The Early Days of Microscopy Flashcards
The early mention of the lens:
Aristophanes Play Clouds (424 BC) used what?
used a burning lens (convex, and thus capable of magnification)as a plot device
What did Pliny ( 1st century AD) use a lens for?
physicians in Roam used burning lenses to create therapeutic burns; a globe filled with water can magnify small objects
Alhazen noticed what about lenses in AD 962-1038?
a transparent sphere can produce an enlarged image, but no practical use for this is suggested; he also described how the lens of the eye produces an image on the retina
Robert Grosseteste and Roger Bacon described what?
described what appears to be a telescope; and Bacon describes eyeglasses, burning lenses and magnifiers
When was the compound microscope invented?
1590 by Han Lippershey and Zacharias Janssen
Galileo is known to have built his own compound microscope in 1609
Compound microscopes have what compared to one lens magnifiers?
two lenses and higher magnification than one-lens magnifiers BUT they have more aberrations, which impairs accute viewing
When microscopes first came around what was the public opinion of them?
not everyone trusted the observations of microscopy, which were thought to be unnatural and misleading and in some cases they were correct with that assumption cause fuck I cant ever figure out the ones in the bio lab these days imagine how bad they were
What was the first drawing of a magnified biological object? who made the observation and in what year?
a BEE was observed by Francisco Stelluti in 1630
Who was Robert Hooke?
Curator of the royal society in london
What did Robert Hooke do?
set up a new microscope demonstration every week for the society’s meetings. He gathered his observations in his book “Micrographia” in which he discribed the elements of a magnified cork “CELL”
Who completed in structural terms the model of blood circulation of W. Harvey?
Marcello Malpighi of Bologna who examined frog lungs, and saw the capillary connections between arteries and veins
What else beside frog lungs did Malpighi look at under the microscope?
he observed the early stages of embryological development in chickens
What is the view of an epigeneticist
thought that form arose from formlessness
What is the view of a Preformationists?
thought that because form was growth, form arose from pre existing form
What did Leeuwenhoek do ?
He was a cloth merchant and amateur scientist
Hoe did Leeuwenhok get into microscopes?
he used them to examine different fabrics
What did Leeuwenhoek microscopes look like/ how did he acquire them?
he made his own single lens microscopes.
The one lens meant that they had few aberrations but still allowed him to magnify thing 100-200x which is pretty damn impressive if you ask me
How did van Leeuwenhoek record his scientific findings?
he sent letters (400) to the royal society of england
What were some of leeuwenhoek’s results? (4)
Blood circulation - he discovered blood capillaries independently of Malpighi after him
Microorganisms- wishing to find out why pepper tastes hot, he incubated pepper in water and then looked through his microscope ( he expected to see small needles) could you imagine how scare that would be to see little things swimming around?
Generative cells- a medical student drew his attention to tiny motile cells he had seen in semen of a patient with gonorrhoea
Spontaneous generation disproval - he doubted that corn in storage could spontaneously produce corn weevils, and he followed the corn weevil like cycle from egg to egg to disprove this
What happened to microscopy after the 17th century?
after a promising start it kinda fell off the map until the 19th century when there was an improvement in lenses with fewer aberrations and clearer viewing
