Notes:

The History of the Microscope

Magnifying Glass, 13th C

• First used as a “burning glass”

• Began being used to improve vision in the early 13th century

Glass Lens, 1268

• Discovered by Roger Bacon in 1268

• Began use in eyeglasses between 1268 and 1289

Telescope, 16th C

• Invented by Hans Lippershay

• Improved by Galileo Galilei, who was the pioneer for modern astronomy

First Microscope, late 16th C

• Basically, this was a tube with a plate at one end and a lens at the other

• Magnified objects 10X

Improvements

• Zaccharias Jansseen, and his son Hans, added a second lens in 1597

Marcello Malphighi

• Studied human “physiology” (cells of the human body)

• Worked from 1653 until his death in 1694

Robert Hooke• First looked at cork under the

microscope; gave them the name “cells”

• Wrote the book Micrographia in 1665

• Considered the “English father of microscopy”

• Developed and used the compound microscope

Antoni van Leeuwenhoek

• Dutch maker of microscopes

• Also called the “father of microscopy”

• Was able to invent a microscope that magnified 270X

• Made over 500 microscopes

Microscopes of Today

• Compound microscope: creation of microscope stages and clips, slides, and objective lenses; smooth focus and magnification; uses 2 lenses

Electron Microscope

• Uses electrons to light up an image

• Electron gun emits electrons in a vacuum

• Electrons strike substance and image is recorded on a computer monitor

• Two Types-

Two Types of Electron Microscopes

1. Transmission Electron Microscope (TEM)- looks at large samples

2. Scanning electron microscope (SEM)- looks at thinly cut samples

Scanning Probe Microscope

• Uses a probe to scan the surface of a sample and provides a 3-D image

• Probe has a sharp metal point (single atom thick at the tip)

• Probe moves up and down over the surface of the object and feeds data into a computer, which provides the image