Early Days in Microscopy - MT2 Flashcards
Aristophanes
His play clouds uses a burning lens (convex and thus capable of magnification) as a lot device
Pliny
Physicians in Rome used burning lenses to create therapeutic burns
- a globe filled with water can magnify small objects
Alhazen
A transparent sphere can produce an enlarged image, but no practical use for this is suggested
- he also describes how the lens of the eye produces an image on the retina
What did Robert Grosseteste and Roger Bacon describe?
Telescopes
- Bacon describes eyeglasses, burning lenses and magnifiers
When was the compound microscope invented?
1590
Who invented the compound microscope? (3)
- Hans Janssen
- Zacharias Janssen
- Hans Lippershey
What 2 things does compound microscopes have?
- Higher magnification than 1 lens magnifiers
2. More aberrations
What do aberrations do?
They impair accurate viewing
What did people who didnt trust microscopes think they were? (2)
- Unnatural
2. Misleading
What was the large leap with microscopes?
Imagination to accept that you could see thing with a tool that could not be seen from a human eye
What did Robert Hooke do?
He set up a new microscope demonstration every week for the Royal Society’s meetings
Who was the Royal Society?
They were the first people to be interested in science
What did Marcell Malpighi of Bologna do?
Completed Harvey’s model of blood circulation was completed in structural terms
- he examined frog lungs and saw the capillary connections between arteries and veins
What did Malpighi observe?
The early stages of embryological development in chickens through his microscope
How does biological form develop? (2)
- Epigeneticists
2. Preformationists
Epigeneticists
Form developed from formlessness
- human egg/embryo was formless
Preformationists
Form didnt develop, form grew
- believed little people existed in sperm
What was Leeuwenhoek’s advantage to having a non-science background?
An independent mind
What was Leeuwenhoek’s disadvantage to having a non-science background?
- Lack of communication
2. Lack of training
How did Leeuwenhoek make his lenses? (4)
- Melted glass
- Pulled the filaments
- Broke it
- Cooled it
What did Leeuwenhoek discover?
Blood capillaries (independently but after Malpighi)
What did Leeuwenhoek find when he was trying to discover why pepper was hot?
After incubation of pepper in water he found motile bacteria and protozoa
What was Leeuwenhoek greatest achievement?
That motility meant life
Generative cells
A medical student drew Leeuwenhoek’s attention to tiny motile cells he had seen in semen of a patient with gonorrhea
- Leeuwenhoek opposed the idea animacules
Animacules
Tiny little sperm people
Spontaneous generation
Leeuwenhoek doubted that corn in storage could spontaneously produce corn weevils and he followed corn weevil life cycle from egg to egg to disprove it
What was Leeuwenhoek also interested in?
Lice
- he experimented on them by introducing them to his leg hair
What did microscopy languish until the 19th century?
Leeuwenhoek refused to train students with microscopy
How were compound microscopes fixed from aberrations?
They put a coating on the lenses in order to correct its viewing errors
