Satire is a technique used by writers to criticize/ridicule mankind and/or his institutions. Satire specifically uses humor in order to perform the ridicule and point out flaws or faults. The intention of satire is to point out the faults of something in order to bring about reform and improvement. "The Stolen Bacillus" is definitely a satire about science and scientists; however, the humor doesn't appear until the final third of the story. Before specifically discussing the satire, I will go through the story's use of tension and fear.
Tension, fear, and worry are all initiated in the very first sentence of the story.
“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 Bacteriologist is working with an incredibly dangerous bacteria. Wells could have had the scientist working with the bacteria that causes strep throat (or something similar). It's worrisome, but ultimately it isn't likely life threatening. Cholera, on the other hand, can be deadly within hours. I'd say that Wells does a nice job of establishing a high degree of tension by simply choosing the right bacteria.
The tense atmosphere is increased by the presence of an unknown visitor to the lab. It's one thing to have a trained scientist working with dangerous cultures. It's an entirely different matter to have a pale faced visitor get a "gleam of satisfaction" by being so close to dangerous biologicals.
The Bacteriologist watched the morbid pleasure in his visitor’s expression.
The unknown visitor just sounds like bad news because he's so excited by something so deadly.
The Bacteriologist notices his visitor's keen interest in the deadly test tubes, so the Bacteriologist takes the opportunity to really drive home the seriousness of the tube in his hand. He goes into an extended monologue that focuses on the death that would result if the tube were to break.
"Only break such a little tube as this into a supply of drinking-water, say to these minute particles of life that one must needs stain and examine with the highest powers of the microscope even to see, and that one can neither smell nor taste — say to them, 'Go forth, increase and multiply, and replenish the cisterns,' and death — mysterious, untraceable death, death swift and terrible, death full of pain and indignity — would be released upon this city, and go hither and thither seeking his victims."
Notice the repetition of the word "death." Holding something so dangerous in a fragile glass tube is ominous enough, but the repetition of the death that it will bring feels like repeated hammer blows to a reader. This scientist is casually holding something that all of mankind should fear. The mood is definitely tense at this point.
The fearful and tense atmosphere reaches a peak once the reader realizes that the unknown visitor has stolen a vial from the lab. We know exactly how deadly this bacteria could be. It's a city killer.
"Once start him [the bacterium] at the water supply, and before we could ring him in, and catch him again, he would have decimated the metropolis.”
It's at this point in the story that the text turns toward satire. The entire chase scene is just ridiculous. Cab drivers even pause to cheer on the silly "race."
“Go it, George!” “It’s a race!” “You’ll ketch ’em!” “Whip up!”
Wells does a wonderful job of portraying the Bacteriologist as an absent-minded professor. He runs out of his lab half dressed and completely unaware of that fact. He's also more troubled at the fact that he has to prepare more samples than he is at the fact that the anarchist could have actually gotten away with cholera. It's cute and funny to see the professor this way . . . until you think about the message. Real scientists in real life might have the very same attitude about their work. They are so involved with what they can do that they aren't thinking about what they should be doing and the security around it.