Germs, dust and disease : two chapters in our life history / by Andrew Smart.

  • Smart, Andrew.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: Germs, dust and disease : two chapters in our life history / by Andrew Smart. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

    19/76 (page 3)
    THE GERM THEORY. man at the end of life ; but their direct eruptions are excessively fatal to men in the prime and vigour of age. These weighty words of the two greatest living authorities on this subject ought to be well pondered. Mr Simon reckons the deaths from these diseases at 120,000 in England and Wales alone. If we add those in Scotland and Ireland, from the same causes, the total mortality is over 150,000, every one of which is a needless death. Does this not strike you as a frightful waste of life 1 If we now compute that each one of these deaths represents, at a moderate estimate, thirty instances in which there is loss of health short of death, the aggregate of need- less death aud suffering becomes perfectly astounding, and affords a sufficiently cogent reason why zymotic diseases are specially singled out to be dealt with by stringent enactments having for their object their prevention, and ultimately total extinction. THE GERM THEORY OF INFECTIOUS DISEASES. How THEY Originate.—The term Zymotic is applied by those who believe that in these disorders there takes place a process which bears a strikins; resemblance to that of fermentation. This resemblance was first pointed out by Leibig. Thus, when yeast is added to a solution of sugar, the yeast cells rapidly mul- tiply by feeding on it—alcohol and carbonic acid being given off during the process. Yeast, I should tell you, is a rudi- mentary plant composed of cells, which, when placed in a suitable medium, actively multiply, living at the expense of the medium in which they exist, and ultimately changing its character. (See Diagram.) This is fermentation, as it occurs outside of living bodies, and is the starting-point of the idea that germs of different kinds—animal and vegetable—are the active agents in the production of zymotic diseases. That these germs do exist abundantly in the air, and elsewhere, has been proved by the experiments of many observers, and especially by Pasteur, a French physiologist. [Here describe and show Pasteur's experiments with air and liquids in sealed flasks.]