|
Main
- books.jibble.org
My Books
- IRC Hacks
Misc. Articles
- Meaning of Jibble
- M4 Su Doku
- Computer Scrapbooking
- Setting up Java
- Bootable Java
- Cookies in Java
- Dynamic Graphs
- Social Shakespeare
External Links
- Paul Mutton
- Jibble Photo Gallery
- Jibble Forums
- Google Landmarks
- Jibble Shop
- Free Books
- Intershot Ltd
|
books.jibble.org
Previous Page
| Next Page
Page 3
CHAPTER XII
THE RAPID DEVELOPMENT OF MEDICINE IN THE LAST FIFTY YEARS.--THE
INFLUENCE OF DARWIN.--PREVENTIVE MEDICINE.--THE DISSEMINATION OF
MEDICAL KNOWLEDGE.--THE DEVELOPMENT OF CONDITIONS IN RECENT YEARS
WHICH ACT AS FACTORS OF DISEASE.--FACTORY LIFE.--URBAN LIFE.--THE
INCREASE OF COMMUNICATION BETWEEN PEOPLES.--THE INTRODUCTION OF PLANT
PARASITES.--THE INCREASE IN ASYLUM LIFE.--INFANT MORTALITY.--WEALTH
AND POVERTY AS FACTORS IN DISEASE 241
GLOSSARY 250
INDEX 252
DISEASE AND ITS CAUSES
CHAPTER I
DEFINITION OF DISEASE.--CHARACTERISTICS OF LIVING MATTER.--CELLS AS
THE LIVING UNITS.--AMOEBA AS TYPE OF A UNICELLULAR ANIMAL.--THE
RELATION OF LIVING MATTER TO THE ENVIRONMENT.--CAPACITY OF ADAPTATION
TO THE ENVIRONMENT SHOWN BY LIVING MATTER--INDIVIDUALITY OF LIVING
MATTER.--THE CAUSES OF DISEASE.--EXTRINSIC.--THE RELATION OF THE HUMAN
BODY TO THE ENVIRONMENT.--THE SURFACES OF THE BODY.--THE INCREASE OF
SURFACE BY GLAND FORMATION.--THE REAL INTERIOR OF THE BODY REPRESENTED
BY THE VARIOUS STRUCTURES PLACED BETWEEN THE SURFACES.--THE FLUIDS OF
THE BODY.--THE NERVOUS SYSTEM.--THE HEART AND BLOOD-VESSELS.--THE
CELLS OF THE BLOOD.--THE DUCTLESS GLANDS.
There is great difficulty, in the case of a subject so large and
complex as is disease, in giving a definition which will be accurate
and comprehensive. Disease may be defined as "A change produced in
living things in consequence of which they are no longer in harmony
with their environment." It is evident that this conception of disease
is inseparable from the idea of life, since only a living thing can
become diseased. In any dead body there has been a pre�xisting disease
or injury, and, in consequence of the change produced, that particular
form of activity which constitutes life has ceased. Changes such as
putrefaction take place in the dead body, but they are changes which
would take place in any mass similarly constituted, and are not
influenced by the fact that the mass was once living. Disease may also
be thought of as the negation of the normal. There is, however, in
living things no definite type for the normal. An ideal normal type
may be constructed by taking the average of a large number of
individuals; but any single individual of the group will, to a greater
or less extent, depart from it. No two individuals have been found in
whom all the Bertillon measurements agree. Disease has reference to
the individual; conditions which in one individual would be regarded
as disease need not be so regarded in another. Comparisons between
health and disease, the normal and the abnormal, must be made not
between the ideal normal and abnormal, but between what constitutes
the normal or usual and the abnormal in a particular individual.
The conception of disease is so inseparably associated with that of
life that a brief review of the structure and properties of living
things is necessary for the comprehension of the definition which has
been given. Living matter is subject to the laws which govern matter,
and like matter of any other sort it is composed of atoms and
molecules. There is no force inherent in living matter, no vital force
independent of and differing from the cosmic forces; the energy which
living matter gives off is counterbalanced by the energy which it
receives. It undergoes constant change, and there is constant
interchange with the environment. The molecules which compose it are
constantly undergoing change in their number, kind and arrangement.
Atom groups as decomposition products are constantly given off from
it, and in return it receives from without other atom groups with
which it regenerates its substance or increases in amount. All
definitions of life convey this idea of activity. Herbert Spencer
says, "Life is the continuous adjustment of internal relations to
external conditions." The molecules of the substances forming the
living material are large, complex and unstable, and as such they
constantly tend to pass from the complex to the simple, from unstable
to stable equilibrium. The elementary substances which form living
material are known, but it has hitherto not been found possible
artificially so to combine these substances that the resulting mass
will exhibit those activities which we call the phenomena of life. The
distinction between living and nonliving matter is manifest only when
the sum of the activities of the living matter is considered; any
single phenomenon of the living may appear also in the non-living
material. Probably the most distinguishing criterion of living matter
is found in its individuality, which undoubtedly depends upon
differences in structure, whether physical or chemical, between the
different units.
Previous Page
| Next Page
|
|