While double-lens microscopes appeared early in the 17th century, these microscopes could only magnify objects up to 20 to 30 times its size. As a result, the microscopic world as we know it today was largely unknown then. It was not until Anton van Leeuwenhoek created a single-lens hand-ground lens microscope that could amplify objects up to 200 times its size that blood cells, animal and plant tissues, bacteria, minerals, and other objects impossible to see at plain sight could be discovered, examined, and studied. In a chapter from his book Breakthroughs of Science, Isaac Asimov explores his life and contributions to science. I transcribed it in Centennial Gregg for the blog.
Attachment: anton-van-leeuwenhoek-he-discovered-an-invisible-world.pdf