A manual of infectious diseases / by E.W. Goodall and J.W. Washbourn.

  • Goodall, E. W. (Edward Wilberforce), 1861-
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: A manual of infectious diseases / by E.W. Goodall and J.W. Washbourn. Source: Wellcome Collection.

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    decolorising in the acid ; the tubercle bacilli then appear red, and the nuclei of the cells and any other bacteria present blue. Motility. Many bacteria are motile, and when examined under the microscope in the living state can be observed to move about from place to place, either with rapid darting or with slow undulatory movements. These bacteria are provided with one or more thread-like appendages, called flagella, which can be demonstrated by special methods of staining.* Chemical Products of Bacteria. Toxines. The bacteria produce a number of chemical changes in the media in which they grow. These changes are of two kinds: the one is the elaboration of bodies of a more or less complex nature, the other is the splitting up of complex molecules into simple bodies, such as carbonic acid and sulphuretted hydrogen. The two processes, the building up and the breaking down, go on at the same time. All bacteria during their growth elaborate from the medium the protoplasm of which they are composed. The principal chemical constituent of the protoplasm is a substance called protein. This substance appears to be the same for all kinds of bacteria. Some bacteria are able to elaborate their protoplasm out of simple organic bodies such as tartrates, while others require more complex bodies as proteids. Besides protein other complex bodies are elaborated, which serve various purposes in the econor^y of the bacteria. Many bacteria produce pigments,