V. CAUSES OF ILL-HEALTH

 

With the establishment of the correctness of the germ theory of
disease and development of scientific knowledge has come an ever in-~
creasing accumulation of information about the exact causes of ill health,

For purposes of study these causes of ill health may be classified
as to:

{a} Exciting Agents

 

1. Living or animate, as: micro-organisms.

2. Mechenicél, as: automobile accidents, etc.

3. Chemical, as: lead poisoning, etc.

4. Physical, as: heat, cold, or electricity, etc.

or as to:

 

(b} Mode of Transmission

1. Communicable, as: diphtheria, etc.
2. Non-communicable, as: heart disease.

LIVING CAUSES OF ILL HEALTH

 

Our remarkable progress in the control of disease has come as a result
of the proof that certain of our deadliest diseases are caused by living
micro-organisms. For these contributions to the welfare of mankind we have
to thank that remarkable group of scientific workers who founded the science
of bacteriology.

The list of these benefactors is too long for us’ to any more than men-
tion 2° few of the more prominent ones. Pasteur, Koch, Neisser, Laverean,
Eberth, Klebs, Loeffler, Shandim, Hoffman and Noguchi. We are prone to
remember and honor the men of history who were great generals or admirals
and were famous for destroying human life while we are apt to ignore or
forget the men whose fame rests upon preserving human life. Review the
lives of a few of this latter group.

Micro-organisms and Disease

 

Year after year we have seen a gradually lengthening list of micro-
organisms that have been convicted of causing disease in man. These or-
ganisms may be classified in two great groups: (a) Bacteria; (b) Protozoa.

Bacteria-—-The group of bacteria includes a long list of members which
may be considered from the standpoint of their action when taken into the
human body, as:

(a) Pathogenic or disease producing.
(b) Non-pathogenic or non-disease producing.

Non-Pathogens. The importance of non-pathogenic bacteria to humans
and plants is seldom fully realized. The carbon cycle end nitrogen cycle
are necessary for life. They are dependent upon the action of non-patho-
genic bacteria. Commercially these bacteria are essential for the pro-
duction of butter, cheese, tanning hides, curing tobacco, etc.