The Stolen Bacillus and Other Incidents is a collection of fifteen fantasy and science fiction short stories written by the English author H. G. Wells between 1893 and 1895. It was first published by Methuen & Co. in 1895 and was Wells's first book of short stories. All of the stories had first been published in various weekly and monthly periodicals. (source: Wikipedia)
"This again," said the Bacteriologist, slipping a glass slide under the microscope, "is a preparation of the celebrated Bacillus of cholera—the cholera germ." The pale–faced man peered down the microscope. He was evidently not accustomed to that kind of thing, and held a limp white hand over his disengaged eye. "I see very little," he said. "Touch this screw," said the Bacteriologist; "perhaps the microscope is out of focus for you. Eyes vary so much. Just the fraction of a turn this way or that."