In most of the great scientific discoveries there has been one part deliberate research and one part luck. (Louis) Pasteur, a man of unusual firmness of purpose who sought the truth with a combination of pure reason and experiment, was sometimes helped by Chance. (p. 123)
Fleming put the Petri (it is capitalized in the quote) dish aside. He was to keep it as a precious treasure for the rest of his life. He showed it to one of his colleagues: ‘Take a look at that,’ he said, it’s interesting—the kind of thing I like: it may well turn out to be important. (p. 125)
An account of his discovery of nitrous air, its antiseptic qualities, &c. is given with his usual accuracy in the first volume.” Furthermore, it says, “Several new and valuable discoveries, the result of various, and some of them dangerous experiments, are detailed in the second volume. (p. 63)