Available online
Description
The programme looks at the impact of the microscope and other techniques which lead to the discovery of microbes and how the modern germ theory of disease grew out of careful investigation and acci...dental discoveries.
The programme looks at the impact of the microscope and other techniques which lead to the discovery of microbes and how the modern germ theory of disease grew out of careful investigation and acci...dental discoveries.
| Module code and title: | U202, Inquiry |
|---|---|
| Item code: | U202; 04 |
| First transmission date: | 22-04-1981 |
| Published: | 1981 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | Tony Jolly |
| Contributor: | Jennifer Trusted |
| Publisher: | BBC Open University |
| Keyword(s): | Anthrax; Bacteria; Germ theory; Leeuwenboek; Louis Pasteur; Microbes; Microscopes |
| Footage description: | The programme begins with shots of bacteria dividing (seen through a microscope). Jennifer Trusted describes what is being shown and then explains the objective of the programme which is to see how bacteria and microbes were discovered and how their connection with disease established. Jennifer describes a range of microscopes and magnifying glasses which have been used since the 17th century. These include Leeuwenhoek's glass bead, several 18th century instruments with various attachments for improving the lighting of the specimen. Powell and Zealand's microscope of 1862 and two modern instruments, Watson's from 1930 and the Wilde microscope of the 70s. She then shows two drawings, of the red mite and of a frog, which were made from using the early instruments. She now compares the images produced by l8th, 19th and 20th century microscope. First of all she looks at blood samples, then pond water and finally human sperm. Jennifer describes how scientists reacted to these findings and explains why it took 200 years before it was suggested that these animalculae might cause disease, she describes how the early work of Pasteur prompted Davaine to suggest that anthrax in sheep was caused by microbes. Shots of anthrax bacilli and red blood cells. There follows an extract from episode 3 of the BBC series Microbes and Men, "men of little faith" in which Pasteur is seen defending the work of Koch against criticism from medical colleagues. Koch is then shown explaining his ideas on bacilli to Rudolf Virchow, in 1878. Virchow dismisses them as an inadequate explanation of the cause of disease. Shots of a meeting at which a Dr. Chassaignac dismisses the idea that disease is caused by organisms. The commentary describes how chance was to provide Pasteur with practical results which would prove his theories. Shots of Pasteur and his assistants preparing cultures of a microbe that killed chickens. The story of how Pasteur and his assistants discovered a vaccine for this disease is then shown. The accidental injection of an old culture gave the chicken some immunity to the disease. Pasteur realised what had happened and repeated the chance occurrence in a controlled way in order to produce a vaccine - Jennifer Trusted describes Pasteur's reaction to his discovery and also justifies the responses of some of his opponents - The objections they raised were often reasonable. Germ theory had to develop before it could account for other factors related to the incidence of disease. The work of Koch, in distinguishing and identifying microbes, is described and illustrated. Shots of stained cells and microbes and the four main types of bacteria. Jennifer Trusted describes how Koch's work led to the acceptance of the germ theory and then describes how this has developed in the 20th century with the discovery of viruses. Shots of virus magnified over a million times. Jennifer describes how viruses reproduce by injecting DNA into a living cell forcing it to make viral DNA instead of its own. She describes current debate about the nature of viruses and argues that this indicates that germ theory, like all good theories, is still developing and stimulating more inquiry. |
| Master spool number: | 6HT/73470 |
| Production number: | FOUD117X |
| Videofinder number: | 1300 |
| Available to public: | no |
