Page 74 - My FlipBook

48 THE MICRO-ORGANISMS OF THE HUMAN MOUTH.

METHODS OF BACTERIOLOGICAL INVESTIGATION.
It was not mj design, when I began the preparation of this
book, to present even a summary of the various methods
employed in bacteriological investigations. These have be-
come so numerous within the last few years that an exhaust-
ive treatment of the subject is a work of itself, and must be
sought in treatises devoted to that alone. For these reasons
I passed over this important matter in the German edition,
with a bare mention. Since, however, some have expressed dis-
appointment at tliis omission, I have concluded to present in
this edition a brief summary of the most important methods
now in use. This task I now undertake all the more willingly,
because I am convinced that some of my readers in the dental
and medical professions may in this way obtain a certain knowl-
edge of the methods of bacteriological experimentation, which
they would not do if they w^ere obliged to consult a separate
work for that purpose, and furthermore, because for every one, a
knowledge of at least the fundamental principles of research
very much facilitates the ready understanding of the results
obtained by them. I must repeat, however, that it is only the
most important and most commonly used methods that I pro-
pose briefly to consider here. In the first place, let me say that
there is at present no science which opens up so broad and fruit-
ful fields of study, and is so accessible to ever\' one, as the sci-
ence of bacteriology. Of course, we often find ourselves con-
fronted by an apparently insoluble problem ; but on the whole
the study of bacteriology compared with that of chemistry is,
we may almost say, child's play. This is testified to by the fact
that a course of six weeks usually suffices to put one in pos-
session of nearly all the important methods of bacteriological
research. The application of the methods, however, sometimes
involves an immense amount of time, and hard, patient labor.

Definitions of a Few Terms used in the Folloaving Pages.

Agar-agar : the name given to various algaB growing on the
coast of the East Indian archipelago, particularly Gracilaria
lichenoides, Euchema spinosum, Gigartina speciosa, etc., which I