A text-book of general bacteriology / by Edwin O. Jordan.

  • Edwin O. Jordan
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of general bacteriology / by Edwin O. Jordan. Source: Wellcome Collection.

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    ever, Muller succeeded in discovering many structural details of which his predecessors had been ignorant. Indeed, he succeeded in depicting several kinds of bacteria so accurately that they can be identified today as belonging to one or another of the chief group-forms. Another unequivocal advance was made by Ehrenberg (1795- 1876). His principal work upon the “ infusion animals/’ “ infusoria,” or “Infusionstierchen,” as the animalcules found in infusions of hay, meat, and other organic substances were termed, was published in 1838, and brought together much more definite and detailed information concerning bacteria than had previously been secured. The chief merit of Ehrenberg’s work lay in the system that it introduced into the study of micro-organisms. This investigator was able to establish a number of different groups among the organ¬ isms now called bacteria, and recognized clearly the fundamental differences between the larger forms, such as the screw-shaped or spirally-twisted organisms, and certain of the true protozoa with which they had heretofore been classed. Some of the names which Ehrenberg conferred upon his “infusion animals,” such as bacterium and spirillum, are still current in bacteriologic nomenclature, although with changed signification. In the two or three decades succeeding Ehrenberg’s work con¬ siderable knowledge was amassed concerning the mode of develop¬ ment and physiology of bacteria, as well as their position in bio¬ logic classification, but the labors of Dujardin, Perty, Cohn, Nageli, and others, although important, are quite overshadowed by the work of Pasteur. Up to the period of Pasteur’s investigations the role played by bacteria in various familiar natural processes, such as putrefac¬ tion, decay, and fermentation, had been, perhaps, vaguely suspected, but had not received conclusive demonstration. The memorable researches of Pasteur (1822-1895) upon spontaneous generation and fermentation imparted to the stud} of bacteria a broad biologic importance that it had not hitherto possessed. Bacteria and kin¬ dred micro-organisms were shown to be responsible for setting in motion and carrying out many every-day processes, the nature of which had not before been understood or which had been in¬ correctly assigned to “the oxygen of the air ” or to other inorganic
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