Pathogenic micro-organisms : including bacteria and Protozoa; a practical manual for students, physicians and health officers / by William Hallock Park ; assisted by Anna W. Williams.
- William Hallock Park
- Date:
- 1908
Licence: In copyright
Credit: Pathogenic micro-organisms : including bacteria and Protozoa; a practical manual for students, physicians and health officers / by William Hallock Park ; assisted by Anna W. Williams. Source: Wellcome Collection.
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![ing that the temperature of boiling water was not sufficient to destroy all living organisms, and that, especially in alkaline liquids, a higher temperatnreNvas required to ensure sterilization. He showed, how- ever, that at a temperature of 110° to 112° C., which he ohtained by boiling under a pressure of one and one-half atmospheres, all living organisins were invariably killed. Pasteur at a later date (1865) demonstrated the fact that the organisms which resist boiling temperature are, in fact, reproductive bodies, which are now known as spores. In 1876 the development of spores was carefully investigated and explained by Perdinand Cohn. He, and a little later Koch, showed that certain rod-shaped organisins possess the power of passing into a resting or spore stage under ]>eculiar conditions of growth, and when in this stage they are mnch less susceptible to the injurious action of higher temperatures than in their normal vegetative condition. With this discovery the controversy of spontaneous generation, in so far as it related to identified bacteria, was finally settled. If these microorganisms, some of which, being capable of producing the more resistant spores, were present in the air, dust, soil, water, etc., it was easy enough to explain the irregularities in the previous experiments; nor was it any longer to be doubted that these bacteria, through their products, were the cause, not the effect, of fermentation and putrefac- tion,-and that when organic substances ivere completely sterilized and protected against the entrance of living germs from without, no devel- opment of microorganisms occurred in them. Stimulated by the establishment of the fact, through Pasteur’s investigations, that fermentation and putrefaction were due to the action of living organisms reproduced from similar preexisting forms, and that each form of fermentation was due to a special microorgan- ism, the study of the causal relation of microorganisms to disease was taken up with renewed vigor. Peference has already been made to the opinions and hypotheses of the earlier observers as to the microbie origin of infections diseases. Tbc first positive grounds, however, for this doctrine, founded npon actual experiment, were the investi- gations into the cau.se of certain infectious diseases in insects and plants. Thus, Passi in 1837 demonstrated that a fatal infectious malady of the silkworm—rnuscardine—was due to a parasitic micro- organism. Pasteur later devoted several years’ study to an exhaus- tive investigation into the same subject; and in like manner Tulasse in 1864 and Kiihne in 1855 showed that certain specific affections in grains, the potato, etc., were due to the invasion of parasites. \ ery soon after this it was demonstrated that microorganisms were probably the cause of certain infections diseases in man and the higher animals. Bacteriological research has always been of special interest to physicians. Many of the most distinguished physicians of the day, in the earlier history of the science, concerned themselves in these investigations, and the progress made during the past fifteen](https://iiif.wellcomecollection.org/image/b28137541_0023.jp2/full/800%2C/0/default.jpg)
