch, gum, and sugar, are in the same ratio as the
carbon and hydrogen in the different kinds of fat ; for

44-91 : 6-11 = 79 : 10'99
42-58 : 6-37 = 79 : 11-80

From which it follows, that sugar, starch, and gum,
by the mere separation of a part of their oxygen,
may pass into fat, or at least into a substance having
exactly the composition of fat. If from the formula

DOMESTICATED ANIMALS. 85

of starch, C12H10010, we take 9 equivalents of oxy-
gen, there will remain in 100 parts —

CI3 79-4

H10 10-8

O 9-8

The empirical formula of fat which comes nearest
to this is CHH100, which gives in 100 parts —

Cu 78-9

H10 11-6

O 9.5

According to this formula, an equivalent of
starch, in order to be changed into fat, would lose 1
equivalent of carbonic acid, C02, and 7 equivalents
of oxygen.

Now the composition of all saponifiable fatty
bodies agrees very closely with one or other of
these two formulae.

If from 3 equivalents of sugar of milk, 3C12H12012
= CggHggOgg , we take awRy foui equivalents of wa-
ter and 31 of oxygen, there will remain C36H220, a
formula which accurately represents the composition
of cholesterine, the fat of bile. (18)

Whatever views we may entertain regarding the
origin of the fatty constituents of the body, this
much at least is undeniable, that the herbs and roots
consumed by the cow contain no butter; that in
hay or the other fodder of oxen no beef suet exists ;
that no hog's lard can be found in the potato refuse
given to swine ; and that the food of geese or fowls
contains no goose fat or capon fat. The masses of

86 THE FORMATION OF FAT

fat found in the bodies of these animals are formed
in their organism ; and when the full value of this
fact is recognized, it entitles us to conclude that a
certain quantity of oxygen, in some form or other,
separates from the constituents of their food ; for
without such a separation of oxygen, no fat could
possibly be formed from any one of these sub-
stances.

The chemical analysis of the constituents of the
food of the graminivora shews in the clearest man-
ner that they contain carbon and oxygen in certain
proportions ; which, when reduced to equivalents,
yield the following series : —

In vegetable fibrine, albumen, and caseine, there are con-
tained, for 120 eq. carbon, 36 eq. oxygen

In starch 120 100

Incanesugar 120 110

In gum 120 110

In sugar of milk 120 120

In grape sugar 120 140

Now in aU fatty bodies there are contained, on an
average —

for 120 eq.carb. only 10 eq. oxygen.

Since the carbon of the fatty constituents of the
animal body is derived from the food, seeing that
there is no other source whence it can be derived,
it is obvious, if we suppose fat to be formed from
albumen, fibrine, or caseine, that, for every 120 equi-
valents of carbon deposited as fat, 26 equivalents of
oxygen must be separated from the elements of these
substances ; and further, if we conceive fat to be

IS A SOURCE OF OXYGEN. 87

formed from starch, sugar, or sugar of milk, that for
the same amount of carbon there must be separated
90, 100, and 110 equivalents of oxygen from these
compounds respectively.

There is, therefore, but one way in which the
formation of fat in the animal body is possible, and
this is absolutely the same in which its formation in
plants takes place ; it is a separation of oxygen from
the elements of the food.

The carbon which we find deposited in the seeds
and fruits of vegetables, in the form of oil and fat,
was previously a constituent of the atmosphere, and
was absorbed by the plant as carbonic acid. Its
conversion into fat was accomplished under the in-
fluence of light, by the vital force of the vegetable ;
and the greater part of the oxygen of this carbonic
acid was returned to the atmosphere as oxygen
gas.*

In contradistinction to this phenomenon of vitality
in plants, we know that the animal system absorbs
oxygen from the atmosphere, and that this oxygen
is again given out in combination with carbon or
hydrogen ; we know, that in the formation of car-
bonic acid and water, the heat necessary to sustain
the constant temperature of the body is produced,
and that a process of oxidation is the only source of
animal heat.

Whether fat be formed by the decomposition of

* See Appendix, No. 19, on the formation of wax and honey
by the bee.

88 FAT IS FORMED WHEN THE

fibrine and albumen, the chief constituents of blood,
or by that of starch, sugar, or gum, this decomposi-
tion must be accompanied by the separation of oxy-
gen from the elements of these compounds. But
this oxygen is not given out in the free state, be-
cause it meets in the organism with substances
possessing the property of entering into combination
with it. In fact, it is given out in the same forms
as that which is absorbed from the atmosphere by
the skin and lungs.

It is easy to see, from the above considerations,
that a very remarkable connection exists between
the formation of fat and the respiratory process.

XVIII. The abnormal condition, which causes
the deposit of fat in the animal body, depends, as
was formerly stated, on a disproportion between the
quantity of carbon in the food and that of oxygen
absorbed by the skin and lungs. In the normal
condition, the quantity of carbon given out is ex-
actly equal to that which is taken in the food, and
the body acquires no increase of weight from the
accumulation of substances containing much carbon
and no nitrogen.

If we increase the supply of highly carbonised
food, then the normal state can only be preserved
on the condition that, by exercise and labour, the
waste of the body is increased, and the supply of
oxygen augmented in the same proportion.

The production of fat is always a consequence of

OXYGEN IS DEFICIENT. 89

a deficient supply of oxygen, for oxygen is abso-
lutely indispensable for the dissipation of the excess
of carbon in the food. This excess of carbon, de-
posited in the form of fat, is never seen in the
Bedouin or in the Arab of the desert, who exhibits
with pride to the traveller his lean, muscular, sinewy
limbs, altogether free from fat ; but in prisons and
jails it appears as a puffiness in the inmates, fed, as
they are, on a poor and scanty diet ; it appears in
the sedentary females of oriental countries ; and
finally, it is produced under the well-known condi-
tions of the fattening of domestic animals.

The formation of fat depends on a deficiency of
oxygen ; but in this process, in the formation of fat
itself, there is opened up a new source of oxygen, a
new cause of animal heat.

The oxygen set free in the formation of fat is
given out in combination with carbon or hydrogen ;
and whether this carbon and hydrogen proceed from
the substance that yields the oxygen, or from other
compounds, still there must have been generated by
this formation of carbonic acid or water as much
heat as if an equal weight of carbon or hydrogen
had been burned in air or in oxygen gas.

If we suppose that from 2 equivalents of starch
18 equivalents of oxygen are disengaged, and that
these 18 equivalents of oxygen combine with 9
equivalents of carbon, from the bile, for example,
no one can doubt that, in this case, exactly as much
heat must be developed, as if these 9 equivalents of

90 THE FORMATION OF FAT IS

carbon had been directly burned. In this form,
therefore, the disengagement of heat as a conse-
quence of the formation of fat would be undeni-
able ; and it could only be considered hypothetical,
on the supposition that carbon and oxygen were
disengaged from one and the same substance, in the
proportions to yield carbonic acid.

If, for example, we suppose that from 2 atoms
of starch, C24H20020, the elements of 9 equivalents
of carbonic acid are separated, there will remain a
compound containing, for 15 equivalents of carbon,
20 of hydrogen and 2 of oxygen ; for

Or, if we assume that oxygen is separated from
starch in the form both of carbonic acid and water,
then, after subtracting the elements of 6 equivalents
of water and 6 of carbonic acid, there would remain
the compound C18H1402 ; for

CAD* = C6012 + H606 + C18H1402.

Assuming, then, the separation of oxygen in either
of these forms, it remains to be decided whether the
carbonic acid and water given off were contained, as
such, in the starch, or not.

If they were ready formed in the starch, the
separation might occur without the disengagement
of heat ; but if the carbon and hydrogen were pre-
sent in any other form in the starch (or in the com-
pound from which the fat was produced), it is obvious
that a change in the arrangement of the atoms must
have occurred, in consequence of which the atoms

A SOURCE OF ANIMAL HEAT. 91

of the carbon and of the hydrogen have united with
those of the oxygen, to form carbonic acid and water.

Now, so far as chemical researches have gone,
our knowledge of the constitution of starch, and of
the varieties of sugar, will justify no other conclu-
sion than this, that these substances contain no ready
formed carbonic acid.

We are acquainted with a large number of pro-
cesses of metamorphosis of a similar kind, in which
the elements of carbonic acid and water are sepa-
rated from certain pre-existing compounds ; and we
know with certainty that all these processes are
accompanied by a disengagement of heat, exactly
as if the carbon and hydrogen combined directly
with oxygen.

Such a disengagement of carbonic acid, for ex-
ample, occurs in all processes of fermentation or
putrefaction, which are, without exception, accom-
panied with the generation of heat.

In the fermentation of a saccharine solution, in
consequence of a new arrangement of the elements
of the sugar, a certain part of its carbon and oxygen
unite to form carbonic acid, which separates as gas ;
and as another result of this decomposition, we ob-
tain a volatile combustible liquid, containing little
oxygen, namely, alcohol.

If we add to 2 equivalents of sugar the elements of
12 equivalents of water, and subtract from the sum
of the atoms 24 equivalents of oxygen, there re-
main 6 equivalents of alcohol.

92 THE FORMATION OF FAT IS

* + HuA,) — 024 = C^H^Ou = 6 eq. alcohol.

These 24 equivalents of oxygen suffice to oxidise
completely a third equivalent of sugar — that is, to
convert its carbon into carbonic acid and its hydro-
gen into water, and by this oxidation we recover the
12 equivalents of water supposed to be added in the
former part of the process, exactly as if this water
had taken no share in it.

C12H12012 + O^ = 12C02 + 12HO.

According to the ordinary view, 12 equivalents of
carbonic acid separate from 3 of sugar, yielding 6
of alcohol — that is, exactly the same amount of these
products as if two-thirds of the sugar had yielded
oxygen to the remaining third, so as completely to
oxidise its elements.

CHH.A, = C^Ou, + 12C02.*

By a comparison of these two methods of repre-
senting the same change, it will easily be seen that
the division or splitting of a compound like sugar
into carbonic acid, on the one hand, and a compound
containing little oxygen, on the other, is in its results
perfectly equivalent to a separation of oxygen from
a certain portion of the compound and the oxidation
or combustion of another portion of it at the ex-
pense of this oxygen.

It is well known that the temperature of a fer-
menting liquid rises ; and if we assume that a hogs-
head of wort, holding 1,200 litres = 2,400 Ibs.,

* For an explanation of the formulae and equations employed,
see the Introduction to the Appendix.

A SOURCE OF ANIMAL HEAT. 93

French weight, contains 16 per cent, of sugar, in all
384 Ibs., then, during the fermentation of this sugar,
an amount of heat must be generated equal to that
which would be produced by the combustion of
51 Ibs. of carbon.

This is equal to a quantity of heat by which
every pound of the liquid might be heated by
297'9°; that is, supposing the decomposition of
the sugar to occur in a period of time too short
to be measured. This is well known not to be
the case; the fermentation lasts five or six days,
and each pound of liquid receives the 297*9 de-
grees of heat during a period of 120 hours. In
each hour there is, therefore, set free an amount
of heat capable of raising the temperature of each
pound of liquid 1'4 degree ; a rise of tempera-
ture which is very powerfully counteracted by ex-
ternal cooling and by the vaporization of alcohol
and water.

The formation of fat, like other analogous phe-
nomena in which oxygen is separated in the form
of carbonic acid, is consequently accompanied by a
disengagement of heat. This change supplies to
the animal body a certain proportion of the oxygen
indispensable to the vital processes ; and this espe-
cially in those cases in which the oxygen absorbed
by the skin and lungs is not sufficient to convert
into carbonic acid the whole of the carbon adapted
for this combination.

*

94 FORMATION OF FAT.

This excess of carbon, as it cannot be employed to
form a part of any organ, is deposited in the cellular
tissue in the form of tallow or oil.

At every period of animal life, when there occurs
a disproportion between the carbon of the food and
the inspired oxygen, the latter being deficient, fat
must be formed. Oxygen separates from existing
compounds, and this oxygen is given out as carbonic
acid or water. The heat generated in the formation
of these two products contributes to keep up the
temperature of the body.

Every pound of carbon which obtains the oxy-
gen necessary to convert it into carbonic acid from
substances which thereby pass into fat, must dis-
engage as much heat as would raise the tempera-
ture of 200 Ibs. of water by 70°, — that is, from 32°
to 102°.

Thus, in the formation of fat, the vital force pos-
sesses a means of counteracting a deficiency in the
supply of oxygen, and consequently in that of the
heat indispensable for the vital process.

Experience teaches us that in poultry, the maxi-
mum of fat is obtained by tying the feet, and by a
medium temperature. These animals in such cir-
cumstances may be compared to a plant possessing
in the highest degree the power of converting all
food into parts of its own structure. The excess of
the constituents of blood forms flesh and other
organised tissues, while that of starch, sugar, &c.,

CONSTITUENTS OF FOOD. 95

is converted into fat. When animals are fattened
on food destitute of nitrogen, only certain parts of
their structure increase in size. Thus, in a goose,
fattened in the method above alluded to, the liver
becomes three or four times larger than in the same
animal, when well fed with free motion, while we
cannot say that the organised structure of the liver
is thereby increased. The liver of a goose fed in the
ordinary way is firm and elastic ; that of the im-
prisoned animal is soft and spongy. The difference
consists in a greater or less expansion of its cells,
which are filled with fat.

In some diseases, the starch, sugar, &c., of the
food obviously do not undergo the changes which
enable them to assist in respiration, and consequently
to be converted into fat. Thus, in diabetes mellitus,
the starch is only converted into grape sugar, which
is expelled from the body without further change.

In other diseases, as for example in inflammation
of the liver, we find the blood loaded with fat and
oil ; and in the composition of the bile there is
nothing at all inconsistent with the supposition that
some of its constituents may be transformed into fat.

XIX. According to what has been laid down in
the preceding pages, the substances of which the
food of man is composed may be divided into two
classes ; into nitrogenised and non-nitrogenised. The
former are capable of conversion into blood ; the
latter incapable of this transformation.

96 NITROGENISED AND NON-NITROGENISED

Out of those substances which are adapted to the
formation of blood are formed all the organised
tissues. The other class of substances, in the normal
state of health, serve to support the process of res-
piration. The former may be called the plastic ele-
ments of nutrition; the latter, elements of respiration.

Among the former we reckon —

Vegetable fibrine.
Vegetable albumen.
Vegetable caseine.
Animal flesh.
Animal blood.

Among the elements of respiration in our food,
are —

Fat. Pectine.

Starch. Bassorine.

Gum. Wine.

Cane Sugar. Beer.

Grape Sugar. Spirits.
Sugar of milk.

XX. The most recent and exact researches have
established as a universal fact, to which nothing yet
known is opposed, that the nitrogenised constituents
of vegetable food have a composition identical with
that of the constituents of the blood.

No nitrogenised compound, the composition of
which differs from that of fibrine, albumen, and
caseine, is capable of supporting the vital process in
animals.

The animal organism unquestionably possesses the

ELEMENTS OF FOOD. 97

power of forming, from the constituents of its blood,
the substance of its membranes and cellular tissue,
of the nerves and brain, of the organic part of carti-
lages and bones. But the blood must be supplied
to it ready formed in every thing but its form — that
is, in its chemical composition. If this be not done,
a period is rapidly put to the formation of blood,
and consequently to life.

This consideration enables us easily to explain
how it happens that the tissues yielding gelatine or
chondrine, as, for example, the gelatine of skin or of
bones, are not adapted for the support of the vital
process ; for their composition is different from that
of fibrine or albumen. It is obvious that this means
nothing more than that those parts of the animal
organism which form the blood do not possess the
power of effecting a transformation in the arrange-
ment of the elements of gelatine, or of those tissues
which contain it. The gelatinous tissues, the gela-
tine of the bones, the membranes, the cells, and the
skin, suffer, in the animal body, under the influence
of oxygen and moisture, a progressive alteration ; a
part of these tissues is separated, and must be re-
stored from the blood ; but this alteration and re-
storation is obviously confined within very narrow
limits.

While, in the body of a starving or sick individual,
the fat disappears, and the muscular tissue takes
once more the form of blood, we find that the ten-
dons and membranes retain their natural condition ;
H *

98 GELATINE MAY SERVE TO

the limbs of the dead body retain their connections,
which depend on the gelatinous tissues.

On the other hand, we see that the gelatine of
bones devoured by a dog entirely disappears, \vhile
only the bone earth is found in his excrements.
The same is true of man, when fed on food rich
in gelatine, as, for example, strong soup. The gela-
tine is not to be found either in the urine or in the
faeces, and consequently must have undergone a
change, and must have served some purpose in the
animal economy. It is clear, that the gelatine must
be expelled from the body in a form different from
that in which it was introduced as food.

When we consider the transformation of the
albumen of the blood into a part of an organ com-
posed of fibrine, the identity in composition of the
two substances renders the change easily conceivable.
Indeed we find the change of a dissolved substance
into an insoluble organ of vitality, chemically speak-
ing, natural and easily explained, on account of this
very identity of composition. Hence the opinion is
not unworthy of a closer investigation, that gela-
tine, when taken in the dissolved state, is again con-
verted, in the body, into cellular tissue, membrane
and cartilage ; that it may serve for the reproduction
of such parts of these tissues as have been wasted,
and for their growth.

And when the powers of nutrition in the whole
body are affected by a change of the health, then,
even should the power of forming blood remain the

NOURISH THE GELATINOUS TISSUES. 99

same, the organic force by which the constituents
of the blood are transformed into cellular tissue and
membranes must necessarily be enfeebled by sick-
ness. In the sick man, the intensity of the vital
force, its power to produce metamorphoses, must be
diminished as well in the stomach as in all other
parts of the body. In this condition, the uniform
experience of practical physicians shews that gela-
tinous matters in a dissolved state exercise a most
decided influence on the state of the health. Given
in a form adapted for assimilation, they serve to
husband the vital force, just as may be done, in the
case of the stomach, by due preparation of the food
in general. Brittleness in the bones of graminivo-
rous animals is clearly owing to a weakness in those
parts of the organism whose function it is to convert
the constituents of the blood into cellular tissue
and membrane ; and if we can trust to the reports
of physicians who have resided in the East, the
Turkish women, in their diet of rice, and in the
frequent use of enemata of strong soup, have united
the conditions necessary for the formation both of
cellular tissue and of fat.

H 2

PART II.

THE

METAMORPHOSIS OF TISSUES,

THE

METAMORPHOSIS OF TISSUES.

1, THE absolute identity of composition in the
chief constituents of blood and the nitrogenised
compounds in vegetable food would, some years ago,
have furnished a plausible reason for denying the
accuracy of the chemical analyses leading to such a
result. At that period, experiment had not as yet
demonstrated the existence of numerous compounds,
both containing nitrogen and devoid of that element,
which, with the greatest diversity in external charac-
ters, yet possess the very same composition in 100
parts ; nay, many of which even contain the same
absolute amount of equivalents of each element.
Such examples are now very frequent, and are
known by the names of isomeric and polymeric
compounds.

2. Cyanuric acid, for example, is a nitrogenised
compound which crystallizes in beautiful transparent
octahedrons, easily soluble in water and in acids,
and very permanent. Cyamelide is a second bodyr
absolutely insoluble in water and acids, white
and opaque like porcelain or magnesia. Hydrated
cyanic acid is a third compound, which is a liquid,
more volatile than pure acetic acid, which blisters

104 ISOMERIC BODIES.

the skin, and cannot be brought in contact with
water without being instantaneously resolved into
new products. These three substances not only
yield, on analysis, absolutely the same relative
weights of the same elements, but they may be
converted and reconverted into one another, even
in hermetically closed vessels — that is, without the
aid of any foreign matter. (See Appendix, 21.)
Again, among those substances which contain no
nitrogen, we have aldehyde, a combustible liquid
miscible with water, which boils at the temperature
of the hand, attracts oxygen from the atmosphere
with avidity, and is thereby changed into acetic acid.
This compound cannot be preserved, even in close
vessels ; for after some hours or days, its consistence,
its volatility, and its power of absorbing oxygen, all
are changed. It deposits long, hard, needle-shaped
crystals, which at 212° are not volatilized, and the
supernatant liquid is no longer aldehyde. It now
boils at 140°, cannot be mixed with water, and when
cooled to a moderate degree crystallizes in a form
like ice. Nevertheless, analysis has proved, that
these three bodies, so different in their characters,
are identical in composition. (21)

3. A similar group of three occurs in the case of
albumen, fibrine, and caseine. They differ in exter-
nal character, but contain exactly the same propor-
tions of organic elements.

When animal albumen, fibrine, and caseine are
dissolved in a moderately strong solution of caustic

DISCOVERY OF PROTEINE. 105

potash, and the solution is exposed for some time
to a high temperature, these substances are decom-
posed. The addition of acetic acid to the solution
causes, in all three, the separation of a gelatinous
translucent precipitate, which has exactly the same
characters and composition, from whichever of the
three substances above mentioned it has been ob-
tained.

MULDER, to whom we owe the discovery of this
compound, found, by exact and careful analysis, that
it contains the same organic elements, and exactly
in the same proportion, as the animal matters from
which it is prepared ; insomuch, that if we deduct
from the analysis of albumen, fibrine, and caseine,
the ashes they yield, when incinerated, as well as
the sulphur and phosphorus they contain, and then
calculate the remainder for 100 parts, we obtain
the same result as in the analysis of the precipitate
above described, prepared by potash, which is free
from inorganic matter. (22)

Viewed in this light, the chief constituents of the
blood and the caseine of milk may be regarded as
compounds of phosphates and other salts, and of
sulphur and phosphorus, with a compound of carbon,
nitrogen, hydrogen, and oxygen, in which the rela-
tive proportion of these elements is invariable ; and
this compound may be considered as the com-
mencement and starting-point of all other animal
tissues, because these are all produced from the
blood.

10G PROTEINE EXISTS IN FIBRINE,

These considerations induced Mulder to give to
this product of the decomposition of albumen, &c.
by potash, the name of proteine (from 7rpa>Te6«>, " I
take the first rank "). The blood, or the constitu-
ents of the blood, are consequently compounds of
this proteine with variable proportions of inorganic
substances.

Mulder further ascertained, that the insoluble
nitrogenised constituent of wheat flour (vegetable
fibrine), when treated with -potash, yields the very
same product, proteine; and it has recently been
proved that vegetable albumen and caseine are
acted on by potash precisely as animal albumen
and caseine are.

4. As far, therefore, as our researches have
gone, it may be laid down as a law, founded on
experience, that vegetables produce, in their organ-
ism, compounds of proteine ; and that out of these
compounds of proteine the various tissues and parts
of the animal body are developed by the vital force,
with the aid of the oxygen of the atmosphere and
of the elements of water.*

* The experiment of Tiedemann and Gmelin, who found it im-
possible to sustain the life of geese by means of boiled white of
€gg, may be easily explained, when we reflect that a graminivo-
rous animal, especially when deprived of free motion, cannot
obtain, from the transformation or waste of the tissues alone,
enough of carbon for the respiratory process. 2 Ibs. of albumen
contain only 3£ oz. of carbon, of which, among the last products
of transformation, a fourth part is given off in the form of uric
acid.

ALBUMEN, AND CASEINE. 107

Now, although it cannot be demonstrated that
proteine exists ready formed in these vegetable and
animal products, and although the difference in
their properties seems to indicate that their ele-
ments are not arranged in the same manner, yet
the hypothesis of the pre-existence of proteine, as
a point of departure in developing and comparing
their properties, is exceedingly convenient. At all
events, it is certain that the elements of these com-
pounds assume the same arrangement when acted
on by potash at a high temperature.

All the organic nitrogenised constituents of the
body, how different soever they may be in composi-
tion, are derived from proteine. They are formed
from it, by the addition or subtraction of the ele-
ments of water or of oxygen, and by resolution
into two or more compounds.

5. This proposition must be received as an un-
deniable truth, when we reflect on the develope-
ment of the young animal in the egg of a fowl.
The egg can be shewn to contain no other nitro-
genised compound except albumen. The albumen
of the yolk is identical with that of the white ; (23)
the yolk contains, besides, only a yellow fat, in
which cholesterine and iron may be detected. Yet
we see, in the process of incubation, during which
no food and no foreign matter, except the oxygen
of the air, is introduced, or can take part in the
developement of the animal, that out of the albu-
men, feathers, claws, globules of the blood, fibrme,

108 DIGESTION COMPARED

membrane and cellular tissue, arteries and veins,
are produced. The fat of the yolk may have con-
tributed, to a certain extent, to the formation of
the nerves and brain ; but the carbon of this fat
cannot have been employed to produce the organ-
ised tissues in which vitality resides, because the
albumen of the white and of the yolk already con-
tains, for the quantity of nitrogen present, exactly
the proportion of carbon required for the formation
of these tissues.

6. The true starting-point for all the tissues is,
consequently, albumen ; all nitrogenised articles of
food, whether derived from the animal or from the
vegetable kingdom, are converted into albumen
before they can take part in the process of nutri-
tion.

All the food consumed by an animal becomes in
the stomach soluble, and capable of entering into
the circulation. In the process by which this solu-
tion is effected, only one fluid, besides the oxygen
of the air, takes a part ; it is that which is secreted
by the lining membrane of the stomach.

The most decisive experiments of physiologists
have shewn that the process of chymificatioii is
independent of the vital force ; that it takes place
in virtue of a purely chemical action, exactly simi-
lar to those processes of decomposition or transfor-
mation which are known as putrefaction, fermenta-
tion, or decay (eremacausis).

7. When expressed in the simplest form, fer-

TO FERMENTATION. 109

mentation, or putrefaction, may be described as a
process of transformation — that is, a new arrange-
ment of the elementary particles, or atoms, of a
compound, yielding two or more new groups or
compounds, and caused by contact with other sub-
stances, the elementary particles of which are them-
selves in a state of transformation or decomposition.
It is a communication, or an imparting of a state of
motion, which the atoms of a body in a state of
motion are capable of producing in other bodies,
whose elementary particles are held together only
by a feeble attraction.

8. Thus the clear gastric juice contains a sub-
stance in a state of transformation, by the con-
tact of which with those constituents of the food
which, by themselves, are insoluble in water, the
latter acquire, in virtue of a new grouping of
their atoms, the property of dissolving in that fluid.
During digestion, the gastric juice, when separated,
is found to contain a free mineral acid, the presence
of which checks all further change. That the food is
rendered soluble quite independently of the vitality
of the digestive organs has been proved by a num-
ber of the most beautiful experiments. Food, en-
closed in perforated metallic tubes, so that it could
not come into contact with the stomach, was found
to disappear as rapidly, and to be as perfectly di-
gested, as if the covering had been absent; and
fresh gastric juice, out of the body, when boiled
white of egg, or muscular fibre, were kept in

110 POWER OF ANIMAL MEMBRANE

contact with it for a time at the temperature of
the body, caused these substances to lose the solid
form and to dissolve in the liquid.

9. It can hardly be doubted that the substance
which is present in the gastric juice in a state of
change is a product of the transformation of the
stomach itself. No substances possess, in so high
a degree as those arising from the progressive de-
composition of the tissues containing gelatine or
chondrine, the property of exciting a change in the
arrangement of the elements of other compounds.
When the lining membrane of the stomach of any
animal, as, for example, that of the calf, is cleaned
by continued washing with water, it produces no
effect whatever, if brought into contact with a solu-
tion of sugar, with milk, or other substances. But
if the same membrane be exposed for some time
to the air, or dried, and then placed in contact with
such substances, the sugar is changed, according to
the state of decomposition of the animal matter,
either into lactic acid, into mannite and mucilage,
or into alcohol and carbonic acid ; while milk is
instantly coagulated. An ordinary animal bladder
retains, when dry, all its properties unchanged ; but
when exposed to air and moisture, it undergoes a
change not indicated by any obvious external signs.
If, in this state, it be placed in a solution of sugar
of milk, that substance is quickly changed into
lactic acid.
1 10. The fresh lining membrane of the stomach of

TO PRODUCE FERMENTATION. Ill

a calf, digested with weak muriatic acid, gives to
this fluid no power of dissolving boiled flesh or co-
agulated white of egg. But if previously allowed to
dry, or if left for a time in water, it then yields, to
water acidulated with muriatic acid, a substance in
minute quantity, the decomposition of which is
already commenced, and is completed in the solu-
tion. If coagulated albumen be placed in this so-
lution, the state of decomposition is communicated
to it, first at the edges, which become translucent,
pass into a mucilage, and finally dissolve. The same
change gradually affects the whole mass, and at last
it is entirely dissolved, with the exception of fatty
particles, which render the solution turbid. Oxygen
is conveyed to every part of the body by the arterial
blood ; moisture is everywhere present ; and thus we
have united the chief conditions of all transforma-
tions in the animal body.

Thus, as in the germination of seeds, the presence
of a body in a state of decomposition or transforma-
tion, which has been called diastase, effects the solu-
tion of the starch — that is, its conversion into sugar ;
so, a product of the metamorphosis of the substance
of the stomach, being itself in a state of metamor-
phosis which is completed in the stomach, effects the
dissolution of all such parts of the food as are capable
of assuming a soluble form. In certain diseases,
there are produced from the starch, sugar, &c., of the
food, lactic acid and mucilage. (24) These are the
very same products which we can produce out of

112 LACTIC ACID NOT FORMED

sugar by means of membrane in a state of decompo-
sition out of the body ; but in a normal state of
health, no lactic acid is formed in the stomach.

11. The property possessed by many substances,
such as starch and the varieties of sugar, by contact
with animal substances in a state of decomposition,
to pass into lactic acid, has induced physiologists,
without further inquiry, to assume the fact of the
production of lactic acid during digestion ; and the
power which this acid has of dissolving phosphate of
lime has led them to ascribe to it the character of a
general solvent. But neither Prout nor Braconnet
could detect lactic acid in the gastric juice ; and even
Lehmann (see his "Lehrbuch der Physiologischen
Chemie," torn. i. p. 285) obtained from the gastric
juice of a cat only microscopic crystals, which he
took for lactate of zinc, although their chemical
character could not be ascertained. The presence
of free muriatic acid in the gastric juice, first ob-
served by Prout, has been confirmed by all those
chemists who have examined that fluid since. This
muriatic acid is obviously derived from common salt,
the soda of which plays a very decided part in the
conversion of fibrine and caseine into blood.

Muriatic acid yields to no other acid in the power
of dissolving bone earth, and even acetic acid, in this
respect, is equal to lactic acid. There is conse-
quently no proof of the necessity of lactic acid in
the digestive process ; and we know with certainty,
that in artificial digestion it is not formed. Berze-

IN THE HEALTHY STOMACH. 113

lius indeed has found lactic acid in the blood and
flesh of animals ; but when his experiments were
made, chemists were ignorant of the extraordinary
facility and rapidity with which this acid is formed
from a number of substances containing its elements,
when in contact with animal matter.

In the gastric juice of a dog, Braconnet found,
along with free muriatic acid, distinct traces of a salt
of iron, which he at first held to be an accidental
admixture. But in the gastric juice of a second
dog, collected with the utmost care, the iron was
again found. (Ann. de Ch. et de Ph. lix. p. 249.)
This occurrence of iron is full of significance in
regard to the formation of the blood.

12. In the action of the gastric juice on the
food, no other element takes a share, except the
oxygen of the atmosphere and the elements of water.
This oxygen is introduced directly into the stomach.
During the mastication of the food, there is secreted
into the mouth from organs specially destined to
this function, a fluid, the saliva, which possesses the
remarkable property of enclosing air in the shape of
froth, in a far higher degree than even soap-suds.
This air, by means of the saliva, reaches the stomach
with the food, and there its oxygen enters into com-
bination, while its nitrogen is given out through the
skin and lungs. The longer digestion continues, that
is, the greater the resistance offered to the solvent
action by the food, the more saliva, and consequently
the more air enters the stomach. Rumination, in

114 USE OF THE SALIVA.

certain graminivorous animals, has plainly for one
object a renewed and repeated introduction of oxy-
gen ; for a more minute mechanical division of the
food only shortens the time required for solution.

The unequal quantities of air which reach the
stomach with the saliva in different classes of ani-
mals explain the accurate observations made by
physiologists, who have established beyond all doubt
the fact, that animals give out pure nitrogen through
the skin and lungs, in variable quantity. This fact
is so much the more important, as it furnishes the
most decisive proof, that the nitrogen of the air is
applied to no use in the animal economy.

The fact that nitrogen is given out by the skin
and lungs, is explained by the property which animal
membranes possess of allowing all gases to permeate
them, a property which can be shewn to exist by the
most simple experiments. A bladder, filled with
carbonic acid, nitrogen, or hydrogen gas, if tightly
closed and suspended in the air, loses in twenty-four
hours the whole of the enclosed gas ; by a kind of
exchange, it passes outwards into the atmosphere,
while its place is occupied by atmospherical air. A
portion of intestine, a stomach, or a piece of skin
or membrane, acts precisely as the bladder, if filled
with any gas. This permeability to gases is a me-
chanical property, common to all animal tissues;
and it is found in the same degree in the living as
in the dead tissue.

It is known that in cases of wounds of the lungs

GASES PERMEATE MEMBRANES. 115

a peculiar condition is produced, in which, by the
act of inspiration, not only oxygen but atmospheri-
cal air, with its whole amount (£ths) of nitrogen,
penetrates into the cells of the lungs. This air is
carried by the circulation to every part of the body,
so that every part is inflated or puffed up with the
air, as with water in dropsy. This state ceases,
without pain, as soon as the entrance of the air
through the wound is stopped. There can be no
doubt that the oxygen of the air, thus accumu-
lated in the cellular tissue, enters into combination,
while its nitrogen is expired through the skin and
lungs.

Moreover, it is well known that in many gramini-
vorous animals, when the digestive organs have been
overloaded with fresh juicy vegetables, these sub-
stances undergo in the stomach the same decompo-
sition as they would at the same temperature out of
the body. They pass into fermentation and putre-
faction, whereby so great a quantity of carbonic acid
gas and of inflammable gas is generated, that these
organs are enormously distended, sometimes even to
bursting. From the structure of their stomach or
stomachs, these gases cannot escape through the
oesophagus ; but in the course of a few hours, the
distended body of the animal becomes less swoln,
and at the end of twenty-four hours no trace of the
gases is left. (25)

Finally, if we consider the fatal accidents which
so frequently occur in wine countries from the
i 2

116 SOURCES OF THE NITROGEN

drinking of what is called feather-white wine (der
federweisse Wein), we can no longer doubt that gases
of every kind, whether soluble or insoluble in water,
possess the property of permeating animal tissues,
as water penetrates unsized paper. This poison-
ous wine is wine still in a state of fermentation,
which is increased by the heat of the stomach. The
carbonic acid gas which is disengaged penetrates
through the parietes of the stomach, through the
diaphragm, and through all the intervening mem-
branes, into the air-cells of the lungs, out of which
it displaces the atmospherical air. The patient dies
with all the symptoms of asphyxia caused by an
irrespirable gas ; and the surest proof of the pre-
sence of the carbonic acid in the lungs is the fact,
that the inhalation of ammonia (which combines
with it) is recognized as the best antidote against
this kind of poisoning.

The carbonic acid of effervescing wines and of
soda-water, when taken into the stomach, or of
water saturated with this gas, administered in the
form of enema, is given out again through the
skin and lungs ; and this is equally true of the
nitrogen which is introduced into the stomach with
the food in the saliva.

No doubt a part of these gases may enter the ve-
nous circulation through the absorbent and lymphatic
vessels, and thus reach the lungs, where they are
exhaled ; but the presence of membranes offers not
the slightest obstacle to their passing directly into

EXHALED FROM THE LUNGS. 117

the cavity of the chest. It is, in fact, difficult to
suppose that the absorbents and lymphatics have
any peculiar tendency to absorb air, nitrogen, or hy-
drogen, and convey these gases into the circulation,
since the intestines, the stomach, and all spaces in
the body not filled with solid or liquid matters, con-
tain gases, which only quit their position when their
volume exceeds a certain point, and which, conse-
quently, are not absorbed. More especially in refer-
ence to nitrogen, we must suppose that it is removed
from the stomach by some more direct means, and
not by the blood, which fluid must already, in passing
through the lungs, have become saturated with that
gas, that is, must have absorbed a quantity of it,
proportioned to its solvent power, like any other
liquid. By the respiratory motions all the gases
which fill the otherwise empty spaces of the body
are urged towards the chest ; for by the motion of
the diaphragm and the expansion of the chest a par-
tial vacuum is produced, in consequence of which
air is forced into the chest from all sides by the at-
mospheric pressure. The equilibrium is, no doubt,
restored, for the most part, through the windpipe,
but all the gases in the body must, nevertheless,
receive an impulse towards the chest. In birds and
tortoises these arrangements are reversed. If we
assume that a man introduces into the stomach in
each minute only ^th of a cubic inch of air with the
saliva, this makes in eighteen hours 135 cubic inches;
and if Jth be deducted as oxygen, there will still

118 TRUE NATURE OF THE

remain 108 cubic inches of nitrogen, which occupy
the space of 3 Ibs. of water. Now whatever may be
the actual amount of the nitrogen thus swallowed,
it is certain that the whole of it is given out again
by the mouth, nose, and skin ; and when wre consider
the very large quantity of nitrogen found in the in-
testines of executed criminals by Magendie, as well
as the entire absence of oxygen in these organs (26),
we must assume that air, and consequently nitrogen,
enters the stomach by resorption through the skin,
and is afterwards exhaled by the lungs.

When animals are made to respire in gases con-
taining no nitrogen, more of that gas is exhaled,
because in this case the nitrogen within the body
acts towards the external space as if the latter were
a vacuum. (See Graham, " On the Diffusion of
Gases.")

The differences in the amount of expired nitrogen
in different classes of animals are thus easily ex-
plained ; the herbivora swallow with the saliva more
air than the carnivora ; they expire more nitrogen
than the latter, — less when fasting than immediately
after taking food.

13. In the same way as muscular fibre, when
separated from the body, communicates the state of
decomposition existing in its elements to the per-
oxide of hydrogen, so a certain product, arising by
means of the vital process, and in consequence of the
transposition of the elements of parts of the sto-
mach and of the other digestive organs, while its own

DIGESTIVE PROCESS, 119

metamorphosis is accomplished in the stomach, acts
on the food. The insoluble matters become soluble
- — they are digested.

It is certainly remarkable, that hard-boiled white
of egg or fibrine, when rendered soluble by certain
liquids, by organic acids, or weak alkaline solutions,
retain all their properties except the solid form
(cohesion) without the slightest change. Their ele-
mentary molecules, without doubt, assume a new
arrangement ; they do not, however, separate into
two or more groups, but remain united together.

The very same thing occurs in the digestive pro-
cess ; in the normal state, the food only undergoes
a change in its state of cohesion, becoming fluid
without any other change of properties.

The greatest obstacle to forming a clear concep-
tion of the nature of the digestive process, which is
here reckoned among those chemical metamorphoses
which have been called fermentation and putrefac-
tion, consists in our involuntary recollection of the
phenomena which accompany the fermentation of
sugar and of animal substances (putrefaction), which
phenomena, we naturally associate with any similar
change ; but there are numberless cases in which a
complete chemical metamorphosis of the elements
of a compound occurs without the smallest disen-
gagement of gas, and it is chiefly these which must
be borne in minjd, if we would acquire a clear and
accurate idea of the chemical notion or conception
of the digestive process.

120 NATURE OF FERMENT.

All substances which can arrest the phenomena
of fermentation and putrefaction in liquids, also ar-
rest digestion when taken into the stomach. The
action of the empyreumatic matters in coffee and
tobacco-smoke, of creosote, of mercurials, &c. &c., is
on this account worthy of peculiar attention with
reference to dietetics.

The identity in composition of the chief consti-
tuents of blood and of the nitrogenised constituents
of vegetable food has certainly furnished, in an un-
expected manner, an explanation of the fact that
putrefying blood, white of egg, flesh, and cheese pro-
duce the same effects in a solution of sugar as yeast
or ferment ; that sugar, in contact with these sub-
stances, according to the particular stage of decom-
position in which the putrefying matters may be,
yields, at one time, 'alcohol and carbonic acid ; at
another, lactic acid, mannite, and mucilage. The
explanation is simply this, that ferment, or yeast,
is nothing but vegetable fibrine, albumen, or caseine
in a state of decomposition, these substances having
the same composition with the constituents of flesh,
blood, or cheese. The putrefaction of these animal
matters is a process identical with the metamorpho-
sis of the vegetable matters identical with them ;
it is a separation or splitting up into new and less
complex compounds. And if we consider the trans-
formation of the elements of the animal body (the
waste of matter in animals) as a chemical process
which goes on under the influence of the vital force,

COMPOSITION OF PROTEINE. 121

then the putrefaction of animal matters out of the
body is a division into simpler compounds, in which
the vital force takes no share. The action in both
cases is the same, only the products differ. The
practice of medicine has furnished the most beau-
tiful and interesting observations on the action of
empyreumatic substances, such as wood, vinegar,
creosote, &c., on malignant wounds and ulcers. In
such morbid phenomena two actions are going on
together ; one metamorphosis, which strives to com-
plete itself under the influence of the vital force,
and another, independent of that force. The latter
is a chemical process, which is entirely suppressed
or arrested by empyreumatic substances ; and this
effect is precisely opposed to the poisonous influence
exercised on the organism by putrefying blood when
introduced into a fresh wound.

14. The formula C48H36N6014* is that which
most accurately expresses the composition of pro-
teine, or the relative proportions of the organic
elements in the blood, as ascertained by analysis.
Albumen, fibrine, and caseine contain proteine ;
caseine contains, besides, sulphur, but no phospho-
rus ; albumen and fibrine contain both these sub-
stances chemically combined — the former more sul-
phur than the latter. We cannot directly ascertain
in what form the phosphorus exists, but we have
decided proof that the sulphur cannot be in. the

* For the method of converting this and other formulae into
proportions per cent, see Appendix.

122 COMPOSITION OF FIBRINE,

oxidised state. All these substances, when heated
with a moderately strong solution of potash, yield
the sulphur which we find in the solution as sul-
phuret of potassium ; and on the addition of an
acid it is given off as sulphuretted hydrogen. When
pure fibrine or ordinary albumen is dissolved in a
weak solution of potash, and acetate of lead is added
to the solution, in such proportion that the whole of
the oxide of lead remains dissolved in the potash,
the mixture, if heated to the boiling point, becomes
black like ink, and sulphuret of lead is deposited
as a fine black powder.

It is extremely probable, that by the action of
the alkali the sulphur is removed as sulphuretted
hydrogen, the phosphorus as phosphoric or phos-
phorous acid. Since, in this case, sulphur and phos-
phorus are eliminated on the one hand, and oxygen
and hydrogen on the other, it might be concluded
that fibrine and albumen, when analysed with their
sulphur and phosphorus, would yield a larger pro-
portion of oxygen and hydrogen than is found in
proteine. But this cannot be shewn in the analysis ;
for fibrine, for example, has been found to contain
0*36 per cent, of sulphur. Assuming, then, that:
this sulphur is eliminated by the alkali in combina-
tion with hydrogen, proteine would yield 0-0225
per cent, less hydrogen than fibrine ; instead of the
mean amount of 7'062 per cent, of hydrogen, the
proteine should yield 7'04 per cent. In like man-
ner, by the elimination of the phosphorus in combi-

ALBUMEN, AND CASEINE. 123

nation with oxygen, the amount of oxygen in fibrine
would be reduced from 22*715 — 22-00 per cent, to
22-5 — 21-8 per cent, in proteine. But the limits of
error in our analyses are, on an average, beyond
xVth per cent, in the hydrogen, and beyond T4oths
per cent, in the oxygen ; while in the supposed case
the difference in the hydrogen would not be greater
than Tsth per cent.

Finally, if we reflect, that the elimination of oxy-
gen and hydrogen with the sulphur and phosphorus
does not exclude the addition of the elements of
water, and if we assume that fibrine and albu-
men, in passing into proteine, do combine with a
certain quantity of water, an occurrence which is
highly probable, we shall see that there is no proba-
bility that the ultimate analysis of these compounds
shall ever enable us to decide such questions, or to
fix the chemical view of the relation of proteine to
albumen, fibrine, or caseine, farther than has been
done above.

Some have endeavoured to prove the existence of
unoxidised phosphorus in albumen and fibrine from
the formation of sulphuret of potassium when they
are acted on by potash, supposing the oxygen of the
potash to have formed phosphoric acid with the
phosphorus ; but caseine, \vhich contains no phos-
phorus, yields sulphuret of potassium, just like the
otherieubstances ; and here its formation cannot be
accounted for, unless we admit the previous pro-
duction of sulphuretted hydrogen. In the mere

124 COMPOSITION OF FIBRINE, &c.

boiling of flesh, for the purpose of making soup, sul-
phuretted hydrogen, as Chevreul has shewn, is dis-
engaged.

Moreover, the proportion of sulphur, for the same
amount of phosphorus, is not the same in fibrine
and albumen, from which no other conclusion can
be drawn, but that the formation of sulphuret of
potassium has no relation to the presence of phos-
phorus. Sulphuret of potassium is formed from
caseine, which is not supposed to contain any un-
combined phosphorus; and it is formed, also, from
albumen, which contains only half as much phos-
phorus as fibrine.

Every attempt to give the true absolute amount
of the atoms in fibrine and albumen in a rational
formula, in which the sulphur and phosphorus are
taken, not in fractions, but in entire equivalents,
must be fruitless, because we are absolutely unable
to determine with perfect accuracy the exceedingly
minute quantities of sulphur and phosphorus in
such compounds ; and because a variation in the
sulphur or phosphorus, smaller in extent than
the usual limit of errors of observation, will affect
the number of atoms of carbon, hydrogen, or oxy-
gen to the extent of 10 atoms or more.

We must be careful not to deceive ourselves in
our expectations of what chemical analysis can do.
We know, with certainty, that the numbers repre-
senting the relative proportions of the organic ele-
ments are the same in albumen and fibrine, and

COMPOSITION OF TISSUES. 125

hence we conclude that they have the same com-
position. This conclusion is not affected by the
fact, that we do not know the absolute number of
the atoms of their elements, which have united to
form the compound atom.

15. A formula for proteine is nothing more
than the nearest and most exact expression in
equivalents, of the result of the best analyses ; it
is a fact established so far, free from doubt, and
this alone is, for the present, valuable to us.

If we reflect, that from the albumen and fibrine of
the body all the other tissues are derived, it is per-
fectly clear, that this can only occur in two ways.
Either certain elements have been added to, or
removed from, their constituent parts.

If we now, for example, look for an analytical
expression of the composition of cellular tissue, of
the tissues yielding gelatine, of tendons, of hair, of
horn, &c., in which the number of atoms of carbon
is made invariably the same as in albumen and
fibrine, we can then see, at the first glance, in what
way the proportion of the other elements has been
altered; but this includes all that physiology re-
quires in order to obtain an insight into the true
nature of the formative and nutritive processes in
the animal body.

From the researches of Mulder and Scherer we
obtain the following empirical formulae :^ —

126 DIFFERENCES IN COMPOSITION

Composition of organic tissues.

Albumen C^N^Ou + P + S*

Fibrine C48N6H3eO,4 + P + 2S

Caseine C^H^Ou + S

Gelatinous tissues, tendons ... C48N7.5H4iOi3

Chondrine C^NeH^Oao

Hair, horn C^N^A;

Arterial membrane C48N6H38O16

The composition of these formulae shews, that
when proteine passes into chondrine (the substance
of the cartilages of the ribs), the elements of water,
with oxygen, have been added to it ; while in the
formation of the serous membranes, nitrogen also
has entered into combination.

If we represent the formula of proteine, C48N6
HseOu by Pr, then nitrogen, hydrogen, and oxygen
have been added to it in the form of known com-
pounds, and in the following proportions, in form-
ing the gelatinous tissues, hair, horn, arterial mem-
brane, &c.

Proteine. Ammonia. Water. Oxygen.

Fibrine, Albumen Pr

Arterial membrane ... Pr + 2HO

Chondrine Pr + 4HO + 2O.

Hair.horn Pr -f NH3 + 3O.

Gelatinous tissues ... 2Pr + 3NH3 + HO + 7O.

17. From this general statement it appears that
all the tissues of the body contain, for the same

* The quantities of sulphur and phosphorus here expressed by
S and P are not equivalents, but only give the relative proportions
of these two elements to each other, as found by analysis.

OF ORGANIC TISSUES. 127

amount of carbon, more oxygen than the consti-
tuents of blood. During their formation, oxygen,
either from the atmosphere or from the elements
of water, has been added to the elements of pro-
teine. In hair and gelatinous membrane we ob-
serve, further, an excess of nitrogen and hydrogen,
and that in the proportions to form ammonia.

Chemists are not yet agreed on the question, in
what manner the elements of sulphate of potash are
arranged ; it would therefore be going too far, were
they to pronounce arterial membrane a hydrate of
proteine, chondrine a hydrated oxide of proteine,
and hair and membranes compounds of ammonia
with oxides of proteine.

The above formulae express with precision the
differences of composition in the chief constituents
of the animal body ; they shew, that for the same
amount of carbon the proportion of the other ele-
ments varies, and how much more oxygen or nitro-
gen one compound contains than another.

18. By means of these formulae we can trace the
production of the different compounds from the
constituents of blood ; but the explanation of their
production may take two forms, and we have to
decide which of these comes nearest to the truth.

For the same amount of carbon, membranes and
the tissues which yield gelatine contain more nitro-
gen, oxygen, and hydrogen than proteine. It is
conceivable that they are formed from albumen by
the addition of oxygen, of the elements of water,

128 GELATINE CONTAINS NO PROTEINE.

and of those of ammonia, accompanied by the sepa-
ration of sulphur and phosphorus ; at all events,
their composition is entirely different from that of
the chief constituents of blood.

The action of caustic alkalies on the tissues yield-
ing gelatine shews distinctly that they no longer
contain proteine ; that substance cannot in any way
be obtained from them ; and all the products formed
by the action of alkalies on them differ entirely
from those produced by the compounds of proteine
in the same circumstances. Whether proteine exist,
ready formed, in fibrine, albumen, and caseine, or
not, it is certain that their elements, under the in-
fluence of the alkali, arrange themselves so as to
form proteine ; but this property is wanting in the
elements of the tissues which yield gelatine.

The other, and perhaps the more probable expla-
nation of the production of these tissues from pro-
teine, is that which makes it dependent on a sepa-
ration of carbon.

If we assume the nitrogen of proteine to remain
entire in the gelatinous tissue, then the composition
of the latter, calculated on 6 equivalents of nitrogen,
would be represented by the formula, C38N6H32Oi4.
This formula approaches most closely to the analysis
of Scherer, although it is not an exact expression of
his results. A formula corresponding more per-
fectly to the analyses, is C32N5H27O12 ; or, calculated
according to Mulder's analysis, C^NgH^Oa,,.*

* The formula C^NgH.^;*,, adopted by Mulder, gives, when

ORIGIN OF GELATINE. 129

According to the first formula, carbon and hydro-
gen have been separated ; according to the two
last, a certain proportion of all the elements has
been removed.

19. We must admit, as the most important re-
sult of the study of the composition of gelatinous
tissue, and as a point undeniably established, that,
although formed from compounds of proteine, it no
longer belongs to the series of the compounds of
proteine. Its chemical characters and composition
justify this conclusion.

No fact is as yet opposed to the law, deduced
from observation, that nature has exclusively des-
tined compounds of proteine for the production of
blood.

No substance analogous to the tissues yielding
gelatine is found in vegetables. The gelatinous
substance is not a compound of proteine ; it con-
tains no sulphur, no phosphorus, and it contains
more nitrogen or less carbon than proteine. The
compounds of proteine, under the influence of the
vital energy of the organs which form the blood,
assume a new form, but are not altered in composi-
tion ; while these organs, as far as our experience
reaches, do not possess the power of producing
compounds of proteine, by virtue of any influence,
out of substances which contain no proteine. Ani-
mals which were fed exclusively with gelatine, the

reduced to 100 parts, too little nitrogen to be considered an exact
expression of his analyses.

K

130 ORIGIN OF GELATINE.

most highly nitrogenised element of the food of
carnivora, died with the symptoms of starvation ; in
short, the gelatinous tissues are incapable of conver-
sion into blood.

But there is no doubt that these tissues are
formed from the constituents of the blood ; and we
can hardly avoid entertaining the supposition, that
the fibrine of venous blood, in becoming arterial
fibrine, passes through the first stage of conversion
into gelatinous tissue. We cannot, with much pro-
bability, ascribe to membranes and tendons the
power of forming themselves out of matters brought
by the blood ; for how could any matter become a
portion of cellular tissue, for example, by virtue of
a force which has as yet no organ? An already
existing cell may possess the power of reproducing
or of multiplying itself, but in both cases the pre-
sence of a substance identical in composition with
cellular tissue is essential. Such matters are formed
in the organism, and nothing can be better fitted
for their production than the substance of the cells
and membranes which exist in animal food, and
become soluble in the stomach during digestion, or
which are taken by man in a soluble form.

20. In the following pages I offer to the reader
an attempt to develope analytically the principal
metamorphoses which occur in the animal body;
and, to preclude all misapprehension, I do this with
a distinct protest against all conclusions and deduc-
tions which may now or at any subsequent period be

METAMORPHOSIS OF TISSUES. 131

derived from it in opposition to the views developed
in the preceding part of this work, with which it
has no manner of connection. The results here to
be described have surprised me no less than they
will others, and have excited in my mind the same
doubts as others will conceive ; but they are not the
creations of fancy, and I give them because I enter-
tain the deep conviction that the method which has
led to them is the only one by which we can hope
to acquire insight into the nature of the organic
processes.

The numberless qualitative investigations of ani-
mal matters which are made are equally worthless
for physiology and for chemistry, so long as they are
not instituted with a well-defined object, or to answer
a question clearly put.

If we take the letters of a sentence which we wish
to decipher, and place them in a line, we advance
not a step towards the discovery of their meaning.
To resolve an enigma, we must have a perfectly clear
conception of the problem. There are many ways
to the highest pinnacle of a mountain ; but those
only can hope to reach it who keep the summit
constantly in view. All our labour and all our
efforts, if we strive to attain it through a morass,
only serve to cover us more completely with mud ;
our progress is impeded by difficulties of our own
creation, and at last even the greatest strength
must give way when so absurdly wasted.

21. If it be true that all parts of the body are
K 2

132 THE SECRETIONS CONTAIN

formed and developed from the blood or the con-
stituents of the blood, that the existing organs at
every moment of life are transformed into new com-
pounds under the influence of the oxygen introduced
in the blood, then the animal secretions must of
necessity contain the products of the metamorphosis
of the tissues.

22. If it be further true, that the urine con-
tains those products of metamorphosis which contain
the most nitrogen, and the bile those which are
richest in carbon, from all the tissues which in the
vital process have been transformed into unorganised
compounds, it is clear that the elements of the bile
and of the urine, added together, must be equal, in
the relative proportion of these elements to the com-
position of the blood.

23. The organs are formed from the blood, and
contain the elements of the blood ; they become
transformed into new compounds, with the addition
only of oxygen and of water. Hence the relative
proportion of carbon and nitrogen must be the same
as in the blood.

If then we subtract from the composition of blood
the elements of the urine, then the remainder, de-
ducting the oxygen and water which have been
added, must give the composition of the bile.

Or if from the elements of the blood, we subtract
the elements of the bile, the remainder must give
the composition of urate of ammonia, or of urea
and carbonic acid.

ALL THE ELEMENTS OF THE BLOOD. 133

It will surely appear remarkable that this manner
of viewing the subject has led to the true formula
of bile, or, to speak more accurately, to the most
correct empirical expression of its composition ;
and has furnished the key to its metamorphoses,
under the influence of acids and alkalies, which had
previously been sought for in vain.

24. When fresh drawn blood is made to trickle
over a plate of silver, heated to 140°, it dries to
a red, varnish-like matter, easily reduced to pow-
der. Muscular flesh, free from fat, if dried first in
a gentle heat, and then at 212°, yields a brown,
pulverizable mass.

The analyses of PLAYFAIR and BOECKMANN (28)
give for flesh (fibrine, albumen, cellular tissue, and
nerves) and for blood, as the most exact expres-
sion of their numerical results, one and the same
formula, namely, C48N6H39O15. This may be called
the empirical formula of blood.

25. The chief constituent of bile, according
to the researches of DEMAR^AY, is a compound,
analogous to soaps, of soda with a peculiar sub-
stance, which has been named choleic acid. This
acid is obtained in combination with oxide of lead,
when bile, purified by means of alcohol from all
matters insoluble in that menstruum, is mixed with
acetate of lead.

Choleic acid is resolved, by the action of muriatic
acid, into ammonia, taurine, and a new acid, cliolo-
idic acid, which contains no nitrogen.

134 METAMORPHOSES OF BILE.

When boiled with caustic potash, choleic acid
is resolved into carbonic acid, ammonia, and another
new acid, cJiolic acid (distinct from the cholic acid
of Gmelin).

Now it is clear that the true formula of choleic
acid must include the analytical expression of these
modes of decomposition ; in other words, that it
must enable us to shew that the composition of the
products derived from it is related, in a clear and
simple manner, to the composition of the acid itself.
This is the only satisfactory test of a formula ; and
the analytical expression thus obtained loses nothing
of its truth or value, if it should appear, as the re-
searches of BERZELIUS seem to shew, that choleic
and choloidic acids are mixtures of different com-
pounds ; for the relative proportions of the ele-
ments cannot in any way be altered by this circum-
stance.

26. In order to develope the metamorphoses
which choleic acid suffers under the influence of
acids and alkalies, the following formula alone can
be adopted as the empirical expression of the results
of its analysis.

Formula of choleic acid : C^N^O^. (29)

I repeat, that this formula may express the com-
position of one, or of two or more compounds ;
no matter of how many compounds the so-called
choleic acid may be made up, the above formula
represents the relative proportions of all their ele-
ments taken together.

METAMORPHOSES OF BILE. 135

If now we subtract from the elements of choleic
acid, the products formed by the action of muriatic
acid, namely, ammonia and taurine, we obtain the
empirical formula of choloidic acid. Thus: from the

Formula of choleic acid ............ G^NgH^s

Subtract —
1 atom taurine ......... C4NH7O1

1 eq. ammonia ......... NH3

There remains the formula of cho-

loidic acid .; ...................... = Cn H5A2(30)

27. Again, if from the formula of choleic acid
we subtract the elements of urea and 2 atoms of
water (— 2 eq. carbonic acid and 2 eq. ammonia),
there will remain the formula and composition of
cholic acid. Thus ; from the

10~1
J = : C4

Formula of choleic acid =

subtract —

2 eq. carbonic acid = Cj O4~l _
2 eq. ammonia = N2H6 j

Remains the formula of cholic acid = C74 H^O^ (31)

When we consider the very close coincidence be-
tween these formulae and the actual results of ana-
lysis (see Appendix, 29, 30, 31), it is scarcely possible
to doubt that the formula above adopted for choleic
acid expresses, as accurately as is to be expected in
the analysis of such compounds, the relative propor-
tion of its elements, no matter in how many differ-
ent forms they may be united to produce that acid.

28. Let us now add the half of the numbers
which represent the formula of choleic acid, to the

136 RELATION OF BILE TO FIBRINE.

elements of the urine of serpents — that is, to neu-
tral urate of ammonia, as follows :

£ the formula of choleic acid ...... = C^N H^On

Add to this —
1 eq. uric acid ...... = C10N4H4O61 ^_ Q N,H_ Q6

1 eq. ammonia ...... = N H3 J

The sum is ........................ - C^NeH^Cv

29. But this last formula expresses the composi-
tion of blood, with the addition of 1 eq. oxygen and
1 eq. water.

Formula of blood ........................ C^NgHagOjs

1 «i- water .................. - HO~U H o2

1 eq. oxygen .................. = Oj

The sum is ........................... =

30. If, moreover, we add to the elements of pro-
teine those of 3 eq. water, we obtain, with the ex-
ception of 1 eq. hydrogen, exactly the same formula.

Formula of proteine .................. = C^NsE^O^

Add 3 eq. of water .................. = H3O3

The sum is ........................

differing only by 1 eq. of hydrogen from the formula
above obtained by adding together choleic acid and
urate of ammonia.

31. If, then, we consider choleic acid and urate
of ammonia the products of the transformation of
muscular fibre, since no other tissue in the body
contains proteine (for albumen passes into tissues,
without our being able to say, that in the vital pro-
cess it is directly resolved into choleic acid, and
urate of ammonia), there exist in fibrine, with the

OXIDATION OF URIC ACID. 137

addition of the elements of water, all the elements
essential to this metamorphosis ; and, except the
sulphur and phosphorus, both of which are probably
oxidised, no element is separated.

This form of metamorphosis is applicable to the
vital transformations in the lower classes of amphi-
bia, and perhaps in worms and insects. In the
higher classes of animals the uric acid disappears in
the urine, and is replaced by urea.

The disappearance of uric acid and the production
of urea plainly stand in a very close relation to the
amount of oxygen absorbed in respiration, and to
the quantity of water consumed by different animals
in a given time.

When uric acid is subjected to the action of
oxygen, it is first resolved, as is well known, into
alloxan and urea. (32) A new supply of oxygen
acting on the alloxan causes it to resolve itself
either into oxalic acid and urea, into oxaluric and
parabanic acids, (33) or into carbonic acid and urea.

32. In the so-called mulberry calculi we find
oxalate of lime, in other calculi urate of ammonia,
and always in persons, in whom, from want of ex-
ercise and labour, or from other causes, the supply
of oxygen has been diminished. Calculi containing
uric acid or oxalic acid are never found in phthisical
patients ; and it is a common occurrence in France,
among patients suffering from calculous complaints,
that when they go to the country, where they take
more exercise, the compounds of uric acid, which

138 URIC ACID AND UREA DERIVED

were deposited in the bladder during their residence
in town, are succeeded by oxalates (mulberry calcu-
lus), in consequence of the increased supply of oxy-
gen. With a still greater supply of oxygen they
would have yielded, in healthy subjects, only the
last product of the oxidation of uric acid, namely,
carbonic acid and urea.

An erroneous interpretation of the undeniable
fact that all substances incapable of further use in
the organism are separated by the kidneys and ex-
pelled from the body in the urine, altered or
unaltered, has led practical medical men to the
idea, that the food, and especially nitrogenised food,
may have a direct influence on the formation of
urinary calculi. There are no reasons which support
this opinion, while those opposed to it are innume-
rable. It is possible that there may be taken, in
the food, a number of matters changed by the
culinary art, which, as being no longer adapted to
the formation of blood, are expelled in the urine,
more or less altered by the respiratory process. But
roasting and boiling alter in no way the composition
of animal food. (34)

Boiled and roasted flesh is converted at once into
blood ; while the uric acid and urea are derived
from the metamorphosed tissues. The quantity of
these products increases with the rapidity of trans-
formation in a given time, but bears no proportion
to the amount of food taken in the same period. In
a starving man who is any way compelled to undergo

FROM THE METAMORPHOSED TISSUES. 139

severe and continued exertion, more urea is secreted
than in the most highly fed individual, if in a state
of rest. In fevers and during rapid emaciation the
urine contains more urea than in the state of health.
(PROUT.)

33. In the same way, therefore, as the hippuric
acid, present in the urine of the horse when at rest,
is converted into benzoate of ammonia and carbonic
acid as soon as the animal is compelled to labour,
so the uric acid disappears in the urine of man,
when he receives, through the skin and lungs, a
quantity of oxygen sufficient to oxidise the products
of the transformation of the tissues. The use of
wine and fat, which are only so far altered in the
organism that they combine with oxygen, has a
marked influence on the formation of uric acid.
The urine, after fat food has been taken, is turbid,
and deposits minute crystals of uric acid. (PROUT.)
The same thing is observed after the use of wines
in which the alkali necessary to retain the uric acid
in solution is wanting, but never from the use of
Rhenish wines, which contain so much tartar.

In animals which drink much water, by means of
which the sparingly soluble uric acid is kept dis-
solved, so that the inspired oxygen can act on it, no
uric acid is found in the urine, but only urea. In
birds, which seldom drink, uric acid predominates.

If to 1 atom of uric acid we add 6 atoms of oxy-
gen and 4 atoms of water, it resolves itself into urea
and carbonic acid :

140 RELATION OF BLOOD TO URINE.

1 at. uric acid C10N4H4O6 -j

4 at. water 1 ^ L/2 at- urea C4N4H8O4

6 at. oxygen) __^°J ^ &t' Carb°nic add C_! ^

C10N4H8016 C10N4HS016

34. The urine of the herbivora contains no uric
acid, but ammonia, urea, and hippuric or benzoic
acid. By the addition of 9 atoms of oxygen to the
empirical formula of their blood multiplied by 5, we
obtain the elements of 6 at. of hippuric acid, 9
at. of urea, 3 at. of choleic acid, 3 at. of water, and
3 at. of ammonia ; or, if we suppose 45 atoms of
oxygen to be added to the blood during its meta-
morphosis, then we obtain 6 at. of benzoic acid,
13^ at. of urea, 3 at. of choleic acid, 15 at. of car-
bonic acid, and 12 at. of water.

6 at. hippuric acid, 6 (C18N H8 O5 ) = C108N6 H48 O^

9 at. urea 9 (C2 N2H4 O2 ) = C^N^H^O^

3 at. choleic acid, 3 (C^N HaAO = C114N3 H^ O33
3 at. ammonia ... 3 ( N H3 )= N3 H9
3 at. water 3 ( H3 O3 ) = H3 O3

The sum is

or —
5
6 at. benzoic acid 6 (C14 H5 O3 ) = C^ H^ O18

27/2 at. urea 27 (C NH2 O ) = C^N^H^O^

3 at. choleic acid 3 (C^NH^On) = C114N3 H,,,, O-a
15 at. carbonic acid, 15 (C O2) = C15 Oao

12 at. water 12 ( H O ) = H12 OI2

The sum is

35. Lastly, let us follow the metamorphosis of

RELATION OF PROTEINE TO ALLANTOINE. 141

the. tissues in the foetal calf, considering the pro-
teine furnished in the blood of the mother as the
substance which undergoes or has undergone a
transformation ; it will appear that 2 at. of pro-
teine, without the addition of oxygen or any other
foreign element, except 2 at. of water, contain the
elements of 6 at. of allantoine and 1 at. of cholo-
idic acid, (meconium ?)

2 at. proteine=2 (C^N^Ou) + 2at.water=2 HO=C96N
' 6 at. allantoine, 6 (C4N2H3O3) = C24N12Hi8O13
1 at. choloidic acid = C7, JLfiO,,

36. But the elements of the six atoms of al-
lantoine in the last equation correspond exactly to
the elements of 2 at. of uric acid, 2 at. of urea,
and 2 at. of water.

(2 at. uric acid C^ H8 O12
2 at. urea C4 N4 H8 O4
2 at. water H2 O2

C24N12Hi8O18

The relations of allantoine, which is found in the
urine of the foetal calf, to the nitrogenised con-
stituents of the urine in animals which respire, are,
as may be seen by comparing the above formula*,
such as cannot be overlooked or doubted. Allan-
toine contains the elements of uric acid and urea — •
that is, of the nitrogenised products of the transfor-
mation of the compounds of proteine.

37. Further, if to the formula of proteine, multi-
plied by 3, we add the elements of 4 at. of water,

142 RELATION OF PROTEINE TO GELATINE.

and if we deduct from the sum of all the elements
half of the elements of choloidic acid, there remains
a formula which expresses very nearly the composi-
tion of gelatine. From

3 (Cysr6H36014) + 4 HO... = C144NUH1120«
Subtract | at. choloidic acid = C^

There remain ............... CJ08Ni8H ^Ao (35)

38. Subtracting from this formula of gelatine
the elements of 2 at. of proteine, there remain the
elements of urea, uric acid, and water, or of 3 at. of
allantoine and 3 at. of water. Thus —

Formula of gelatine (Mulder) C^
Subtract 2 at. proteine

There remain ............ C J2N GH12O12 =

f 1 at. uric acid C,0N4H4 O6 1 f

= 1 at. urea... C2 N2H4 O2 J 3 at. allantoine C12N6H9 O9
[4 at. water H4 O4 J [3 at. water ... H3 O3

C12N6H12012 C12N6H12O12

39. The numerical proportions calculated from
the above formula differ from those actually ob-
tained in the analyses of MULDER and SCHERER in
this, that the latter indicate somewhat less of nitro-
gen in gelatine ; but if we assume the formula to
be correct, it then appears, from the statement just
given, that the elements of two atoms of proteine,
plus the nitrogenised products of the transformation
of a third atom of proteine (uric acid and urea) and
water ; or three atoms of proteine, minus the ele-
ments of a compound containing no nitrogen, which

ORIGIN OF GELATINE. 143

actually occurs as one of the products of the trans-
formation of choleic acid, yield in both cases a for-
mula closely approaching to the composition of
gelatinous tissues. We must, however, attach to
such formulae, and to the considerations arising from
them, no more importance than justly belongs to
them. I would constantly remind the reader that
their use is to serve as points of connection, which
may enable us to acquire more accurate views as to
the production and decomposition of those com-
pounds which form the animal tissues. They are
the first attempts to discover the path which we
must follow in order to attain the object of our re-
searches; and this object, the goal we strive to
reach, is, and must be, attainable.

The experience of all those who have occupied
themselves with researches into natural phenomena
leads to this general result, that these phenomena
are caused, or produced, by means far more simple
than was previously supposed, or than we even
now imagine; and it is precisely their simplicity
which should most powerfully excite our wonder
and admiration.

Gelatinous tissue is formed from blood, from
compounds of proteine. It may be produced by
the addition, to the elements of proteine, of allan-
toine and water, or of water, urea, and uric acid ;
or by the separation from the elements of proteine
of a compound containing no nitrogen. The solu-
tion of such problems becomes less difficult, when

144 ORIGIN OF THE BILE.

the problem to be solved, the question to be an-
swered, is matured and clearly put. Every experi-
mental decision of any such question in the nega-
tive forms the starting-point of a new question, the
solution of which, when obtained, is the necessary
consequence of our having put the first question.

40. In the foregoing sections, no other consti-
tuent of the bile, besides choleic acid, has been
brought into the calculation; because it alone is
known with certainty to contain nitrogen. Now, if
it be admitted that its nitrogen is derived from the
metamorphosed tissues, it is not improbable that
the carbon, and other elements which it contains,
are derived from the same source.

There cannot be the smallest doubt, that in the
carnivora, the constituents of the urine and the bile
are derived from the transformation of compounds
of proteine ; for, except fat, they consume no food
but such as contains proteine, or has been formed
from that substance. Their food is identical with
their blood ; and it is a matter of indifference which
of the two we select as the starting-point of the
chemical developement of the vital metamorphoses.

There can be no greater contradiction, with re-
gard to the nutritive process, than to suppose that
the nitrogen of the food can pass into the urine as
urea, without having previously become part of an
organized tissue ; for albumen, the only constituent
of blood, which, from its amount, ought to be taken
into consideration, suffers not the slightest change

ORIGIN OF THE BILE. 145

in passing through the liver or kidneys ; we find it
in every part of the body with the same appearance
and the same properties. These organs cannot be
adapted for the alteration or decomposition of the
substance from which all the other organs of the
body are to be formed.

41. From the characters of chyle and lymph, it
appears with certainty that the soluble parts of the
food or of the chyme acquire the form of albumen.
Hard-boiled white of egg, boiled or coagulated
fibrine, which have again become soluble in the
stomach, but have lost their coagulability by the
action of air or heat, recover these properties by de-
grees. In the chyle, the acid re-action of the chyme
has already passed into the weak alkaline re-action
of the blood ; and the chyle, when, after passing
through the mesenteric glands, it has reached the
thoracic duct, contains albumen coagulable by heat ;
and, when left to itself, deposits fibrine. All the
compounds of proteine, absorbed during the passage
of the chyme through the intestinal canal, take the
form of albumen, which, as the results of incubation
in the fowl's egg testify, contains the fundamental
elements of all organized tissues, with the exception
of iron, which is obtained from other sources.

Practical medicine has long ago answered the
question, what becomes in man of the compounds of
proteine taken in excess, what change is undergone
by the superabundant nitrogenised food ? The blood-
vessels are distended with excess of blood, the other

146 ORIGIN OF THE BILE

vessels with excess of their fluids, and if the too
great supply of food be kept up, and the blood, or
other fluids adapted for forming blood, be not applied
to their natural purposes, if the soluble matters be
not taken up by the proper organs, various gases
are disengaged, as in processes of putrefaction, the
excrements assume an altered quality in colour,
smell, &c. Should the fluids in the absorbent and
lymphatic vessels undergo a similar decomposition,
this is immediately visible in the blood, and the nu-
tritive process then assumes new forms.

42. No one of all these appearances should occur,
if the liver and kidneys were capable of effecting the
resolution of the superabundant compounds of pro-
teine into urea, uric acid, and bile. All the observa-
tions which have been made in reference to the
influence of nitrogenised food on the composition of
the urine have failed entirely to demonstrate the
existence of any direct influence of the kind ; for the
phenomena are susceptible of another and a far more
simple interpretation, if, along with the food, we con-
sider the mode of life and habits of the individuals
who have been the subjects of investigation. Gravel
and calculus occur in persons who use very little
animal food. Concretions of uric acid have never
yet been observed in carnivorous mammalia, living
in the wild state,* and among nations which live

* The occurrence of urate of ammonia in a concretion found in
a dog, which was examined by Lassaigne, is to be doubted, unless
Lassaigne extracted it himself from the bladder of the animal.

IN THE HERBIVORA. 147

entirely on flesh, deposits of uric acid concretions
in the limbs or in the bladder are utterly unknown.

43. That which must be viewed as an undeniable
truth in regard to the origin of the bile, or, more
accurately speaking, of choleic acid in the carnivora,
cannot hold in regard to all the constituents of the
bile secreted by the liver in the herbivora, for with
the enormous quantity of bile produced, for example,
by the liver of an ox, it is absolutely impossible to
suppose that all its carbon is derived from the me-
tamorphosed tissues.

Assuming the 59 oz. of dry bile (from 371bs. of
fresh bile secreted by an ox) to contain the same per-
centage of nitrogen as choleic acid (3'86 per cent.),
this would amount to nearly 2^oz. of nitrogen ; and
if this nitrogen proceed from metamorphosed tissues,
then, if all the carbon of these tissues passed into
the bile, it would yield, at the utmost, a quantity of
bile corresponding to 7*15 oz. of carbon. This is,
however, far below the quantity which, according to
observation, is secreted in this class of animals.

44. Other substances, besides compounds of pro-
teine, must inevitably take part in the formation of
bile in the organism of the herbivora ; and these
substances can only be the non-nitrogenised con-
stituents of their food.

45. The sugar of bile of Gmelin (picromel or
biline of Berzelius), which Berzelius considers as
the chief constituent of bile, while Demar^ay as-
signs that place essentially to choleic acid, burns,

L 2

148 STARCH, &c. CONTRIBUTE TO THE

when heated in the air, like resin, yields ammoniacal
products, and when treated with acids, yields taurine
and the products of the decomposition of choleic
acid ; when acted on by alkalies, it yields ammonia
and cholic acid. At all events, the sugar of bile
contains nitrogen, and much less oxygen than starch
or sugar, but more oxygen than the oily acids.
When, in the metamorphosis of sugar of bile or
choleic acid by alkalies, wre cause the separation of
the nitrogen, wre obtain a crystallized acid, very
similar to the oily acids (cholic acid), and capable
of forming with bases salts, which have the general
characters of soaps. Nay, we may even consider
the chief constituents of the bile, sugar of bile and
choleic acid, as compounds of oily acids with organic
oxides, like the fat oils, and only differing from
these in containing no oxide of glycerule. Choleic
acid, for example, may be viewed as a compound of
choloidic acid with allantoine and water :

Choloidic acid. Allantoine. Water. Choleic acid.
,2 + C4N2H303 + H707 = C^H^

Or as a compound of cholic acid, urea, and water :

Cholicacid. Urea. Water. Choleic acid.
+ C2N2H402 + H202

46. If, in point of fact, as can hardly be doubted,
the elements of such substances as starch, sugar,
&c., take part in the production of bile in the
organism of the herbivora, there is nothing opposed
to such a view in the composition of the chief

FORMATION OF BILE IN HERBIVORA. 149

constituents of bile, as far as our knowledge at
present extends.

If starch be the chief agent in this process, it
can happen in no other way but this — that, as when
it passes into fat, a certain quantity of oxygen is
separated from the elements of the starch, which,
for the same amount of carbon (for 72 atoms), con-
tains five times as much oxygen as choloidic acid.

Without the separation of oxygen from the ele-
ments of starch, it is impossible to conceive its
conversion into bile ; and this separation being ad-
mitted, its conversion into a compound interme-
diate in composition between starch and fat offers
no difficulty.

47. Not to render these considerations a mere
idle play with formulae, and not to lose sight of our
chief object, we observe, therefore, that the consi-
deration of the quantitative proportion of the bile
secreted in the herbivora leads to the following
conclusions : —

The chief constituents of the bile of the herbi-
vora contain nitrogen, and this nitrogen is derived
from compounds of proteine.

The bile of this class of animals contains more
carbon than corresponds to the quantity of nitro-
genised food taken, or to the portion of tissue that
has undergone metamorphosis in the vital process.

A part of this carbon must, therefore, be derived
from the non-nitrogenised parts of the food (starch,
sugar, &c.) ; and in order to be converted into a

150 PRODUCTION OF HIPPURIC ACID

nitrogenised constituent of bile, a part of the ele-
ments of these bodies must necessarily have com-
bined with a nitrogenised compound derived from a
compound of proteine.

In reference to this conclusion, it is quite indif-
ferent whether that compound of proteine be de-
rived from the food or from the tissues of the body.

48. It has very lately been stated by A. Ure,
that benzoic acid, when administered internally,
appears in the urine in the form of hippurie acid.

Should this observation be confirmed,* it will ac-
quire great physiological significance, since it would
plainly prove that the act of transformation of the
tissues in the animal body, under the influence of
certain matters taken in the food, assumes a new
form with respect to the products which are its
result ; for hippurie acid contains the elements of
lactate of urea, with the addition of those of benzoic
acid :

1 at. urea C2N2H4O21 f

2 at. crystallized hippurie acid

1 at. lactic acid... C6 H4 O4 \=>

2 at. benzoic acid C^ H10O6

H = 2(C18NH906)

49. If we consider the act of transformation of
the tissues in the herbivora as wre have done in the

* The analysis of the crystals deposited from the urine on the
addition of muriatic acid has not been performed. Besides, the
statement of A. Ure, that hippurie acid, dissolved in nitric acid,
is reddened by ammonia, is erroneous, and shews that the crys-
tals he obtained must have contained uric acid.

IN THE URINE OF HERBIVORA. 151

carnivora, then the blood of the former must yield,
as the last products of the metamorphosis, from all
the organs taken together, choleic acid, uric acid,
and ammonia (see p. 136) ; and if we ascribe to the
uric acid an action similar to that of the benzoic
acid in Ure's observation — such, namely, that the
further transformation, owing to the presence of
this acid, assumes another form, the elements of the
uric acid being incorporated in the final products —
it will appear, for example, that 2 at. of proteine,
with the addition of the elements of 3 at. of uric
acid and 2 at. of oxygen, might give rise to the pro-
duction of hippuric acid and urea.

2 at. proteine, 2 (C^N^O,,) == C% N^

3 at. uric acid, 3 (C10N4H4 OG ) = C^ N12H12O18
2 at. oxygen O2

Thesumis ...............

J6 at. hippuric acid, 6 (C18N H8O5) = C108N
\9 at. urea ......... 9 (C2N2H4O2) = C^N

Thesumis

50. Finally, if we bear in mind, that, in the her-
bivora, the non-nitrogenised constituents of their
food (starch, &c.) must, as we have shewn, play an
essential part in the formation of the bile ; that to
their elements must of necessity be added those of
a nitrogenised compound, in order to produce the
nitrogenised constituents of the bile, the most strik-
ing result of the combinations thus suggested is
this, that the elements of starch added to those of

152 PRODUCTION OF THE CHIEF

hippuric acid are equal to the elements of choleic
acid, plus a certain quantity of carbonic acid :
2 at. hippuric acid, 2 (C18NH8 O5 ) = C36N2H16O10

5 at. starch 5 (C12 Hi0O,0) = Cw H.x£>-M

2 at. oxygen O.2

The sum is =

f 2 at. choleic acid 2 (CagNHjAO =
[20 at. carbonic acid 20 (C O2 ) =

The sum is =

51. Now, since hippuric acid may be derived,
along with urea, from the compounds of proteine,
when to the elements of the latter are added those
of uric acid (see p. 151) ; since, further, uric acid,
choleic acid, and ammonia contain the elements of
proteine in a proportion almost identical with that
of proteine itself (see p. 136) ; it is obvious that, if
from 5 at. of proteine, with the addition of oxygen
and of the elements of water, there be removed the
elements of choleic acid and ammonia, the re-
mainder will represent the elements of hippuric
acid and of urea ; and that if, when this separation
occurs, and during the further transformation, the
elements of starch be present and enter into the
new products, we shall obtain an additional quantity
of choleic acid, as well as a certain amount of car-
bonic acid gas.

That is to say — that if the elements of proteine and
starch, oxygen and water being also present, undergo
transformation together and mutually affect each other,
we obtain, as the products of this metamorphosis, urea,

SECRETIONS AND EXCRETIONS. 153

choleic acid, ammonia, and carbonic acid, and besides
these, no other product whatever.
The elements of

5 at. proteine "J f 9 at. choleic acid
15 at. starch | I 9 at. urea
12 at. water | j 3 at. ammonia
5 at. oxygen J [60 at. carbonic acid
In detail —

5 at. proteine, 5 (C^H^Ou) =
15 at. starch, 15 (Ci2 Hi0Ow) =
12 at. water, 12 ( HO ) = H12 O12

5 at. oxygen O5

The sum is .................. = C420N30H342O237

and—

9 at. choleic acid, 9 (C^N H^On) = C^Ng H^Og.,
9 at. urea, ......... 9 (C2N2H4O2) = C18N18H36O18

3 at. ammonia, ... 3 ( N H3 )= N3H9
60 at. carbonic acid, 60 (C O2 ) = Cw O120

The sum is

The transformation of the compounds of proteine
present in the body is effected by means of the
oxygen conveyed by the arterial blood, and if the
elements of starch, rendered soluble in the stomach,
and thus carried to every part, enter into the newly
formed compounds, we have the chief constituents
of the animal secretions and excretions ; carbonic
acid, the excretion of the lungs, urea and carbonate
of ammonia, excreted by the kidneys, and choleic
acid, secreted by the liver.

Nothing, therefore, in the chemical composition
of those matters which may be supposed to take a

154 SODA ESSENTIAL TO THE

share in these metamorphoses, is opposed to the
supposition that a part of the carbon of the non-
azotised food enters into the composition of the bile.
52. Fat, in the animal body, disappears when
the supply of oxygen is abundant. When that sup-
ply is deficient, choleic acid may be converted into
hippuric acid, lithofellic acid, (37) and water. Li-
thofellic acid is known to be the chief constituent
of the bezoar stones, which occur in certain herbi-

vorous animals :

C 2 at. hip. acid C^H^Ou
2at.chole1cac1dC76N2H660,=f iat>lit^ac.d ^ —

\14 at. water ... HMOM

53. For the production of bile in the animal
body a certain quantity of soda is, in all circum-
stances, necessary ; without the presence of a com-
pound of sodium no bile can be formed. In the
absence of soda, the metamorphosis of the tissues
composed of proteine can yield only fat and urea.
If we suppose fat to be composed according to the
empirical formula CnH100, then, by the addition of
oxygen and the elements of water to the elements
of proteine, we have the elements of fat, urea, and
carbonic acid.

Proteine. Water. Oxygen.

2 (C^NeHsA.,) -f 12 HO + 14 O = C96N12H84OM =
r 6 at. urea ......... = C12Ni2H24O12

= ) Fat ............... = CBS HeA,

I 18 at. carbonic acid = C18 O3S

FORMATION OF THE BILE. 155

The composition of all fats lies between the em-
pirical formulae CnH10O and C12H100. If we adopt
the latter, then the elements of 2 at. proteine, with
the addition of 2 at. oxygen and 12 at. water, will
yield 6 at. urea, fat (C72H6006), and 12 at. carbonic
acid.

It is worthy of observation, in reference to the
production of fat, that the absence of common salt
(a compound of sodium which furnishes soda to the
animal organism) is favourable to the formation of
fat ; that the fattening of an animal is rendered
impossible, when we add to its food an excess of
salt, although short of the quantity required to pro-
duce a purgative effect.

54. As a kind of general view of the metamor-
phoses of the nitrogenised animal secretions, atten-
tion may here be very properly directed to the
fact, that the nitrogenised products of the transfor-
mation of the bile are identical in ultimate compo-
sition with the constituents of the urine, if to the
latter be added a certain proportion of the elements
of water :

1 at. uric acid

:id C10N4H4O6^

...W«*L{!*

H2aoffl L3

1 at. urea ... C, N2H4 O2 (.=* " "" t& ^ „ __
22 at. water »- f 1 3 at. ammoma N3Hg

1 at. allantoine C4N2H3 O3 "I _ [1 at. taurine C4 N H7 O10
7 at. water ... H7 O7 J ^1 at. ammonia N H3

C4N2H10010 C4N2H10010

55. In reference to the metamorphoses of uric

156 RELATION OF URINE TO BILE.

acid and of the products of the transformation of
the bile, it is not less significant, and worthy of
remark, that the addition of oxygen and the ele-
ments of water to the elements of uric acid may
yield either taurine and urea, or taurine, carbonic
acid, and ammonia.

1 at. uric acid C10N4H4 O6 -i

f2 at. taurine C8 N2H14O2o

14 at. water H14OM l=J

rt ( | 1 at. urea ... C2N2H O2

2 at. oxygen ... O2 I

2 at.' taurine .

2 at. carbon, acid C2 O4

2 at. ammonia N2H6

56. Alloxan, plus a certain amount of water, is
identical in the proportion of elements with taurine ;
and finally, taurine contains the elements of super-
oxalate of ammonia.

1 at. alloxan* C8N2H4 O10"| Taurine.

10 at. water H10O10/ = 2 (C^NHAo)

{2 at. oxalic acid C4 O6
1 at. ammonia NH3
4 at. water ... H4O4

C4NH7O10

* It would be most interesting to investigate the action of
alloxan on the human body. Two or three drachms, in crystals,
had no injurious action on rabbits to which it was given. In
man, a large dose appeared to act only on the kidneys. In
certain diseases of the liver, alloxan would very probably be
found a most powerful remedy. — J. L.

RELATION OF STARCH TO BILE. 157

57. The comparison of the amount of carbon in
the bile secreted by an herbivorous animal, with the
quantity of carbon of its tissues, or of the nitrogen-
ised constituents of its food, which in consequence
of the constant transformations may pass into bile,
indicates, as we have just seen, a great difference.

The carbon of the bile secreted amounts, at least,
to more than five times the quantity of that which
could reach the liver in consequence of the change
of matter in the body, either from the metamor-
phosed tissues or from the nitrogenised constituents
of the food ; and we may regard as well founded the
supposition that the non-azotised constituents of
the food take a decided share in the production of
bile in the herbivora ; for neither experience nor
observation contradicts this opinion.

58. We have given, in the foregoing paragraphs,
the analytical proof, that the nitrogenised products
of the transformation of bile, namely, taurine and
ammonia, may be formed from all the constituents
of the urine, with the exception of urea — that is,
from hippuric acid, uric acid, and allantoine; and
when we bear in mind that, by the mere separation
of oxygen and the elements of water, choloidic acid
may be formed from starch ; —

From 6 at. starch = 6 (C12H10O10) = C^M^Oso
Subtract 44 at. oxygen"] _ H Q

4 at. water J =

Remains choloidic acid = C^H56O12 ; —

that, finally, choloidic acid, ammonia, and taurine,

158 RELATION OF STARCH, &c. TO BILE.

if added together, contain the elements of choleic

acid; —

1 at. choloidic acid = C73 H^O^

1 at. taurine = C4N H7 O,0

1 at. ammonia ... = N H3

1 at. oholeic acid =

if all this be considered, every doubt as to the pos-
sibility of these changes is removed.

59. Chemical analysis and the study of the living
animal body mutually support each other; and
both lead to the conclusion that a certain portion
of the carbon of the non-azotised constituents of
food (of starch, &c., the elements of respiration)
is secreted by the liver in the form of bile ; and
further, that the nitrogenised products of the trans-
formation of tissues in the herbivora do not, as in
the carnivora, reach the kidneys immediately or
directly, but that, before their expulsion from the
body in the form of urine, they take a share in cer-
tain other processes, especially in the formation of
the bile.

They are conveyed to the liver with the non-
azotised constituents of the food ; they are returned
to the circulation in the form of bile, and are not
expelled by the kidneys till they have thus served
for the production of the most important of the sub-
stances employed in respiration.

60. When the urine is left to itself, the urea
which it contains is converted into carbonate of
ammonia ; the elements of urea are in such propor-

ORIGIN OF THE BILE. 159

tion, that by the addition of the elements of water,
all its carbon is converted into carbonic acid, and all
its nitrogen into ammonia.

1 at. urea C2N2H4O2~^ J"2 at. carbonic acid C2 O4

2 at. water H2OJ='[_2 at. ammonia ... N2H6

C2N2H604 C2N2H604

61. Were we able directly to produce taurine
and ammonia out of uric acid or allantoine, this
might perhaps be considered as an additional proof
of the share which has been ascribed to these com-
pounds in the production of bile ; it cannot, how-
ever, be viewed as any objection to the views above
developed on the subject, that, with the means we
possess, we have not yet succeeded in effecting
these transformations out of the body. Such an
objection loses all its force, when \ve consider that
we cannot admit, as proved, the pre-existence of
taurine and ammonia in the bile ; nay, that it is not
even probable that these compounds, which are
only known to us as products of the decomposition
of the bile, exist ready formed, as ingredients of
that fluid.

By the action of muriatic acid on bile, we, in a
manner, force its elements to unite in such forms
as are no longer capable of change under the influ-
ence of the same re-agent; and when, instead of
the acid, we use potash, we obtain the same ele-
ments, although arranged in another, and quite a
different manner. If taurine were present, ready

160 ORIGIN OF THE BILE.

formed, in bile, we should obtain the same products
by the action of acids and of alkalies. This, how-
ever, is contrary to experience.

Thus, even if we could convert allantoine, or uric
acid and urea, into taurine and ammonia, out of the
body, we should acquire no additional insight into
the true theory of the formation of bile, just because
the pre-existence of ammonia and taurine in the
bile must be doubted, and because we have no rea-
son to believe that urea or allantoine, as such, are
employed by the organism in the production of bile.
We can prove that their elements serve this pur-
pose, but we are utterly ignorant how these ele-
ments enter into these combinations, or what is the
chemical character of the nitrogenised compound
which unites with the elements of starch to form
bile, or rather choleic acid.

62. Choleic acid may be formed from the ele-
ments of starch with those of uric acid and urea, or
of allantoine, or of uric acid, or of alloxan, or of ox-
alic acid and ammonia, or of hippuric acid. The
possibility of its being produced from so great a va-
riety of nitrogenised compounds is sufficient to
shew that all the nitrogenised products of the meta-
morphosis of the tissues may be employed in the
formation of bile, while we cannot tell in what pre-
cise way they are so employed.

By the action of caustic alkalies allantoine may
be resolved into oxalic acid and ammonia ; the
same products are obtained when oxamide is acted

VITAL METAMORPHOSES. 161

on by the same re-agents. Yet we cannot, from
the similarity of the products, conclude that these
two compounds have a similar constitution. In like
manner the nature of the products formed by the
action of acids on choleic acid does not entitle us
to draw any conclusion as to the form in which its
elements are united together.

63. If the problem to be solved by organic che-
mistry be this, namely, to explain the changes which
the food undergoes in the animal body ; then it is
the business of this science to ascertain what ele-
ments must be added, what elements must be se-
parated, in order to effect, or, in general, to ren-
der possible, the conversion of a given compound
into a second or a third; but we cannot expect
from it the synthetic proof of the accuracy of the
views entertained, because every thing in the orga-
nism goes on under the influence of the vital force,
an immaterial agency, which the chemist cannot
employ at will.

The study of the phenomena which accompany
the metamorphoses of the food in the organism, the
discovery of the share which the atmosphere or the ele-
ments of water take in these changes, lead at once
to the conditions which must be united in order to
the production of a secretion or of an organized part.

64. The presence of free muriatic acid in the
stomach, and that of soda in the blood, prove beyond
all doubt the necessity of common salt for the or-
ganic processes ; but the quantities of soda required

162 USES OF COMMON1 SALT

by animals of different classes, to support the vital
processes, are singularly unequal.

If we suppose, that a given amount of blood,
considered as a compound of soda, passes, in the
body of a carnivorous animal, in consequence of the
change of matter, into a new compound of soda,
namely, the bile, we must assume, that in the nor-
mal condition of health, the proportion of soda in
the blood is amply sufficient to form bile with the
products of transformation. The soda which has
been used in the vital processes, and any excess of
soda, must be expelled in the form of a salt, after
being separated from the blood by the kidneys.

Now, if it be true, that, in the body of an herbivo-
rous animal, a much larger quantity of bile is pro-
duced than corresponds to the amount of blood
formed or transformed in the vital processes ; if the
greater part of the bile, in this case, proceeds from
the non-azotised constituents of the food, then the
soda of the blood which has been formed into or-
ganised tissue (assimilated or metamorphosed) can-
not possibly suffice for the supply of the daily secre-
tion of bile. The soda, therefore, of the bile of the
herbivora must be supplied directly in the food ;
their organism must possess the power of applying
directly to the formation of bile all the compounds
of soda present in the food, and decomposable by
the organic process. All the soda of the animal
body obviously proceeds from the food ; but the
food of the carnivora contains, at most, only the

IN THE ORGANIC PROCESSES. 163

amount of soda necessary to the formation of blood ;
and in most cases, among animals of this class, we
may assume that only as much soda as corresponds
to the proportion employed to form the blood is
expelled in the urine.

When the carnivora obtain in their food as much
soda as suffices for the production of their blood, an
equal amount is excreted in the urine ; when the
food contains less, a part of that which would other-
wise be excreted is retained by the organism.

All these statements are most unequivocally con-
firmed by the composition of the urine in these
different classes of animals.

65. As the ultimate product of the changes of
all compounds of soda in the animal body, we find
in the urine the soda in the form of a salt, and the
nitrogen in that of ammonia or urea.

The soda in the urine of the carnivora is found
in combination with sulphuric and phosphoric acids ;
and along with the sulphate and phosphate of soda
we never fail to find a certain quantity of a salt of
ammonia, either muriate or phosphate of ammonia.
There can be no more decisive evidence in favour
of the opinion, that the soda of their bile or of the
metamorphosed constituents of their blood is very
far from sufficing to neutralize the acids which are
separated, than the presence of ammonia in their
urine. This urine, moreover, has an acid re-action.

In contradistinction to this, we find, in the urine
of the herbivora, soda in predominating quantity;
.M 2

164 LARGE AMOUNT OF ALKALIES

and that not combined with sulphuric or phosphoric
acids, but with carbonic, benzoic, or hippuric acids.

66. These well-established facts demonstrate
that the herbivora consume a far larger quantity
of soda than is required merely for the supply of
the daily consumption of blood. In their food are
united all the conditions for the production of a
second compound of soda, destined for the support
of the respiratory process ; and it can only be a very
limited knowledge of the vast wisdom displayed in
the arrangements of organized nature which can
look on the presence of so much soda in the food
and in the urine of the herbivora as accidental.

It cannot be accidental, that the life, the develope-
ment of a plant is dependant on the presence of the
alkalies which it extracts from the soil. This plant
serves as food to an extensive class of animals, and
in these animals the vital process is again most
closely connected with the presence of these alkalies.
We find the alkalies in the bile, and their presence
in the animal body is the indispensable condition
for the production of the first food of the young
animal ; for without an abundant supply of potash,
the production of milk becomes impossible.

67. All observation leads, as appears from the
preceding exposition, to the opinion, that certain
non-azotised constituents of the food of the herbi-
vora (starch, sugar, gum, &c.) acquire the form of
a compound of soda, which, in their bodies, serves
for the same purpose as that which we know cer-

REQUIRED BY THE HERBIVORA. 165

tainly to be served by the bile (the most highly car-
bonized product of the transformation of their tissues)
in the bodies of the carnivora. These substances
are employed to support certain vital actions, and
are finally consumed in the generation of animal
heat, and in furnishing means of resistance to the
action of the atmosphere. In the carnivora, the
rapid transformation of their tissues is a condition of
their existence, because it is only as the result of
the change of matter in the body that those sub-
stances can be formed, which are destined to enter
into combination with the oxygen of the air ; and
in this sense we may say that the non-azotised con-
stituents of the food of the herbivora impede the
change of matter, or retard it, and render unneces-
sary, at all events, so rapid a process as occurs in
the carnivora.

68. The quantity of azotised matter, proportion-
ally so small, which the herbivora require to sup-
port their vital functions, is closely connected with
the power possessed by the non-azotised parts of
their food to act as means of supporting the respi-
ratory process ; and this consideration seems to
render it not improbable, that the necessity for
more complex organs of digestion in the herbivora
is rather owing to the difficulty of rendering soluble
and available for the vital processes certain non-
azotised compounds (gum ? amylaceous fibre ?) than
to any thing in the change or transformation of
vegetable fibrine, albumen, and caseine into blood;

166 STARCH, ETC. ASSIST IN FORMING

since, for this latter purpose, the less complex di-
gestive apparatus of the carnivora is amply suffi-
cient.

69. If, in man, when fed on a mixed diet, starch
perform a similar part to that which it plays in the
body of the herbivora ; if it be assumed that the
elements of starch are equally necessary to the for-
mation of the bile in man as in these animals ; then
it follows that a part of the azotised products of the
transformation of the tissues in the human body,
before they are expelled through the bladder, re-
turns into the circulation from the liver in the shape
of bile, and is separated by the kidneys from the
blood, as the ultimate product of the respiratory
process.

70. When there is a deficiency of non-azotised
matter in the food of man, this form of the produc-
tion of bile is rendered impossible. In that case,
the secretions must possess a different composition ;
and the appearance of uric acid in the urine, the
deposition of uric acid in the joints and in the
bladder, as well as the influence which an excess of
animal food (which must be considered equivalent to
a deficiency of starch, &c.) exercises on the separa-
tion of uric acid in certain individuals, may be
explained on this principle. If starch, sugar, &c.,
be deficient, then a part of the azotised compounds
formed during the change of matter will either
remain in the situation where they have been
formed, in which case they will not be sent from

BILE IN THE HUMAN BODY. 167

the liver into the circulation, and therefore will not
undergo the final changes dependant on the action
of oxygen ; or they will be separated by the kid-
neys in some form different from the normal one.

71. In the preceding paragraphs I have endea-
voured to prove that the non-azotised constituents
of food exercise a most decided influence on the
nature and quality of the animal secretions. Whe-
ther this occur directly ; whether, that is to say,
their elements take an immediate share in the act
of transformation of tissues ; or whether their share
in that process be an indirect one, is a question
probably capable of being resolved by careful and
cautious experiment and observation. It is possible,
that the non-azotised constituents of food, after
undergoing some change, are carried from the intes-
tinal canal directly to the liver, and that they are
converted into bile in this organ, where they meet
with the products of the metamorphosed tissues,
and subsequently complete their course through the
circulation.

This opinion appears more probable, when we
reflect that as yet no trace of starch or sugar has
been detected in arterial blood, not even in animals
which had been fed exclusively with these sub-
stances. We cannot ascribe to these substances,
since they are wanting in arterial blood, any share
in the nutritive process ; and the occurrence of
sugar in the urine of those affected with diabetes
mellitus (which sugar, according to the best obser-

168 ORIGIN OF THE NITROGEN

vations, is derived from the food) coupled with its
total absence in the blood of the same patients, ob-
viously proves that starch and sugar are not, as such,
taken into the circulation.

72. The writings of physiologists contain many
proofs of the presence of certain constituents of the
bile in the blood of man in a state of health, al-
though their quantity can hardly be determined.
Indeed, if we suppose 8£ Ibs. (58,000 grs.) of blood
to pass through the liver every minute, and if from
this quantity of blood 2 drops of bile (3 grains to
the drop) are secreted, this would amount to Wooth
part of the wreight of the blood, a proportion far too
small to be quantitatively ascertained by analysis.

73. The greater part of the bile in the body of
the herbivora, and in that of man fed on mixed
food, appears from the preceding considerations to
be derived from the elements of the non-azotised
food. But its formation is impossible without the
addition of an azotised body, for the bile is a com-
pound of nitrogen. All varieties of bile yet exa-
mined yield, when subjected to dry distillation,
ammonia and other nitrogenised products. Taurine
and ammonia may easily be extracted from ox bile ;
and the only reason why we cannot positively prove
that the same products may be obtained from the
bile of other animals is this, that it is not easy to
procure, in the case of many of these animals, a
sufficient quantity of bile for the experiment.

Now, whether the nitrogenised compound which

CONTAINED IN HUMAN BILE. 1G9

unites with the elements of starch to form bile be
derived from the food or from the substance of the
metamorphosed tissues, the conclusion that its pre-
sence is an essential condition for the secretion of
bile cannot be considered doubtful.

Since the herbivora obtain in their food only such
nitrogenised compounds as are identical in composi-
tion with the constituents of their blood, it is at all
events clear, that the nitrogenised compound which
enters into the composition of bile is derived from
a compound of proteine. It is either formed in
consequence of a change which the compounds of
proteine in the food have undergone, or it is pro-
duced from the blood or from the substance of the
tissues by the act of their metamorphosis.

74. If the conclusion be accurate, that nitrogen-
ised compounds, whether derived from the blood or
from the food, take a decided share in the formation
of the secretions, and particularly of the bile, then
it is plain that the organism must possess the power
of causing foreign matters, which are neither parts
nor constituents of the organs in which vital activity
resides, to serve for certain vital processes. All nitro-
genised substances capable of being rendered soluble,
without exception, when introduced into the organs
of circulation or of digestion, must, if their compo-
sition be adapted for such purposes, be employed by
the organism in the same manner as the nitrogen-
ised products which are formed in the act of meta-
morphosis of tissues.

170 CERTAIN REMEDIES TAKE A

We are acquainted with a multitude of sub-
stances, which exercise a most marked influence on
the act of transformation as well as on the nutritive
process, while their elements take no share in the
resulting changes. These are uniformly substances
the particles of which are in a certain state" of
motion or decomposition, which state is communi-
cated to all such parts of the organism as are ca-
pable of undergoing a similar transformation.

75. Medicinal and poisonous substances form
a second and most extensive class of compounds,
the elements of which are capable of taking a direct
or an indirect share in the processes of secretion
and of transformation. These may be subdivided
into three great orders; the first (which includes
the metallic poisons) consists of substances which
enter into chemical combination with certain parts
or constituents of the body, while the vital force
is insufficient to destroy the compounds thus formed.
The second division, consisting of the essential oils,
camphor, empyreumatic substances, and antiseptics,
&c., possesses the property of impeding or retarding
those kinds of transformation to which certain very
complex organic molecules are liable; transforma-
tions which, when they take place out of the body,
are usually designated by the names of fermentation
and putrefaction.

The third division of medicinal substances is
composed of bodies, the elements of which take a
direct share in the changes going on in the animal

SHARE IN THE VITAL TRANSFORMATIONS. 171

body. When introduced into the system, they
augment the energy of the vital activity of one or
more organs ; they excite morbid phenomena in the
healthy body. All of them produce a marked effect
in a comparatively small dose, and many are poi-
sonous when administered in larger quantity. None
of the substances in this class can be said to take a
decided share in the nutritive process, or to be em-
ployed by the organism in the production of blood ;
partly, because their composition is different from
that of blood, and, partly, because the proportion in
which they must be given, to exert their influence, is
as nothing, compared with the mass of the blood.

These substances, when taken into the circula-
tion, alter, as is commonly said, the quality of the
blood, and in order that they may pass from the
stomach into the circulation with their entire effi-
cacy, we must assume that their composition is not
affected by the organic influence of the stomach.
If insoluble when given, they are rendered soluble
in that organ, but they are not decomposed ; other-
wise, they would be incapable of exerting any influ-
ence on the blood.

76. The blood, in its normal state, possesses two
qualities closely related to each other, although we
may conceive one of them to be quite independent
of the other.

The blood contains, in the form of the globules,
the carriers, as it were, of the oxygen which serves
for the production of certain tissues, as well as for

172 ARTERIAL BLOOD ACTS BY ITS

the generation of animal heat. The globules of
the blood, by means of the property they possess
of giving off the oxygen they have taken up in
the lungs, without losing their peculiar character,
determine generally the change of matter in the
body.

The second quality of the blood, namely, the
property which it possesses of becoming part of an
organised tissue, and its consequent adaptation to
promote the formation and the growth of organs, as
well as to the reproduction or supply of waste in
the tissues, is owing, chiefly, to the presence of dis-
solved fibrine and albumen. These two chief con-
stituents, wrhich serve for nutrition and reproduc-
tion of matter, in passing through the lungs are
saturated with oxygen, or, at all events, absorb so
much from the atmosphere as entirely to lose the
power of extracting oxygen from the other sub-
stances present in the blood.

77. We know for certain that the globules of
the venous blood, when they come in contact with
air in the lungs, change their colour, and that this
change of colour is accompanied by an absorption of
oxygen ; and that all those constituents of the blood,
which possess in any degree the power of combining
with oxygen, absorb it in the lungs, and become sa-
turated with it. Although in contact with these
other compounds, the globules, when arterialised,
retain their florid, red colour in the most minute
ramifications of the arteries ; and we observe them

OXYGEN, FIBRINE, AND ALBUMEN. 173

to change their colour, and to assume the dark red
colour which characterizes venous blood, only during
their passage through the capillaries. From these
facts we must conclude that the constituents of
arterial blood are altogether destitute of the power
to deprive the arterialised globules of the oxygen
which they have absorbed from the air ; and we
can draw no other conclusion from the change of
colour which occurs in the capillaries, than that the
arterialised globules, during their passage through
the capillaries, return to the condition which cha-
racterized them in venous blood ; that, consequently,
they give up the oxygen absorbed in the lungs, and
thus acquire* the power of combining with that
element afresh.

78. We find, therefore, in arterial blood, albu-
men, which, like all the other constituents of that
fluid, has become saturated with oxygen in its pas-
sage through the lungs, and oxygen gas, which is
conveyed to every particle in the body in chemical
combination with the globules of the blood. As
far as our observations extend (in the developement
of the chick during incubation), all the conditions
seem to be here united which are necessary to the
formation of every kind of tissue ; while that por-
tion of oxygen which is not consumed in the growth
or reproduction of organs combines with the sub-
stance of the living parts, and produces, by its
union with their elements, the act of transforma-
tion which we have called the change of matter.

174 MODUS OPERANDI OF

79. It is obvious, that all compounds, of what-
ever kind, which are present in the capillaries,
whether separated there, or introduced by endos-
mosis or imbibition, if not altogether incapable of
uniting with oxygen, must, when in contact with
the arterialised globules, the carriers of oxygen, be
affected exactly in the same way as the solids form-
ing part of living organs. These compounds, or their
elements, will enter into combination with oxygen,
and in this case there will either be no change of
matter, or that change will exhibit itself in another
form, yielding products of a different kind.

80. The conception, then, of a change in the two
qualities of the blood above alluded to, by means of
a foreign body contained in the blood or introduced
into the circulation (a medicinal agent), presupposes
two kinds of operation.

Assuming that the remedy cannot enter into any
such chemical union with the constituents of the
blood as puts an end to the vital activity ; assuming,
further, that it is not in a condition of transforma-
tion capable of being communicated to the consti-
tuents of the blood or of the organs, and of continu-
ing in them ; assuming, lastly, that it is incapable,
by its contact with the living parts, of putting a
stop to the change of matter, the transformation
of their elements ; then, in order to discover the
modus operandi of this class of medicinal agents,
nothing is left but to conclude that their elements
take a share in the formation of certain constituents

ORGANIC REMEDIAL AGENTS. 175

of the living body, or in the production of certain
secretions.

81. The vital process of secretion, in so far as it
is related to the chemical forces, has been subjected
to examination in the preceding pages. In the car-
nivora we have reason to believe, that, without the
addition of any foreign matter in the food, the bile
and the constituents of the urine are formed in
those parts where the change of matter takes place.
In other classes of animals, on the other hand, we
may suppose that in the organ of secretion itself,
the secreted fluid is produced from certain matters
conveyed to it ; in the herbivora, for example, the
bile is formed from the elements of starch along
with those of a nitrogenised product of the meta-
morphosis of the tissues. But this supposition by
no means excludes the opinion, that in the carni-
vora the products of the metamorphosed tissues are
resolved into bile, uric acid, or urea, only after reach-
ing the secreting organ ; nor the opinion that the
elements of the non-azotise^ food, conveyed directly
by the circulation to every part of the body, where
change of matter is going on, may there unite with
the elements of the metamorphosed tissues," to form
the constituents of the bile and of the urine.

82. If we now assume, that certain medicinal
agents may become constituents of secretions, this
can only occur in two ways. Either they enter the
circulation, and take a direct share in the change of
matter, in so far as their elements enter into the

176 NITROGENISED ORGANIC REMEDIES.

composition of the new products ; or they are con-
veyed to the organs of secretion, where they exert
an influence on the formation or on the quality of a
secretion by the addition of their elements.

In either case, they must lose in the organism
their chemical character ; and we know with suffi-
cient certainty, that this class of medicinal bodies
disappears in the body without leaving a trace. In
fact, if we ascribe to them any effect, they cannot
lose their peculiar character by the action of the
stomach ; their disappearance, therefore, presupposes
that they have been applied to certain purposes,
which cannot be imagined to occur without a change
in their composition.

83. Now, however limited may be our knowledge
of the composition of the different secretions, with
the exception of the bile, this much is certain, that
all the secretions contain nitrogen chemically com-
bined. They pass into fetid putrefaction, and yield
either in this change, or in the dry distillation, am-
moniacal products. Even the saliva, when acted on
by caustic potash, disengages ammonia freely.

84. Medicinal or remedial agents may be divided
into two classes, the nitrogenised and the non-ni-
trogenised. The nitrogenised vegetable principles,
whose composition differs from that of the proper
nitrogenised elements of nutrition, also produced by
a vegetable organism, are distinguished, beyond all
others, for their powerful action on the animal eco-
nomy.

VEGETABLE ALKALIES, ETC. 177

The effects of these substances are singularly
varied; from the mildest form of the action of
aloes, to the most terrible poison, strychnia, we
observe an endless variety of different actions.

With the exception of three, all these substances
produce diseased conditions in the healthy organ-
ism, and are poisonous in certain doses. Most of
them are, chemically speaking, basic or alkaline.

No remedy, devoid of nitrogen, possesses a poison-
ous action in a similar dose.*

85. The medicinal or poisonous action of the
nitrogenised vegetable principles has a fixed rela-
tion to their composition ; it cannot be supposed
to be independent of the nitrogen they contain,
but is certainly not in direct proportion to the quan-
tity of nitrogen.

Solanine (38), and picrotoxine (39), which con-
tain least nitrogen, are powerful poisons. Quinine
(40) contains more nitrogen than morphia (41).
Caffeine (42), and theobromine, the most highly
nitrogenised of all vegetable principles, are not
poisonous.

86. A nitrogenised body, which exerts, by means
of its elements, an influence on the formation or on
the quality of a secretion, must, in regard to its

* This consideration or comparative view has led lately to a
more accurate investigation of the composition of picrotoxine,
the poisonous principle of cocculus indicus ; and M. Francis has
discovered the existence of nitrogen in it, hitherto overlooked,
and has also determined its amount.

178 MODE OF ACTION OF NITROGENISED

chemical character, be capable of taking the same
share as the nitrogenised products of the animal
body do in the formation of the bile ; that is, it
must play the same part as a product of the vital
process. On the other hand, a non-azotised medi-
cinal agent, in so far as its action affects the secre-
tions, must be capable of performing in the animal
body the same part as that which we have ascribed
in the formation of the bile, to the non-azotised
elements of food.

Thus, if we suppose that the elements of hippuric
or uric acids are derived from the substance of the
organs in which vitality resides ; that, as products
of the transformation of these organs, they lose the
vital character, without losing the capacity of under-
going changes under the influence of the inspired
oxygen, or of the apparatus of secretion; we can
hardly doubt that similar nitrogenised compounds,
products of the vital process in plants, when intro-
duced into the animal body, may be employed by
the organism exactly in the same way as the nitro-
genised products of the metamorphosis of the ani-
mal tissues themselves. If hippuric and uric acids,
or any of their elements, can take a share, for ex-
ample, in the formation and supply of bile, we must
allow the same power to other analogous nitro-
genised compounds.

We shall never, certainly, be able to discover
how men were led to the use of the hot infusion of
the leaves of a certain shrub (tea), or of a decoction

VEGETABLE PRODUCTS! CAFFEINE. 179

of certain roasted seeds (coffee). Some cause there
must be, which would explain how the practice has
become a necessary of life to whole nations. But
it is surely still more remarkable, that the beneficial
effects of both plants on the health must be ascribed
to one and the same substance, the presence of
which in two vegetables, belonging to different
natural families, and the produce of different quar-
ters of the globe, could hardly have presented itself
to the boldest imagination. Yet recent researches
have shewn, in such a manner as to exclude all
doubt, that caffeine, the peculiar principle of coffee,
and theine, that of tea, are, in all respects, identical.

It is not less worthy of notice, that the American
Indian, living entirely on flesh, discovered for him-
self, in tobacco smoke, a means of retarding the
change of matter in the tissues of his body, and
thereby of making hunger more endurable ; and
that he cannot withstand the action of brandy,
which, acting as an element of respiration, puts
a stop to the change of matter by performing the
function which properly belongs to the products of
the metamorphosed tissues. Tea and coffee were
originally met with among nations whose diet is
chiefly vegetable.

87. Without entering minutely into the medi-
cinal action of caffeine (theine), it will surely appear
a most striking fact, even if we were to deny its
influence on the process of secretion, that this sub-
stance, with the addition of oxygen and the elements
N 2

180 RELATION OF CAFFEINE, ASPARAGINE,

of water, can yield taurine, the nitrogenised com-
pound peculiar to bile :

1 at. caffeine or theine = C8N2H5 O2
9 at. water ............ = H9 O9

9 at. oxygen ............ = O9

= 2 at. taurine..... ....... = 2 (C4NH7O10)

A similar relation exists in the case of the pecu-
liar principle of asparagus and of althaea, asparagine;
which also, by the addition of oxygen and the
elements of water, yields the elements of taurine :

1 at. asparagine = C8N2H8 O6
6 at. water ...... = H6 O6

8 at. oxygen ... = O8

= 2 at. taurine = 2 (C4NH7Oi0)

The addition of the elements of water and of a
certain quantity of oxygen to the elements of theo-
bromine, the characteristic principle of the cacao
bean (theobroma cacao), yields the elements of
taurine and urea, of taurine, carbonic acid, and
ammonia, or of taurine and uric acid :

1 at. theobromine Ci8N6H,0O4 ^ r
22 at. water ..

16 at. oxygen ... O

22 f ~] 1 at. urea... C2 N2H4 O,,
u J

or —

1 at. theobromine CJ8N6 H10O4 "j |"4 at. taurine C16N4
24 at. water ...... H24O24 > = < 2 at. carb . acid C2 O4

16 at. oxygen ...... O16J 12 at. ammonia N2 H6

C18N6H34 044

AND THEOBROMINE TO BILE AND URINE. 181

or —

1 at. theobromine CJ8N6H10O4 ^ C

8 at. water H8 O8 U 2 &t' taurine

14 at. oxygen oj [l at' Uric acid

C18N6H18026 C18N6H1802

88. To see how the action of caffeine, asparagine,
theobromine, &c., may be explained, we must call
to mind that the chief constituent of the bile
contains only 3'8 per cent, of nitrogen, of which
only the half, or 1/9 per cent., belongs to the tau-
rine.

Bile contains, in its natural state, water and solid
matter, in the proportion of 90 parts by weight of the
former to 10 of the latter. If we suppose these 10
parts by weight of solid matter to be choleic acid,
with 3'87 per cent, of nitrogen, then 100 parts of
fresh bile will contain 0*171 parts of nitrogen in
the shape of taurine. Now this quantity is con-
tained in 0*6 parts of caffeine ; or 2-fyths grains of caf-
feine can give to an ounce of bile the nitrogen it
contains in the form of taurine. If an infusion of
tea contain no more than the ^th of a grain of caf-
feine, still, if it contribute in point of fact to the
formation of bile, the action, even of such a quan-
tity, cannot be looked upon as a nullity. Neither
can it be denied that in the case of an excess of
non-azotised food and a deficiency of motion, which
is required to cause the change of matter in the tis-
sues, and thus to yield the nitrogenised product
which enters into the composition of the bile ; that

182 MODE OF ACTION OF VEGETABLE

in such a condition, the health may be benefited by
the use of compounds which are capable of sup-
plying the place of the nitrogenised product pro-
duced in the healthy state of the body, and essen-
tial to the production of an important element of
respiration. In a chemical sense — and it is this
alone which the preceding remarks are intended to
shew — caffeine or theine, asparagine, and theobro-
mine, are, in virtue of their composition, better
adapted to this purpose than all other nitrogen-
ised vegetable principles. The action of these sub-
stances, in ordinary circumstances, is not obvious,
but it unquestionably exists.

89. With respect to the action of the other nitro-
genised vegetable principles, such as quinine, or the
alkaloids of opium, &c., which manifests itself, not in
the processes of secretion, but in phenomena of an-
other kind, physiologists and pathologists entertain
no doubt that it is exerted chiefly on the brain and
nerves. This action is commonly said to be dyna-
mic— that is, it accelerates, or retards, or alters in
some way the phenomena of motion in animal life.
If we reflect that this action is exerted by sub-
stances which are material, tangible and ponder-
able ; that they disappear in the organism ; that a
double dose acts more powerfully than a single one ;
that, after a time, a fresh dose must be given, if we
wish to produce the action a second time ; all these
considerations, viewed chemically, permit only one
form of explanation ; the supposition, namely, that

ALKALIES ON THE NERVOUS SYSTEM. 183

these compounds, by means of their elements, take
a share in the formation of new, or the transforma-
tion of existing brain and nervous matter.

However strange the idea may, at first sight, ap-
pear, that the alkaloids of opium or of cinchona
bark, the elements of codeine, morphia, quinine,
&c., may be converted into constituents of brain
and nervous matter, into organs of vital energy,
from which the organic motions of the body derive
their origin ; that these substances form a consti-
tuent of that matter, by the removal of which the
seat of intellectual life, of sensation, and of con-
sciousness, is annihilated: it is, nevertheless, cer-
tain, that all these forms of power and activity are
most closely dependant, not only on the existence,
but also on a certain quality of the substance of the
brain, spinal marrow, and nerves; insomuch, that
all the manifestations of the life or vital energy of
these modifications of nervous matter, which are
recognized as the phenomena of motion, sensation,
or feeling, assume another form as soon as their
composition is altered. The animal organism has
produced the brain and nerves out of compounds
furnished to it by vegetables ; it is the constituents
of the food of the animal, which, in consequence
of a series of changes, have assumed the properties
and the structure which we find in the brain and
nerves.

90. If it must be admitted as an undeniable
truth, that the substance of the brain and nerves is

184 COMPOSITION AND ORIGIN

produced from the elements of vegetable albumen,
fibrine and caseine, either alone, or with the aid of
the elements of non-azotised food, or of the fat
formed from the latter, there is nothing absurd in
the opinion, that other constituents of vegetables,
intermediate in composition between the fats and
the compounds of proteine, may be applied in the
organism to the same purpose.

91. According to the researches of Fremy, the
chief constituent of the fat found in the brain is a
compound of soda with a peculiar acid, the cerebric
acid., which contains, in 100 parts,

Carbon 66'7

Hydrogen ... ... ...... 10'6

Nitrogen - : ..W 2'3

Phosphorus 0'9

Oxygen 19'5

It is easy to see that the composition of cerebric
acid differs entirely, both from that of ordinary fats
and of the compounds of proteine. Common fats
contain no nitrogen, while the compounds of pro-
teine contain nearly 17 per cent. Leaving the
phosphorus out of view, the composition of this
acid approaches most nearly to that of choleic acid,
although these two compounds are quite distinct.

92. Brain and nervous matter is, at all events,
formed in a manner similar to that in which bile is
produced ; either by the separation of a highly ni-
trogenised compound from the elements of blood, or
by the combination of a nitrogenised product of the

OF THE NERVOUS MATTER. 185

vital process with a non-azotised compound (pro-,
bably, a fatty body). All that has been said in the
preceding pages on the various possible ways by
which the bile might be supposed to be formed, all
the conclusions which we attained in regard to the
co-operation of azotised and non-azotised ^elements
of food, may be applied with equal justice and equal
probability to the formation and production of the
nervous substance.

We must not forget that, in whatever light we
may view the vital operations, the production of
nervous matter from blood presupposes a change in
the composition and qualities of the constituents of
blood. That such a change occurs is as certain as
that the existence of the nervous matter cannot be
denied. In this sense, we must assume, that from
a compound of proteine may be formed a first, se-
cond, third, &c., product, before a certain number of
its elements can become constituents of the nervous
matter ; and it must be considered as quite certain,
that a product of the vital process in a plant, intro-
duced into the blood, will, if its composition be
adapted to this purpose, supply the place of the first,
second, or third product of the alteration of the
compound of proteine. Indeed it cannot be consi-
dered merely accidental, that the composition of the
most active remedies, namely, the vegetable alka-
loids, cannot be shewn to be related to that of any
constituent of the body, except only the substance
of the nerves and brain. All of these contain a

186 RELATION OF VEGETABLE ALKALIES

certain quantity of nitrogen, and, in regard to their
composition, they are intermediate between the
compounds of proteine and the fats.

93. In contradistinction to their chemical charac-
ter, we find that the substance of the brain exhibits
the characters of an acid. It contains far more
oxygen than the organic bases or alkaloids. We
observe, that quinine and cinchonine, morphia and
codeine, strychnia and brucia, which are, respectively,
so nearly alike in composition, if they do not pro-
duce absolutely the some effect, yet resemble each
other in their action more than those which differ
more widely in composition. We find that their
energy of action diminishes, as the amount of oxy-
gen they contain increases (as in the case of narco-
tine), and that, strictly speaking, no one of them
can be entirely replaced by another. There cannot
be a more decisive proof of the nature of their ac-
tion than this last fact ; it must stand in the closest
relation to their composition. If these compounds,
in point of fact, are capable of taking a share in
the 'formation or in the alteration of the qualities
of brain and nervous matter, their action on the
healthy as well as the diseased organism admits of
a surprisingly simple explanation. If we are not
tempted to deny, that the chief constituent of soup
may be applied to a purpose corresponding to its
composition in the human body, or that the organic
constituent of bones may be so employed in the
body of the dog, although that substance (gelatine

TO THE NERVOUS MATTER. 187

in both cases) is absolutely incapable of yielding
blood ; if, therefore, nitrogenised compounds, to-
tally different from the compounds of proteine, may
be employed for purposes corresponding to their
composition ; we may thence conclude that a product
of vegetable life, also different from proteine, but
similar to a constituent of the animal body, may be
employed by the organism in the same way and for
the same purpose as the natural product, originally
formed by the vital energy of the animal organs,
and that, indeed, from a vegetable substance.

The time is not long gone by, when we had not
the very slightest conception of the cause of the vari-
ous effects of opium, and when the action of cinchona
bark was shrouded in incomprehensible obscurity.
Now that we know that these effects are caused by
crystallizable compounds, which differ as much in
composition as in their action on the system ; now
that we know the substances to which the medi-
cinal or poisonous energy must be ascribed, it would
argue only want of sense to consider the action of
these substances inexplicable ; and to do so, as
many have done, because they act in very minute
doses, is as unreasonable as it would be to judge of
the sharpness of a razor by its weight.

94. It would serve no purpose to give these con-
siderations a greater extension at present. How-
ever hypothetical they may appear, they only de-
serve attention in so far as they point out the way
which chemistry pursues, and which she ought not

188 THEORY OF THE ACTION OF

to quit, if she would really be of service to physio-
logy and pathology. The combinations of the che-
mist relate to the change of matter, forwards and
backwards, to the conversion of food into the various
tissues and secretions, and to their metamorphosis
into lifeless compounds ; his investigations ought to
tell us what has taken place and what can take
place in the body. It is singular that we find me-
dicinal agencies all dependant on certain matters,
which differ in composition ; and if, by the intro-
duction of a substance, certain abnormal conditions
are rendered normal, it will be impossible to reject
the opinion, that this phenomenon depends on a
change in the composition of the constituents of the
diseased organism, a change in which the elements
of the remedy take a share ; a share similar to that
which the vegetable elements of food have taken in
the formation of fat, of membranes, of the saliva, of
the seminal fluid, &c. Their carbon, hydrogen, or
nitrogen, or whatever else belongs to their compo-
sition, are derived from the vegetable organism ;
and, after all, the action and effects of quinine, mor-
phia, and the vegetable poisons in general, are no
hypotheses.

95. Thus, as we may say, in a certain sense, of
caffeine or theine and asparagine, &c., as well as
of the non-azotised elements of food, that they are
food for the liver, since they contain the elements,
by the presence of which that organ is enabled to
perform its functions, so we may consider these ni-

NITROGENISED VEGETABLE PRODUCTS. 189

trogenised compounds, so remarkable for their action
on the brain and on the substance of the organs of
motion, as elements of food for the organs as yet
unknown, which are destined for the metamorphosis
of the constituents of the blood into nervous sub-
stance and brain. Such organs there must be in
the animal body, and if, in the diseased state, an ab-
normal process of production or transformation of
the constituents of cerebral and nervous matter has
been established ; if, in the organs intended for this
purpose, the power of forming that matter out of
the constituents of blood, or the power of resisting
an abnormal degree of activity in its decomposition
or transformation, has been diminished ; then, in a
chemical sense, there is no objection to the opinion,
that substances of a composition analogous to that
of nervous and cerebral matter, and, consequently,
adapted to form that matter, may be employed, in-
stead of the substances produced from the blood,
either to furnish the necessary resistance, or to re-
store the normal condition.

96. Some physiologists and chemists have ex-
pressed doubts of the peculiar and distinct character
of cerebric acid, a substance which, from its amount
of carbon and hydrogen, and from its external cha-
racters, resembles a nitrogenised fatty acid. But
a nitrogenised fat, having an acid character, is,
in fact, no anomaly. Hippuric acid is in many of
its characters very similar to the fatty acids, but is
essentially distinguished from them by containing

190 PHOSPHORUS SEEMS ESSENTIAL

nitrogen. The organic constituents of bile resem-
ble the acid resins in physical characters, and yet
contain nitrogen. The organic alkalies are inter-
mediate in their physical characters between the
fats and resins, and they all contain nitrogen. A
nitrogenised fatty acid is as little improbable as the
existence of a nitrogenised resin with the characters
of a base.

97. An accurate investigation would probably
discover differences in the composition of the brain,
spinal marrow, and nerves. According to the ob-
servations of Valentin, the quality of the cerebral
and nervous substance is very rapidly altered from
the period of death, and very uncommon precau-
tions would be required for the separation of foreign
matters, not properly belonging to the substance of
the spinal marrow or brain. But, however difficult
it may appear, the investigation seems yet to be
practicable. We know, in the meantime, that all
experience is against the notion of a large amount
of carbon and hydrogen in the substance of the
brain. The absence of nitrogen as an element of
the cerebral and nervous matter, appears, at all
events, improbable. This substance, moreover, can-
not be classed with ordinary fats, because we find
the cerebric acid combined with soda, whereas, all
fats are compounds of fatty acids with oxide of
glycerule. In regard to the phosphorus of the
brain, we can only guess as to the form in which
the phosphorus exists. Walchner observed re-

TO THE NERVOUS MATTER. 191

cently that bubbles of spontaneously inflammable
phosphuretted hydrogen were disengaged from the
trough of a spring in Carlsruhe, on the bottom of
which fish had putrefied ; and gases containing phos-
phorus have also been observed among the products
of the putrefaction of the brain.*

* The curator of the museum at Geneva gave to M. Leroyer,
apothecary, a large quantity of spirit of wine, which had been
used for the preservation of fishes, and which he undertook to
purify. He distilled it from a mixture of chloride of calcium and
quicklime, and evaporated the residue in the air, over a fire. As
soon as the mass had acquired a certain consistence, and a higher
temperature, a prodigious quantity of spontaneously inflammable
phosphuretted hydrogen was disengaged. (Dumas, V. 267.)

PART III.

I'HE

PHENOMENA OF MOTION

IN THE

ANIMAL ORGANISM.

THE

PHENOMENA OF MOTION

IN THE

ANIMAL ORGANISM.

I.

IT might appear an unprofitable task to add one
more to the innumerable forms under which the
human intellect has viewed the nature and essence
of that peculiar cause which must be considered
as the ultimate source of the phenomena which
characterize vegetable and animal life, were it not
that certain conceptions present themselves as ne-
cessary deductions from the views on this subject
developed in the introduction to the first part of
this work. The following pages will be devoted
to a more detailed examination of these deductions.
It must be admitted here, that all these conclu-
sions will lose their force and significance, if it can
be proved that the cause of vital activity has in
its manifestations nothing in common with other
known causes which produce motion or change of
form and structure in matter.

But a comparison of its peculiarities with the

modus operandi of these other causes, cannot, at

all events, fail to be advantageous, inasmuch as

the nature and essence of natural phenomena are

o 2

196 THE PHENOMENA OF MOTION

recognizable, not by abstraction, but only by com-
parative observations.

If the vital phenomena be considered as mani-
festations of a peculiar force, then the effects of
this force must be regulated by certain laws, which
laws may be investigated ; and these laws must be
in harmony with the universal laws of resistance
and motion, which preserve in their courses the
worlds of our own and other systems, and which
also determine changes of form and structure in
material bodies; altogether independently of the
matter in which vital activity appears to reside, or
of the form in Avhich vitality is manifested.

The vital force in a living animal tissue appears
as a cause of growth in the mass, and of resistance
to those external agencies which tend to alter the
form, structure, and composition of the substance of
the tissue in which the vital energy resides.

This force further manifests itself as a cause of
motion and of change in the form and structure of
material substances, by the disturbance and abolition
of the state of rest in which those chemical forces
exist, by which the elements of the compounds
conveyed to the living tissues, in the form of food,
are held together.

The vital force causes a decomposition of the
constituents of food, and destroys the force of at-
traction which is continually exerted between their
molecules ; it alters the direction of the chemical
forces in such wise, that the elements of the con-

IN THE ANIMAL ORGANISM. 197

stituents of food arrange themselves in another
form, and combine to produce new compounds,
either identical in composition with the living
tissues, or differing from them ; it further changes
the direction and force of the attraction of co-
hesion, destroys the cohesion of the nutritious com-
pounds, and forces the new compounds to assume
forms altogether different from those which are the
result of the attraction of cohesion when acting
freely, that is, without resistance.

The vital force is also manifested as a force of
attraction, inasmuch as the new compound produced
by the change of form and structure in the food,
when it has a composition identical with that of the
living tissue, becomes a part of that tissue.

Those newly-formed compounds, whose compo-
sition differs from that of the living tissue, are
removed from the situation in which they are
formed, and, in the shape of certain secretions,
being carried to other parts of the body, undergo
in contact with these a series of analogous changes.

The vital force is manifested in the form of
resistance, inasmuch as by its presence in the living
tissues, their elements acquire the power of with-
standing the disturbance and change in their form
and composition, which external agencies tend to
produce ; a power which, simply as chemical com-
pounds, they do not possess.

As in the case of other forces, the conception of
an unequal intensity of the vital force comprehends

198 THE PHENOMENA OF MOTION

not only an unequal capacity for growth in the
mass, and an unequal power of overcoming che-
mical resistance, but also an inequality in the
amount of that resistance which the parts or con-
stituents of the living tissue oppose to a change in
their form and composition, from the action of new
external active causes of change ; just as the force
of cohesion or of affinity is in direct proportion to
the resistance which these forces oppose to any ex-
ternal cause, mechanical or chemical, tending to
separate the molecules, or the elements of an exist-
ing compound.

The manifestations of the vital force are depen-
dent on a certain form of the tissue in which it re-
sides, as well as on a fixed composition in the sub-
stance of the living tissue.

The capacity of growth in a living tissue is de-
termined by the immediate contact with matters
adapted to a certain decomposition, or the elements
of which are capable of becoming component parts
of the tissue in which vitality resides.

The phenomenon of growth, or increase in the
mass, presupposes that the acting vital force is more
powerful than the resistance which the chemical
force opposes to the decomposition or transforma-
tion of the elements of the food.

The manifestations of the vital force are depen-
dent on a certain temperature. Neither in a plant
nor in an animal do vital phenomena occur when
the temperature is lowered to a certain extent.

IN THE ANIMAL ORGANISM. 199

The phenomena of vitality in a living organism
diminish in intensity when heat is abstracted, pro-
vided the lost heat be not restored by other causes.

Deprivation of food soon puts a stop to all mani-
festations of vitality.

The contact of the living tissues with the ele-
ments of nutrition is determined in the animal body
by a mechanical force produced within the body,
which gives to certain organs the power of causing
change of place, of producing motion, and of over-
coming mechanical resistance.

We may communicate motion to a body at rest
by means of a number of forces, very different in
their manifestations. Thus, a time-piece may be
set in motion by a falling weight (gravitation), or
by a bent spring (elasticity). Every kind of motion
may be produced by the electric or magnetic force,
as well as by chemical attraction ; while we cannot
say, as long as we only consider the manifestation of
these forces in the phenomenon or result produced,
which of these various causes of change of place has
set the body in motion.

In the animal organism we are acquainted with
only one cause of motion ; and this is the same
cause which determines the growth of living tissues,
and gives them the power of resistance to external
agencies ; it is the vital force.

In order to attain a clear conception of these
manifestations of the vital force, so different in
form, we must bear in mind, that every known

200 THE PHENOMENA OF MOTION

force is recognized by two conditions of activity,
entirely different in the phenomena they offer to the
attention of the observer.

The force of gravitation inherent in the particles
of a stone, gives to them a continual tendency to
move towards the centre of the earth.

This effect of gravitation becomes inappreciable
to the senses when the stone, for example, rests
upon a table, the particles of which oppose a resist-
ance to the manifestation of its gravitation. The
force of gravity, however, is constantly present, and
manifests itself as a pressure on the supporting
body ; but the stone remains at rest ; it has no mo-
tion. The manifestation of its gravity in the state
of rest we call its weight.

That which prevents the stone from falling is a
resistance produced by the force of attraction, by
which the particles of the wood cohere together ; a
mass of water would not prevent the fall of the stone.

If the force which impelled the mass of the stone
towards the centre of the earth were greater than
the force of cohesion in the particles of the wood,
the latter would be overcome ; it would be unable
to prevent the fall of the stone.

When we remove the support, and with it the
force which has prevented the manifestation of the
force of gravity, the latter at once appears as the
cause of change of place in the stone, which acquires
motion, or falls. Resistance is invariably the result
of a force in action.

IN THE ANIMAL ORGANISM. 201

According as the stone is allowed to fall during a
longer or shorter time, it acquires properties which
it had not while at rest ; it acquires, for example,
the power of overcoming more feeble or more pow-
erful obstacles, or that of communicating motion to
bodies in a state of rest.

If it fall from a certain height it makes a per-
manent impression on the spot on which it falls ; if
it fall from a still greater height (during a longer
time) it perforates the table; its own motion is
communicated to a certain number of the particles
of the wood which now fall along with the stone
itself. The stone, while at rest, possessed none of
these properties.

The velocity of the falling body is always the
effect of the moving force, and is, ceteris paribus,
proportional to the force of gravitation.

A body, falling freely, acquires at the end of one
second a velocity of 30 feet. The same body, if
falling on the moon, would acquire in one second
only a velocity of ^ths of a foot=l inch, because,
in the moon, the intensity of gravitation (the pressure
acting on the body, the moving power) is 360 times
smaller.

If the pressure continue uniform, the velocity is
directly proportional to it ; so that, for example,
the body falling 360 times slower, will, after 360
seconds, have the same velocity as the other body
after one second.

Consequently, the effect is proportional, not to

202 THE PHENOMENA OF MOTION

the moving force alone, nor to the time alone, but
to the pressure multiplied into the time, which is
called the momentum of force.

In two equal masses the velocity expresses the
momentum of force. But under the same pressure
a body moves more slowly as its mass is greater ; a
mass twice as great requires, in order to attain in
the same time an equal velocity, twice the pressure ;
or, under the single pressure, it must continue in
motion twice as long.

In order, therefore, to have an expression for the
whole effect produced, we must multiply the mass
into the velocity. This product is called the
amount of motion.

The amount of motion in a given body must in all
cases correspond exactly to the momentum of force.

These two, the amount of motion and the mo-
mentum of force, are also called simply force;
because we suppose that a less pressure acting, for
example, during 10 seconds, is equal to a pressure
ten times greater, acting only during one second.

The momentum of motion in mechanics signifies
the effect of a moving force, without reference to
the time (velocity) in which it was manifested. If
one man, for example, raises 30 Ibs. to a height of
100 feet, and a second one 30 Ibs. to a height of
200 feet, then the latter has expended twice as
much force as the former. A third who raises
60 Ibs. to a height of 50 feet, expends no more force
than the first did in raising SOlbs. to the height of

IN THE ANIMAL ORGANISM. 203

100 feet. The momentum of motion of the first
(30X100) is equal to that of the third (60X50),
while that of the second (30X200) is twice as
great.

Momentum of force and momentum of motion
in mechanics are therefore expressions or measures
for effects of force, having reference to the velocity
attained in a given time, or to a given space ; and
in this sense they may be applied to the effects of all
other causes of motion, or of change in form and
structure, however great or however small may be
the space or the time in which their effects are dis-
played to the senses.

Every force, therefore, exhibits itself in matter
either in the form of resistance to external causes
of motion, or of change in form and structure ; or
as a moving force when no resistance is opposed to
it ; or, finally, in overcoming resistance.

One and the same force communicates motion
and destroys motion ; the former, when its manifes-
tations are opposed by no resistance ; the latter.,
when it puts a stop to the manifestation of some
other cause of motion, or of change in form and
structure. Equilibrium or rest is that state of
activity in which one force or momentum of motion
is destroyed by an opposite force or momentum of
motion.

We observe both these manifestations of activity
in that force which gives to the living tissues their
peculiar properties.

204 THE PHENOMENA OF MOTION

The vital force appears as a moving force or
cause of motion when it overcomes the chemical
forces (cohesion and affinity) which act between the
constituents of food, and when it changes the posi-
tion or place in which their elements occur ; it is
manifested as a cause of motion in overcoming the
chemical attraction of the constituents of food,
and is, further, the cause which compels them to
combine in a new arrangement, and to assume new
forms.

It is plain that a part of the animal body pos-
sessed of vitality, which has therefore the power of
overcoming resistance, and of giving motion to the
elementary particles of the food, by means of the
vital force manifested in itself must have a mo-
mentum of motion, which is nothing else than the
measure of the resulting motion or change in form
and structure.

We know that this momentum of motion in the
vital force, residing in a living part, may be em-
ployed in giving motion to bodies at rest (that is, in
causing decomposition, or overcoming resistance),
and if the vital force is analogous in its manifesta-
tions to other forces, this momentum of motion
must be capable of being conveyed or communi-
cated by matters, which in themselves do not de-
stroy its effect by an opposite manifestation of force.

Motion, by whatever cause produced, cannot in
itself be annihilated ; it may indeed become inap-
preciable to the senses, but even when arrested by

IN THE ANIMAL ORGANISM. 205

resistance (by the manifestation of an opposite
force), its effect is not annihilated. The falling
stone, by means of the amount of motion acquired
in its descent, produces an effect when it reaches
the table. The impression made on the wood, the
velocity communicated by its parts to those of the
wood, — all this is its effect.

If we transfer the conceptions of motion, equi-
librium, and resistance, to the chemical forces,
which, in their modus operandi, approach to the
vital force infinitely nearer than gravitation does,
we know with the utmost certainty, that they are
active only in the case of immediate contact. We
know also, that the unequal capacity of chemical
compounds to offer resistance to external disturbing
influences, to those of heat, or of electricity, which
tend to separate their particles, as well as their
power of overcoming resistance in other compounds
(of causing decomposition) ; that, in a word, the
active force in a compound depends on a certain
order or arrangement, in which its elementary par-
ticles touch each other.

The same elements, united in a different order,
when in contact with other compounds, exert a
most unequal power of offering or overcoming re-
sistance. In one form the force manifested is
available (the body is active, an acid, for example) ;
in another not (the body is indifferent, neutral) ; in
a third form, the momentum of force is opposed to
that of the first (the body is active, but a base).

206 THE PHENOMENA OF MOTION

If we alter the arrangement of the elements, we are
able to separate the constituents of a compound by
means of another active body ; while the same ele-
ments, united in their original order, would have
opposed an invincible resistance to the action of the
decomposing agent.

In the same way as two equal inelastic masses,
impelled with equal velocity from opposite points,
on coming into contact are brought to rest ; in the
same way, therefore, as two equal and opposite mo-
menta of motion mutually destroy each other ; so
may the momentum of force in a chemical com-
pound be destroyed in whole or in part by an equal
or unequal, and opposite momentum of force in a
second compound. But it cannot be annihilated
as long as the arrangement of the elementary
particles, by which its inherent force was mani-
fested, is not changed.

The chemical force of sulphuric acid is present
in sulphate of lime as entire as in oil of vitriol. It
is not appreciable by the senses ; but if the cause
be removed which prevented its manifestation, it
appears in its full force in the compound in which
it properly resides.

Thus the force of cohesion in a solid may disap-
pear, to the senses, from the action of a chemical
force (in solution), or of heat (in fusion), without
being in reality annihilated or even weakened. " If
we remove the opposing force or resistance, the force
of cohesion appears unchanged in crystallization.

IN THE ANIMAL ORGANISM. 207

By means of the electrical force, or that of heat,
we can give the most varied directions to the mani-
festations of chemical force. By these means we
can fix, as it were, the order in which the elemen-
tary particles shall unite. Let us remove the cause
(heat or electricity) which has turned the balance
in favour of the weaker attraction in one direction,
and the stronger attraction will shew itself continu-
ally active in another direction ; and if this stronger
attraction can overcome the vis inertias of the ele-
mentary particles, they will unite in a new form,
and a new compound of different properties must
be the result.

In compounds of this kind, in which, therefore,
the free manifestation of the chemical force has
been impeded by other forces, a blow, or mechanical
friction, or the contact of a substance, the particles
of which are in a state of motion (decomposition,
transformation), or any external cause, whose ac-
tivity is added to the stronger attraction of the ele-
mentary particles in another direction, may suffice
to give the preponderance to this stronger attrac-
tion, to overcome the vis inertiae, to alter the form
and structure of the compound, which are the
result of foreign causes, and to produce the resolu-
tion of the compound into one or more new com-
pounds with altered properties.

Transformations, or as they may be called, phe-
nomena of motion, in compounds of this class, may
be effected by means of the free and available

208 THE PHENOMENA OF MOTION

chemical force of another chemical compound, and
that without its manifestation being enfeebled or
arrested by resistance. Thus the equilibrium in the
attraction between the elements of cane-sugar is
destroyed by contact with a very small quantity of
sulphuric acid, and it is converted into grape-sugar.
In the same way we see the elements of starch,
under the same influence, arrange themselves with
those of water in a new form, while the sulphuric
acid, which has served to produce these transforma-
tions, loses nothing of its chemical character. In
regard to other substances on which it acts, it
remains as active as before, exactly as if it had
exerted no sort of influence on the cane-sugar or
starch.

In contradistinction to the manifestations of the
so-called mechanical forces, we have recognized in
the chemical forces causes of motion and of change
in form and structure, without any observable ex-
haustion of the force by which these phenomena
are produced ; but the origin of the continued
manifestation of activity remains still the same ; it
is the absence of an opposite force (a resistance)
capable of neutralizing it or bringing it into the
state of equilibrium.

As the manifestations of chemical forces (the
momentum of force in a chemical compound) seem
to depend on a certain order in which the elemen-
tary particles are united together, so experience
tells us, that the vital phenomena are inseparable

IN THE ANIMAL ORGANISM. 209

from matter ; that the manifestations of the vital
force in a living part are determined by a certain
form of that part, and by a certain arrangement of
its elementary particles. If we destroy the form, or
alter the composition of the organ, all manifesta-
tions of vitality disappear.

There is nothing to prevent us from considering
the vital force as a peculiar property, which is pos-
sessed by certain material bodies, and becomes sen-
sible when their elementary particles are combined
in a certain arrangement or form.

This supposition takes from the vital phenomena
nothing of their wonderful peculiarity ; it may
therefore be considered as a resting point, from
which an investigation into these phenomena, and
the laws which regulate them, may be commenced ;
exactly as we consider the properties and laws of
light to be dependant on a certain luminiferous
matter, or ether, which has no further connection
with the laws ascertained by investigation.

Considered under this form, the vital force unites
in its manifestations all the peculiarities of chemical
forces, and of the not less wonderful cause, which
we regard as the ultimate origin of electrical phe-
nomena.

The vital force does not act, like the force of gra-
vitation or the magnetic force, at infinite distances,
but, like chemical forces, it is active only in the
case of immediate contact. It becomes sensible by
means of an aggregation of material particles.

210 THE PHENOMENA OF MOTION

A living part acquires, on the above supposition,
the capacity of offering and of overcoming re-
sistance, by the combination of its elementary par-
ticles in a certain form; and as long as its form
and composition are not destroyed by opposing
forces, it must retain its energy uninterrupted and
unimpaired.

When, by the act of manifestation of this energy
in a living part, the elements of the food are made
to unite in the same form and structure as the
living organ possesses, then these elements acquire
the same powers. By this combination, the vital
force inherent in them is enabled to manifest itself
freely, and may be applied in the same way as that
of the previously existing tissue.

If, now, we bear in mind, that all matters
which serve as food to living organisms are com-
pounds of two or more elements, which are kept
together by certain chemical forces ; if we reflect
that in the act of manifestation of force in a liv-
ing tissue, the elements of the food are made to
combine in a new order ; — it is quite certain that
the momentum of force or of motion in the vital
force was more powerful than the chemical attrac-
tion existing between the elements of the food.*

* The hands of a man, who raises with a rope and simple
pulley, 301bs. to the height of 100 feet, pass over a space of
100 feet, while his muscular energy furnishes the equilibrium to a
pressure of 301bs. Were the force which the man could exert
not greater than would suffice to keep in equilibrium a pressure of

IN THE ANIMAL ORGANISM. 211

The chemical force which kept the elements to-
gether acted as a resistance, which was overcome
by the active vital force.

Had both forces been equal, no kind of sensible
effect would have ensued. Had the chemical force
been the stronger, the living part would have under-
gone a change.

If we now suppose that a certain amount of vital
force must have been expended in bringing to an
equilibrium the chemical force, there must still re-
main an excess of force, by which the decompo-
sition was effected. This excess constitutes the
momentum of force in the living part, by means of
which the change was produced ; by means of this
excess the part acquires a permanent power of
causing further decompositions, and of retaining its
condition, form, and structure, in opposition to ex-
ternal agencies.

We may imagine this excess to be removed, and
employed in some other form. This would not of
itself endanger the existence of the living part,
because the opposing forces would be left in equi-
librio ; but, by the removal of the excess of force, the
part would lose its capacity of growth, its power to
cause further decompositions, and its ability to re-
sist external causes of change. If, in this state of
equilibrium, oxygen (a chemical agent) should be
brought in contact with it, then there would be no

301bs., he would be unable to raise the weight to the height men-
tioned.

212 THE PHENOMENA OF MOTION

resistance to the tendency of the oxygen to combine
with some element of the living part, because its
power of resistance has been taken away by some
other application of its excess of vital force. Ac-
cording to the amount of oxygen brought to it, a
certain proportion of the living part would lose its
condition of vitality, and take the form of a che-
mical combination, having a composition different
from that of the living tissue. In a word, there
would occur a change in the properties of the living
compound, or what we have called a change of
matter.

If we reflect that the capacity of growth or
increase of mass in plants is almost unlimited ; that
a hundred twigs from a willow tree, if placed in the
soil, become a hundred trees ; we can hardly enter-
tain a doubt, that with the combination of the ele-
ments of the food of the plant so as to form a part
of it, a fresh momentum of force is added in the
newly formed part to the previously existing mo-
mentum in the plant ; insomuch, that with the in-
crease of mass, the sum of vital force is augmented.

According to the amount of available vital force,
the products formed by its activity from the food
are varied. The composition of the buds, of the
radical fibres, of the leaf, of the flower, and of the
fruit, are very different one from the other ; and
the chemical force by which their elements are held
together is very different in each of these eases.

Of the non-azotised constituents of plants we

IN THE ANIMAL ORGANISM. 213

may assert, that no part of the momentum of force
is expended in maintaining their form and structure,
when their elements have once combined in that
order in which they become parts of organs endued
with vitality.

Very different is the character of the azotised
vegetable principles ; for, when separated from the
plant, they pass, as is commonly said, spontaneously,
into fermentation and putrefaction. The cause of
this decomposition or transformation of their ele-
ments is the chemical action which the oxygen of the
atmosphere exercises on one of their constituents.
Now we know, that as long as the plant exhibits
the phenomena of life, oxygen gas is given off from
its surface ; that this oxygen is altogether without
action on the constituents of the living plant, for
which, in other circumstances, it has the strongest
attraction. It is obvious, therefore, that a certain
amount of vital force must be expended, partly to
retain the elements of the complex azotised prin-
ciples in the form, order, and structure which be-
long to them ; and partly as a means of resistance
against the incessant tendency of the oxygen of the
atmosphere to act on their elements, as well as
against that of the oxygen separated in the organ-
ism of the plant by the vital process.

With the increase of these easily altered com-
pounds, in the flower and in the fruit, for example,
the sum of chemical force (the free manifestation
of which, counteracted by an equal measure of vital

214 THE PHENOMENA OF MOTION

force, is employed to furnish resistance) also in-
creases.

The plant increases in mass until the vital force
inherent in it comes into equilibrium with all the
other causes opposed to its manifestation. From
this period, every new cause of disturbance, added
to those previously existing (a change of tempera-
ture, for example), deprives it of the power of offer-
ing resistance, and it dies down.

In perennial plants (in trees, for example), the
mass of the easily decomposable (azotised) com-
pounds, compared with that of the non-azotised, is
so small, that of the whole sum of force, only a mi-
nimum is expended as resistance. In animals, this
proportion is reversed.

During every period of the life of a plant, the
available vital force (that which is not neutralized
by resistance) is expended only in one form of vital
manifestation, that of growth or increase of mass,
or the overcoming of resistance. No part of this
force is applied to other purposes.

In the animal organism, the vital force exhibits
itself, as in the plant, in the form of the capacity of
growth, and as the means of resistance to external
agencies ; but both of these manifestations are con-
fined within certain limits.

We observe in animals, that the conversion of
food into blood, and the contact of the blood with
the living tissues, are determined by a mechanical
force, whose manifestation proceeds from distinct

IN THE ANIMAL ORGANISM. 215

organs, and is effected by a distinct system of or-
gans, possessing the property of communicating and
extending the motion which they receive. We find
the power of the animal to change its place and to
produce mechanical effects by means of its limbs,
dependant on a second similar system of organs or
apparatus. Both of these systems of apparatus, as
well as the phenomena of motion proceeding from
them, are wanting in plants.

In order to form a clear conception of the origin
and source of the mechanical motions in the animal
body, it may be advantageous to reflect on the mo-
dus operandi of other forces, which in their mani-
festations are most closely allied to the vital force.

When a number of plates of zinc and copper,
arranged in a certain order, are brought into con-
tact with an acid, and when the extremities of the
apparatus are joined by means of a metallic wire, a
chemical action begins at the surface of the plates
of zinc, and the wire, in consequence of this action,
acquires the most singular and wonderful properties.

The wire appears as the carrier or conductor of a
force, which may be conducted and communicated
through it in every direction with amazing velocity.
It is the conductor or propagator of an uninterrupted
series of manifestations of activity.

Such a propagation of motion is inconceivable, if
in the wire there were a resistance to be overcome ;
for every resistance would convert a part of the
moving force into a force at rest.

21 G THE PHENOMENA OF MOTION

When the wire is divided in the middle, and
its continuity interrupted, the propagation of force
ceases, and we observe, that in this case the action
between the zinc and the acid is immediately
stopped.

If the communication be restored, the action
which had disappeared reappears with all its origi-
nal energy.

By means of the force present in the wire, we
can produce the most varied effects ; we can over-
come all kinds of resistance, raise weights, set ships
in motion, &c. And, what is still more remarkable,
the wire acts as a hollow tube, in which a current
of chemical force circulates freely and without hin-
drance.

Those properties which, when firmly attached to
certain bodies, we call the strongest and most ener-
getic affinities, we find, to all appearance, free and
uncombined in the wire. We can transport them
from the wire to other bodies, and thereby give to
them an affinity (a power of entering into combina-
tion) which in themselves they do not possess. Ac-
cording to the amount of force circulating in the
wire, we are able by means of it to decompose com-
pounds, the elements of which have the strongest
attraction for each other. Yet the substance of the
wire takes not the smallest share in all these mani-
festations of force; it is merely the conductor of
force.

We observe, further, in this wire, phenomena of

IN THE ANIMAL ORGANISM. 217

attraction and repulsion, which we must ascribe to
the disturbance of the equilibrium in the electric
or magnetic force ; and when this equilibrium is
restored, the restoration is accompanied by the de-
velopement of light and heat, its never-failing com-
panions.

All these remarkable phenomena are produced
by the chemical action which the zinc and the acid
exert on each other; they are accompanied by a
change in form and structure, which both undergo.

The acid loses its chemical character ; the zinc
enters into combination with it. The manifestations
of force produced in the wire are the immediate
consequence of the change in the properties of the
acid and the metal.

One particle of acid after another loses its pecu-
liar chemical character ; and we perceive that in
the same proportion the wire acquires a chemical,
mechanical, galvanic, or magnetic force, whatever
name be given to it. According to the number of
acid particles which in a given time undergo this
change, that is, according to the surface of the zinc,
the wire receives a greater or less amount of these
forces.

The continuance of the current of force depends
on the duration of the chemical action ; and the
duration of the latter is most closely connected with
the carrying away, by conduction, of the force.

If we check the propagation of the current of
force, the acid retains its chemical character. If

218 THE PHENOMENA OF MOTION

we employ it to overcome chemical or mechanical
resistance, to decompose chemical compounds, or
to produce motion, the chemical action continues ;
that is to say, one particle of acid after another
changes its properties.

In the preceding paragraphs we have considered
these remarkable phenomena in a form which is
independent of the explanations of the schools. Is
the force which circulates in the wire the electrical
force? Is it chemical affinity? Is it propagated
in the conductor like a fluid set in motion, or in
the form of a series of momenta of motion, like
light and sound, from one particle of the conductor
to another? All this we know not, and we shall
never know. All the suppositions which may be
employed as explanations of the phenomena have
not the slightest influence on the truth of these
phenomena ; for they refer merely to the form in
which they are manifested.

On some points, however, there is no doubt ;
namely, that all the effects which may be produced
by the wire are determined by the change of pro-
perties in the zinc and in the acid ; for the term
" chemical action " signifies neither more nor less
than the act of change in them ; that these effects
depend on the presence of a conductor, of a sub-
stance which propagates in all directions, where it
is not neutralized by resistance, the force or mo-
mentum produced ; that this force becomes a mo-
mentum of motion, by means of which we can pro-

IN THE ANIMAL ORGANISM. 219

duce mechanical effects, and which, when transferred
to other bodies, communicates to them all those pro-
perties, the ultimate cause of which is the chemical
force itself; for these bodies acquire the power of
causing decompositions and combinations, such as,
without a supply of force through the conductor,
they could not effect.

If we employ these well-known facts as means
to assist us in investigating the ultimate cause of
the mechanical effects in the animal organism, ob-
servation teaches us, that the motion of the blood
and of the other animal fluids proceeds from distinct
organs, which, as in the case of the heart and in-
testines, do not generate the moving power in them-
selves, but receive it from other quarters.

We know with certainty that the nerves are the
conductors and propagators of mechanical effects ;
we know, that by means of them motion is propa-
gated in all directions. For each motion we recog-
nize a separate nerve, a peculiar conductor, with
the conducting power of which, or with its interrup-
tion, the propagation of motion is affected or de-
stroyed.

By means of the nerves all the parts of the body,
all the limbs, receive the moving force which is in-
dispensable to their functions, to change of place,
to the production of mechanical effects. Where
nerves are not found, motion does not occur. The
excess of force generated in one place is conducted
to other parts by the nerves. The force which one

220 THE PHENOMENA OF MOTION

organ cannot produce in itself is conveyed to it
from other quarters ; and the vital force which is
wanting to it, in order to furnish resistance to ex-
ternal causes of disturbance, it receives in the form
of excess from another organ, an excess which that
organ cannot consume in itself.

We observe further, that the voluntary and in-
voluntary motions, in other words, all mechanical
effects in the animal organism, are accompanied by,
nay, are dependant on, a peculiar change of form
and structure in the substance of certain living
parts, the increase or diminution of which change
stands in the very closest relation to the measure of
motion, or the amount of force consumed in the
motions performed.

As an immediate effect of the manifestation of
mechanical force, we see, that a part of the mus-
cular substance loses its vital properties, its cha-
racter of life ; that this portion separates from the
living part, and loses its capacity of growth and its
power of resistance. We find that this change of
properties is accompanied by the entrance of a
foreign body (oxygen) into the composition of the
muscular fibre (just as the acid lost its chemical
character by combining with zinc) ; and all experi-
ence proves, that this conversion of living muscular
fibre into compounds destitute of vitality is accele-
rated or retarded according to the amount of force
employed to produce motion. Nay, it may safely
be affirmed, that they are mutually proportional ;

IN THE ANIMAL ORGANISM. 221

that a rapid transformation of muscular fibre, or, as
it may be called, a rapid change of matter, deter-
mines a greater amount of mechanical force; and
conversely, that a greater amount of mechanical
motion (of mechanical force expended in motion)
determines a more rapid change of matter.

From this decided relation between the change
of matter in the animal body and the force con-
sumed in mechanical motion, no other conclusion
can be drawn but this, that the active or available
vital force in certain living parts is the cause of the
mechanical phenomena in the animal organism.

The moving force certainly proceeds from living
parts ; these parts possessed a momentum of force
or of motion, which they lost, in proportion as other
parts acquired a momentum of force or of motion ;
they lose their capacity of growth, and their power
to resist external causes of change. It is obvious
that the ultimate cause, the vital force, from which
they acquired those properties, has served for the
production of mechanical force, that is, has been
expended in the shape of motion.

How, indeed, could we conceive that a living part
should lose the condition of life, should become in-
capable of resisting the action of the oxygen con-
veyed to it by the arterial blood, and should be
deprived of the power to overcome chemical re-
sistance, unless the momentum of the vital force,
which had given to it all these properties, had been
expended for other purposes?

222 THE PHENOMENA OF MOTION

By the power of the conductors, the nerves, to
propagate the momentum of force in a living part,
or the effect which the active vital force inherent in
the part produces on all the surrounding parts, in
all directions where the force, or rather its mo-
mentum of motion, is consumed without resistance
(for without motion no change of matter occurs,
and when motion has begun, there is no longer re-
sistance), an equilibrium is obviously established in
the living part, between the chemical forces and
the remaining vital force ; which equilibrium would
not have occurred had not vital force been expended
in producing mechanical motion.

In this state, any external cause capable of ex-
erting an influence on the form, structure, and com-
position of the organ meets with no further re-
sistance. If oxygen were not conveyed to it, the
organ would maintain its condition, but without any
manifestation of vitality. It is only with the com-
mencement of chemical action that the change of
matter, that is, the separation of a part of the organ
in the form of lifeless compounds, begins.

The change of matter, the manifestation of me-
chanical force, and the absorption of oxygen, are, in
the animal body, so closely connected with each
other, that we may consider the amount of motion,
and the quantity of living tissue transformed, as
proportional to the quantity of oxygen inspired and
consumed in a given time by the animal. For a
certain amount of motion, for a certain proportion

IN THE ANIMAL ORGANISM 223

of vital force consumed as mechanical force, an
equivalent of chemical force is manifested ; that is,
an equivalent of oxygen enters into combination
with the substance of the organ which has lost the
vital force ; and a corresponding proportion of the
substance of the organ is separated from the living
tissue in the shape of an oxidised compound.

All those parts of the body which nature has
destined to effect the change of matter, that is, to
the production of mechanical force, are penetrated
in all directions by a multitude of the most minute
tubes or vessels, in which a current of oxygen con-
tinually circulates, in the form of arterial blood.
To the above-mentioned separation of part of the
elements of these parts, in other words, to the dis-
turbance of their equilibrium, this oxygen is abso-
lutely essential.

As long as the vital force of these parts is not
conducted away and applied to other purposes, the
oxygen of the arterial blood has not the slightest
effect on the substance of the organized parts ; and
in all cases, only so much oxygen is taken up as
corresponds to the conducting power, and, conse-
quently, to the mechanical effects produced.

The oxygen of the atmosphere is the proper, ac-
tive, external cause of the waste of matter in the
animal body ; it acts like a force which disturbs
and tends to destroy the manifestation of the vital
force at every moment. But its effect as a che-
mical agent, the disturbance proceeding from it, is

224 THE PHENOMENA OF MOTION

held in equilibrium by the vital force, which is free
and available in the living tissue, or is annihilated
by a chemical agency opposed to that of oxygen,
the manifestation of which must be considered as
dependant on the vital force.

In chemical language, to annihilate the chemical
action of oxygen, means, to present to it substances,
or parts of organs, which are capable of combining
with it.

The action of oxygen (affinity) is either neutra-
lized by means of the elements of organized parts,
which combine with it (after the free vital force has
been conducted away), or else the organ presents to
it the products of other organs, or certain matters
formed from the elements of the food, by the vital
activity of certain systems of apparatus.

It is only the muscular system which, in this
sense, produces in itself a resistance to the che-
mical action of oxygen, and neutralizes it com-
pletely.

The substance of cellular tissue, of membranes,
and of the skin, the minutest particles of which are
not in immediate contact with arterial blood (with
oxygen), are not destined to undergo this change of
matter. Whatever changes they may undergo in
the vital process, affect, in all cases, only their
surface.

The gelatinous tissues, mucous membranes, ten-
dons, &c., are not designed to produce mechanical
force ; they contain in their substance no con-

IN THE ANIMAL ORGANISM. 225

ductors of mechanical effects. But the muscular
system is interwoven with innumerable nerves.
The substance of the uterus is in no respect differ-
ent in chemical composition from the other mus-
cles ; but it is not adapted to the change of matter,
to the production of force, and contains no organs
for conducting away the moving power. Cellular
tissue, gelatinous membranes, and mucous mem-
branes, are far from being destitute of the power of
combining with oxygen, when moisture is present ;
we know that, when moist, they cannot be brought
in contact with oxygen without undergoing a pro-
gressive alteration. But one surface of the intes-
tines and the cells of the lungs are constantly in
contact with oxygen ; and it is obvious that they
must be as rapidly altered by the chemical action of
the oxygen in the body as out of it, were it not
that there exists in the organism itself a source of
resistance, which completely neutralizes the action
of the oxygen. Among the means by which this
resistance is furnished we may include all sub-
stances which are capable of combining with oxy-
gen, or acquire that property under the influence
of the vital force, and which surpass the tissues
above mentioned in their power of neutralizing its
chemical action.

All those constituents of the body which, in
themselves, do not possess, in the form of vital
force, the power of resisting the action of oxygen,
must be far better adapted for the purpose of com-

22G THE PHENOMENA OF MOTION

billing with, and neutralizing it, than those tissues
which are under the influence of the vital force,
although only through the nerves. In this point of
view, we cannot fail to perceive the importance of
the bile in regard to the substance of the intestines,
and that of the pulmonary cells, as well as that of
fat, of mucus, and of the secretions generally.

When the membranes are compelled from their
own substance to furnish resistance to the action
of the oxygen, that is, when there is a deficiency of
the substances destined by nature for their protec-
tion, they must, since their renewal is confined
within narrow limits, yield to the chemical action.
The lungs and intestines will always simultaneously
suffer abnormal changes.

From the change of matter itself, from the meta-
morphosis of the living muscular tissue, these organs
receive the means of resistance to the action of oxy-
gen which are indispensable to their preservation.
According to the rapidity of this process, the quan-
tity of bile secreted increases ; while that of the fat
present in the body diminishes in the same propor-
tion.

For carrying on the involuntary motions in the
animal body, a certain amount of vital force is ex-
pended at every moment of its existence ; and, con-
sequently, an incessant change of matter goes on ;
but the amount of living tissue, which, in conse-
quence of this form of consumption of vital force,
Closes its condition of life and its capacity of growth,

IN THE ANIMAL ORGANISM. 227

is confined within narrow limits. It is directly
proportional to the force required for these involun-
tary motions.

Now, although we may suppose that the living
muscular tissue, with a sufficient supply of food,
never loses its capacity of growth ; that this form
of vital manifestation is continually effective ; this
cannot apply to those parts of the body whose avail-
able vital force has been expended in producing me-
chanical effects. For the waste of matter, in con-
sequence of motion and laborious exertion, is ex-
tremely various in different individuals.

If we reflect, that the slightest motion of a finger
consumes force ; that in consequence of the force
expended, a corresponding portion of muscle dimi-
nishes in volume ; it is obvious, that an equilibrium
between supply and waste of matter (in living tissues)
can only occur when the portion separated or ex-
pelled in a lifeless form is, at the same instant in
which it loses its vital condition, restored in another
part.

The capacity of growth or increase in mass de-
pends on the momentum of force belonging to each
part ; and must be capable of continued manifesta-
tion (if there be a sufficient supply of nourishment),
as long as it does not lose this momentum, by ex-
pending it, for example, in producing motion.

In all circumstances, the growth itself is restricted
to the time ; that is to say, it cannot be unlimited
in a limited time.

228 THE PHENOMENA OF MOTION

A living part cannot increase in volume at the
same moment in which a portion of it loses the
vital condition, and is expelled from the organ in
the form of a lifeless compound ; on the contrary,
its volume must diminish.

The continued application of the momentum of
force in living tissues to mechanical effects deter-
mines, therefore, a continued separation of matter ;
and only from the period at which the cause of
waste ceases to operate, can the capacity of growth
be manifested.

Now, since, in different individuals, according to
the amount of force consumed in producing volun-
tary mechanical effects, unequal quantities of living
tissue are wasted, there must occur, in every indi-
vidual, unless the phenomena of motion are to cease
entirely, a condition in which all voluntary mo-
tions are completely checked, in which, therefore,
these occasion no waste. This condition is called
sleep,

The growth of one part, which is not deprived of
its vital force, cannot be in the slightest degree
affected by the consumption of the vital force of
another part in producing motion. The one may
increase in volume, while the other diminishes ; and
the waste in one can neither increase nor diminish
the supply in the other.

Now, since the consumption of force for the in-
voluntary motions continues in sleep, it is plain that
a waste of matter also continues in that state ; and

IN THE ANIMAL ORGANISM. 229

if the original equilibrium is to be restored, we must
suppose that, during sleep, an amount of force is
accumulated in the form of living tissue, exactly
equal to that which was consumed in voluntary and
involuntary motion during the preceding waking
period.

If the equilibrium between waste and supply of
matter be in the least degree disturbed, this is in-
stantly seen in the different amount of force avail-
able for mechanical purposes.

It is further obvious, that if there should occur a
disproportion between the conducting power of the
nerves of voluntary and involuntary motion, a dif-
ference in the phenomena of motion themselves
will be perceptible, in the same proportion as the
one or the other is capable of propagating the
momentum of force, generated by the change of
matter. As the motions of the circulating system
and of the intestines increase, the power of pro-
ducing mechanical effects in the limbs must dimi-
nish in the same proportion (as in wasting fevers) ;
and if, in a given time, more vital force has been
consumed for mechanical purposes (labour, running,
dancing, &c.) than is properly available for the vo^-
luntary and involuntary motions; if force be ex-
pended more rapidly than the change of matter can
be effected in the same time ; then a part of that
force which is necessary for the involuntary mo-
tions must be expended in restoring the excess of
force consumed in voluntary motion. The motions

230 THE PHENOMENA OF MOTION

/)f the heart and of the intestines, in this case, will
be retarded, or will entirely cease.

From the unequal degree of conducting power in
the nerves, we must deduce those conditions which
are termed paralysis, syncope, and spasm. Para-
lysis of the nerves of voluntary motion may exist
without emaciation; but frequently recurring at-
tacks of epilepsy (in which vital force is rapidly
wasted in producing mechanical effects) are always
accompanied by remarkably rapid emaciation.

It ought to excite the highest admiration when
we consider with what infinite wisdom the Creator
has divided the means by which animals and plants
are qualified for their functions, for their peculiar
vital manifestations.

The living part of a plant acquires the whole
force and direction of its vital energy from the ab-
sence of all conductors of force. By this means the
•leaf is enabled to overcome the strongest chemical
attractions, to decompose carbonic acid, and to as-
similate the elements of its nourishment.

In the flower alone does a process similar to the
change of matter in the animal body occur. There,
phenomena of motion appear ; but the mechanical
effects are not propagated to a distance, owing to
the absence of conductors of force.

The same vital force which we recognize in the
plant as an almost unlimited capacity of growth,
is converted in the animal body into moving
power (into a current of vital force) ; and a most

IN THE ANIMAL ORGANISM. 231

wonderful and wise economy has destined for the
nourishment of the animal only such compounds as
have a composition identical with that of the organs
which generate force, that is, with the muscular
tissue. The expenditure of force which the living
parts of animals require, in order to reproduce
themselves from the blood ; the resistance of the
chemical force which has to be overcome in the
azotised constituents of food by the vital agency of
the organs destined to convert them into blood ;
these are as nothing compared to the force with
which the elements of carbonic acid are held to-
gether. A certain amount of force would necessa-
rily be prevented from assuming the form of mov-
ing power, if it were to be expended in overcoming
chemical resistance ; for the momentum of motion
of the vital force is diminished by all obstacles. But
the conversion of the constituents of blood into mus-
cular fibre (into an organ which generates force) is
only a change of form. Both have the same com-
position ; blood is fluid, muscular fibre is solid blood.
We may even suppose that this change takes place
without any expenditure of vital force ; for the mere
passage of a fluid body into the solid state requires
no manifestation of force, but only the removal of
obstacles, which oppose that force (cohesion), which
determines the form of matter, in its manifestations.
In what form or in what manner the vital force
produces mechanical effects in the animal body is
altogether unknown, and is as little to be ascer-

232 THE PHENOMENA OF MOTION

tained by experiment as the connection of chemical
action with the phenomena of motion which we can
produce with the galvanic battery. All the expla-
nations which have been attempted are only repre-
sentations of the phenomenon ; they are, more or
less, exact descriptions and comparisons of known
phenomena with these, whose cause is unknown.
In this respect we are like an ignorant man, to
whom the rise and fall of an iron rod in a cylinder,
in which the eye can perceive nothing, and its con-
nection with the turning and motion of a thousand
wheels at a distance from the piston-rod, appear
incomprehensible.

We know not how a certain something, invisible
and imponderable in itself (heat), gives to certain
bodies the power of exerting an enormous pressure
on surrounding objects ; we know not even how this
something itself is produced when we burn wood or
coals.

So is it with the vital force, and with the phe-
nomena exhibited by living bodies. The cause of
these phenomena is not chemical force ; it is not
electricity, nor magnetism ; it is a force which has
certain properties in common with all causes of
motion and of change in form and structure in mate-
rial substances. It is a peculiar force, because it ex-
hibits manifestations which are found in no other
known force.

IN THE ANIMAL ORGANISM. 233

II.

In the living plant, the intensity of the vital force
far exceeds that of the chemical action of oxygen.

We know, with the utmost certainty, that, by
the influence of the vital force, oxygen is separated
from elements to which it has the strongest affinity ;
that it is given out in the gaseous form, without
exerting the slightest action on the juices of the
plant.

How powerful, indeed, must the resistance ap-
pear which the vital force supplies to leaves charged
with oil of turpentine or tannic acid, when we con-
sider the affinity of oxygen for these compounds !

This intensity of action or of resistance the plant
obtains by means of the sun's light ; the effect of
which in chemical actions may be, and is, com-
pared to that of a very high temperature (a mode-
rate red heat).

During the night an opposite process goes on in
the plant ; we see then that the constituents of the
leaves and green parts combine with the oxygen of
the air, a property which in daylight they did not
possess.

From these facts we can draw no other conclu-
sion but this : that the intensity of the vital force
diminishes with the abstraction of light ; that with
the approach of night a state of equilibrium is esta-
blished, and that in complete darkness all those con-

234 THE PHENOMENA OF MOTION

stituents of plants which, during the day, possessed
the power of separating oxygen from chemical com-
binations, and of resisting its action, lose this power
completely.

A precisely similar phenomenon is observed in
animals.

The living animal body exhibits its peculiar mani-
festations of vitality only at certain temperatures.
When exposed to a certain degree of cold, these
vital phenomena entirely cease.

The abstraction of heat must, therefore, be viewed
as quite equivalent to a diminution of the vital
energy ; the resistance opposed by the vital force to
external causes of disturbance must diminish, in
certain temperatures, in the same ratio in which the
tendency of the elements of the body to combine
with the oxygen of the air increases.

By the combination of oxygen with the consti-
tuents of the metamorphosed tissues, the tempera-
ture necessary to the manifestations of vitality is
produced in the carnivora. In the herbivora, again,
a certain amount of heat is developed by means of
those elements of their non-azotised food which
have the property of combining with oxygen.

It is obvious that the temperature of an animal
body cannot change, if the amount of inspired oxy-
gen increases in the same ratio as the loss of heat
by external cooling.

Two individuals, carnivora, of equal weight, ex-
posed to unequal degrees of cold, lose, in a given

IN THE ANIMAL ORGANISM. 235

time, by external cooling, unequal quantities of
heat. Experience teaches, that if their peculiar
temperature and their original weight are to remain
unaltered, they require unequal quantities of food ;
more in the lower temperature than in the higher.

The circumstance that the original weight remains
the same, with unequal quantities of food, obviously
presupposes, that in the same time a quantity of
oxygen proportional to the temperature has been
absorbed ; more in the lower than in the higher
temperature.

We find that the weight of both individuals, at
the end of 24 hours, is equal to the original weight.
But we have assumed that their food is converted
into blood ; that the blood has served for nutrition ;
and it is plain, that when the original weight has
been restored, a quantity of the constituents of the
body, equal in weight to those of the food, has lost
its condition of life, and has been expelled in com-
bination with oxygen.

The one individual, which, being exposed to the
lower temperature, consumed more food, has also
absorbed more oxygen ; a greater quantity of the
constituents of its body has been separated in com-
bination with oxygen ; and, in consequence of this
combination with oxygen, a greater amount of heat
has been liberated, by which means the heat ab-
stracted has been restored, and the proper tempera-
ture of the body kept up.

Consequently, by the abstraction of heat, provided

236 THE PHENOMENA OF MOTION

there be a full supply of food and free access of
oxygen, the change of matter must be accelerated ;
and, along with the augmented transformation, in a
given time, of living tissues, a greater amount of
vital force must be rendered available for mecha-
nical purposes.

With the external cooling, the respiratory mo-
tions become stronger ; in a lower temperature more
oxygen is conveyed to the blood ; the wraste of
matter increases, and if the supply be not kept in
equilibrium with this waste, by means of food, the
temperature of the body gradually sinks.

But, in a given time, an unlimited supply of
oxygen cannot be introduced into the body ; only a
certain amount of living tissue can lose the state of
life, and only a limited amount of vital force can be
manifested in mechanical phenomena. It is only,
therefore, when the cooling, the generation of force,
and the absorption of oxygen are in equilibrium
together, that the temperature of the body can re-
main unchanged. If the loss of heat by cooling go
beyond a certain point, the vital phenomena dimi-
nish in the same ratio ; for the temperature falls,
and the temperature must be considered as a uni-
form condition of their manifestation.

Now experience teaches, that when the tempera-
ture of the body sinks, the power of the limbs to
produce mechanical effects (or the force necessary
to the voluntary motions) is also diminished. The
condition of sleep ensues, and at last even the invo-

IN THE ANIMAL ORGANISM. 237

luntary motions (those of the heart and intestines,
for example) cease, and apparent death or syncope
supervenes.

It is obvious that the cause of the generation of
force, namely the change of matter, is diminished,
because, with the abstraction of heat, as in the plant
by abstraction of light, the intensity of the vital force
diminishes. It is also obvious that the momentum
of force in a living part depends on its proper tem-
perature; exactly as the effect of a falling body
stands in a fixed relation to certain other conditions ;
for example, to the velocity attained in falling.

When the temperature sinks, the vital energy
diminishes ; when it again rises, the momentum of
force in the living parts appears once more in all its
original intensity.

The production of force for mechanical purposes,
and the temperature of the body, must, consequently*
bear a fixed relation to the amount of oxygen which
can be absorbed in a given time by the animal body.

The quantities of oxygen which a whale and a
carrier's horse can inspire in a given time are very
unequal. The temperature, as well as the quantity
of oxygen, is much greater in the horse.

The force exerted by a whale, when struck with
the harpoon, his body being supported by the sur^
rounding medium, and the force exerted by a car-
rier's horse, which carries its own weight and a
heavy burden for eight or ten hours, must both l>ear
the same ratio to the oxygen consumed. If we

238 THE PHENOMENA OF MOTION

take into consideration the time during which the
force is manifested, it is obvious that the amount of
force developed by the horse is far greater than in
the case of the whale.

In climbing high mountains, where, in conse-
quence of the respiration of a highly rarefied atmo-
sphere, much less oxygen is conveyed to the blood,
in equal times, than in valleys or at the level of the
sea, the change of matter diminishes in the same
ratio, and with it the amount of force available for
mechanical purposes. For the most part, drowsiness
and want of force for mechanical exertions come
on ; after twenty or thirty steps, fatigue compels us
to a fresh accumulation of force by means of rest
(absorption of oxygen without waste of force in
voluntary motions).

By the absorption of oxygen into the substance
of living tissues, these lose their condition of life,
and are separated as lifeless, unorganised com-
pounds ; but the whole of the inspired oxygen is not
applied to these transformations : the greater part
serves to convert into gas and vapour all matters
which no longer belong to the organism ; and, as
formerly mentioned, the combination of the ele-
ments of such compounds with the oxygen produces
the temperature proper to the animal organism.

The production of heat and the change of matter
are closely related to each other ; but although heat
can be produced in the body without any change of
matter in living tissues, yet the change of matter

IN THE ANIMAL ORGANISM. 239

cannot be supposed to take place without the co-
operation of oxygen.

According to all the observations hitherto made,
neither the expired air, nor the perspiration, nor the
urine, contains any trace of alcohol, after indulgence
in spirituous liquors; and there can be no doubt
that the elements of alcohol combine with oxygen
in the body ; that its carbon and hydrogen are given
off as carbonic acid and water.

The oxygen which has accomplished this change
must have been taken from the arterial blood ; for
we know of ho channel, save the circulation of the
blood, by which oxygen can penetrate into the inte-
rior of the body.

Owing to its volatility, and the ease with which
its vapour permeates animal membranes and tissues,
alcohol can spread throughout the body in all direc-
tions.

If the power of the elements of alcohol to com-
bine with oxygen were not greater than that of the
compounds formed by the change of matter, or that
of the substance of living tissues, they (the elements
of alcohol) could not combine with oxygen in the
body.

It is, consequently, obvious, that by the use of
alcohol a limit must rapidly be put to the change
of matter in certain parts of the body. The oxygen
of the arterial blood, which, in the absence of alco-
hol, would have combined with the matter of the
tissues, or with that formed by the metamorphosis

240 THE PHENOMENA OF MOTION

of these tissues, now combines with the elements of
alcohol. The arterial blood becomes venous, with-
out the substance of the muscles having taken any
share in the transformation.

Now we observe, that the developement of heat
in the body, after the use of wine, increases rather
than diminishes, without the manifestation of a cor-
responding amount of mechanical force.

A moderate quantity of wine, in women and chil-
dren unaccustomed to its use, produces, on the con-
trary, a diminution of the force necessary for volun-
tary motions. Weariness, feebleness in the limbs,
and drowsiness, plainly shew that the force available
for mechanical purposes, in other words, the change
of matter, has been diminished.

A diminution of the conducting power of the
nerves of voluntary motion may doubtless take a
certain share in producing these symptoms ; but this
must be altogether without influence on the sum of
available force.

What the conductors of voluntary motion cannot
carry away for effects of force, must be taken up by
the nerves of involuntary motion, and conveyed to
the heart, lungs, and intestines. In this case, the
circulation will appear accelerated at the expense of
the force available for voluntary motion ; but, as
was before remarked, without the production of a
greater amount of mechanical force by the process
of oxidation of the alcohol.

Finally, we observe, in hybernating animals, that,

IN THE ANIMAL ORGANISM. 241

during their winter sleep, the capacity of increase in
mass (one of the chief manifestations of the vital
force), owing to the absence of food, is entirely sup-
pressed. In several, apparent death occurs in con-
sequence of the low temperature and of the diminu-
tion of vital energy thus produced ; in others, the
involuntary motions continue, and the animal pre-
serves a temperature independent of the surround-
ing temperature. The respirations go on ; oxygen,
the condition which determines the production of
heat and of force, is absorbed now as well as in the
former state of the animal ; and previous to the
winter sleep, we find all those parts of their body,
which in themselves are unable to furnish resistance
to the action of the oxygen, and which, like the
intestines and membranes, are not destined for the
change of matter, covered with fat ; that is, sur-
rounded by a substance which supplies the want of
resistance.

If we now suppose, that the oxygen absorbed
during the winter sleep combines, not with the ele-
ments of living tissues, but with those of the fat,
then the living part, although a certain momentum
of motion be expended in keeping up the circula-
tion, will not be separated and expelled from the
body.

With the return of the higher temperature, the
capacity of growth increases in the same ratio, and
the motion of the blood increases with the absorp-
tion of oxygen. Many of these animals become
R

242 THE PHENOMENA OF MOTION

emaciated during the winter sleep, others not till
after awaking from it.

In hybernating animals the active force of the
living parts is exclusively devoted, during hyberna-
tlon, to the support of the involuntary motions. The
expenditure of force in voluntary motion is entirely
suppressed.

In contradistinction to these phenomena, we
know that, in the case of excess of motion and
exertion, the active force in living parts may be
exclusively and entirely consumed in producing
voluntary mechanical effects ; in suchwise that no
force shall remain available for the involuntary mo-
tions. A stag may be hunted to death ; but this
cannot occur without the metamorphosis of all the
living parts of its muscular system, and its flesh be-
comes uneatable. The condition of metamorphosis
into which it has been brought by an enormous
consumption both of force and of oxygen, continues
when all phenomena of motion have ceased. In the
living tissues, all the resistance offered by the vital
force to external agencies of change is entirely de-
stroyed.

But however closely the conditions of the produc-
tion of heat and of force may seem to be connected
together, with reference to mechanical effects, yet
the disengagement of heat can in no way be consi-
dered as in itself the only cause of these effects.

All experience proves, that there is, in the organ-
ism, only one source of mechanical power ; and this

IN THE ANIMAL ORGANISM. 243

source is the conversion of living parts into lifeless,
amorphous compounds.

Proceeding from this truth, which is independent
of all theory, animal life may be viewed as deter-
mined by the mutual action of opposed forces ; of
which one class must be considered as causes of in-
crease (of supply of matter), and the other as causes
of diminution (of waste of matter).

The increase of mass is effected in living parts by
the vital force ; the manifestation of this power is
dependant on heat ; that is, on a certain tempera-
ture peculiar to each specific organism.

The cause of waste of matter is the chemi-
cal action of oxygen; and its manifestation is de-
pendant on the abstraction of heat as well as on
the expenditure of the vital force for mechanical
purposes.

The act of waste of matter is called the change of
matter ; it occurs in consequence of the absorption of
oxygen into the substance of living parts. This ab-
sorption of oxygen occurs only when the resistance
which the vital force of living parts opposes to the
chemical action of the oxygen is weaker than that che-
mical action ; and this weaker resistance is determined
by the abstraction of heat, or by the expenditure in
mechanical motions of the available force of living
parts.

By the combination of the oxygen introduced in
the arterial blood with such constituents of the body
as offer no resistance to its action, the temperature

R2

244 THE PHENOMENA OF MOTION

necessary for the manifestation of vital activity is
produced.

From the relations between the consumption of
oxygen on the one hand, and the change of matter
and developement of heat on the other, the follow-
ing general rules may be deduced.

For every proportion of oxygen which enters into
combination in the body, a corresponding proportion
of heat must be generated.

The sum of force available for mechanical pur-
poses must be equal to the sum of the vital forces
of all tissues adapted to the change of matter.

If, in equal times, unequal quantities of oxygen
are consumed, the result is obvious, in an unequal
amount of heat liberated, and of mechanical force.

When unequal amounts of mechanical force are
expended, this determines the absorption of corre-
sponding and unequal quantities of oxygen.

For the conversion of living tissues into lifeless
compounds, and for the combination of oxygen with
such constituents of the body as have an affinity for
it, time is required.

In a given time, only a limited amount of me-
chanical force can be manifested, and only a limited
amount of heat can be liberated.

That which is expended, in mechanical effects, in
the shape of velocity, is lost in time ; that is to say,
the more rapid the motions are, the sooner or the
more quickly is the force exhausted.

The sum of the mechanical force produced in a

IN THE ANIMAL ORGANISM. 245

given time is equal to the sum of force necessary,
during the same time, to produce the voluntary and
involuntary motions ; that is, all the force which
the heart, intestines, &c., require for their motions
is lost to the voluntary motions.

The amount of azotised food necessary to restore
the equilibrium between waste and supply is directly
proportional to the amount of tissues metamor-
phosed.

The amount of living matter, which in the body
loses the condition of life, is, in equal temperatures,
directly proportional to the mechanical effects pro-
duced in a given time.

The amount of tissue metamorphosed in a given
time may be measured by the quantity of nitrogen
in the urine.

The sum of the mechanical effects produced in
two individuals, in the same temperature, is propor-
tional to the amount of nitrogen in their urine ;
whether the mechanical force has been employed in
voluntary or involuntary motions, whether it has
been consumed by the limbs or by the heart and
other viscera.

That condition of the body which is called health
includes the conception of an equilibrium among
all the causes of waste and of supply ; and thus
animal life is recognized as the mutual action of
both ; and appears as an alternating destruction and
restoration of the state of equilibrium.

In regard to its absolute amount, the waste and

246 THE PHENOMENA OF MOTION

supply of matter is, in the different periods of life,
unequal ; but, in the state of health, the available
vital force must always be considered as a constant
quantity, corresponding to the sum of living par-
ticles.

Growth, or the increase of mass, stands, at every
age, in a fixed relation to the amount of vital force
consumed as moving power.

The vital force, which is expended for mechanical
purposes, is subtracted from the sum of the force
available for the purpose of increase of mass.

The active force, which is consumed in the body
in overcoming resistance (in causing increase of
mass), cannot, at the same time, be employed to
produce mechanical effects.

Hence it follows necessarily, that when, as in
childhood, the supply exceeds the waste of matter,
the mechanical effects produced must be less in the
same proportion.

With the increase of mechanical effects produced,
the capacity of increase of mass or of the supply of
waste in living tissues must diminish in the same
proportion.

A perfect balance between the consumption of
vital force for supply of matter and that for me-
chanical effects occurs, therefore, only in the adult
state. It is at once recognized in the complete
supply of the matter consumed. In old age more
is wasted ; in childhood more is supplied than
wasted.

IN THE ANIMAL ORGANISM. 247

The force available for mechanical purposes in an
adult man is reckoned, in mechanics, equal to £th
of his own weight, which he can move during eight
hours, with a velocity of five feet in two seconds.

If the weight of a man be 150 Ibs., his force is
equal to a weight of 30 Ibs. carried by him to a
distance of 72,000 feet. For every second his
momentum of force is = 30x2'5 = 75 Ibs.; and for
the whole day's work, his momentum of motion
is = 30 x 72,000 == 216,000.

By the restoration of the original weight of his
body, the man collects again a sum of force which
allows him, next day, to produce, without exhaus-
tion, the same amount of mechanical effects.

This supply of force is furnished in a seven hours'
sleep.

In manufactories of rolled iron it frequently hap-
pens, that the pressure of the engine, going at its
ordinary rate, is not sufficient to force a rod of iron
of a certain thickness to pass below the cylinders.
The workman, in this case, allows the whole force
of the steam to act on the revolving wheel, and not
until this has acquired a great velocity does he bring
the rod under the rollers ; when it is instantly flat-
tened with great ease into a plate, while the wheel
gradually loses the velocity it had acquired. What
the wheel gained in velocity, the roller gained in
force ; by this process force was obviously collected,
accumulated in the velocity ; but in this sense force
does not accumulate in the living organism.

248 THE PHENOMENA OF MOTION

The restoration of force is effected, in the animal
body, by the transformation of the separated parts,
destined for the production of force, and by the ex-
penditure of the active vital force in causing forma-
tion of new parts ; and, with the restoration of the
separated or effete parts, the organism recovers a
force equal to that which has been expended.

It is plain, that the vital force manifested, during
sleep, in the formation of new parts must be equal
to the whole sum of the moving power expended in
the waking state in all mechanical effects whatever,
plus a certain amount of force, which is required for
carrying on those involuntary motions which con-
tinue during sleep.

From day to day, the labouring man, with suffi-
cient food, recovers, in seven hours' sleep, the whole
sum of force ; and without reckoning the force
necessary for the involuntary motions which may
be considered equal in all men, we may assume, that
the mechanical force available for work is directly
proportional to the number of hours of sleep.

The adult man sleeps 7 hours, and wakes 17
hours ; consequently, if the equilibrium be restored in
24 hours, the mechanical effects produced in 17 hours
must be equal to the effects produced during 7
hours in the shape of formation of new parts.

An old man sleeps only 3^ hours ; and if every
thing else be supposed the same as in the case of
the adult, he will be able, at all events, to produce
half of the mechanical effects produced by an adult

IN THE ANIMAL ORGANISM. 249

of equal weight ; that is, he will be able to carry
only 15 Ibs. instead of 30 to the same distance.

The infant at the breast sleeps 20 hours and
wakes only four ; the active force consumed in forma-
tion of new parts is, in this case, to that consumed in
mechanical effects (in motion of the limbs), as 20 to
4 ; but his limbs possess no momentum of force, for
he cannot yet support his own body. If we assume,
that the aged man and infant consume in mechani-
cal effects a quantity of force corresponding to the
proportion available in the adult, then the mechani-
cal effects are proportional to the number of waking
hours, the formation of new parts to the number of
hours of sleep, and we shall have :

Force expended in Force expended in

mechanical effects. formation of new parts.

In the adult 17 : 7

In the infant 4 : 20

In the old man 20 : 4

In the adult, a perfect equilibrium takes place
between waste and supply ; in the old man and in
the infant, waste and supply are not in equilibrium.
If we make the consumption of force in the 17
waking hours equal to that required for the restora-
tion of the equilibrium during sleep = 100 = 17
waking hours, — 7 hours of sleep, we obtain the
following proportions. The mechanical effects are
to those in the shape of formation of new parts :

In the adult man = 100 : 100
In the infant ... = 25:250
In the old man... = 125: 50

250 THE PHENOMENA OF MOTION

Or the increase of mass to the diminution by
waste:

In the adult man = 100 : 100
In the infant ... = 100: 10
In the old man... = 100 : 250

It is consequently clear, that if the old man
performs an amount of work proportional to the
sleeping hours of the adult, the waste will be greater
than the supply ; that is, his body will rapidly de-
crease in weight, if he carry 15 Ibs. to the distance
of 72,000 feet with a velocity of 2^ feet in the
second; but he will be able, without injury, to
carry 6 Ibs. to the same distance.

In the infant the increase is to the decrease as
10 to 1, and consequently, if we in his case increase
the expenditure of force in mechanical effects to ten
times its proper amount, there will thus be estab-
lished only an equilibrium between waste and sup-
ply. The child, indeed, will not grow ; but neither
will it lose weight.

If, in the adult man, the consumption of force
for mechanical purposes in 24 hours be augmented
beyond the amount restorable in seven hours of
sleep, then, if the equilibrium is to be restored, less
force, in the same proportion, must be expended in
mechanical effects in the next 24 hours. If this be
not done, the mass of the body decreases, and the
state characteristic of old age more or less decidedly
supervenes.

With every hour of sleep the sum of available

IN THE ANIMAL ORGANISM. 251

force increases in the old man, or approaches the
state of equilibrium between waste and supply
which exists in the adult.

It is further evident, that if a part of the force
which is available for mechanical purposes, without
disturbing the equilibrium, should not be consumed
in moving the limbs, in raising weights, or in other
labour, it will be available for involuntary motions.
If the motion of the heart, of the fluids, and of the
intestines (the circulation of the blood and diges-
tion), are accelerated in proportion to the amount
of force not consumed in voluntary motions, the
weight of the body will neither increase nor diminish
in 24 hours. The body, therefore, can only increase
in mass, if the force accumulated during sleep, and
available for mechanical purposes, is employed nei-
ther for voluntary nor for involuntary motions.

The numerical values above given for the expen-
diture of force in the human body refer, as has been
expressly stated, only to a given, uniform tempe-
rature. In a different temperature, and with defi-
cient nourishment, all these proportions must be
changed.

If we surround a part of the body with ice or
snow, while other parts are left in the natural state,
there occurs, more or less quickly, in consequence of
the loss of heat, an accelerated change of matter in
the cooled part.

The resistance of the living tissues to the action
of oxygen is weaker at the cooled part than in the

252 THE PHENOMENA OF MOTION

other parts ; and this, in its eftects, is equivalent to
an increase of resistance in these other parts.

The momentum of force of the vitality in the
parts which are not cooled is expended, as before,
in mechanical motion ; but the whole action of the
inspired oxygen is exerted on the cooled part.

If we imagine an iron cylinder, into which we
admit steam under a certain pressure, then if the
force with which the particles of the iron cohere be
equal to the force which tends to separate them, an
equilibrium will result ; that is, the whole effect of
the steam will be neutralized by the resistance.
But if one of the sides of the cylinder be moveable,
a piston-rod, for example, and offer to the pressure
of the steam a less resistance than other parts, the
whole force will be expended in moving this one
side — that is, in raising the piston-rod. If we do not
introduce fresh steam (fresh force), an equilibrium
will soon be established. The piston-rod resists a
certain force without moving, but is raised by an in-
creased pressure. When this excess of force has
been consumed in motion, it cannot be raised
higher ; but if new vapour be continually admitted,
the rod will continue to move.

In the cooled part of the body, the living tissues
offer a less resistance to the chemical action of the
inspired oxygen ; the power of the oxygen to unite
with the elements of the tissues is, at this part, ex-
alted. When the part has once lost its condition of
life, resistance entirely ceases ; and in consequence of

IN THE ANIMAL ORGANISM. 253

the combination of the oxygen with the elements of
the metamorphosed tissues, a greater amount of
heat is liberated.

For a given amount of oxygen, the heat produced
is, in all cases, exactly the same. In the cooled
part, the change of matter, and with it the disen-
gagement of heat, increases ; while in the other
parts the change of matter and liberation of heat
decrease. But when the cooled part, by the union
of oxygen with the elements of the metamorphosed
tissues, has recovered its original temperature, the
resistance of its living particles to the oxygen con-
veyed to them again increases, and, as the resistance
of other parts is now diminished, a more rapid
change of matter now occurs in them, their tempe-
rature rises, and along with this, if the cause of the
change of matter continue to operate, a larger
amount of vital force becomes available for mecha-
nical purposes.

Let us now suppose that heat is abstracted from
the whole surface of the body ; in this case the
whole action of the oxygen will be directed to the
skin, and in a short time the change of matter
must increase throughout the body. Fat, and all
such matters as are capable of combining with the
oxygen which is brought to them in larger quantity
than usual, will be expelled from the body in the
form of oxidised compounds.

254

III.
THEORY OF DISEASE.

Every substance or matter, every chemical or
mechanical agency, which changes or disturbs the
restoration of the equilibrium between the mani-
festations of the causes of waste and supply, in such
a way as to add its action to the causes of waste, is
called a cause of disease. Disease occurs when the
sum of vital force, which tends to neutralize all
causes of disturbance (in other words, when the
resistance offered by the vital force), is weaker than
the acting cause of disturbance.

Death is that condition in which all resistance on
the part of the vital force entirely ceases. So long
as this condition is not established, the living tis-
sues continue to offer resistance.

To the observer, the action of a cause of disease
exhibits itself in the disturbance of the proportion
between waste and supply which is proper to each
period of life. In medicine, every abnormal condi-
tion of supply or of waste, in all parts or in a single
part of the body, is called disease.

It is evident that one and the same cause of dis-
ease will produce in the organism very different
effects, according to the period of life ; and that a
certain amount of disturbance, which produces dis-
ease in the adult state, may be without influence in

THEORY OF DISEASE. 255

childhood or in old age. A cause of disease may,
when it is added to the cause of waste in old age,
produce death (annihilate all resistance on the part
of the vital force) ; while in the adult state it may
produce only a disproportion between supply and
waste ; and in infancy, only an equilibrium between
supply and waste (the abstract state of health).

A cause of disease which strengthens the causes
of supply, either directly, or indirectly by weakening
the action of the causes of waste, destroys, in the
child and in the adult, the relative normal state of
health ; while in old age it merely brings the waste
and supply into equilibrium.

A child, lightly clothed, can bear cooling by a low
external temperature without injury to health ; the
force available for mechanical purposes and the tem-
perature of its body increase with the change of
matter which follows the cooling; while a high
temperature, which impedes the change of matter,
is followed by disease.

On the other hand, we see, in hospitals and chari-
table institutions (in Brussels, for example) in which
old people spend the last years of life, when the
temperature of the dormitory, in winter, sinks 2
or 3 degrees below the usual point, that by this
slight degree of cooling the death of the oldest and
weakest, males as well as females, is brought about.
They are found lying tranquilly in bed, without the
slightest symptoms of disease, or of the usual recog-
nizable causes of death.

256 THEORY OF DISEASE

A deficiency of resistance, in a living part, to the
causes of waste is, obviously, a deficiency of resist-
ance to the action of the oxygen of the atmosphere.

When, from any cause whatever, this resistance
diminishes in a living part, the change of matter
increases in an equal degree.

Now, since the phenomena of motion in the ani-
mal body are dependant on the change of matter,
the increase of the change of matter in any part is
followed by an increase of all motions. According
to the conducting power of the nerves, the available
force is carried away by the nerves of involuntary
motion alone, or by all the nerves together.

Consequently, if, in consequence of a diseased
transformation of living tissues, a greater amount of
force be generated than is required for the produc-
tion of the normal motions, it is seen in an accele-
ration of all or some of the involuntary motions, as
well as in a higher temperature of the diseased part.

This condition is called fever.

When a great excess of force is produced by
change of matter, the force, since it can only be
consumed by motion, extends itself to the apparatus
of voluntary motion.

This state is called a febrile paroxysm.

In consequence of the acceleration of the circu-
lation in the state of fever, a greater amount of
arterial blood, and, consequently, of oxygen, is con-
veyed to the diseased part, as well as to all other
parts ; and if the active force in the healthy parts

THEORY OF DISEASE. 257

continue uniform, the whole action of the excess of
oxygen must be exerted on the diseased part alone.

According as a single organ, or a system of organs,
is affected, the change of matter extends to one
part alone, or to the whole affected system.

Should there be formed, in the diseased parts,
in consequence of the change of matter, from the
elements of the blood or of the tissue, new products,
which the neighbouring parts cannot employ for
their own vital functions ; — should the surrounding
parts, moreover, be unable to convey these products
to other parts, where they may undergo transforma-
tion, then these new products will suffer, at the place
where they have been formed, a process of decom-
position analogous to fermentation or putrefaction.

In certain cases, medicine removes these diseased
conditions, by exciting in the vicinity of the dis-
eased part, or in any convenient situation, an artifi-
cial diseased state (as by blisters, sinapisms, or
setons) ; thus diminishing, by means of artificial
disturbance, the resistance offered to the external
causes of change in these parts by the vital force.
The physician succeeds in putting an end to the
original diseased condition, when the disturbance
artificially excited (or the diminution of resistance
in another part) exceeds in amount the diseased
state to be overcome.

The accelerated change of matter and the ele-
vated temperature in the diseased part shew, that
the resistance offered by the vital force to the
s

258 THEORY OF DISEASE.

action of oxygen is feebler than in the healthy
state. But this resistance only ceases entirely when
death takes place. By the artificial diminution of
resistance in another part, the resistance in the dis-
eased organ is not indeed directly strengthened ; but
the chemical action (the cause of the change of
matter) is diminished in the diseased part, being di-
rected to another part, where the physician has suc-
ceeded in producing a still more feeble resistance
to the change of matter (to the action of oxygen).

A complete cure of the original disease occurs,
when external action and resistance, in the diseased
part, are brought into equilibrium. Health and the
restoration of the diseased tissue to its original con-
dition follow, \vhen we are able so far to weaken
the disturbing action of oxygen, by any means, that
it becomes inferior to the resistance offered by the
vital force, which, although enfeebled, has never
ceased to act ; for this proportion between these
causes of change is the uniform and necessary con-
dition of increase of mass in .the living organism.

In cases of a different kind, where artificial ex-
ternal disturbance produces no effect, the physician
adopts other indirect methods to exalt the resist-
ance offered by the vital force. These methods, the
result of ages of experience, are such, that the most
perfect theory could hardly have pointed them out
more acutely or more justly than has been done
by the observation of sagacious practitioners. He
diminishes, by blood-letting, the number of the

THEORY OF DISEASE. 259

carriers of oxygen (the globules), and by this means
the conditions of change of matter; he excludes
from the food all such matters as are capable of
conversion into blood ; he gives chiefly or entirely
non-azotised food, which supports the respiratory
process, as well as fruit and vegetables, which con-
tain the alkalies necessary for the secretions.

If he succeed, by these means, in diminishing the
action of the oxygen in the blood on the diseased
part, so far that the vital force of the latter, its
resistance, in the smallest degree overcomes the
chemical action ; and if he accomplish this, with-
out arresting the functions of the other organs, then
restoration to health is certain.

To the method of cure adopted in such cases, if
employed with sagacity and acute observation, there
is added, as we may call it, an ally on the side of
the diseased organ, and this is the vital force of the
healthy parts. For, when blood is abstracted, the
external causes of change are diminished also in
them, and their vital force, formerly neutralized by
these causes, now obtains the preponderance. The
change of matter, indeed, is diminished throughout
the body, and with it the phenomena of motion ;
but the sum of all resisting powers, taken together,
increases in proportion as the amount of the oxygen
acting on them in the blood is diminished. In the
sensation of hunger, this resistance, in a certain
sense, makes itself known ; and the preponderat-
ing vital force exhibits itself, in many patients,
s 2

THEORY OF DISEASE.

when hunger is felt, in the form of an abnormal
growth, or an abnormal metamorphosis of certain
parts of organs. Sympathy is the transference of
diminished resistance from one part, not exactly to
the next, but to more distant organs, when the
functions of both mutually influence each other.
When the action of the diseased organ is connected
with that of another — when, for example, the one
no longer produces the matters necessary to the per-
formance of the functions of the other — then the
diseased condition is transferred, but only appa-
rently, to the latter.

In regard to the nature and essence of the vital
force, we can hardly deceive ourselves, when we
reflect, that it behaves, in all its manifestations,
exactly like other natural forces ; that it is devoid
of consciousness or of volition, and is subject to the
action of a blister.

The nerves, which accomplish the voluntary and
involuntary motions in the body, are, according to
the preceding exposition, not the producers, but
only the conductors of the vital force ; they propa-
gate motion, and behave towards other causes of
motion, which in their manifestations are analogous
to the vital force, towards a current of electricity,
for example, in a precisely analogous manner. They
permit the current to traverse them, and present, as
conductors of electricity, all the phenomena which
they exhibit as conductors of the vital force. In
the present state of our knowledge, no one, proba-

THEORY OF DISEASE. 261

bly, will imagine that electricity is to be considered
as the cause of the phenomena of motion in the
body ; but still, the medicinal action of electricity,
as well as that of a magnet, which, when placed in
contact with the body, produces a current of elec-
tricity, cannot be denied. For to the existing force
of motion or of disturbance there is added, in the
electrical current, a new cause of motion and of
change in form and structure, which cannot be
considered as altogether inefficient.

Practical medicine, in many diseases, makes use
of cold in a highly rational manner, as a means of
exalting and accelerating, in an unwonted degree, the
change of matter. This occurs especially in certain
morbid conditions in the substance of the centre of
the apparatus of motion ; when a glowing heat and a
rapid current of blood towards the head point out an
abnormal metamorphosis of the brain. When this
condition continues beyond a certain time, experi-
ence teaches that all motions in the body cease. If
the change of matter be chiefly confined to the
brain, then the change of matter, the generation of
force, diminishes in all other parts. By surrounding
the head with ice, the temperature is lowered, but
the cause of the liberation of heat continues ; the
metamorphosis, which decides the issue of the dis-
ease, is limited to a short period. We must not
forget, that the ice melts and absorbs heat from the
diseased part ; that if the ice be removed before the
completion of the metamorphosis, the temperature

262 THEORY OF DISEASE.

again rises ; that far more heat is removed by means
of ice than if we were to surround the head with a
bad conductor of heat. There has obviously been
liberated in an equal time a far larger amount of
heat than in the state of health ; and this is only
rendered possible by an increased supply of oxygen,
which must have determined a more rapid change
of matter.

The self-regulating steam-engines, in which, to
produce a uniform motion, the human intellect has
shewn the most admirable acuteness and sagacity,
furnish no unapt image of what occurs in the animal
body.

Every one knows, that in the tube which conveys
the steam to the cylinder where the piston-rod is
to be raised, a stop-cock of peculiar construction
is placed, through which all the steam must pass.
By an arrangement connected with the regulating-
wheel, this stop-cock opens when the wheel moves
slower, and closes more or less completely when
the wheel moves faster than is required for a
uniform motion. When it opens, more steam is
admitted (more force), and the motion of the ma-
chine is accelerated. When it shuts, the steam is
more or less cut off, the force acting on the piston-
rod diminishes, the tension of the steam increases,
and this tension is accumulated for subsequent use.
The tension of the vapour, or the force, so to speak,
is produced by change of matter, by the combustion
of coals in the fire-place. The force increases (the

THEORY OF DISEASE. 263

amount of steam generated and its tension increase)
with the temperature in the fire-place, which de-
pends on the supply of coals and of air. There are
in these engines other arrangements, all intended
for regulation. When the tension of steam in the
boiler rises beyond a certain point, the passages for
admission of air close themselves ; the combustion
is retarded, the supply of force (of steam) is dimin-
ished. When the engine goes slower, more steam
is admitted to the cylinder, its tension diminishes,
the air passages are opened, and the cause of dis-
engagement of heat (or production of force) in-
creases. Another arrangement supplies the fire-
place incessantly with coals in proportion as they
are wanted.

If we now lower the temperature at any part of
the boiler, the tension within is diminished ; this is
immediately seen in the regulators of force, which
act precisely as if we had removed from the boiler
a certain quantity of steam (force). The regulator
and the air passages open, and the machine supplies
itself with more coals.

The body, in regard to the production of heat and
of force, acts just like one of these machines. With
the lowering of the external temperature, the respi-
rations become deeper and more frequent ; oxygen
is supplied in greater quantity and of greater den-
sity ; the change of matter is increased, and more
food must be supplied, if the temperature of the
body is to remain unchanged.

264 THEORY OF DISEASE.

It is hardly necessary to mention, that in the
body, the tension of vapour cannot, any more than
an electrical current, be considered the cause of the
production of force.

From the theory of disease developed in the pre-
ceding pages, it follows obviously, that a diseased
condition once established, in any part of the body,
cannot be made to disappear by the chemical action
of a remedy. A limit may be put by a remedy to
an abnormal process of transformation ; that process
may be accelerated or retarded ; but this alone does
not restore the normal (healthy) condition.

The art of the physician consists in the knowledge
of the means which enable him to exercise an in-
fluence on the duration of the disease ; and in the
removal of all disturbing causes, the action of which
strengthens or increases that of the actual cause of
disease.

It is only by a just application of its principles
that any theory can produce really beneficial results.
The very same method of cure may restore health
in one individual, which, if applied to another, may
prove fatal in its effects. Thus in certain inflamma-
tory diseases, and in highly muscular subjects, the
antiphlogistic treatment has a very high value;
while in other cases blood-letting produces unfavour-
able results. The vivifying agency of the blood
must ever continue to be the most important condi-
tion in the restoration of a disturbed equilibrium,
which result is always dependant on the saving of

THEORY OF RESPIRATION. 265

time ; and the blood must, therefore, be considered
and constantly kept in view, as the ultimate and
most powerful cause of a lasting vital resistance, as
well in the diseased as in the unaffected parts of
the body.

It is obvious, moreover, that in all diseases where
the formation of contagious matter and of exanthe-
mata is accompanied by fever, two diseased condi-
tions simultaneously exist, and two processes are
simultaneously completed ; and that the blood, as
it were by re-action (i. e. fever), becomes a means of
cure, as being the carrier of that substance (oxygen)
without the aid of which the diseased products can-
not be rendered harmless, destroyed, or expelled
from the body ; a means of cure by which, in short,
neutralization or equilibrium is effected.

IV.
THEORY OF RESPIRATION.

During the passage of the venous blood through
the lungs, the globules change their colour ; and
with this change of colour, oxygen is absorbed from
the atmosphere. Further, for every volume of oxy-
gen absorbed, an equal volume of carbonic acid is,
in most cases, given out.

The red globules contain a compound of iron;
and no other constituent of the body contains iron.

Whatever change the other constituents of the

266 THEORY OF RESPIRATION.

blood undergo in the lungs, thus much is certain,
that the globules of venous blood experience a
change of colour, and that this change depends on
the action of oxygen.

Now we observe that the globules of arterial
blood retain their colour in the larger vessels, and
lose it only during their passage through the ca-
pillaries. All those constituents of venous blood,
which are capable of combining with oxygen, take
up a corresponding quantity of it in the lungs.
Experiments made with arterial serum have shewn,
that when in contact with oxygen it does not dimin-
ish the volume of that gas. Venous blood, in con-
tact with oxygen, is reddened, while oxygen is ab-
sorbed ; and a corresponding quantity of carbonic
acid is formed.

It is evident that the change of colour in the
venous globules depends on the combination of some
one of their elements with oxygen ; and that this
absorption of oxygen is attended with the separation
of a certain quantity of carbonic acid gas.

This carbonic acid is not separated from the se-
rum ; for the serum does not possess the property,
when in contact with oxygen, of giving off carbonic
acid. On the contrary, when separated from the
globules, it absorbs from half its volume to an equal
volume of carbonic acid, and, at ordinary tempera-
tures, is not saturated with that gas. (See the ar-
ticle " Blut " in the " Handwb'rterbuch der Chemie
von Poggendorff, Wo'hler, and Liebig, p. 877.)

THEORY OF RESTORATION. 267

Arterial blood, when drawn from the body, is
soon altered ; its florid colour becomes dark red.
The florid blood, which owes its colour to the glo-
bules, becomes dark by the action of carbonic acid,
and this change of colour affects the globules, for
florid blood absorbs a number of gases which do not
dissolve in the fluid part of the blood when sepa-
rated from the globules. It is evident, therefore, that
the globules have the power of combining with gases.

The globules of the blood change their colour in
different gases ; and this change may be owing either
to a combination or to a decomposition.

Sulphuretted hydrogen turns them blackish green
and finally black ; and the original red colour can-
not, in this case, be restored by contact with oxygen.
Here a decomposition has obviously taken place.

The globules darkened by carbonic acid become
again florid in oxygen, with disengagement of car-
bonic acid. The same thing takes place in nitrous
oxide. It is clear that they have here undergone
no decomposition, and, consequently, they possess
the power of combining with gases, while the com-
pound they form with carbonic acid is destroyed by
oxygen. When left to themselves, out of the body,
the compound formed with oxygen again becomes
dark, but does not recover its florid colour a second
time by the action of oxygen.

The globules of the blood contain a compound of
iron. From the never-failing presence of iron in
red blood, we must conclude, that it is unquestion-

268 THEORY OF RESPIRATION.

ably necessary to animal life ; and, since physiology
has proved, that the globules take no share in the
process of nutrition, it cannot be doubted that they
play a part in the process of respiration.

The compound of iron in the globules has the
characters of an oxidised compound ; for it is de-
composed by sulphuretted hydrogen, exactly in the
same way as the oxides or other analogous com-
pounds of iron. By means of diluted mineral acids,
peroxide (sesquioxide) of iron may be extracted, at
the ordinary temperature, from the fresh or dried
red colouring matter of the blood.

The characters of the compounds of iron may,
perhaps, assist us to explain the share which that
metal takes in the respiratory process. No other
metal can be compared with iron, for the remark-
able properties of its compounds.

The compounds of protoxide of iron possess the
property of depriving other oxidised compounds of
oxygen ; while the compounds of peroxide of iron,
under other circumstances, give up oxygen with the
utmost facility.

Hydrated peroxide of iron, in contact with organic
matters destitute of sulphur, is converted into car-
bonate of the protoxide.

Carbonate of protoxide of iron, in contact with
water and oxygen, is decomposed ; all the carbonic
acid is given off, and, by absorption of oxygen, it
passes into the hydrated peroxide, which may again
be converted into a compound of the protoxide.

THEORY OF RESPIRATION. 269

Not only the oxides of iron, but also the cyanides
of that metal, exhibit similar properties. Prussian
blue contains iron in combination with all the or-
ganic elements of the body ; hydrogen and oxygen
(water), carbon and nitrogen (cyanogen).

When it is exposed to light, cyanogen is given
off, and it becomes white ; in the dark it attracts
oxygen, and recovers its blue colour.

All these observations, taken together, lead to the
opinion that the globules of arterial blood contain
a compound of iron saturated writh oxygen, which,
in the living blood, loses its oxygen during its pas-
sage through the capillaries. The same thing occurs
when it is separated from the body, and begins to
undergo decomposition (to putrefy). The compound,
rich in oxygen, passes, therefore, by the loss of oxy-
gen (reduction), into one far less charged with that
element. One of the products of oxidation formed
in this process is carbonic acid. The compound of
iron in the venous blood possesses the property of
combining with carbonic acid; and it is obvious,
that the globules of the arterial blood, after losing a
part of their oxygen, will, if they meet with car-
bonic acid, combine with that substance.

When they reach the lungs, they will again take
up the oxygen they have lost ; for every volume of
oxygen absorbed, a corresponding volume of car-
bonic acid will be separated; they will return to
their former state ; that is, they will again acquire
the power of giving off oxygen.

270 THEORY OF RESPIRATION.

For every volume of oxygen which the globules
can give off, there will be formed (as carbonic acid
contains its own volume of oxygen, without conden-
sation) neither more nor less than an equal volume
of carbonic acid. For every volume of oxygen
which the globules are capable of absorbing, no
more carbonic acid can possibly be separated than
that volume of oxygen can produce.

When carbonate of protoxide of iron, by the
absorption of oxygen, passes into the hydrated
peroxide, there are given off, for every volume of
oxygen necessary to the change from protoxide to
peroxide, four volumes of carbonic acid gas.

But from one volume of oxygen only one volume
of carbonic acid can be produced ; and the absorption
of one volume of oxygen can only cause, directly,
the separation of an equal volume of carbonic acid.
Consequently, the substance or compound which has
lost its oxygen, during the passage of arterial into
venous blood, must have been capable of absorbing or
combining with carbonic acid ; and we find, in point
of fact, that the living blood is never, in any state,
saturated with carbonic acid ; that it is capable of
taking up an additional quantity, without any appa-
rent disturbance of the function of the globules.
Thus, for example, after drinking effervescing wines,
beer, or mineral waters, more carbonic acid must
necessarily be expired than at other times. In all
cases, where the oxygen of the arterial globules has
been partly expended, otherwise than in the forma-

THEORY OF RESPIRATION. 271

tion of carbonic acid, the amount of this latter gas
expired will correspond exactly with that which has
been formed ; less, however, will be given out after
the use of fat and of still wines, than after cham-
pagne.

According to the views now developed, the glo-
bules of arterial blood, in their passage through the
capillaries, yield oxygen to certain constituents of
the body. A small portion of this oxygen serves to
produce the change of matter, and determines the
separation of living parts and their conversion into
lifeless compounds, as well as the formation of the
secretions and excretions. The greater part, how-
ever, of the oxygen is employed in converting into
oxidised compounds the newly formed substances,
which no longer form part of the living tissues.

In their return toAvards the heart, the globules
which have lost their oxygen combine with carbonic
acid, producing venous blood ; and, when they reach
the lungs, an exchange takes place between this
carbonic acid and the oxygen of the atmosphere.

The organic compound of iron, which exists in
venous blood, recovers in the lungs the oxygen it
has lost, and, in consequence of this absorption of
oxygen, the carbonic acid in combination with it is
separated.

All the compounds present in venous blood, which
have an attraction for oxygen, are converted, in the
lungs, like the globules, into more highly oxidised
compounds ; a certain amount of carbonic acid is

272 THEORY OF RESPIRATION.

formed, of which a part always remains dissolved in
the serum of the blood.

The quantity of carbonic acid dissolved, or of that
combined with soda, must be equal in venous and
arterial blood, since both have the same tempera-
ture ; but arterial blood, when drawn, must, after a
short time, contain a larger quantity of carbonic
acid than venous blood, because the oxygen of the
globules is expended in producing that compound.

Hence, in the animal organism, two processes of
oxidation are going on ; one in the lungs, the other
in the capillaries. By means of the former, in spite
of the degree of cooling, and of the increased evapo-
ration which takes place there, the constant tempe-
rature of the lungs is kept up ; while the heat of
the rest of the body is supplied by the latter.

A man, who expires daily 13*9 oz. of carbon, in
the form of carbonic acid, consumes, in 24 hours,
37 oz. of oxygen, which occupy a space equal to
807 litres = 51,648 cubic inches (hessian).

If we reckon 18 respirations to a minute, we
have, in 24 hours, 25,920 respirations ; and, conse-
quently, in each respiration, there are taken into the
blood ££«-£« = 1*99 cubic inch of oxygen.

In one minute, therefore, there are added to the
constituents of the blood 18 X 1-99 = 35'8 cubic
inches of oxygen, which, at the ordinary tempera-
ture, weigh rather less than 12 grains.

If we now assume, that in one minute 10 Ibs. of
blood pass through the lungs (Miiller, Physiologic,

THEORY OP RESPIRATION. 273

vol. i. p. 345), and that this quantity of blood mea-
sures 320 cubic inches, then 1 cubic inch of oxygen
unites with 9 cubic inches of blood, very nearly.

According to the researches of Denis, Richardson,
and Nasse (Handwb'rterbuch der Physiologie, vol. i.
p. 1 38), 10,000 parts of blood contain 8 parts of per-
oxide of iron. Consequently, 76,800 grains (10 Ibs.
hessian) of blood contain 61*54 grains of peroxide
of iron in arterial blood, = 55-14 of protoxide in
venous blood.

Let us now assume that the iron of the globules
of venous blood is in the state of protoxide. It
follows, that 55-14 grains of protoxide of iron, in
passing through the lungs, take up, in one minute,
6'40 grains of oxygen (the quantity necessary to
convert it into peroxide). But since, in the same
time, the 10 Ibs. of blood have taken up 12 grains
of oxygen, there remain 5*60 grains of oxygen,
which combine with the other constituents of the
blood.

Now, 55'14 grains of protoxide of iron combine
with 34- 8 grains of carbonic acid, which occupy the
volume of 73 cubic inches. It is obvious, therefore,
that the amount of iron present in the blood, if in
the state of protoxide, is sufficient to furnish the
means of carrying or transporting twice as much
carbonic acid as can possibly be formed by the
oxygen absorbed in the lungs.

The hypothesis just developed rests on well-known
observations, and, indeed, explains completely the
T

274 THEORY OF RESPIRATION.

process of respiration, as far as it depends on the
globules of the blood. It does not exclude the
opinion that carbonic acid may reach the lungs in
other ways ; that certain other constituents of the
blood may give rise to the formation of carbonic
acid in the lungs. But all this has no connection
with that vital process by which the heat necessary
for the support of life is generated in every part of
the body. Now it is this alone which, for the pre-
sent, can be considered as the object truly worthy
of investigation. It is not, indeed, uninteresting to
inquire, why dark blood becomes florid by the action
of nitre, common salt, &c. ; but this question has no
relation to the natural respiratory process.

The frightful effects of sulphuretted hydrogen,
and of prussic acid, which, when inspired, put a stop
to all the phenomena of motion in a few seconds,
are explained in a natural manner by the well-known
action of these compounds on those of iron, when
alkalies are present ; and free alkali is never absent
in the blood.

Let us suppose that the globules lose their pro-
perty of absorbing oxygen, and of afterwards giving
up this oxygen and carrying off the resulting car-
bonic acid ; such a hypothetical state of disease
must instantly become perceptible in the tempera-
ture and other vital phenomena of the body. The
change of matter will be arrested, while yet the vital
motions will not be instantly stopped.

The conductors of force, the nerves, will convey,

THEORY OF RESPIRATION. 275

as before, to the heart and intestines the power
necessary for their functions. This power they will
receive from the muscular system, while, as no
change of matter takes place in the latter, the
supply must soon fail. As no change of matter
occurs, no lifeless compounds are separated, neither
bile nor urine can be formed ; and the temperature
of the body must sink.

This state of matters soon puts a stop to the
process of nutrition, and, sooner or later, death must
follow, but unaccompanied by febrile symptoms,
which, in this case, is a very important fact.

This example has been selected in order to shew
the importance and probable advantage of an exa-
mination of the blood in analogous diseased condi-
tions. It cannot be, in the slightest degree, doubtful
that the function ascribed to the blood globules
may be considered as fully explained and cleared
up, if, in such morbid conditions, we shall discover
a change in their form, structure, or chemical cha-
racters, a change which must be recognizable by the
use of appropriate re-agents.

If we consider the force which determines the
vital phenomena as a property of certain substances,
this view leads of itself to a new and more rigorous
consideration of certain singular phenomena, which
these very substances exhibit, in circumstances in
which they no longer make a part of living or-
ganisms.

APPENDIX;

CONTAINING

THE ANALYTICAL EVIDENCE

REFERRED TO IN THE SECTIONS IN WHICH ARE DESCRIBED

THE

CHEMICAL PROCESSES OP RESPIRATION, OP
NUTRITION,

AND OF THE

METAMORPHOSIS OF TISSUES.

'#* The Notes correspond with the numbers in parentheses in the text.
All the Analyses quoted, which have the mark * attached, have been
made in the chemical laboratory of the University of Giessen.

APPENDIX.

INTRODUCTION TO THE ANALYSES.

THE method formerly employed to exhibit the differ-
ences in composition of different substances, that, namely,
of giving the proportions of the various elements in 100
parts, has been long abandoned by chemists ; because it
affords no insight into the relations which exist between
two or more compounds. In order to give some proofs
of this statement, we shall here state, in that form, the
composition of aldehyde and acetic acid, of oil of bitter
almonds and benzoic acid.

Acetic acid. Aldehyde. Benzoic acid.

Carbon ...... 40'00 55'024 69' 25 79'56

Hydrogen ... 6 "67 8'983 4'86 5'56

Oxygen ...... 53'33 35'993 25-89 14-88

Now aldehyde is converted into acetic acid, and oil of
bitter almonds into benzoic acid, simply by the addition
of oxygen, without any change in regard to the other
elements. This important relation cannot be traced in
the mere numerical results of analysis as above given • but

280 APPENDIX.

if the composition of the related compounds be expressed
in formulae, according to equivalents, the connection in
each case becomes obvious, even to him who knows no
more of chemistry than that C represents an equivalent
or combining proportion of carbon, H an equivalent of
hydrogen, and O an equivalent of oxygen.

Formula Formula

of acetic acid, of aldehyde. of benzoic acid, of oil of bitter almonds.

C4H404. C4H402. C14H604. C14H602.

These formulae are exact expressions of the results of
analysis, which, in each of the two cases quoted, refer to
a fixed quantity of carbon ; in one to 4 equivalents, in the
other to 14. They shew, that acetic acid differs from
aldehyde, and benzoic acid from oil of bitter almonds,
only in the proportion of oxygen.

Nor is it more difficult to understand the signification
of the following formulae.

Cyamelide. 1 eq. cyanuric acid. 3 eq. hydrated cyanic acid.

C6N3H3O6 = Cy3(= C6N3)03 + 3HO = 3(CyO + HO) =
^ C6N3H306 = C6N3H306.

(In these formulae, N represents an equivalent of nitro-
gen, and Cy an equivalent of cyanogen. This latter sub-
stance being composed of 2 equivalents of carbon and 1
eq. of nitrogen, Cy = C2N.)

The first formula (that of cyamelide) is what is called
an empirical formula, in which the relative proportions of
the elements are, indeed, exactly known, but where we
have not even a theory, far less any actual knowledge, of
the order in which they are arranged. The second for-
mula is intended to express the opinion that 3 eq. of
cyanogen (= 6 eq, of carbon + 3 eq. of nitrogen) having

ANALYTICAL EVIDENCE. 281

united to form a compound atom or molecule, have com-
bined with 3 eq. of oxygen and 3 eq. of water, to form
1 eq. of hydrated cyanuric acid. The third expresses the
order in which the elements are supposed to be arranged
in hydrated cyanic acid, the whole multiplied by 3. Each
equivalent of cyanic acid is formed of 1 eq. of cyanogen,
1 eq. of oxygen, and 1 eq. of water ; and hence the same
number of atoms of each element, which together formed
1 eq. of cyanuric acid, is here so divided as to yield 3 eq.
of cyanic acid.

We have here, therefore, the same absolute and relative
amount of atoms of each element, arranged in three diffe-
rent ways; yet in each of these the proportions of the
elements, calculated for 100 parts, must of course be the
same. It is easy, therefore, to see the advantage we pos-
sess by the use of formulae ; that, namely, of exhibiting
the relations existing between compounds of different
composition ; and that also of expressing the actual,
probable, or possible differences between substances
whose composition, in 100 parts, is the same, while their
properties, as in the case above quoted, are perfectly
distinct.

It does not come within our province here to explain
the method or rule by which the composition of a sub-
stance, in 100 parts (as it is always obtained in analysis),
is expressed in a formula ; we shall only describe the rule
for calculating, from a given formula, the composition in
100 parts. For this purpose it must be noted that C, in
a chemical formula, signifies a weight of carbon expressed
by the number 76*437 (according to the most recent
determinations 75'8 or 75'0, a variation which has no
effect whatever on the formulae here adduced, all of
which are calculated on the number 76'437); that H
signifies a weight of hydrogen = 12'478 ; N a weight of

282 APPENDIX.

nitrogen = 177*04; and lastly O a weight of oxygen
= 100.

The formula of proteine, C^NgR,/),* expresses, there-
fore,

48 times 76*437 = 3668'88 carbon,
6 times 177.040 = 1062*24 nitrogen,
36 times 12*478 = 449*26 hydrogen,
14 times 100*000 = 1400*00 oxygen.

The sum gives a weight of 6580*38 proteine.
Therefore—

In 100 parts.

In 6580-38 parts of proteine are contained 3668-88 carbon 55-742
In 6580-38 ditto 1062-24 nitrogen 16-143

In 6580-38 ditto 449-26 hydrogen 6'827

In 6580-38 ditto 1400-00 oxygen 21*288

100-000

The actual results of analysis, reduced to 100 parts,
when compared with the above numbers, will shew how
far the assumed formula is correct ; or, supposing the for-
mula ascertained, they will shew the degree of accuracy
displayed by the experimenter. Thus the proportions in
100 parts, calculated from the formula, furnish an impor-
tant check to the operator, and, conversely, the formula
calculated from his results, when compared with other
known formulae, supplies a test of his accuracy, or of the
purity of the substance analyzed.

ANALYTICAL EVIDENCE.

283

NOTE (1), p. 12.

CONSUMPTION OF OXYGEN BY AN ADULT.
An adult man

consumes of oxygen
in 24 hours

produces of carbonic
acid in 24 hours

in the
carbonic acid.

According to

* 1

, '

*

cubic in.

grains.

cubic in.

grains.

grains.

Lavoisier and Seguin

46,037

15,661

14,930

8,584

2,820 French.

Menzies

51,480

17,625

English.

Davy

45,504

15,751

31,680

17,811

4,853 do.

Allen and Pepys ...

39,600

13,464

39,600

18,612

5,148 do.

NOTE (2), p. 13.
COMPOSITION OF DRY BLOOD (see note 28).

In 100 parts. In 4-8 Ibs. Hessian = 36,864 grains.

Carbon 51'96 19154-5

Hydrogen... 7'25 2672-7

Nitrogen ... 15'07 5555'4

Oxygen ... 21-30 7852-0

Ashes .. 4-42 , 1629*4

100-00 36864-0

Grains. Grains.

19154-5 carbon form, with 50539-5 oxygen, carbonic acid.
2672'7 hydrogen do. 21415-8 do. water.

Sum = 71955-3 do.
Deduct oxygen present"!
in blood J

Remain ... 64103-3 grains of oxygen, required
for the complete combustion of 4*8 Ibs. of dry blood.

It is assumed, in this calculation, that 24 Ibs. of blood
yield 4-8 Ibs. (20 per cent.) of dry residue. The re-
mainder, 80 per cent., is water.

7852-0

284 APPENDIX.

NOTE (3), p. 14.

DETERMINATION OF THE AMOUNT OF CARBON
EXPIRED.

1. ANALYSIS OF

FcBces.

2-356 dry faeces left 0'320 ashes (13'58 per cent.)
0-352 dry fzeces yielded 0'576 carbonic acid, and 0-218 water.

Lentils.

0-566 lentils, dried at 212°, yielded 0'910 carbonic acid, and
0-366 water.

Pease.

1-060 pease, dried at 212°, left 0'037 ashes.
0-416 do. do. yielded 0-642 carbonic acid, and

0-241 water.

Potatoes.

0-443 dried potatoes yielded 0'704 carbonic acid, and 0'248
water.

Black Bread (Schwarzbrod).

0-302 dried black bread yielded 0'496 carbonic acid, and 0'175
water.

0-241 do. 0-393 do. 0'142

water.

From the above, which are the direct results of experi-
ment, the composition in 100 parts is calculated as in the
following table.

ANALYTICAL EVIDENCE.
2. COMPOSITION

285

Of Faeces. Of Black Bread. Of Potatoes. Of Flesh.

Playfair.* Bceckmann.* ' BoussingaultTBceckmann.*

Carbon ... 45-24 45-09 45-41 44-1 43-944 (Seenote

Hydrogen 6-88 6'54 6'45 5-8 6'222 28.)

Nitrogen

Oxygen ^ ™'73 45'12 44'89 45'1 44'919

Ashes

Water

} 34-73 45-12 44-89 45'1 44-!

13-15 3-25 3-25 5'0 4-915

100-00 100-00 100-00 100-0 100000
300-00

400-00

Of Pease.
Playfair.*

Carbon ............... 35'743

Hydrogen ......... 5'401

......... 39-366

Oxygen J

Ashes ............... 3-490

Water ............... 16-000

Of Lentils. Of Beans.
Playfair.* Playfair.*

37-38 38-24

5-54

37-98

3-20
15-90

100-000 100-00

100-00

Water

Fresh Meat.
Bceckmann.*

75 74-8
25 25-2

Potatoes. Black Bread.
Boussingault. Boeckmann.*

72-2

27-8

73-2

26-8

33

67

31-418
68-592

Dry Matter

100 100-0 100-0 100-0 100 100-000

3. CALCULATION,

with the help of the preceding data, of the amount of
carbon expired by an adult man. The following results
are deduced from observations made (see table) on the
average daily consumption of food, by from 27 to 30
soldiers in barracks for a month, or by 855 men for one

286 APPENDIX.

day. The food, consisting of bread, potatoes, meat,
lentils, pease, beans, &c., was weighed, with the utmost
exactness, every day during a month (including even
pepper, salt, and butter); and each article of food was
separately subjected to ultimate analysis. The only ex-
ceptions, among the men, to the uniform allowance of
food, were three soldiers of the guard, who, in addi-
tion to the daily allowance of 2 Ibs. of bread, received,
during each of the periods allotted for the pay of the
troops, 2^ Ibs. extra ; and one drummer, who, in the
same period, left 2^ Ibs. unconsumed. According to an
approximative report by the sergeant-major, each soldier
consumes daily, on an average, out of barracks, 3 oz.
of sausage, f oz. of butter, | pint of beer, and tV Pmt of
brandy; the carbon of which articles amounts to more
than double that of the faeces* and urine taken together.
In the soldier, the faeces amount daily, on an average, to
5i| oz. ; they contain 75 per cent, of water, and the dry
residue contains 45'24 per cent, of carbon, and 13' 15 per
cent, of ashes. 100 parts of fresh faeces consequently
contain 11 '31 per cent, of carbon, veiy nearly the same
proportion as in fresh meat. In the calculation, the car-
bon of the faeces and of the urine has been assumed as equal
to that of the green vegetables, and of the food (sausages,
butter, beer, &c.) consumed in the alehouse.
' From the observations, as recorded in the table, the
following conclusions are deduced.

Flesh. — Meat devoid of fat, if reckoned at 74 per cent,
water, and 26 per cent, dry matter, contains in 100 parts
very nearly 13'6 parts of carbon. Ordinary meat con-
tains both fat and cellular tissue, which together amount
to |th of the weight of the meat as bought from the but-
cher. The number of ounces consumed (by 855 men) was
4,448, consisting, therefore, of

ANALYTICAL EVIDENCE. 287

3812-5 oz. of flesh, free from fat, containing of carbon 518-5 oz.
635-5 oz. of fat and cellular tissue, ditto 449-0 oz.

4448-0 oz. In all, carbon 967'5 oz.

With the bones, the meat, as purchased, contains 29
per cent, of fixed matter, including bones; 4,448 oz. of
flesh therefore contain 448 oz. of dry bones. These have
not been included in the calculation, although, when
boiled, they yield from 8 to 10 per cent, of gelatine, which
is taken as food in the soup.

Fat. — The amount of fat consumed was 56 oz. ; which,
the carbon being calculated at 80 per cent., contain in all
44-8 oz. of carbon.

Lentils, pease, and leans. — There were consumed 53-5
oz. of lentils, 185'5oz. of pease, and 218 oz. of beans.
Assuming the average amount of carbon in the'se vege-
tables to be 37 per cent., the total quantity of carbon
consumed in this form was 169' 1 oz.

Potatoes. — 100 parts of fresh potatoes contain 12'2
parts of carbon. In the 15,876 oz. of potatoes consumed,
therefore, the amount of carbon was 1936-85 oz.

Bread. — 855 men eat daily 855 times 32 oz., besides
361bs. of bread in the soup, which in all amounts to
27,936 oz. 100 oz. of fresh bread contain, on an average,
30-15 oz. of carbon; consequently, the carbon consumed
in the bread amounts to 8771-5 oz.

The total consumption, therefore, was,

In the meat 967'50 oz. of carbon.

In the fat 44-80 ditto

In the lentils, pease, and beans ... 1 69- 10 ditto

In the potatoes 1936'85 ditto

In the bread 8771-50 ditto

Consumed by 855 men 11889-75 ditto

Consumed by 1 man 13-9 ditto

288 APPENDIX.

The feces of a soldier weigh 5-5 oz., and contain, in the
fresh state, 1 1 per cent, of carbon. For 86 kreutzer (about
2s. 5d. sterling) there may be bought, on an average,
172 Ibs. of vegetables, such as cabbages, greens, turnips,
&c. : 25 maas of sour krout weigh 100 Ibs. ; and for 48<|
kreutzer (Is. 5d. sterling) there are bought, on an average,
24£ Ibs. of onions, leeks, celery, &c.* 855 men consumed

Of green vegetables 2,802 oz.

Of sour krout 1,600

Of onions, &c 388

In all 4,790

And one man 5'6 oz.

For this reason, the carbon of the last-mentioned ar-
ticles of food has been assumed as equal to that of the
faeces and urine. Sausages, brandy, beer, in short, the
small quantity of food taken irregularly in the 'alehouse,
has not been included in the calculation.

The daily allowance of bread, being uniformly 2 Ibs. per
man, with the exceptions formerly mentioned, has not
been inserted in the table, which includes only those
matters of which, from the daily allowance being variable,
an average was required. The small quantity of bread in
the table is that given in the soup, which is over and
above the daily supply.

* In the original table, the quantities of these vegetables are entered ac-
cording to their value in kreutzers, but they are here calculated by weight
from the above data, as this appeared better adapted for comparison in this
country than the prices would have been. — ED.

!

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l|Sj|

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ji*a.* -s-

s*

sts

4|

life

s«

8

8

ssll

^tKfe»

11

jO «* CO CO Tt« i« CO

S

Ha

a

!|St

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jj*-?* "'

S

4s

•a

111!

1*1

ffl en

jV^o S»

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i

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iSS

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JS 2 g 3 2 Jg :

S

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lili

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« O <O «O O • "M

.a <M i-i 1-1 »-i : co

1

31bs. llT9J,oz.

o

m

id ounces, the di
yr be omitted, witf
ssian _ 16 oz. Hes
7712, or as 1 : 1'1(

j

o .... *?*"-,

CO

o

s

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§

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lifl

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^ t^ lO CO !>. — 1 !>.

<N

1
i

• i

•£

If

0.

CO

So«S

!

J--!|^

•

i
3

11

I

/ -r i - • r i ^ cs O
-2 CO CO CO CO CO CO

S

1

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HIS

III.I

OS tf5 O to t>* C^l

S

i

a

'

flip

|oS|

vE— ,

._.Q,

glllf

1840.
November,
in the period
from the

£ g 1 1 II

2322 22

2 * S 1 II

I

The average
number of
men daily

&>J ;„ 855

28£,th3e5re-
fore each
man had

N. B.-As
excepting the
wish to reduce
since the 1 Ib. a
while 1 oz, avoi

290 APPENDIX.

TABLE II.— Note (4), p. 14. a

FOOD CONSUMED BY A HORSE IN TWENTY-FOUR HOURS.

Articles of
food.

Weight
in the
fresh
state.

Weight
in the
dry
state.

Carbon.

Hydro-
gen.

Oxygen.

Nitro-
gen.

Salts
and
earthy
matters.

Hav .

7500

6465

2961-0

323-2

2502-0

97-0

581-8

Oats
Water

2270
16000

1927

977-0

123-3

707-2

42-4

77-1
13-3

Total ...

25770

8392

3938-0

446-5

3209-2

139-4

672-2

EXCRETIONS OF A HORSE IN TWENTY-FOUR HOURS.

Excretions.

Weight
in the
fresh
state.

Weight
in the
dry
state.

Carbon.

Hydro-
gen.

Oxygen.

Nitro-
gen.

Salts
and
earthy
matters.

Urine
Excrements

1330
14250

302
3525

108-7
1364-4

11-5

179-8

34-1
1328-9

37-8
77-6

109-9
574-6

Total ...

15580

3827

1472-9

191-3

1363-0

115-4

684-5

Total from
the previous
part of this
Table.

25770

8392

3938-0

446-5

3209-2

139-4

672-2

Difference

10190

4565

2465-1

255-2

1846-2

24-0

12-3

+ or —

—

—

—

—

—

—

+

a Boussingault, Ann. de Ch. et de Phys., LXX., 136. The weights in this
table are given in grammes. 1 gramme = 15-44 grains Troy, very nearly.

ANALYTICAL EVIDENCE. 291

TABLE II.— Note (4), p. 14 (concluded).

FOOD CONSUMED BY A COW IN TWENTY-FOUR HOURS.

Articles of
food.

Weight
in the
fresh
state.

Weight
in the
dry state.

Carbon.

Hydro-

gen.

Oxygen.

Nitro-
gen.

Salts
and
earthy
matters.

Potatoes ...

15000

4170

1839-0

241-9

1830-6

50-0

208-5

After Grass

7500

6315

2974-4

353-6

2204-0

151-5

631-5

Water

60000

50'0

Total ...

82500

10485

4813-4

595-5

4034-6

201-5

889-0

EXCRETIONS OF A COW IN TWENTY-FOUR HOURS.

Excretions.

Weight
in the
fresh
state.

Weight
in the
dry state.

Carbon.

Hydro-
gen.

Oxygen.

Nitro-
gen.

Salts
and
earthy
matters.

Excrements
Urine
Milk

28413
8200
8539

4000-0
960-8
1150-6

1712-0
261-4
628-2

208-0
25-0
99-0

1508-0
253-7
321-0

92-0
36-5
46-0

480-0
384-2
56-4

Total ...

45152

6111-4

2601-6

332-0

2082-7

174-5

920-6

Total of
first part of
this Table.

82500

10485-0

4813-4

595-5

4034-6

201-5

889-0

Difference

37348

4374-6

2211-8

263-5

1951-9

27-0

31-6

+ or —

—

—

—

—

—

—

-r-

u V

292 APPENDIX.

NOTE (5), p. 19.

TEMPERATURE OF THE BLOOD AND FREQUENCY OF
THE PULSE.

According to Prevost and Dumas,

In the Pigeon

The mean
temperature is

107-6°
106-7°
108-5°
108-5°
117-2°
95-9°
100-4°
99-3°
101-3°
102-5°
100-4°
98-2°
98-6°

The frequency

of the pulse
in the minute.

136
140
170
110
200
90
WO
90
100
84
120
56
72

of the respiration
in the minute.

34
30
21
21
22
30
36
28
24
24
36
16
18

Common Fowl

Duck

Raven

Lark

Simia Callitriche ...
Guinea Pig

Dos

Cat

Goat

Hare

Horse

Man

Man (Liebig)
Woman (Liebig) ...

97-7°
98-2°

65
60

17
15

The temperature of a child is 102-2°.

The temperature of the human body, in the mouth or
in the rectum, for example, is from 97'7° to 98'6°. That
of the blood (Majendie) is from 100'6° to 101-6°. As a
mean temperature, 99 -5° has been adopted in this work,
page 19.

ANALYTICAL EVIDENCE.

293

NOTE (6), p. 36.

The prisoners in the house of arrest at Giessen receive
daily 1£ Ib. of bread (24 oz.), which contain 7£ oz. of
carbon. They receive, besides, 1 Ib. of soup daily, and
on each alternate day, 1 Ib. of potatoes.

1£ Ib. of bread contains 7'25 oz. of carbon.

1 Ib. of soup contains 0'75 ditto

J Ib . of potatoes contains 1 • 00 ditto

Total 9-00 ditto*

NOTE (7), p. 43.

COMPOSITION OF THE FIBRINE AND ALBUMEN OF
BLOOD, a

Albumen from Serum of Blood.
Scherer.*

Carbon 53-850

Hydrogen 6 '983

Nitrogen 15'673

Oxygen..

Sulphur <> 23-494

Phosphorus

II.

55-461
7-201
15-673

III.
56-097

15-681

I.

53-671
6-878
15-763

Fibrine.
Scherer.» Mulder.

II. III.

54-454 54-56

7-069 6-90

15-762 15-72

21-655 22-342 23-688 22-715 22-82

a Annalen der Chem. und Pharm., XXVIII., 74, and XL., 33, 36.

For additional analyses of animal fibrine and albumen,
see Note (27), which also contains analyses of the various
animal tissues.

J At page 36 the carbon contained in the daily food of these prisoners is cal-
culated at 8£ oz., and the appendix in the original makes the number also 8' 5,
apparently by an error in adding up the above numbers, which yield the sum
of 9 oz. Possibly there may be an error in excess in the proportion of carbon
calculated for the soup, which, in that case, ought to be 0-25 oz. — EDITOR.

294

APPENDIX.

NOTE (8), p. 48.

COMPOSITION OF VEGETABLE FIBRINE, VEGETABLE
ALBUMEN, VEGETABLE CASEINE, AND VEGETABLE
GLUTEN.

VEGETABLE FIBRINE.

Scherer.*
I. II. III.

Carbon 53-064 54-603 54'617

Hydrogen 7'132 7'302 7'491

Nitrogen 15-359 15-809 15-809

Oxygen

GLUTEN,

As obtained from

wheat flour.
Jones.'6 Mareet.c Boussingault.

IV.

53-83
7-02
15-58

I. II.

55-7 53-5

14-5 15-0

7-8 7-0

Sulphur I 24-445 22-285 22-Q83 23-56 22-0
Phosphorus J

a Ann. der Chem., und Pharm., XL., 7.

* Ibid., XL., 65.

c L. Gmelin's Theor. Chemie, II., 1092.

24-5

VEGETABLE ALBUMEN, a
From Rye. From Wheat. From Gluten. From Almonds.

Carbon 54'74

Hydrogen 7*77

Nitrogen 15'85

Oxygen 1

J

Sulphur

Jones.*

55-01

7-23

15-92

21-84

Varrentrapp it. Will.*

54-85
6-98

15-88

Junes. «

57-03

7-53

13-48

21-96

21-64 21-84 22-39

Phosphorus

Boussingault. Varrentrapp anil Will.*

Carbon 52'7

Hydrogen 6'9

Nitrogen 18*4 15-70

Oxygen, &c 22'0

* Ann. der Chem. und Pharm., XL., 66, and XXXIX., 291.

ANALYTICAL EVIDENCE.

295

VEGETABLE CASEINS, a

Carbon 54*138

Hydrogen 7'156

Nitrogen 15'672

Oxygen, &c. ... 23-034

Jones.'

55-05

7-59

15-89

21-47

Sulphate of Caseine

and Potash.
Varrentrapp and WilL

51-41

7-83

14-48

51-24

6-77

13-23

a Ann. der Chem. und Pharm., XXXIX., 291, and XL., 8 and 67.
VEGETABLE GLUTEN.

Jones.' a

Carbon 55'22

Hydrogen 7*42

Nitrogen 15'98

Oxygen, &c 21*38

a Ann. der Chem. und Pharm., XL., 66.

The pure gluten, analyzed by Jones, was that portion
of the raw gluten from wheat flour which is soluble in hot
alcohol. The insoluble portion is vegetable fibrine, the
analysis of which has been already given.

NOTE (9), p. 51.

COMPOSITION OF ANIMAL CASEINE. a

Scherer.

From fresh

From sour

From milk by

Albuminous sub-

milk.

milk

acetic acid.

stance in milk.6

I.

' II.

IIL S

IV.

V.

Carbon

54-825

54-721

54-665

54-580

54-507

Hydrogen

7-153

7-239

7-465

7-352

6-913

Nitrogen ...

15-628

15-724

15-724

15-696

15-670

Oxygen -»
SulpburJ'"

22-394

22-316

22-146

22-372

22-910

a Ann. der Chem. und Pharm., XL., 40 et seq.

* This substance, called, in German, zieger, is contained in the whey of
milk after coagulation by an acid. It is coagulated by heat, and very much
resembles albumen.

296 APPENDIX.

Mulder, a

Carbon 54'96

Hydrogen 7'15

Nitrogen 15'80

Oxygen 21'73

Sulphur 0-36

« For the analysis of vegetable caseine, see the preceding note.

NOTE (10), p. 64.

AMOUNT OF MATTER SOLUBLE IN ALCOHOL IN THE
SOLID EXCREMENTS OF THE HORSE AND COW.

(WILL.*)

18-3 grammes of dried horse-dung lost, by the action
of alcohol, O995 gramme. The residue, when dry, had
the appearance of saw-dust, after it has been deprived,
by boiling, of all soluble matter.

14-98 grammes of dry cow-dung lost, by the same
treatment, 0'625 gramme.

NOTE (11), p. 70.
COMPOSITION OF STARCH, a

Calculated From From From From

Ci2 Hio OIP. Peas. Lentils. Beans. Buckwheat.

Carbon 44'91 44'33 44'46 44'16 44'23

Hydrogen... 6- 11 6"57 6'54 6'69 6'40

Oxygen ... 48'98 49'09 49-00 49'15 49'37

ANALYTICAL EVIDENCE.

297

/

\

From maize.

From horse-chesnuts.

From wheat.

From rye.

Carbon . . ,

,... 44-27

44-44

44.26

44-16

Hydrogen

6-67

6-47

6-70

6-64

Oxygen

... 49-06

49-08

49-04

49.20

Streckei

From rice.

From
dahlia roots.

From
unripe apples.

From
unripe pears.

Carbon

44-69

44-13

44-10

44-14

Hydrogen

... 6-36

6-56

6-57

6-75

Q

48-QS

49-21

49 33

49*11

From potatoes. From arrow-root.

From yams. a

Berzelius.

Gay Lussac & Thenard? ProuL

Ortigosa.*

Carbon ...

44-250

43-55

44-40

44-2

Hydrogen

6-674

6-77

6-18

6-5

Oxygen . . .

49-076

49-68

49-42

49.3

a The starch employed for the analyses, made by Strecker and Ortigosa.
was prepared from the chemical laboratory at Giessen, from the respective
seeds, bulbs, and fruits.

NOTE (12), p. 71.
COMPOSITION OF GRAPE SUGAR. (STARCH SUGAR.)

From grapes. a From starch.* From honey.c Calculated.
DeSaussure. Prout Cu HuOu

Carbon ... ' 36'7l 37-29 36'36 36-80

Hydrogen 6'78 6-84 7'09 7'01

Oxygen... 56'51 55.87 56'55 56'19

a Ann. de Chimie, XI., 381.
b Ann. of Philosophy, VI., 426.
c Philosoph. Trans. 1827, 373.

298 APPENDIX.

NOTE (13), p. 72.
COMPOSITION OF SUGAR OF MILK.

I

ar

jay mssac
id Thenard.

Prout.

Brunn.

Berzelius.

Liebig.»

Cl2Hi20]

Carbon ...

38-825

40-00

40-437

39-474

40-00

40-46

Hydrogen

7-341

6-66

6-711

7-167

6-73

6-61

Oxygen ...

53-834

53-34

52-852

53,359

53-27

52-93

NOTE (14), p. 72.
COMPOSITION OF GUM.

Gay Lussac

1
Carbon

ind Thenard.

42-23

GoebeL

42-2

Berzelius.

42-682

CuH.lOn,

42-58

Hydrogen

6-93
50-84

6-6
51-2

6-374
50-944

6-37
51-05

NOTE (15), p. 74.

ANALYSIS OF OATS (BoilSSingault). a
1 00 parts of oats contain of dry matter 84 • 9

Ditto

water 17'1

100-0

100 parts of oats dried at 212° = 117-7 parts dried at
the ordinary temperature, contain

Carbon 50'7

Hydrogen 6'4

Oxygen 36'7

Nitrogen 2'2

Ashes... 4-0

100-0
Water.... 17'7

Oats dried in the air ... 117*7 contain, in 100 parts,
1-867 of nitrogen.
a Ann. de Chimie et de Phys., LXXI., 130.

ANALYTICAL EVIDENCE. 299

ANALYSIS OF HAY.

100 parts of hay dried in the air contain 86 of dry matter,

14 of water.

100

100 parts of hay dried at 212° = 116-2 parts dried in
air, contain

Carbon 45'8

Hydrogen 5'0

Oxygen 38'7

Nitrogen T5

Ashes 9'0

100-0
16. 2 water,

11 6' 2 hay dried in the air.

100-0 of hay dried at the ordinary temperature contain T29
of nitrogen.
240 oz. of such hay = 15 Ibs. contain ... 3-095 oz. of nitrogen.

72 oz. of oats = 4£ Ibs. contain ... T34 ditto

Total .. .. 4-435 ditto

NOTE (16), a, p. 77.

AMOUNT OF CARBON IN FLESH AND IN STARCH.

1 00 parts of starch contain 44 of carbon ; therefore, 64
oz. (4 Ibs.) contain 28-16 oz. of carbon.

100 parts of fresh meat contain 13'6 of carbon (see
Note III.); hence 240 oz. (15 Ibs.) contain 32-64 oz. of
carbon.^

J By an error in calculation in the original, the amount of carbon in 15 Ibs. of
meat is stated to be 27'64oz. It follows, that the carbon of 41bs. of starch is
not equal, as stated in the text, to that of 15 Ibs. of flesh, but to that of 13 Ibs.
This difference, however, is not sufficient to affect the argument at p. 84. —
EDITOR.

300

APPENDIX.

NOTE (16), b, p. 84.

COMPOSITION OF

Hog's Lard. Mutton fat.
Chevreul. a

Human Fat.

79-098 78-996

79.000

ren 11-146 11'700

11-416

9-756 9-304

9-584

a Recherches Chim., sur les corps gras. Paris. 1823.

NOTE (17), p. 84.

COMPOSITION OF CANE SUGAR.

According to

Berzelius.

Prout.

W. Crum.

T . , . . Gay Lussac Calculated
Liebig.* &-rhenard. CuHiiOn.

Carbon

42-225

42-86

42-14

42-301

42-47

42-58

Hydrogen...

6-600

6-35

6-42

6-384

6-90

6-37

Oxygen ...

51-175

50-79

51-44

51-315

50-63

51-05

For the composition of gum and of starch, see Notes
(14) and (11).

NOTE (18), p. 85.
COMPOSITION OF CHOLESTERINE.

According to

Chevreul. a

Couerbe. 6

Marchand.

Calculated.
C36H320.

Carbon ...

85-095

84-895

84-90

84-641

Hydrogen

11-880

12-099

12-00

12-282

Oxygen ...

3-025

3-006

3-10

3-077

a Recherches sur les corps gras, p. 185.
* Ann. de Ch. et de Phys. LVL, p. 164.

ANALYTICAL EVIDENCE. 301

NOTE (19), p. 87.

THE PRODUCTION OF WAX FROM SUGAR, a
As soon as the bees have filled their stomach, or what
is called the honey bladder, with honey, and cannot de-
posit it for want of cells, the honey passes gradually in
large quantity into the intestinal canal, where it is
digested. The greater part is expelled as excrement ; the
rest enters the fluids of the bee. In consequence of this
great flow of juices a fatty substance is produced, which
oozes out on the eight spots formerly mentioned, which
occur on the four lower scales of the abdominal rings,
and soon hardens into laminae of wax. On the other
hand, when the bees can deposit their honey, only so
much enters the intestinal canal as is necessary for their
support. The honey bladder need not be filled with
honey longer than forty hours in order to bring to matu-
rity, on the eight spots, eight laminae of wax, so that the
latter fall off. I made the experiment of giving to bees,
which I had enclosed in a box with their queen about the
end of September, dissolved sugar-candy instead of honey.
Out of this food laminae of wax were formed; but these
would not separate and fall off readily, so that the mass,
which continued to ooze out, remained, in most of the
bees, hanging to the upper lamina; and the laminae of
wax became as thick as four under ordinary circum-
stances. The abdominal scales of the bees were, by
means of the wax, distinctly raised, so that the waxen
laminae projected between them. On examination, I

a From F. W. Gundlach's Natural History of Bees, p. 115. Cassel, 1842.
We are acquainted with no more beautiful or convincing proof of the form-
ation of fatty matter from sugar than the following process of the manu-
facture of wax by the bee as taken from observation.

302 APPENDIX.

found that these thick laminae, which under the micro-
scope exhibited several lamellae, had a sloping surface
downwards near the head, and upwards in the vicinity of
the tail. The first waxen lamina, therefore, must have
been pushed downwards by the second, because, where
the abdominal scales are attached to the skin, there is no
space for two laminae, the second by the third, and thus
the inclined surfaces on the sides of the thick laminae had
been produced. I saw distinctly from this, that the first-
formed laminae are detached by those which follow. The
sugar had been converted into wax by the bees, but it
would seem that there was some imperfection in the pro-
cess, as the laminae did not fall off, but adhered to the
succeeding ones.

In order to produce wax in the manner described, the
bees require no pollen, but only honey. I have placed,
even in October, bees in an empty hive, and fed them
with honey ; they soon formed comb, although the wea-
ther was such that they could not leave the hive. I can-
not, therefore, believe that pollen furnishes food for the
bees, but I think they only swallow it in order, by mixing
it with honey and water, to prepare the liquid food for the
grubs. Besides, bees often starve in April, when their
stock of honey is consumed, and when they can obtain in
the fields abundance of pollen, but no honey. When
pressed by hunger they tear the nymphae out of the cells,
and gnaw them in order to support life by the sweet
juice which they contain. But, if in this condition they are
not artificially fed, or if the fields do not soon yield their
proper food, they die in the course of a few days. Now,
if the pollen were really nourishment for bees, they ought
to be able to support life on it, mixed with water.

Bees never build honeycomb unless they have a queen,
or are provided with young out of which they can educate

ANALYTICAL EVIDENCE. 303

a queen. But if bees be shut up in a hive without a
queen, and fed with honey, we can perceive in forty-eight
hours that they have laminae of wax on their scales, and
that some have even separated. The building of cells is
therefore voluntary, and dependant on certain conditions,
but the oozing out of wax is involuntary.

One might suppose that a large proportion of these
laminae must be lost, since the bees may allow them to
fall off, out of the hive as well as in it ; but the Creator
has wisely provided against such a loss. If we give
to bees engaged in building cells honey in a flat dish, and
cover the dish with perforated paper, that the bees may
not be entangled in the honey, we shall find, after a day,
that the honey has disappeared, and that a large number
of laminae are lying on the paper. It would appear as if
the bees, which have carried off the honey, had let fall
the scales ; but it is not so. For, if above the paper we
lay two small rods, and on these a board, overhanging
the dish on every side, so that the bees can creep under
the board and obtain the honey, we shall find next day
the honey gone, but no laminae on the paper; while
laminae will be found in abundance on the board above.
The bees, therefore, which go for and bring the honey, do
not let fall the laminae of wax, but only those bees which
remain hanging to the top of the hive. Repeated experi-
ments of this kind have convinced me that the bees, as
soon as their laminae of wax are mature, return to the
hive and remain at rest, just as caterpillars do, when
about to change. In a swarm that is actively employed
in building we may see thousands of bees hanging idly at
the top of the hive. These are all bees whose laminae of
wax are about to separate. When they have fallen off,
the activity of the bee revives, and its place is occupied
for the same purpose by another.

304 APPENDIX.

(From page 28 of the same work.) In order to
ascertain how much honey bees require to form wax, and
how often, in a swarm engaged in building, the laminae
attain maturity and fall off, I made the following experi-
ment, which appears to me not uninteresting.

On the 29th of August, of this year (1841), at a time
when the bees could obtain in this district no farther
supply of honey from the fields, I emptied a small hive,
placed the bees in a small wooden hive, having first
selected the queen bee, and shut her up in a box, furnished
with wires, which I placed in the only door of the hive,
so that no embryos could enter the cells. I then placed
the hive in a window, that I might be able to watch it.

At 6 P.M. I gave the bees 6oz. of honey run from the
closed cells, which had thus the exact consistence of
freshly made honey. This had disappeared next morning.
In the evening of the 30th I gave the bees 6oz. more,
which, in like manner, was removed by the next morning ;
but already some laminae of wax were seen lying on the
paper with which the honey was covered. On the 31st
August and the 1st September the bees had in the
evening lOoz., and on the 3rd of September in the evening
7oz. ; in all, therefore, lib. 13oz. of honey, which had
run cold out of cells which the bees had already closed.
On the 5th of September I stupifted the bees, by means
of puff-ball, and counted them. Their number was 2,765,
and they weighed lOoz. I next weighed the hive, the
combs of which were well filled with honey, but the cells not
yet closed ; noted the weight, and then allowed the honey
to be carried off by a strong swarm of bees. This was
completely effected in a few hours. I now weighed it a
second time, and found it 12 oz. lighter; consequently the
bees still had in the hive 12 oz. of the 29oz. of honey
given to them. I next extracted the combs, and found

ANALYTICAL EVIDENCE. 305

that their weight was f of an ounce. I then placed the
bees in another box, provided with empty combs, and fed
them with the same honey as before. In the first few
days they lost daily rather more than 1 oz. in weight, and
afterwards half an ounce daily, which was owing to the
circumstance, that from the digestion of so much honey,
their intestinal canal was loaded with excrements ; for
1,170 bees, in autumn, when they have been but a short
time confined to the hive, weigh 4 oz. ; consequently 2,765
bees should weigh 9oz. But they actually weighed lOoz.,
and therefore had within them 1 oz. of excrement, for
their honey bladders were empty. During the night the
weight of the box did not diminish at all, because the small
quantity of honey the bees had deposited in the cells,
having already the proper consistence, could not lose
weight by evaporation, and because the bees could not
then get rid of their excrements. For this reason, the loss
of weight occurred always during the day.

If, then, the bees, in seven days, required 3^ oz. of
honey to support and nourish their bodies, they must
have consumed 13§ oz. of honey in forming f of an ounce
of wax; and consequently, to form lib. of wax, 201bs. of
honey are required. This is the reason why the strongest
swarms in the best honey seasons, when other hives, that
have no occasion to build, often gain in one day 3 or 41bs.
in weight, hardly become heavier, although their activity
is boundless. All that they gain is expended in making
wax. This is a hint for those who keep bees, to limit the
building of comb. Cnauf has already recommended this,
although he was not acquainted with the true relations of
the subject. From 1 oz. of wax, bees can build cells
enough to contain 1 Ib. of honey.

100 laminae of wax weigh 0'024 gramme (rather more
than £ of a grain), consequently, 1 kilogramme (= 15,360

306 APPENDIX.

grains) will contain 4,166,666 laminse. Hence, | of an
ounce will contain 81,367 laminae. Now this quantity
was produced by 2,765 bees in six days ; so that the bee
requires for the formation of its 8 laminae (one crop)
about thirty-eight hours, which agrees very well with my
observations.

The laminae, when formed, are as white as bleached
wax. The cells also, at first, are quite white, but they are
coloured yellow by the honey, and still more by the
pollen. When the cold weather comes on, the bees
retire to the hive under the honey, and live on the stock
they have accumulated.

P. 54. Many believe that bees are* hybernating
animals ; but this opinion is quite erroneous. They are
lively throughout the winter; and the hive is always
warm in consequence of the heat which they generate.
The more numerous the bees in a hive, the more heat is
developed ; and hence strong hives can resist the most
intense cold. It once happened that I forgot to remove
from the door, which was unusually large, of a hive in
in winter, a perforated plate of tinned iron, which I had
fastened over the opening to » diminish the heat in July;
and yet this hive came well through the winter, although
the cold was very severe, having been for several days
so low as 0°. But I had added to this hive the bees of
two other hives ! When the cold is very intense, the bees
begin to hum. By this means respiration is accelerated
and the developement of heat increased. If, in summer,
bees without a queen are shut up in a glass box, they
become uneasy and begin to hum. So much heat is by
this means developed, that the plates of glass become
quite hot. If the door be not opened in this case, or if
air be not admitted, and if the glass be not cooled by the
aid of water, the bees are soon suffocated.

ANALYTICAL EVIDENCE. 307

COMPOSITION OF BEES' WAX.

De Saussure.6 Oppennann.c Ettling.d He*S.9 c*

Carbon ... 81-784 81-607 81-291 81'15 81'52 81-38

Hydrogen 12-672 13-859 14-073 1375 1323 13-28

Oxygen ... 5-544 4-534 4-636 5-09 5-25 5-34

a Traite de Chimie, par Thenard, 6me- Ed., IV., 477.

* Ann. de Ch. et de Phys., XIII., 310.

c Ibid. XLIX., 224.

d Annal. der Pharm., II., 267.

e Ibid. XXVII., 6.

NOTE (21) a, p. 104.

COMPOSITION OF HYDRATED CYANURIC ACID, OF
HYDRATED CYANIC ACID, AND OF CYAMELIDE, IN
100 PARTS, ACCORDING TO THE ANALYSIS OF
WOHLER AND LIEBIG.* «

Cyanuric acid, cyanic
acid, cyamelide.

Carbon 28'19

Hydrogen 2*30

Nitrogen 32'63

Oxygen 36*87

a PoggendorfFs Annalen, XX., 375 et seq.

NOTE (21) b, p. 104.

COMPOSITION OF ALDEHYDE, METALDEHYDE, AND
ELALDEHYDE. a

Aldehyde. Metaldehyde. Elaldehyde. Calculated

Liebig.* Fehling.* C4H4O2.

Carbon 55'024 54*511 54*620 54*467 55'024

Hydrogen ... 8*983 9*054 9*248 9*075 8*983

Oxygen 35*993 36*435 36*132 36*458 35*993

a Ann. der Pharm., XIV., 142, and XXVII., 319.

x2

308

APPENDIX.

NOTE (22), p. 105.
COMPOSITION OF PROTEINE.

From the From albumen,
crystalline lens. Scherer..8

From fibrin

Carbon

55-300
6-940
16-216
21-544

Scherer.»a

55-160
7-055
15-966
21-819

54-848
6-959
15-847
22-346

ralrnl*

Hydrogen
Nitrogen

From hair.

Fromiorn.

Carbon

54*746

55-150

55-408

54-291

55-742

Hydrogen
Nitrogen...
Oxygen ...

7-129
15-727
22-398

7-197
15-727
21-926

7-238
15-593
21-761

7-082
15-593
23-034

6-827
16-143

21-228

a Ann. der Chim. und Pharm., XL., 43.

From vegetable
albumen.

From fibrine. From albumen. From cheei
Mulder, a

Carbon

54-99

55-44

55-30

55-159

Hydrogen ...

6-87

6-95

6-94

7-176

Nitrogen

15-66

16-05

16-02

15-857

Oxygen

22-48

21-56

21-74

21-808

a Ann. der Pharm., XXVIII., 75.

NOTE (23), p. 107.

COMPOSITION OF THE ALBUMEN OF THE YOLK AND
OF THE WHITE OF THE EGG. a

From the yolk.
Jones.*

From the white.
Scherer.*

Carbon 53'72

7-55
13-60

53-45
7-66
13-34

55-000
7-073
15-920

Hydrogen

Nitrogen ...

Oxygen "j

Sulphur > 25-13 25-55 22-007

Phosphorus J

a Ann. der Chem. und Pharm., XL., 36, ibid. 67.

ANALYTICAL EVIDENCE.

309

NOTE (24), p. 111.
COMPOSITION OF LACTIC ACID.
C6HS05.

Carbon 44-90

Hydrogen 6'11

Oxygen 48'99

NOTE (25), p. 115.
GAS FROM THE ABDOMEN OF COWS AFTER EATING

CLOVER TO EXCESS, OBTAINED BY PUNCTURE,
a Examined by Lameyran and Fremy. b By Vogel.
c By Pfluger.

Carbonic acid. Inflammable gas. Sulphuretted hydrogen.

Air.
a 5
b 25

5 —

- 27

— 60

— 20

15

48
40
80

80 Vol. in 100 Vol.

NOTE (26), p. 118.
MAGENDIE FOUND IN THE STOMACH AND INTESTINES

OF EXECUTED CRIMINALS I

a In the case of an individual who had taken food in
moderation one hour previous to death ; b, in the case of
one who had done so two hours previously ; and c, in the
case of a third, who had done so four hours previous to
execution.

100 Volumes of the gas contained.

{From t
I

Oxygen.

-From the stomach 11-00 Vol.

small intestines ... 00-00
large intestines ... 00-00

/•From the stomach 00-00

b J _ smaU intestines ... 00-00
I _ large intestines ... 00-00

(-From the stomach OO'OO

CJ — smair intestines ... 00-00
I — large intestines ... 00-00

sTitrogen.

Carbonic
acid.

Inflammable
gas.

71-45

14-00

3-55

20-03

24-39

55-53

51-03

43-50

5-47

00-00

00-00

00-00

8-85

40-00

51-15

18-40

70-00

11-60

00-00

00-00

00-00

66-60

25-00

8-40

45-96

42-86

11-18

310

APPENDIX.

NOTE (27), referred to in NOTE (7), p. 43.

COMPOSITION OF ANIMAL ALBUMEN AND FIBRINE,
AND OF THE DIFFERENT TISSUES OF THE BODY.

1. ALBUMEN.

From the serum of blood.
Scherer.*o

From eggs.

From yolk of egg.
Jones.* b

f s~

I.

II.

III.

IV.

V.

VI.

Carbon

... 53-850

55-461

55-097

55-000

53-72

53-45

Hydrogen

... 6-983

7-201

6-880

7-073

7-55

7-66

Nitrogen ....

,.. 15-673

15-673

15-681

15-920

13-60

13-34

Oxygen

1

Sulphur

J23-494

21-655

22-342

22-007

25-13

25-55

Phosphorus J

a Ann. der Chem. und Pharm., XL., 36.
b Ibid. 67.

3sr h^-

From
congestive From pus.
abscess.

From
fluid of
dropsy.

VII. VIII.

IX. X. XI.

XII.

Carbon

55-50 54-921

54-757 54-663 54-101

54-302

Hydrogen ...

7-19 7-077

7-171 7-022 6-947

7-176

Nitrogen ...

16-31 15-465

15-848 15-839 15-660

15-717

Oxygen "1

Sulphur ?

21-00 22-537

22-224 22-476 23'292

22-805

Phosphorus ^

Mulder, o

Carbon

54-84

Hydrogen

7-09

Nitrogen

15-83

Oxygen. . .

21-23

Sulphur

0*68

Phosnhorns

n-aa

a Ann. der Pharm. XXVIII., 74.

ANALYTICAL EVIDENCE.

311

2. FlBRINE.

Scherer.«

Carbon ....
Hydrogen .
Nitrogen .
Oxygen
Sulphur
Phosphorus

I.

53-671
6-878
15-763

II.

54-454
7-069
15-762

III.

55-002
7-216
15-817

IV.

54-967
6-867
15-913

v.

53-571
6-895
15-720

VI.

54-686

6-835

15-720

VII.

54-844

7-219

16-065

23-688 22-715 21-965 22'244 23-814 22-759 21-872

a Ann. der Chem. und Pharm., XL., 33.
Mulder, o

Carbon 54-56

Hydrogen 6'90

Nitrogen 15'7'2

Oxygen 22-13

Sulphur 0-33

Phosphorus 0'36

a Ann. der Pharm., XXVIII., 74.

Isinglass.

Carbon ... 50-557

Hydrogen 6 -903

Nitrogen 18-790

Oxygen... 23'750

3. GELATINOUS TISSUES.

Scherer.* a

Tendons of the
calf's foot.

49.563 50-960 50-774

7-148 7-188 7-152

18-470 18-320 18-320

24-819 23-532 23'754

Tunica Calculated.

sclerotica. C4sH4lNriOl8

50-995
7-075
18-723
23-207

50-207

7-001

18-170

24-622

a Ann. der Chem. und Pharm., XL., 46.

Carbon 50*048 50'048

Hydrogen 6-477 6'643

Nitrogen 18*350 18'388

Oxygen 25-125 24'921

312 APPENDIX.

4. TISSUES CONTAINING CHONDRINE.

f Cartilages of the
ribs of the calf.

Cornea.

Calculated.

C48H40N6 O.'O.

Mulder.

Carbon

49-496

50-895

49-522

50-745

50-607

Hydrogen...

7-133

6-962

7-097

6-904

6-578

Nitrogen ...

14-908

14-908

14-399

14-692

14-437

Oxygen ...

28-463

27-235

28-982

27-659

28-378

a Ann. der Chem. und Pharm., XL., 49.
5. COMPOSITION OF THE MIDDLE MEMBRANE OF ARTERIES.

Scherer.* a

~ N Calculated.

I. II. CteHssNs Oie.

Carbon 53'750 53-393 53'91

Hydrogen 7'079 6'973 6-96

Nitrogen 15'360 15'360 15'60

Oxygen 23'811 24'274 23'53

a Ann. der Chem. und Pharm., XL., 51.

6. COMPOSITION OF HORNY TISSUES.

Scherer.* a.

External skin Hair of Hair of the head. V

of the sole of the foot, the beard. Fair. Brown. Black.

Carbon ... 51-036 50752 51-529 50-652 49'345 50-622 49-935

Hydrogen 6-801 6-761 6-687 6-769 6-576 6-613 6'631

Nitrogen 17-225 17-225 17-936 17-936 17-936 17-936 17-936
Oxygen .,.")

Sulphur }24'938 25'262 23'848 24'643 26'143 24'829 25'498

Buffalo horn. Nails. Wool. ,

Carbon ... 51'990 51-162 51-620 51-540 51-089 50-653 51-718

Hydrogen 6-717 6-597 6-754 6-779 6-824 7-029 6-860

Nitrogen 17-284 17-284 17-284 17-284 16-901 17-710 17-469

xygen — 24>957 24.U2 24-397 25-186 24-608 23-953

n —1

r ...J

Sulphur

a Ann. der Chem. und Pharm., XL., 53.

ANALYTICAL EVIDENCE. 313

The composition of the membrane lining the interior of
the shell of the egg approaches closely to that of horn.
According to Scherer, it contains

Scherer.»a

Carbon 50*674

Hydrogen 6*608

Nitrogen 16761

Oxygen ^

Sulphur' '

a Ann. der Chem. und Pharm., XL., 60.

The composition of feathers is also nearly the same as
that of horn.

Scherer.* a

Beard of the Quill of the Calculated,

feather. feather. C48Hs«N;Ol6.

Carbon 50-434 52'427 52-457

Hydrogen 7'110 7-213 6'958

Nitrogen 17-682 17'893 17'719

Oxygen 24'774 22-467 22-866

The analysis here given of the beard of feathers agrees
closely with that of horn, while that of the quill is more
accurately represented by the attached formula, which dif-
fers from that of horn by 1 eq. of oxygen only.

a Ann. der Chem. und Pharm. XL., 61.
7. COMPOSITION OF THE PIGMENTUM NIGRUM OCULI,

Scherer.' a

Carbon

58-273

58-672

.57-908

Hydrogen...

5-973

5-962

5-817

Nitrogen ...

13-768

13-768

13-768

Oxygen . . .

21-986

21-598

22-507

a Ann. der Chem. und Pharm., XL., 63.

314

APPENDIX.

NOTE (28), p. 133.
According to the analyses of Playfair and Bceckmann,

0-452 parts of dry muscular flesh gave 0-836 of carbonic acid.

0-407 0-279 of water.

0-242 0-450 of carbonic acid and 0'164 of water.

0-191 0-360 0-130

0-305 of dried blood gave 0*575 carbonic acid and 0-202 of water.

0-214 0-402 0-138

1-471 of dried blood, when calcined, left 0-065- of ashes = 4-42 per cent.

The dried flesh was found to contain of ashes 4-23 per cent.

The nitrogen was found to be to the carbon as 1 to 8 in equivalents.

Hence

Flesh (beef).

Ox-blood.

Blood.

Playfair. Bceckmann. Playfair. Boeckmann. Mean of 2 analyses.

Carbon 51-83

Hydrogen 7*57

Nitrogen... 15-01

Oxygen ... 21 '37

Ashes .. 4-23

51-89

7-59

15-05

21-24

4-23

51-95

7-17

15-07

21-39

4-42

51-96

7-33

15-08

21-21

4-42

51-96

7-25

15-07

21-30

4-42

Deducting the ashes, or inorganic matter, the compo-
sition of the organic part is,

Carbon

Hydrogen ...
Nitrogen . . .
Oxygen

54-12

7-89

15-67

22-32

54-18

7'93

15-71

22-18

54-19

7-48

15-72

22-31

54-20

7-65

15-73

22-12

This corresponds to the formula

C48 ........................... 54-62

H ........................... 7-24

15-81
22-33

Ng

ANALYTICAL EVIDENCE.

315

NOTE (29), p. 134.
COMPOSITION OF CHOLEIC ACID.

Demarfay.

Dumas.

Calculate
C?6H66NiO

Carbon

63-707

63-5

63-24

Hydrogen ...

8-821

9-3

8-97

Nitrogen . . .

3-255

3-3

3-86

Oxygen

24-217

23'9

23-95

a Ann. der Pharm,, XXVII., 284 and 293.

NOTE (30), p. 135.

COMPOSITION OF TAURINE AND OF CHOLOIDIC ACID.
1. TAUKINB. a

Demarjay.*

Dumas.

C4H7NOi

Carbon

19-24

19-26

19-48

Hydrogen ...
Nitrogen . . .
Oxygen

5-78
11-29
63-69

5-66
11-19
63-89

5-57
11-27
63*68

a Ann. der Pharm., XXVII., 287 and 292.

2. CHOLOIDIC ACID. «

Demar^ay.*

i.

H.

C36H5GO]

Carbon

73-301

73-522

73-3

74-4

Hydrogen ...
Oxygen

9-511

17-188

9-577
16-901

9-7
17-0

9-4
16-2

a Ann. der Pharm., XXVII., 289 and 293.

In reference to the researches of Demar§ay on the bile
I would make the following observations.

316 APPENDIX.

The matter to which I have given the name of choleic
acid is the bile itself separated from the inorganic con-
stituents (salts, soda, &c.) which it contains. By the
action of subacetate of lead aided by ammonia, all the
organic constituents of the bile are made to unite with
oxide of lead, with which they form an insoluble, resinous
precipitate. The substance here combined with oxide of
lead contains all the carbon and nitrogen of the bile.
The substance which I have named choloidic acid is that
which is obtained, when the bile, purified by alcohol from
the substances insoluble in that fluid, is boiled for some
time with an excess of muriatic acid. It contains all the
carbon and hydrogen of the bile, except those portions
which have separated in the form of taurine and ammonia.
The cholic acid contains the elements of bile, minus
those of carbonate of ammonia.

These three compounds, therefore, contain the products
of the metamorphosis of the entire bile ; their formulae
express the amount of the elements of the constituents of
the bile. No one of them exists ready formed in the bile
in the shape in which we obtain it; their elements are
combined in a different way from that in which they were
united in the bile ; but the way in which these elements
are arranged has not the slightest inference on the deter-
mination by analysis of the relative proportions of the
elements. In the formulae themselves, therefore, is in-
volved no hypothesis ; they are simply expressions of the
results of analysis. It signifies nothing that the choleic
or choloidic acids may be composed of several compounds
united together. No matter how many such they may
contain, the relative proportions of all the elements taken
together is expressed by the formula which is derived
from the analysis.

The study of the products which are produced from the

ANALYTICAL EVIDENCE. 317

bile by the action of the atmosphere, or of chemical re-
agents, may be of importance in reference to certain pa-
thological conditions ; but except as concerns the general
character of the bile, the knowledge of these products
is of no value to the physiologist ; it is only a burthen
which impedes his progress. It cannot be maintained of
any one of the 38 or 40 substances, into which the bile
has been divided or split up, that it exists ready formed
in the healthy secretion ; on the contrary, we know with
certainty that most of them are mere products of the ac-
tion of the re-agents which are made to act on the bile.

The bile contains soda; but it is a most remarkable
and singular compound of soda. When we cause that
part of the bile which dissolves in alcohol (which contains
nearly all the organic part) to combine with oxide of lead,
thus separating the soda, and then remove the oxide of
lead, we obtain a substance, choleic acid, which, when
placed in contact with soda, forms a compound similar to
bile in its taste ; but it is no longer bile ; for bile may be
mixed with organic acids, nay, even with dilute mineral
acids, without becoming turbid or yielding a precipitate ;
while the new compound, choleate of soda, is decomposed
by the feeblest acids, the whole of the choleic acid being
separated. Hence, bile cannot be considered, in any
sense, as choleate of soda. Further, it may be asked, in
what form are the cholesterine, and stearic, and margaric
acids, which are found in bile, contained in that fluid?
Cholesterine is insoluble in water, and not saponifiable by
alkalies ; and if the two fatty acids just named were
really present in the bile as soaps of soda, they would be
instantly separated by other acids. Yet diluted acids cause
no such separation of stearic and margaric acids in bile.

It is possible that, in the course of new and repeated
investigations, the composition of the substances obtained

318 APPENDIX.

from bile may be found different from that which has been
given in our analytical developement of this subject.
But this, if it should happen, can have but little effect on
our formulae ; if the relative proportions of carbon and
nitrogen be not changed, the differences will be confined
to the proportions of oxygen and hydrogen. In that case
it will be necessary for the developement of our views in
formulae, only to assume that more water and oxygen, or
less water and oxygen, have taken a share in the meta-
morphosis of the tissues ; but the truth of the develope-
ment of the process itself will not be by this means
affected.

NOTE (31), p. 135.
COMPOSITION OF CHOLIC ACID, a

Dumas. Calculated C/4H6tOi*.

Carbon 68'5 68'9

Hydrogen 9'7 9'2

Oxygen 21'8 21'9

a Ann. der Pharm., XXVII., 295.

NOTE (32), p. 137.

COMPOSITION OF THE CHIEF CONSTITUENTS OF THE
URINE OF MEN AND ANIMALS.

1. URIC ACID.

Liebig.»o Mitscherlich. 6 Calculated CloH-iN.Os.

Carbon 36'083 35'82 36'00

Hydrogen... 2"441 2'38 23- 6

Nitrogen ... 33'361 34'60 33'37

Oxygen ... 28'126 27'20 28*27

« Ann. der Pharm., X., 47.

b Poggendorff's Ann., XXXIII., 335.

ANALYTICAL EVIDENCE.

319

2. ALLOXAN. a
A PRODUCT OF THE OXIDATION OF URIC ACID.

Wohler and Liebig.*

Calculated CsH4NiOlfl.

Carbon

30-38

30-18

30-34

Hydrogen . . .

2-57

2-48

2-47

Nitrogen ...

17-96

17-96

17-55

Oxygen ...

49-09

49-38

49-64

a Ann. der Pharm., XXVI., 260.

3. UREA.

Carbon

Prout. a

19-99

W/ihler and Liebig. 6'

20-02

Calculated CjH4N.Oj.

20*192

Hydrogen...
Nitrogen ...
Oxygen

6-65
46-65
26-63

6-71
46-73
26-54

6-595
46-782
26-425

a Thomson's Annals, XI., 352.
b Poggend. Ann., XX., 375.

4. CRYSTALLIZED HIPPURIC ACID.

Liebig.* a

Dumas. 6

Mitscherllch. c

Calculated
Cut H8 NO-,.

Carbon

60-742

60-5

60-63

60.76

Hydrogen . . .

4-959

4-9

4-98

4-92

Nitrogen ...

7-816

7-7

7-90

7-82

Oxygen . . .

26-483

26-9

26-49

26-50

a Ann. der Pharm., XII., 20.

* Ann. de Ch. et de Phys., LVIL, 327.

c Poggend. Ann., XXXIII., 335.

5. ALLANTOINE. a

Wi.hler and Liebig.*

30-60

Calculated CsHf.N Ofi.

30-66

3-83

3-75

35-45

35-50

Oxveren

30-12

30-09

a Ann. der Pharm., XXVI., 215.

320 APPENDIX.

6. URIC OR XANTHIC OXIDE, a

WOhler and Liebig.» Calculated C5 H2 N2 O;.

Carbon 39'28 39'86

Hydrogen 2'95 2'60

Nitrogen 36'35 37'72

Oxygen 21'24 20'82

a Ann. der Pharm., XXVI., 344.
7. CYSTIC OXIDE, a

Thaulow.* Calculated Ce He NOi SJ.

Carbon 30'01 30'31

Hydrogen 5'10 4'94

Nitrogen ll'OO 11'70

Oxygen 28'38 26'47

Sulphur 25-51 26'58

a Ann. der Pharm. XXVII., 200.

The cystic oxide is distinguished from all the other
concretions occurring in the urinary bladder by the sul-
phur it contains. It can be shewn with certainty, that
the sulphur is present neither in the oxidised state, nor in
combination with cyanogen ; and in regard to its origin
the remark is not without interest, that four atoms of
cystic oxide contain the elements of uric acid, benzoic
acid, sulphuretted hydrogen, and water ; all of which are
substances, the occurrence of which in the body is beyond
all doubt.

1 atom uric acid ...
1 atom benzoic acid
8 atoms sulphuret-"]
ted hydrogen ...J
7 atoms water

C10N4H406

C14 H5 03

H8 S8
H707

4 atoms cystic oxide = C24N4 H24O16S8 = 4 (C6NH6O4S2).

ANALYTICAL EVIDENCE. 321

An excellent method of detecting the presence of cystic
oxide in calculi or gravel is the following :

The calculus is dissolved in a strong solution of caustic
potash, and to the solution is added so much of a solution
of acetate of lead, that all the oxide of lead is retained in
solution. When this mixture is boiled there is formed a
black precipitate of sulphuret of lead, which gives to the
liquid the aspect of ink. Abundance of ammonia is also
disengaged ; and the alkaline fluid is found to contain,
among other products, oxalic acid.

NOTE (33), p. 137.

COMPOSITION OF OXALIC, OXALURIC, AND PARABA-

NIC ACIDS.
1. OXALIC ACID (hydrated).

Gay Lussac & Th«Snard. Berthollet.

Carbon 26'566 25'13 26'66

Hydrogen ... 2-745 3'09 2'22

Oxygen 70'689 71'78 7M2

2. OXALURIC ACID, a

WohlerandLiebig.* C^Mfc

Carbon 27'600 27'318 27'59

Hydrogen 3" 122 3'072 3'00

Nitrogen 21-218 21-218 21'29

Oxygen 48-060 48'392 48'12

a Ann. der Pharm., XXVI., 289.

3. PARABANIC ACID, a

WijhlerandLiebig."

Carbon 31'95 31-940 31'9l

Hydrogen 2'09 1'876 1'73

Nitrogen 24-66 24-650 24'62

Oxygen 41'30 41-534 41-74

a Ann. der Pharm., XXVI,, 286.
Y

322

APPENDIX.

NOTE (34), p. 138.

COMPOSITION OF ROASTED FLESH.
(1.) 0-307 of flesh gave 0'584 of carbonic acid and 0-206 of water.

(2.) 0-255 do. 0-485

do.

0-181 do.

(3.) 0-179 do. 0-340

do.

0-125 do.

Hence —

Flesh of roedeer (1).

Flesh of beef (2),

Flesh of veal (3).

Boeckmann.*

PI;

jyfair.*
-^- ^

Carbon 52'60

f

52-590

52-52

Hydrogen... 7 '45

7-886

7-87

Nitrogen ... 15 '23

15-214

14-70

?Xygen|... 24-72

24-310

24-91

Ashes J

NOTE (35), p. 142
The formula C^H^N^O^, or
reduced to 100 parts,

gives, when

H42

N9

50-07

6-35

19-32

24-26

Compare this with the composition of gelatine, as given
in Note (27).

NOTE (37), p. 154.
COMPOSITION OF LITHOFELLIC ACID, a

Ettling and Will.* WOhler.

Carbon 71-19 70'80 70-23 70'83 70-83

Hydrogen... 10'S5 10'78 10-95 10'60 10-48

Oxygen 17'96 18-42 18'92 18'57 18'69

a Ann. der Chem und Pharm., XXXIX., 242, XLI., 154.

ANALYTICAL EVIDENCE. 323

NOTE (38), p. 177.

COMPOSITION OF SOLANINE FROM THE BUDS OF
GERMINATING POTATOES, a

Blanchet.

Carbon 62'11

Hydrogen 8'92

Nitrogen 1'64

Oxygen 27'33

« Ann. der Pharm., VII., 150.

NOTE (39), p. 177.
COMPOSITION OF PICROTOXINE. a

Francis.*

Carbon 60'26

Hydrogen 5'70

Nitrogen 1-30

Oxygen 32*74

a In another analysis, M. Francis obtained 0*75 per cent, of nitrogen.
The picrotoxine employed for these analyses was partly obtained from the
manufactory of M. Merck, in Darmstadt, and was partly prepared by M.
Francis himself ; it was perfectly white, and beautifully crystallized. Reg-
nault, as is well known, found no nitrogen in this compound.

NOTE (40), p. 177.
COMPOSITION OF QUININE.

Liebig.* Calculated

C-20H12N02

Carbon 75'76 74'39

Hydrogen 7'52 7'25

Nitrogen 8'11 8'62

Oxygen 8'62 9'64

Y2

324

APPENDIX.

NOTE (41), p. 177.

COMPOSITION OF MORPHIA, a

Liebig.* Regnault.

Calculated

CsoH-uNOfi

Carbon 72*340 72*87 72f41

72-28
6-74
4-80
16-18

Hydrogen ... 6'366 6'86 6'84
Nitrogen 4'995 5*01 5'01
Oxygen 16'299 15'26 15'74
a Ann. der Pharm., XXVI., 23.

NOTE (42), p. 177.

COMPOSITION OF CAFFEINE, THEINE, GUARANINE,
THEOBROMINE, AND ASPARAGINE.

Calculated
Caffeine, a Theine. b Guaramne. c r „ M n
Cs H5 JNs Us
Pfaff and Liebig.* Jobst. Martius.

Carbon 49'77 50-101 49'679 49'798
Hydrogen... 5'33 5'214 5'139 5'082
Nitrogen ... 28' 78 29.009 29'180 28'832
Oxygen ... 16'12 15'676 16'002 16'288

a Ann. der Pharm., I., 17.
b Do. XXV., 63.

c Do. XXVI., 95.

Guaranine is the name given to the crystallized prin-
ciple of the guarana officinalis, till it was shewn to be
identical with caffeine and theine, as the above analyses
demonstrate.

COMPOSITION OF THEOBROMINE. a

Woskreseusky. Calculated Cg Ho N3 O2

Carbon

47.21

46-97

46-71

46-43

Hydrogen . . .

4-53

4-61

4-52

4-20

Nitrogen ...

35-38

35-38

35-38

35-85

Oxygen

12-88

13-04

13-39

13-51

a Ann. der Chem. und Pharm., XLI., 125.

ANALYTICAL EVIDENCE.

325

COMPOSITION OF ASPARAGINE. a

Liebig." Calculated Ca Hs Na Oe + 2HO

Carbon 32'351 32'35

Hydrogen 6' 844 6' 60

Nitrogen 18' 734 18' 73

Oxygen 42'021 42'32

a Ann. der Pharm., VII., 146.

ON THE CONVERSION OF BENZOIC ACID INTO
HIPPURIC ACID.*

BY WILHELM KELLER.
(From the Annalen der Chemie und Pharmacie.)

So early as in the edition of Berzelius's " Lehrbuch der
Chemie," published in 1831, Professor Wb'hler had ex-
pressed the opinion, that benzoic acid, during digestion,
was probably converted into hippuric acid. This opinion
was founded on an experiment which he had made on the
passage of benzoic acid into the urine. He found in the
urine of a dog which had eaten half a drachm of benzoic

* To the evidence produced by A. Ure, of the conversion of benzoic acid
into hippuric acid in the human body, M. Keller has added some very de-
cisive proofs, which I append to this work on account of their physiological
importance. The experiments of M. Keller were made hi the laboratory of
Professor Wohler, at Gottingen ; and they place beyond all doubt the fact
that a non-azotised substance taken in the food can take a share, by means
of its elements, in the act of transformation of the animal tissues, and in the
formation of a secretion. This fact throws a clear light on the mode of action
of the greater number of remedies ; and if the influence of caffeine on the
formation of urea or uric acid should admit of being demonstrated in a similar
way, we shall then possess the key to the action of quinine and of the other
vegetable alkalies.— J. L.

326 APPENDIX.

acid with his food, an acid crystallizing in needle-shaped
prisms, which had the general properties of benzoic acid,
and which he then took for benzoic acid. (Tiedemann's
Zeitschrift fur Physiologic, i. 142.) These crystals were
obviously hippuric acid, as plainly appears from the
statements, that they had the aspect of nitre, and, when
sublimed, left a residue of carbon. But at that time hip-
puric acid was not yet discovered ; and it is well known,
that till 1829, when these acids were first distinguished
from each other by Liebig, it was uniformly confounded
with benzoic acid.

The recently published statement of A. Ure, that he
actually found hippuric acid in the urine of a patient who
had taken benzoic acid, recalled this relation, so remark-
able in a physiological point of view, and induced me to
undertake the following experiments, which, at the sug-
gestion of Professor Wohler, I made on myself. The sup-
posed conversion of benzoic acid into hippuric acid has,
by these experiments, been unequivocally established.

I took, in the evening before bedtime, about thirty-
two grains of pure benzoic acid in syrup. During the
night I perspired strongly, which was probably an effect
of the acid, as in general I am with great difficulty made
to transpire profusely. I could perceive no other effect,
even when, next day, I took the same dose three times ;
indeed, even the perspiration did not again occur.

The urine passed in the morning had an uncommonly
strong acid reaction, even after it had been evaporated,
and had stood for twelve hours. It deposited only the
usual sediment of earthy salts. But when it was mixed
with muriatic acid, and allowed to stand, there were
formed in it long prismatic, brownish crystals, in great
quantity, which, even in this state, could not be taken for
benzoic acid. Another portion, evaporated to the con-

ANALYTICAL EVIDENCE. 327

sistence of syrup, formed, when mixed with muriatic acid,
a magma of crystalline scales. The crystalline mass was
pressed, dissolved in hot water, treated with animal char-
coal, and recrystallized. By this means the acid was
obtained in colourless prisms, an inch in length.

These crystals were pure hippuric acid. When heated,
they melted easily ; and when exposed to a still stronger
heat, the mass was carbonised, with a smell of oil of bitter
almonds, while benzoic acid sublimed. To remove all
doubts, I determined the proportion of carbon in the
crystals, which I found to be 6O4 per cent. Crystallized
hippuric acid, according to the formula Ci8H8NO5 + HO,
contains 60'67 per cent, of carbon; crystallized benzoic
acid, on the other hand, contains 69'10 per cent, of car-
bon.

As long as I continued to take benzoic acid, I was able
easily to obtain hippuric acid in large quantity from the
urine ; and since the benzoic acid seems so devoid of any
injurious effect on the health, it would be easy in this
way to supply one's self with large quantities of hippuric
acid. It would only be necessary to engage a person to
continue for some weeks this new species of manufacture.

It was of importance to examine the urine which con-
tained hippuric acid, in reference to the two normal chief
constituents, urea and uric acid. Both were contained in
it, and apparently in the same proportion as in the nor-
mal urine.

The inspissated urine, after the hippuric acid had been
separated by muriatic acid, yielded, on the addition of
nitric acic, a large quantity of nitrate of urea. It had
previously deposited a powder, the solution of which in
nitric acid gave, when evaporated to dryness, the well-
known purple colour characteristic of uric acid. This
observation is opposed to the statement of Ure ; and he

328 APPENDIX.

is certainly too hasty in recommending benzoic acid as a
remedy for the gouty and calculous concretions of uric
acid. He seems to suppose that the uric acid has been
employed in the conversion of benzoic acid into hippuric
acid ; but as his observations were made on a gouty pa-
tient, it may be supposed that the urine, even without
the internal use of benzoic acid, would have been found
to contain no uric acid. Finally, it is clear that the hip-
puric acid existed in the urine in combination with a base,
because it only separated after the addition of an acid.

INDEX.

INDEX.

A.

ACID.

— Acetic. Composition ; and relation to that of aldehyde, 279,
280.

— Benzole. Composition, and relation to that of oil of bitter
almonds, 279, 280. Converted into hippuric acid in the
human body, 150, 325.

— Carbonic. Is the form in which the inspired oxygen and the
carbon of the food are given out, 13. Its formation in the
body the chief source of animal heat, 17 — 22. Occurs com-
bined with potash and soda, in the serum of the blood, 41.
Formed by the action of oxygen on the products of the
metamorphosis of the tissues, 60. Its formation may also
be connected with the production of fat from starch, 85 — 91.
Generated by putrefaction of food in the stomach of animals,
115. Also by the fermentation of bad wine in man, when
it causes death by. penetrating into the lungs, 116. Escapes
through both skin and lungs, ib. Produced, along with
urea, by the oxidation of uric acid, 140. Produced, with
several other compounds, by the oxidation of blood, ib. May
be formed, along with choleic acid, from hippuric acid,
starch, and oxygen, 152. Also, along with choleic acid,
urea, and ammonia, by the action of water and oxygen on
starch and proteine, ib. Produced, along with fat and urea,
from proteine, by the action of water and oxygen, in the
absence of soda, 154. Combines with the compound of

332 INDEX.

/

ACID.

iron present in venous blood, and is given off when oxygen
is absorbed, 269. Is absorbed by the serum of blood in all
states, 270.

— Cerebric. Its composition, 184. Its properties, 186.

— Choleic. Represents the organic portion of the bile, 133. Its
formula, 134. Its transformations, 125. Half its formula,
added to that of urate of ammonia, is equal to the formula
of blood -f- a little oxygen and water, 136. Produced in
the oxidation of blood, 140. Views which may be taken of
its composition, 148. May be formed by the action of
oxygen and water on proteine and starch, 152. Products of
its oxidation, 154. Various ways in which it may be sup-
posed to be formed in the body, 160. Its composition, 315.
Cannot be said to exist ready formed in the bile, 317.

— Cholic. Its composition, 318. Derived from choleic acid, 134,
135. Possible relation to choleic acid, 148.

— Choloidic. Its composition, 315. Derived from choleic acid,
135. Possible relation to choleic acid, 148. Possible re-
lation to starch, 157. Possible relation to proteine, 141.

— Cyanic. Its formula, 281.

— Cyanuric. Its formula, 281.

— Hippuric. Its composition, 319. Appears in the urine of
stall-fed animals, 82. Is destroyed by exercise, 82, 139. Is
probably formed in the oxidation of blood, 140. Is found
in the human urine after benzoic acid has been administered,
150, 325. May be derived from proteine when acted on by
oxygen and uric acid, 151. With starch and oxygen, it
may produce choleic and carbonic acids, 152. May be de-
rived from the oxidation of choleic acid, 154.

— Hydrocyanic or Prussic. Its poisonous action explained, 274.

— Lithofellic. Its composition, 322. Probably derived from the
oxidation of choleic acid : is the chief constituent of bezoar
stones, 154.

— Lactic. Its composition, 309. Its origin, 111. Does not
exist in the healthy gastric juice, 112.

— Margaric. Exists in bile, 317.

— Muriatic. Exists in the free state in the gastric juice, 109,
112. Is derived from common salt, 112, 161.

— Oxaluric. Analysis of, 321.

INDEX. 333

ACID.

— Parabanic. Analysis of, 321.

— Phosphoric. Exists in the urine of the carnivora in consider-
able quantity, 78, 163. Its proportion very small in that
of the graminivora, 79. Derived from the phosphorus of the
tissues, 78. It is retained in the body to form bones and
nervous matter, 80.

— -Sulphuric. Exists in the urine of the carnivora, 78, 163. De-
rived from the sulphur of the tissues, 78.

— Uric. Its composition, 318. Products of its oxidation, al-
loxan, oxalic acid, carbonic acid, urea, &c., 137, 140. Is
probably derived, along with choleic acid, by the action of
oxygen and water on blood or muscle, 136. Disappears
almost entirely in the system of man and of the higher ani-
mals, 55, 137. Appears as calculus, when there is a defi-
ciency of oxygen, 137. Never occurs in pthisical cases, ib.
Yields mulberry calculus when the quantity of oxygen is
somewhat increased, but only urea and carbonic acid with a
full supply of oxygen, ib. Uric acid calculus promoted by
the use of fat and of certain wines, 139. Unknown on the
Rhine, ib. Uric acid and urea, how related to allantoine,
141 ; to gelatine, 142. Forms the greater part of the
urine of serpents, 54. Yields, with the elements of proteine
and oxygen, hippuric acid and urea, 151. How related to
taurine, 155, 156. Calculi of it never occur in wild car-
nivora, but often in men who use little animal food, 146.
AFFINITY, Chemical. Is the ultimate cause of the vital pheno-
mena, 9, 10. Is active only in the case of contact, and de-
pends much on the order in which the particles are arranged,
205. Its equilibrium renders a compound liable to transfor-
mations, 207. In producing the vital phenomena, it is modi-
fied by other forces, 209. It is not alone the vital force or
vitality, but is exerted in subordination to that force, 232.
AIR. Introduced into the stomach during digestion with the
saliva, 113. Effects of its temperature and density, dryness,
&c., in respiration, 15, 16.

ALBUMEN. Animal and vegetable albumen identical, 47, 48.
Their composition, 293, 294, 308, 309. Vegetable albumen,
how obtained, 45. Is a compound of proteine, and in organic
composition identical with fibrine and caseine, 47, 104, 106.

334 INDEX.

Exists in the yolk as well as the white of eggs, 107. Also in
the serum of the blood, 41. Is the true starting point of all
the animal tissues, 107, 108.

ALCOHOL. Is hurtful to carnivorous savages, 179. Its mode of
action : checks the change of matter, 239. In cold climates
serves as an element of respiration, 22.

ALDEHYDE. Its composition ; how related to that of acetic acid,
279, 280.

ALKALIES. Mineral alkalies essential both to vegetable and ani-
mal life, 164. Vegetable alkalies all contain nitrogen, all act
on the nervous system, and are all poisonous in a moderate
dose, 177, 182. Theory of their action : they take a share in
the transformation or production of nervous matter, for which
they are adapted by their composition, 182 — 189. Action of
caustic alkalies on bile, or choleic acid, 134.

ALLANTOINE. Is found in the urine of the foetal calf. How de-
rived from proteine. How related to uric acid and urea, 141.
How related to choleic acid, 148. Its composition, 319. '

ALLEN and PEPYS. Their calculation of the amount of inspired
oxygen, 283.

ALLOXAN. Formed by the oxidation of uric acid, 137. Con-
verted by oxidation into oxalic acid and urea, oxaluric and
parabanic acids, or carbonic acid and urea, ib. How related to
taurine, 156. Seems to act as a diuretic. Recommended for
experiment in hepatic diseases, ib. (note).

ALMONDS, BITTER. Oil of. Its composition ; how related to ben-
zoic acid, 280.

AMMONIA. Combined with uric acid it forms the urine of ser-
pents, birds, &c., 54. Its relation to choleic, choloidic, and
cholic acids, 135. Is one of the products which may be
formed by the oxidation of blood, 140 ; or of proteine, 152.
Its relation to uric acid, urea, and taurine, 155. To allan-
toine and taurine, 155, 156. To alloxan and taurine, 156.
To choleic and choloidic acid and taurine, 158. To urea,
water, and carbonic acid, 159. Is found in combination with
acids in the urine of the carnivora, 163.

ANALYSIS. Of dry blood, 283, 314. Of dried flesh, 314. Of
faeces, 285. Of black bread, ib. Of potatoes, ib. Of peas,
ib. Of beans, ib. Of lentils, ib. Of fresh meat, ib. Of
moist bread, ib. Of moist potatoes, ib. Of the fibrine and

INDEX. 335

albumen of blood, 293, 310, 311. Of vegetable fibrine and
albumen, vegetable caseine and gluten, 294, 295. Of animal
caseine, 295. Of starch, 296, 297. Of grape or starch sugar,
297. Of sugar of milk, 298. Of gum, ib. Of oats, ib. Of
hay, 299. Of fat, 300. Of cane-sugar, ib. Of cholesterine,
ib. Of wax, 307. Of cyanic acid, cyanuric acid, and cyame-
lide, 308. Of aldehyde, metaldehyde, and elaldehyde, 307. Of
proteine, 308. Of albumen from the yolk and white of egg, ib.
Of lactic acid, 309. Of gas from the stomach of cows after
eating to excess, ib. Of gas from stomach and intestines of
executed criminals, ib. Of gelatinous tissues, 311. Of tissues
containing chondrine, 312. Of arterial membrane, ib. Of
horny tissues, ib. Of the lining membrane of the egg, 313.
Of feathers, ib. Of the pigmentum nigrum, ib. Of choleic
acid, 315. Of taurine, ib. Of choloidic acid, ib. Of cholic
acid, 318. Of uric acid, ib. Of alloxan, 319. Of urea, ib.
Of hippuric acid, ib. Of allantoine, ib. Of xanthic oxide,
320. Of cystic oxide, ib. Of oxalic acid, 320. Of oxaluric
acid, ib. Of parabanic acid, ib. Of roasted flesh, 322. Of
lithofellic acid, ib. Of solanine, 323. Of picrotoxine, ib.
Of quinine, ib. Of morphia, 324. Of caffeine, theine, or
guaranine, ib. Of theobromine, ib. Of asparagine, 325.

ANIMAL HEAT. Derived from the combination of oxygen with
the carbon and hydrogen of the metamorphosed tissues, which
proceed ultimately from the food, 17, 18. Is highest in those
animals whose respiration is most active, 19. Is the same
in man in all climates, 19, 20. Is kept up by the food
in proportion to amount of external cooling, 22. Is not pro-
duced either by any direct influence of the nerves, or by mus-
cular contractions, 29 — 34. Its amount in man, 34. Che-
mical action the sole source of it, 38. The formation of fat
from starch or sugar must produce heat, 91, 94. The ele-
ments of the bile, by combining with oxygen, serve chiefly to
produce it, 61.

ANIMAL LIFE. Distinguished from vegetable life by the absorp-
tion of oxygen, and the production of carbonic acid, 2. Must
not be confounded with consciousness, 6, 7. Conditions ne-
cessary to animal life, 9, 12. Depends on an equilibrium be-
tween waste and supply, 245, 254, 265.

ANTISEPTICS. They act by putting a stop to fermentation, putre-

336 INDEX.

faction, or other forms of metamorphosis, 170. Their action
on wounds and ulcers, 121.

ARTERIES. Composition of their tunica media, 312. How de-
rived from proteine, 126.

ARTERIAL BLOOD. Conveys oxygen to every part of the body,
60, 269. Contains a compound of iron, most probably per-
oxide, 269. Yields oxygen in passing through the capillaries,
60, 271. Contains carbonic acid dissolved or combined with
soda, 272.

ASPARAGINE. Its composition, 325. Its relation to taurine and
bile, 180. Theory of its action on the bile, 181.

ASSIMILATION. In animals it is independent of external influ-
ences, 3. Depends on the presence in the blood of compounds
of proteine, such as fibrine, albumen, or caseine, 40, 106. Is
more energetic in the young than in the adult animal, 67. Is
also more energetic in the herbivora than in the carnivora, 81.

ATMOSPHERE. See AIR.

AZOTISED PRODUCTS. Of vegetable life, 45, 176 — 182. Of the
metamorphosis of tissues. Necessary for the formation of bile
in the herbivora, 158. In man, 166, 168. May be replaced
by azotised vegetable compounds, 1 69 — 1 70. Theory of this,
177 — 182. Of the transformation of the bile, or of choleic
acid ; how related to the constituents of urine, 155.

B.

BEANS. Composition of, 285.

BEER. Forms part of the diet of soldiers in Germany, 286, 288.

BEES. Their power of forming wax from honey, 301 — 306.

BENZOIC ACID. See ACID, Benzole.

BERTHOLLET. His analysis of oxalic acid, 321.

BERZELIUS. His analysis of potato starch, 297 ; of sugar of
milk, 298 ; of gum, ib. ; of cane sugar, 300.

BEZOAR STONES. See ACID, Lithofellic.

BLANCHET. His analysis of solanine, 323.

BILE. In the carnivora is a product of the metamorphosis of the
tissues, along with urate of ammonia, 136. May be repre-
sented by choleate of soda, with which, however, it is not iden-
tical, 317. Products of its transformation, 135, 317. Re-
marks on these, 315 — 318. Origin of bile, 61, 144. Starch,
&c., contribute to its formation in the herbivora, 146 —

INDEX, 337

150, 159, 160, 166. Soda essential to it, 154, 162—164.
Relation of bile to urine, 156. To starch, 157. To fibrine,
136. To caffeine, &c., asparagine, and theobromine, 180.
For the acid substances derived from bile, choleic, choloidic,
and cholic acids, see ACID, choleic, &c. Yields taurine, 135.
Contains cholesterine, 85, 317. Also stearic and margaric
acids, 317. Its function : to support respiration and produce
animal heat by presenting carbon and hydrogen in a very so-
luble form to the oxygen of the arterial blood, 61 — 64.
Amount secreted by the dog, the horse, and man, 64. It re-
turns entirely into the circulation, and disappears completely,
60—66.

BLOOD. The fluid from which every part of the body is formed,
8. Its chief constituents, 40. How formed from vegetable
food, 45. Can only be formed from compounds of proteine, 48.
Is therefore entirely derived from vegetable products in the
herbivora, and indirectly also by the carnivora, which feed on
the flesh of the former, 48. Its composition identical with
that of flesh, 133. Analysis of both, 314. The secretions
contain all the elements of the blood, 132. Its relation to bile
and urine, 136. Products of the oxidation of blood, 140.
Excess of azotised food produces fulness of blood and disease,
145. Soda is present in the blood, 161 — 164. Important
properties of the blood, 171 — 175. Venous blood contains
iron, probably as protoxide ; arterial blood, probably as perox-
ide, 271, 273. Theory of the poisonous action of sulphuretted
hydrogen and Prussic acid : they decompose the compound of
iron in the blood, 274. The blood, in analogous morbid states,
ought to be chemically examined, 275.

BLOOD-LETTING. Theory of its mode of action, 258. It may
produce opposite effects in different cases, 264.

BCECKMANN. His analysis of black bread, 285 ; of potatoes, ib.;
of dry beef, 314 ; of dry blood, ib.; of roasted flesh, 322.

BONES. Phosphoric acid of the food retained to assist in forming
them, 80. Gelatine of bones digested by dogs, 97. See, fur-
ther, GELATINE. Cause of brittleness in bones, 99.

BOUSSINGAULT. His analysis of potatoes, 285. His comparison
of the food and excretions in the horse and cow, Table, 290.
His analysis of gluten, 294 ; of vegetable albumen, ib.; of ve-
getable caseine, 295 ; of oats, 298; of hay, 299.
Z

338 INDEX.

BRACONNOT. On the presence of lactic acid in gastric juice, 112;
of iron in the gastric juice of the dog, 113.

BRAIN. See ACID, Cerebric, and NERVOUS MATTER.

BREAD. Analysis of, 285.

BRUNN. His analysis of sugar of milk, 298.

BUCKWHEAT. Analysis of starch from, 296.

BURDACH. His statement of the amount of bile secreted by ani-
mals, 64.

BUTTER. Forms a part of the food of soldiers in Germany, 286,
288.

BUZZARD. Its excrements consist of urate of ammonia, 54.

C.

CAFFEINE. Identical with theine, 179. Its relation to taurine
and bile, 180. Theory of its mode of action, 181. Its com-
position, 324.

CANE SUGAR. Its composition, 300.

CARBON. Is accumulated in the bile, 61. Is given off as car-
bonic acid, 13. Excess of carbon causes hepatic diseases, 24.
By combining with oxygen, it yields the greater part of the
animal heat. See ANIMAL HEAT, BILE, and ACID, Carbonic.
Amount of carbon oxidised daily in the body of a man, 14.
Calculations on which this statement is founded, 284 — 289.
Amount consumed by the horse and cow, 14. Different pro-
portions of carbon in different kinds of food, 17. Carbon of
flesh compared with that of starch, shewing the advantage of
a mixed diet, 76. Calculation on which this statement is
founded, 299. Amount of carbon in dry blood calculated, 283.
Amount in the food of prisoners calculated, 293.

CARBONIC ACID. See ACID, Carbonic.

CARBONATES. They occur in the blood, 41.

CALCULUS, Mulberry. Derived from the imperfect oxidation of
uric acid, 137. Uric acid calculus is formed in consequence
of deficiency of inspired oxygen, or excess of carbon in the
food, 137. See ACID, Uric. Bezoar stones composed of
lithofellic acid, 154.

CARNIVORA. Their nutrition the most simple, 44. It is ulti-
mately derived from vegetables, 48, 49. Their young, like
graminivora, require non-azotised compounds in their food, 50.
Their bile is formed from the metamorphosis of their tissues,

INDEX. 339

59, 61. The process of assimilation in adult and young car-
nivora compared, 67. Their urine, 78. The assimilative pro-
cess in adult carnivora less energetic than in graminivora, 80.
They are destitute of fat, 82. They swallow less air with
their food than graminivora, 118. Concretions of uric acid
are never found in them, 146. Both soda and ammonia found
in their urine, 163.

CASEINE. One of the azotised nutritious products of vegetable
life, 47. Abundant in leguminous plants, 47. Identical in
organic composition with fibrine and albumen, 47, 48. Animal
caseine found in milk and cheese : identical with vegetable
caseine, 51. Furnishes blood to the young animal, 52. Is
one of the plastic elements of nutrition, 96. Yields proteine,
105, 106. Its relation to proteine, 126. It contains sulphur,
ib. Potash essential to its production, 164. Contains more
of the earth of bones than blood does, 52. Its analysis, 295.

CEREBRIC ACID. See ACID, Cerebric.

CHANGE OF MATTER. See METAMORPHOSIS OF TISSUES.

CHEMICAL ATTRACTION. See AFFINITY.

CHEVREUL. His researches on fat, 84. His analysis of fat, 300 ;
of cholesterine, ib.

CHLORIDE OF SODIUM. See COMMON SALT.

CHOLEIC ACID. See ACID, Choleic.

CHOLESTERINE. See BILE.

CHOLIC ACID. See ACID, Cholic.

CHOLOIDIC ACID. See ACID, Choloidic.

CHONDRINE. Its relation to proteine, 126. Analysis of tissues
containing it, 312.

CHRONIC DISEASES. The action of inspired oxygen is the cause
of death in them, 27, 28.

CHYLE. When it has reached the thoracic duct, it is alkaline,
and contains albumen coagulable by heat, 145.

CHYME. It is formed independently of the vital force, by a che-
mical transformation, 108. The substance which causes this
transformation is derived from the living membrane of the
stomach, 109. Chyme is acid, 145.

CLOTHING. Warm clothing is a substitute for food to a certain
extent, 22. Want of clothing accelerates the rate of cooling,
and the respirations, and thus increases the appetite, ib.

COLD. Increases the appetite by accelerating the respiration, 22.

z 2

340 INDEX.

Is most judiciously employed as a remedy in cerebral inflam-
mation, 261.

CONCRETIONS. See CALCULUS, and ACID, Uric; also ACID,
Lithofellic.

CONSTITUENTS, Azotised. Of blood : see FIBRINE and ALBU-
MEN. Of vegetables : see FIBRINE, Vegetable ; ALBUMEN,
Vegetable ; CASEINE, Vegetable ; ALKALIES, Vegetable ; and
CAFFEINE. Of bile : see ACID, Choleic, Cholic, and Choloidic.
Of urine : see ACID, Uric; UREA, and ALLANTOINE.

COOLING. See COLD and CLOTHING.

COUERBE. His analysis of cliolesterine, 300.

Cow. Amount of carbon expired by the, 14. Comparison of
the food with the excretions of the cow, 291.

CRUM. His analysis of cane sugar, 300.

CULTIVATION. Is the economy offeree, 78.

CYAMELIDE. Its formula, 280.

CYANIC ACID. See ACID, Cyanic.

CYANIDE OF IRON. Its remarkable properties, 269.

CYANURIC ACID. See ACID, Cyanuric.

D.

DAVY. Oxygen consumed by an adult man, 283.

DEATH. Cause of, in chronic diseases, 27, 28. Caused in old
people by a slight depression of temperature, 255. Definition
of it, 254.

DEMARCAY. His analysis of choleic acid, choloidic acid, and
taurine, 315. Remarks on his Researches on Bile, 316.

DENIS. His experiments on the conversion of fibrine into albu-
men, 42.

DESPRETZ. His calculation of the heat developed in the com-
bustion of carbon, 34.

DIABETES MELLITUS. The sugar found in the urine in this
disease is grape sugar, and is derived from the starch of the
food, 95.

DIASTASE. Analogy between its solvent action on starch, and
that of the gastric juice on coagulated albumen, 111.

DIFFUSION OF GASES. Explains the fact that nitrogen is given
out through the skin of animals, 118; and the poisonous
action of feather- white wine, 116.

DIGESTION. Is effected without the aid of the vital force, by a

INDEX. 341

metamorphosis derived from the transformation of a substance

proceeding from the lining membrane of the stomach, 109.

The oxygen introduced with the saliva assists in the process,

113. Lactic acid has no share in it, 111, 112.
DISEASE. Theory of, 254 et seq. Cause of death in chronic

disease, 27. Disease of liver caused by excess of carbon or

deficiency of oxygen, 23. Prevails in hot weather, 24.
DOG. Amount of bile secreted by, 64. Digests the gelatine of

bones, 97. His excrements contain only bone earth, 98.

Concretion of urate of ammonia said to have been found by

Lassaigne in a dog, doubtful, 146 (note).
DUMAS. His analysis of choleic acid, 315; of choloidic acid,

ib. ; of taurine, ib.; of cholic acid, 318; of hippuric acid,

319.

EGGS. Albumen of the white and of the yolk identical, 107.
Analysis of both, 308 ; of lining membrane, 313. The fat of
the yolk may contribute to the formation of nervous matter,
108. This fat contains iron, 107.

ELALDEHYDE. See ALDEHYDE.

ELEMENTS. Of nutrition, 96. Of respiration, ib.

EMPYREUMATICS. They check transformations, 170. Their ac-
tion on ulcers, 121.

EQUILIBRIUM. Between waste and supply of matter is the ab-
stract state of health, 245, 258. Transformations occur in
compounds in which the chemical forces are in unstable equi-
librium, 109.

ETTLING. His analysis of wax, 307. ETTLING and WILL. Their
analysis of lithofellic acid, 322.

EXCREMENTS. Contain little or no bile in man and in the herbi-
vora, none at all in the dog and other carnivora, 64. Those
of the dog are phosphate of Hme, 98. Those of serpents are
urate of ammonia, 54. Those of birds also contain that salt,
54. Those of the horse and cow compared with their food,
290, 291.

EXCRETIONS. Contain, with the secretions, the elements of the
blood or of the tissues, 132—136. Those of the horse and
cow compared with their food, 290, 291. Bile is not an
excretion, 63.

342 INDEX.

F.

F^CES. Analysis of, 285.

FAT. Theory of its production from starch, when oxygen is defi-
cient, 83 et seq. ,- from other substances, 86. The formation
of fat supplies a new source of oxygen, 89 ; and produces heat,
90 et seq. Maximum of fat, how obtained, 94. Carnivora
have no fat, 82. Fat in stall-fed animals, 89. Occurs in some
diseases in the blood, 95. Fat in the women of the East, 99.
Composition compared with that of sugar, 84, 85. Analysis
of fat, 300. Disappears in starvation, 25. Is an element of
respiration, 96.

FATTENING OF ANIMALS. See FAT.
FEATHERWHITE WINE. Its poisonous action, 116.
FEBRILE PAROXYSM. Definition of, 256.
FEHLING. His analysis of metaldehyde and elaldehyde, 307.
FERMENTATION. May be produced by any azotised matter in a
state of decomposition, 1 20. Is arrested by empyreumatics,
ib. Is analogous to digestion, 119.
FEVER. Theory and definition of, 256.
FIBRE. Muscular. See Flesh.

FIBRINE. Is an element of nutrition, 96. Animal and vegetable
fibrine are identical, 45. Is a compound of proteine, 105. Its
relation to proteine, 126. Convertible into albumen, 42. Is
derived from albumen during incubation, 107. Its analysis,
293, 294, 311. Vegetable fibrine, how obtained, 45, 46.
FISHES. Yield phosphuretted hydrogen, 191 (note).
FLESH. Consists chiefly of fibrine, but, from the mixture of fat
and membrane, has the same formula as blood, 133. Analysis
of flesh, 314, 322. Amount of carbon in flesh compared with
that of starch, 77, 299.

FOOD. Must contain both elements of nutrition and elements of
respiration, 96. Nutritious food, strictly speaking, is that
alone which is capable of forming blood, 40. Whether derived
from animals or from vegetables, nutritious food contains pro-
teine, 44, 106 et seq. Changes which the food undergoes in
the organism of the carnivora, 53 et seq. The food of the
herbivora always contains starch, sugar, &c., 70. Food, how
dissolved, 108 et seq. Azotised food has no direct influence on
the formation of uric acid calculus, 138. Effects of super-

INDEX. 343

abundant azotised food, 145, 146. Non-azotised food contri-
butes to the formation of bile, and thus to respiration, 147 et
seq. Salt must be added to the food of herbivora, in order to
yield soda for the bile, 162. Caffeine, &c., serve as food for
the liver, 188. The vegetable alkalies may be viewed as food
for the organs which form the nervous matter, 189. Amount
of food consumed by soldiers in Germany, 286. Its analysis,
284. Food of the horse and cow compared with their excre-
tions, 290, 291.

FORMULAE. Explanation of their use, 280. How reduced to 100
parts, 281. Formulae of albumen, fibrine, caseine, and animal
tissues, 126. Formula of proteine, 121 ; of blood and flesh,
133 ; of fat, 85 ; of cholesterine, 85 ; of aldehyde, acetic acid,
oil of bitter almonds, and benzoic acid, 280 ; of cyamelide,
cyanic acid, and cyanuric acid, 280 ; of choleic acid, 134; of
choloidic acid and cholic acid, 135 ; of gelatine, 142 ; of hip-
puric acid, 150; of lithofellic acid, 154; of taurine, 155 ; of
alloxan, 156. See ANALYSIS.

FRANCIS. His analysis of picrotoxine, 323.

FRKMY. Lameyran and Fre"my. Their analysis of gas from the
abdomen of cows after excess in fresh food, 309. His re-
searches on the brain, 43, 184.

FREQUENCY of the pulse and respiration in different animals, 19,
292.

FRUITS. Contain very little carbon, and hence are adapted for
food in hot climates, 17.

G.

GAS. Analysis of gas from abdomen of cows after excess in fresh
food, 115, 309. Analysis of gas from the stomach and intes-
tines of executed criminals, 115, 309.

GASTRIC JUICE. Contains no solvent but a substance in a state
of metamorphosis, by the presence of which the food is dis-
solved, 109. Contains free acid, ib. Contains no lactic acid,
112. In the dog has been found to contain iron, 113. See
DIGESTION, CHYME, FOOD.

GAY-LUSSAC and THENARD. Their analysis of starch, 297 ; of
sugar of milk, and of gum, 298 ; of cane sugar, 300 ; of wax,
307 ; of oxalic acid, 321.

GELATINE. Is derived from proteine, but is no longer a com-

344 INDEX.

pound of proteine, and cannot form blood, 127 et seq. May
serve as food for the gelatinous tissues, and thus spare the
stomach of convalescents, 98, 130. In starvation the gelati-
nous tissues remain intact, 97. Its relation to proteine, 126.
Its formula, 142. Its analysis, 311, 322.

GOEBEL. His analysis of gum, 298.

GLOBULES of the blood are the carriers of oxygen to all parts of
the body, 171 — 175. They contain iron, 265 et seq.

GLUTEN. Contains vegetable fibrine, 46. Analysis of it, 295.

GMELIN. On the sugar of bile, 147.

GOOSE. How fattened to the utmost, 94.

GRAMINIVORA. See HERBIVORA.

GRAPE-SUGAR. An element of respiration, 96. Is identical with
starch sugar and diabetic sugar, 72. Its composition, 73. Its
analysis, 297.

GROWTH, or increase of mass, greater in graminivora than in
carnivora, 80. Depends on the blood, 40 ; and on compounds
of proteine, 106. See NUTRITION.

GUM. An element of respiration, 96. Its composition, 73. Is
related to sugar of milk, ib. Its analysis, 298.

GUNDLACH. His researches on the formation of wax from honey
by the bee, 301.

H.

HAIR. Analysis of, 312. Its relation to proteine, 126. Ana-
lysis of proteine from hair, 308.

HAY. Analysis of, 299.

HEPATIC DISEASES. Cause of, 23.

HERBIVORA. Their blood derived from compounds of proteine
in their food, 48. But they require also for their support
non-azotised substances, 70. These last assist in the forma-
tion of their bile, 147 et seq. They retain the phosphoric
acid of their food to form bone and nervous matter, 80.
Their urine contains very little phosphoric acid, 79. The
energy of vegetative life in them is very great, 81. They be-
come fat when stall-fed, 82.

HESS. His analysis of wax, 307.

HYBERNATING ANIMALS. Their fat disappears during the win-
ter sleep, 25. They secrete bile and urine during the same
period, 61.

INDEX. 345

HIPPURIC ACID. See ACID, Hippuric.

HORN. Analysis of, 312. Contains proteine ; its relation to

proteine, 126. Analysis of proteine from horn, 308.
HORSE. Amount of carbon expired by, 14. Comparison of his

food with his excretions, 290. Force exerted by a horse in

mechanical motion compared to that exerted by a whale, 337.
HYDROCYANIC ACID. See ACID, Hydrocyanic.
HYDROGEN. By combining with oxygen contributes to produce

the animal heat, 25.

I.

ICE. Is judiciously employed as a remedy in cerebral inflamma-
tion, 261.

INORGANIC constituents of albumen, fibrine, and caseine, 41, 121,
126.

JOBST. His analysis of theine, 324.

JONES, Dr. Bence. His analysis of vegetable fibrine, 294 ; of
vegetable albumen, ib.; of vegetable caseine, 295; of gluten,
ib. ; of the albumen of yolk of egg, 308, 310 ; of the albumen
of brain, 310.

IRON. Is an essential constituent of the globules of the blood,
265 et seq. Is found in the fat of yolk of egg, 107. Also
in the gastric juice of the dog, 113. Singular properties of
its compounds, 268.

ISOMERIC BODIES. 103, 280.

K.

KELLER. His researches on the conversion of benzoic acid into

hippuric acid in the human body, 325.
KIDNEYS. They separate from the arterial blood the nitroge-

nised compounds destined for excretion.

L.

LACTIC ACID. See ACID, Lactic.

LAVOISIER. His calculation of the amount of inspired oxygen,
12, 283.

LEHMANN. On the presence of lactic acid in gastric juice, 112.

LIEBIG. His analysis of sugar of milk, 298 ; of cane sugar,
300 ; of aldehyde, 307 ; of uric acid, 318 ; of hippuric acid,
319; of quinine, 323; of morphia, 324; of asparagine, 325.

346 INDEX.

His calculation of the carbon daily expired as carbonic acid, 14,

284. Table, 289. His remarks on Dema^ay's researches on
bile, 315—318.

LIEBIG AND PFAFF. Their analysis of caffeine, 324.

LIEBIG AND WOHLER. Their analysis of alloxan, 319; of urea,

ib. ; of allantoine, ib. ; of xanthic oxide, 320 ; of oxaluric acid,

321 ; of parabanic acid, ib.
LENTILS. Contain vegetable caseine, 47. Analysis of, 284,

285. Form part of the diet of soldiers in Germany, 287.
Table, 289.

LIGHT. Its influence on vegetable life analogous to that of heat
on animal life, 233.

LIME. Phosphate of. See BONES.

LIVER. It separates from the venous blood the carbonised con-
stituents destined for respiration, 58. Diseases of the liver,
how produced, 23. Accumulation of fat in the liver of the
goose, 95.

M.

MAIZE. Analysis of starch from, 297.
MARCHAND. On the amount of urea in the urine of the dog

when fed on sugar, 61. His analysis of cholesterine, 300.
MARCET. His analysis of gluten, 294.
MARTIUS. His analysis of guaranine, 324.
MECHANICAL EFFECTS. See MOTION.
MEDICINE. Definition of the objects of, 257 et seq. Action of

medicinal agents, 170 et seq.
MENZIES. His calculation of the amount of inspired oxygen, 12,

283.

METALDEHYDE. See ALDEHYDE.
METAMORPHOSIS OF TISSUES. 103 et seq. In other parts of

the volume, passim.
MILK. Is the only natural product perfectly fitted to sustain life,

51. Contains caseine, ib. Fat (butter), ib. Sugar of milk,

ib. Earth of bones, 52. And potash, 164.
MORPHIA. Contains less nitrogen than quinine, 177. Its ana-
lysis, 324.
MITSCHERLICH. His analysis of uric acid, 318 ; of hippuric acid,

319.
MOMENTUM. Of force, 202. Of motion, ib.

INDEX. 347

MOTION. Phenomena of motion in the animal body, 196 et seq.
Different sources of motion 199. Momentum of motion, 202.
Motion propagated by nerves, 219. Voluntary and involun-
tary motions accompanied by a change of form and structure
in living parts, 220. Motion derived from change of matter,
221 et seq. The cause of motion in the animal body is a pe-
culiar force, 232. The sum of the effects of motion in the
body proportional to the amount of nitrogen in the urine, 245.

MULBERRY CALCULUS. See CALCULUS.

MULDER. Discovered proteine, 105. His analysis of fibrine of
blood, 293. Of animal caseine, 296. Of proteine, 308. Of
fibrine, 311. Of gelatine, ib. Of chondrine, 312.

MUSCLE. See FLESH.

MUSCULAR FIBRE. Its transformation depends on the amount
of force expended in producing motion, 220.

N.

NERVES. Are the conductors of the vital force, and of mechani-
cal effects, 219. Effects of the disturbance of their conducting
power, 229. They are not the source of animal heat, 29.

NERVOUS LIFE. Distinguished from vegetative, 38.

NERVOUS MATTER. Contains albumen, and fatty matter of a
peculiar kind, 43. Vegetables cannot produce it, 50. The
fat of yolk of egg probably contributes to its formation, 108.
The phosphoric acid and phosphates, formed in the metamor-
phosis of the tissues of the herbivora, are retained to assist in
the formation of nervous matter, 80. The vegetable alkalies
affect the nervous system, 182 — 184. Composition of cerebric
acid, 184. Theory of the action of the vegetable alkalies, 185.

NITROGEN. Essential to all organised structures, 42, 43. Sub-
stances in the body which are destitute of it not organised, 43.
Abounds in nutritious vegetables, 45. Nutritious forms in
which it occurs, ib. et seq. Occurs in all vegetable poisons,
177 ; also in a few substances which are neither nutritious nor
poisonous, but have a peculiar effect on the system, such as
caffeine, 177 et seq.

NlTROGENISED. See AzOTISED.

NON-AZOTISED. Constituents of food. See STARCH.
NUTRITION. Depends on the blood, 40. On Albumen, fibrine,
or caseine, 40 et seq. Elements of nutrition, 96. Compounds

348 INDEX.

cf proteine alone are nutritious, 106. Occurs when the vital
force is more powerful than the opposing chemical forces, 198.
Theory of it, 210. Is almost unlimited in plants from the ab-
sence of nerves, 212. Depends on the momentum of force
in each part, 227. Depends also on heat, 243.

O.

OATS. Amount required to keep a horse in good condition, 74.
Analysis of, 298.

OIL OF BITTER ALMONDS. Its composition. How related to
benzoic acid, 279, 280.

OLD AGE. Characteristics of, 248 et seq.

OPPERMANN. His analysis of wax, 307.

ORGANS. The food of animals always consists of parts of organs,
2. All organs in the body contain nitrogen, 42, 43. There
must exist organs for the production of nervous matter, 189 ;
and the vegetable alkalies may be viewed as food for these
organs, ib.

ORGANISED TISSUES. All contain nitrogen, 42, 43. All such as
are destined for effecting the change of matter are full of small
vessels, 223. Their composition, 126. The gelatinous and
cellular tissues, and the uterus, not being destined for that
purpose, are differently constructed, 224. Waste of organised
tissues rapid in carnivora, 76.

ORIGIN. Of animal heat, 17, 31. Of fat, 81 et seq. Of the
nitrogen exhaled from the lungs, 114 et seq. Of gelatine, 127
et seq., 143. Of uric acid and urea, 135 et seq. Of bile, 135,
143, 146 et seq., 159. Of hippuric acid, 150, 325. Of the
chief secretions and excretions, 152. Of the soda of the bile,
161 et seq. Of the nitrogen in bile, 168. Of nervous matter,
183 et seq.

ORTIGOSA. His analysis of starch, 297.

OXALIC ACID. A product, along with urea, of the partial oxida-
tion of uric acid, occurring in the form of mulberry calculus,
137. Its analysis, 321.

OXYGEN. Amount consumed by man daily, 12, 283. Amount
consumed daily in oxidising carbon by the horse and cow, 14.
The absorption of oxygen characterizes animal life, 2. The
action of oxygen is the cause of death in starvation and in
chronic diseases, 25 — 28. The amount of oxygen inspired

INDEX. 349

varies with the temperature, dryness, and density of the air,
16. Is carried by arterial blood to all parts of the body, 171.
Fat differs from sugar and starch only in the amount of oxy-
gen, 84. It also contains less oxygen than albumen, fibrine,
&c., 86. The formation of fat depends on a deficiency of oxy-
gen, 88 et seq. ; and helps to supply this deficiency, 89. Oxy-
gen essential to digestion, 113. Relation of oxygen to some
of the tissues formed from proteine, 126. Oxygen and water,
added to blood 'or to flesh, yield the elements of bile and of
urine, 135. Action of oxygen on uric acid, 136, 139 ; on
hippuric acid, 82, 139 ; on blood, 140 ; on proteine, with uric
acid, 151 ; on proteine and starch, with water, 152 ; on cho-
leic acid, 154 ; on proteine, with water, 154. By depriving
starch of oxygen and water, choloidic acid may be formed, 157.
Oxygen is essential to the change of matter, 173. Its action
on the azotised constituents of plants when separated, 213.
Its action on the muscular fibre essential to the production of
force, 220 — 226. Oxygen is absorbed by hybernating animals,
241. Is the cause of the waste of matter, 243 ; and of animal
heat, 244, 252. Blood-letting acts by diminishing the amount
of oxygen which acts on the body, 258. Its absorption is the
cause of the change of colour from venous to arterial blood,
265. The globules probably contain oxide of iron, protox-
ide in venous blood, peroxide in arterial, 267 et seq. All
parts of the arterial blood contain oxygen, 173, 174, 266,

271.

P.

PEARS. Analysis of starch from unripe, 297.

PEAS. Form part of the diet of soldiers in Germany, 287, 289.

Abound in vegetable caseine, 47. Analysis of peas, 285 ; of

starch from peas, 296.
PEPYS and ALLEN. Their calculation of the amount of inspired

oxygen, 283.

PEROXIDE OF IRON. Probably exists in arterial blood, 267 et seq.
PFLUGER. His analysis of the gas obtained by puncture from the

abdomen of cattle after excess in green food, 309.
PHENOMENA of motion in the animal body, 195 et seq.
PHOSPHATES. See BONES.
PHOSPHORIC ACID. See ACID, Phosphoric.
PHOSPHORUS. Exists in albumen and fibrine, 41, 48, 126. It is

350 INDEX.

not known in what form, 121 et seq. Is an essential constitu-
ent of nervous matter, 184, 190.

PHOSPHURETTED HYDROGEN. Occurs among the products of the
putrefaction of fishes, 190, 191.

PICROTOXINE. Contains nitrogen, 177 (note). Its analysis, 323.

PLANTS. Distinguished from animals by fixing carbon and giving
out oxygen, 2, 213 ; by the want of nerves and of locomotive
powers, 3. Their capacity of growth almost unlimited, 212.
Cause of death in plants, 214.

PLAYFAIR, DR. L. His formula for blood, 113. His analysis of
faeces, of peas, of lentils, of beans, 285 ; of flesh and of blood,
314 ; of roasted flesh, 322.

POISONS, VEGETABLE. Always contain nitrogen, 1 76 et seq. Dif-
ferent kinds of poisons, 170. Theory of the action of Prussic
acid and sulphuretted hydrogen, 274.

POLYMERIC BODIES, 103.

POTASH. Essential to the production of caseine or milk, 164.

POTATOES. Amount of carbon in, 287. They form part of the
diet of soldiers in Germany, ib. Analysis of, 285 ; of starch
from, 297 ; of solanine from the buds of germinating potatoes,
323.

PREVOST AND DUMAS. On the frequency of the pulse and respi-
rations, 292.

PRODUCTS. Of the metamorphosis of tissues found in the bile
and urine, 132. Of the action of muriatic acid on bile, 133.
Of the action of potash on bile, 134. Of the action of water
and oxygen on blood or fibre, 136. Of the oxidation of uric
acid, 137. Of the oxidation of blood, 140. Of the action of
water on proteine, 141. Of the action of urea on lactic and
benzoic acids, 150. Of oxygen and uric acid on proteine, 151.
Of oxygen on starch and hippuric acid, 152. Of oxygen and
water on proteine and starch, 153. Of oxygen and water on
proteine when soda is absent, 154. Of the separation of oxy-
gen from starch, 157. Of the action of water on urea, 159.
Of the action of water and oxygen on caffeine or theine, aspa-
ragine, and theobromine, 180.

PROTEINE. Discovered by Mulder, 105. Its composition, ib.
Produced alone by vegetables, 106. Is the source of all the
organic azotised constituents of the body, 107. Its formula,
121. Its relation to fibrine, albumen, caseine, and all the

INDEX. 351

animal tissues, 126. Gelatine no longer yields it, although
formed from it, 129. Its relation to bile and urine, 136. Its
relation to allantoine and choloidic acid, 141 ; to gelatine, 142;
to hippuric acid, 151 ; to the chief secretions and excretions,
152, 153 ; to fat, 154. Analysis of proteine from the crys-
talline lens, from albumen, from fibrine, from hair, from horn,
from vegetable albumen and fibrine, from cheese, 308.

PROUT. His analysis of starch, 297 ; of grape sugar from honey,
ib. ; of sugar of milk, 298 ; of cane sugar, 300 ; of urea, 319.
His discovery of free muriatic acid in the gastric juice, 112.
On the effect of fat food on the urine, 139.

PRUSSIC ACID. See ACID, Hydrocyanic.

PULMONARY DISEASES. Arise from excess of oxygen, 23. Pre-
vail in winter, 24.

PULSE. Its frequency in different animals, 292.

PUTREFACTION. Is a process of transformation, 109. Membranes
very liable to it, 110. Effects of the putrefaction of green food
in the stomach of animals,. 115. Is analogous to digestion,
119. Putrefying animal matters cause the fermentation of
sugar, 120. Is checked by empyreumatics, 121, 170.

Q.
QUININE. Contains nitrogen, 177. Its analysis, 323.

R.

REGNAULT. His analysis of morphia, 324.

REPRODUCTION OP TISSUES. See NUTRITION.

REPRODUCTION OF THE SPECIES, 39.

RHENISH WINES. Contain so much tartar, that their use pre-
vents the formation of uric acid calculus, 139.

RESPIRATION. Theory of, 265 et seq. Its connection with the
food and with the animal heat, 12 et seq.

S.

SALT, Common. Essential to the formation of bile in the her-
bivora, and to that of gastric juice, 161 et seq.

SAUSSURE, DE. His analysis of grape sugar and of starch sugar,
297 ; of wax, 307.

SCHERER, DR. Jos. His analysis of albumen from serum of blood,
293 ; of fibrine of blood, ib. ; of vegetable fibrine, 294 ; of ve-
getable caseine, 295 ; of animal caseine, ib. ; of proteine from

352 INDEX.

different sources, 308 ; of albumen from white of egg, ib.; of
albumen from different sources, 310 ; of fibrine, 311 ; of gela-
tine from different sources, ib.; of tissues containing chondrine,
312 ; of the tunica media of arteries, ib. ; of horny tissues, ib.;
of the lining membrane of the egg, 313 ; of feathers, ib.; of the
pigmentum nigrum oculi, ib. Results of his researches, 125,
126.

SECRETIONS. See BILE and URINE.

SEGUIN. His calculation of the amount of inspired oxygen, 283.

SERPENTS. Their excrements consist of urate of ammonia, 54.
The process of digestion in them, 53.

SLEEP, Theory of, 228. Amount of sleep necessary for the
adult, the infant, and the old man, 247 et seq. Induced by
alcohol or wine, 240.

SODA. Essential to blood and bile, and derived from common
salt, 161 et seq.

SODIUM, Chloride of. See SALT.

SOLANINE. Contains nitrogen, 177. Its analysis, 323.

STARCH. Exists in the food of the herbivora, 70. Is convertible
into sugar, 70, 71. Its relation to gum and sugar, 73. Its
function in food, 74 et seq. Amount of carbon in starch com-
pared with that in flesh, 76, 77. Its composition compared
with that of fat, 84, 90. Is the source of diabetic sugar, 95.
Is an element of respiration, 96. Dissolved by diastase, *1 1 1 .
Its relation to choleic acid, 152. Its relation to the principal
secretions and excretions, 153 ; to choloidic acid, 157 ; to bile.
158, 162, 164, 166. Its analysis from fifteen different plants,
297.

STARVATION. Process of, 25. Cause of death in, 27.

STRECKER. His analysis of starch from 12 different plants, 297.

SUGAR. Analysis of grape-sugar, 597 ; of sugar of milk, 298 ;
of cane-sugar, 300. Is an element of respiration, 96.

SULPHUR. Exists in albumen, fibrine, and caserne, 41, 126.

SULPHURETTED HYDROGEN. Theory of its poisonous action,
274.

SULPHURIC ACID. See ACID, Sulphuric.

SUPPLY of matter. See NUTRITION.

SUPPLY and WASTE. Equilibrium between them constitutes the
abstract state of health, 254, 255. Effects of its disturbance,
ib. et seq. Means for restoring the equilibrium, 248, 257 et

INDEX. 053

T.

TABLES of the food consumed by soldiers in Germany, 289. Of
the food and excretions of the horse and cow, 290, 291.

TAURINE. How produced from bile, 133. Its relation to cho-
leic acid, 135. Its relation to uric acid and urea, and to allan-
toine, 155 ; to uric acid 156 ; to alloxan, ib.; to choloidic and
choleic acids, and ammonia, 158; to caffeine or theine, 180;
to asparagine, ib. ; to theobromine, ib., 181.

TEMPERATURE. Its effects on the amount of inspired oxygen, 16,
and on the appetite, 17 et seq. A slight depression of tem-
perature causes death in aged people, 255. Temperature of
the blood in different animals, 292. Temperature of the body
constantly kept up by internal causes, 19 — 22.

TENDONS. Analysis of, 311.

THAULOW. His analysis of cystic oxide, 320.

THEINE. Identical with caffeine, 179. And with guaranine,
324. Theory of its action, 181 et seq. Its relation to bile,
180. Its analysis, 324.

THEOBROMINE. Analogous to theine, 179. Theory of its action,
181 et seq. Its relation to bile, 180, 181. Its analysis, 324.

THEORY. Of animal heat, 17 et seq. Of digestion, 108 et seq.
Of respiration, 265 et seq. Of the motions in the animal or-
ganism, 195 et seq. Of disease, 254 et seq. Of the action of
caffeine, &c., 181 et seq. Of the action of the vegetable alka-
lies, 182 et seq. Of health, 254, 255.

TIEDEMANN and GMELIN. Their attempt to support a goose upon
albumen alone, unsuccessful, 106.

TISSUES, METAMORPHOSIS OF : see METAMORPHOSIS. Ana-
lysis of the animal tissues, 310, 313. Formulae of, 126.

TOBACCO. Arrests or retards the change of matter, 179.

TRANSFORMATION. See METAMORPHOSIS.

TURNIPS. Juice of, contains vegetable fibrine and albumen, 45,
46.

U.

UREA. Derived from uric acid, 137, 140. Also from the oxi-
dation of blood, 140; from allantoine, 141. Its relation to
choleic acid, 148; to hippuric acid, 150; to proteine, 151 ;
to proteine and starch, 153; to proteine and fat, 154; to
taurine, 155, 156 ; to carbonate of ammonia, 159 ; to theobro-
mine, 180. Its analysis, 319. Occurs in the urine of those
who have taken benzoic acid along with hippuric acid, 327.
2 A

354 INDEX.

URINARY CALCULI. See CALCULUS.
URIC ACID. See ACID, Uric.

V.

VARRENTRAPP and WILL. Their analysis of vegetable albumen,
294. Of sulphate of potash and caseine, 295.

VEGETABLES. Alone produce compounds of proteine, 106.
Azotised constituents of, nutritious, 45 ; medicinal or poison-
ous, 176. Analysis of those vegetables which are used for
food, 285 et seq.

VEGETATIVE LIFE. Distinguished from nervous life, 38. Pre-
dominates in the early stages of life, ib. Also in the female,
39.

VENOUS BLOOD. See BLOOD.

VITAL FORCE, or vitality. Definition of, 1 et 'seq. Theory of,
195 et seq.

VOGEL. His analysis of gas from the abdomen of cattle after
excess in green food, 309.

W.

WATER. Is one of the two constituents of the body which con-
tain no nitrogen, 43. Its use as a solvent, ib. Contributes
to the greater part of the transformations in the body, 136,
140, 141, 142, 148, 153, 154, 155, 156, 157, 159, 180, 181.

WAX. On its production from honey by the bee, 301—306. Its
analysis, 307.

WHEAT. Contains vegetable fibrine, 46. Analysis of fibrine,
albumen, and gluten, from wheat, 294.

WILL and ETTLING. Their analysis of lithofellic acid, 322.

WINE. The wines of the south promote the formation of calcu-
lus, 139. But not Rhenish wines, ib. Theory of its action,
239, 240.

WosKRESENSKr. His analysis of theobromine, 324.

Y.
YAMS. Analysis of starch from, 297.

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