"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."