«let not Vanity ſeduce you to perſiſt in your Miſtake» No, it's not a spelling mistake that you see here. It's the long ſ, which was used in print well into the 18th century. And also the capitalization of nouns, unusual today, was common in 1743 when Henry Baker's treatise The Microscope Made Easy was published in London, UK. Aside from such formal trivia, the title-giving sentence is by no means moral advice, but rather a practical technical tip on the correct use of microscopes by scientists. The introduction to Chap. XV is well worth reading from the beginning (see facsimile below). Once you get into the somewhat dusty language you will appreciate the straightforward lineup of essentials for observing by the scientific method.
I will not let vanity ſeduce me to paraphrase Henry Baker (1698–1774), so, enjoy the original! He was a naturalist in the age of enlightenment, and a technically skilled and inventive microscopist in the tradition of Robert Hooke (1635–1703), who was the first to observe plant "cells" in his microscope. Well, it was actually Antonie van Leeuwenhoek (1632–1723) who first saw and described microbial cells, which he called "Animalcules". But for documentation, all these early microscopists could only draw what they saw at the then available resolution, and describe that best they could only with terms taken from the vocabulary of the macroscopic world (Henry Baker was good in drawing, see his drawing of reproducing polyps on the frontpage). Photography was not available to microscopists until the end of the 19th century (see here an early photograph of Shigella), and the first meaningful electron microscopy pictures of bacteria were published in the 1950s (see here an early EM portrait of Bacillus megaterium). Today, we have confocal laser scanning microscopy, several technical approaches to super-resolution microscopy, atomic force microscopy, and cryo-electron-tomography to not only look at cells but into cells. All these techniques work with digital image acquisition, and with the capability of reconstructing 3D images. Some things have not changed though. The problems early microscopists had with gaining acceptance of the hand-drawings of their microscopic objects are mirrored by the difficulties today's microscopists face with having their software-driven image reconstructions accepted by colleagues.
So, you might feel left with the impression that it's mainly the resolution that has changed over the last 2.5 centuries – coming close to 'atomic resolution' now. No, the most remarkable advancement in microscopy came with the possibility to record time-lapse series or even real-time videos of living cells under the microscope. Just look at V. cholerae using its pilus to 'harpoon' DNA for uptake! Wow!