An introduction to bacteriological and enzyme chemistry / [Gilbert John Fowler].

  • Fowler, Gilbert J. (Gilbert John), 1868-
Date:
[1911]
Catalogue details

Licence: In copyright

Credit: An introduction to bacteriological and enzyme chemistry / [Gilbert John Fowler]. Source: Wellcome Collection.

    29/350 (page 19)
    fblack. According to the form of the hyphae the moulds are j idivided into four divisions, viz.:— i 1. Mucorineae ; I 2. Aspergillinae; I 3. Penicilliaceae; i. Oidaceae, All three classes of organisms, bacteria, yeasts, and moulds, (occur very widely distributed in nature. They are always imost abundant where there is the needful food supply. It is ■•a matter of common knowledge that meat goes bad if long ■exposed to the air, that jam if uncovered develops mould, tthat milk becomes sour, that sewage or excretal matter becomes .offensive if allowed to accumulate. These changes are due to ’micro-organisms either originally present in the decomposing •substance, or carried in air and deposited on substances capable of putrefactive change, which themselves thus become sources - of infection. The presence of bacteria in the air can be demon- .'strated by exposing a slice of potato for some time in a room, dn the course of forty-eight hours or so small spots or t centres of growth will appear, which can be recognised as ' colonies of bacteria or as moulds by methods shortly to be ' described. Certain organisms are capable of producing chemical changes in the bodies of higher living organisms, and have been found to accompany the development of specific diseases; such ' organisms are termed 'pathogenic. Other organisms perform exceedingly useful functions. It is scarcely necessary to refer to the technical importance of I yeasts in the brewing industries. Special varieties of bacteria i are concerned in the production of vinegar and the ripening i of cheese, or are useful at certain stages in the manufacture of j leather in the tannery. The harmless disposal of refuse matter I from men and animals is effected largely by the activity of j bacteria, and the processes of agriculture are increasingly j found to depend upon the activity of the organisms in the soil;