"Using a brightfield microscope, he would use a micropipette to take an individual specimen and watch it at low magnification with no cover slip. At this point, he could gather information about the organism's shape and movement, and then he would apply the cover slip, elevating it with little dots of vaseline underneath the corners to keep from crushing the ciliate. With a needle, he then very gently pushed down the edges until the coverslip was applying just enough pressure to render the organism immobile, but not so much that the slide would squish it to death. The process is delicate, and it takes time to master, but it works."
Journey to the Microcosmos- The Schoolteacher Who Discovered 700 Ciliates
Images Originally Captured by Jam's Germs