The TTL output stage is a rather complicated pushâpull circuit known as a totem-pole output (the transistors, diode, and resistor in the right-most slice of this TTL logic gate circuit). It sinks currents better than it sources current.
The theory for spontaneous generation refers to the idea that life can produced from nonliving things. Lazzaro Spallanzani proposed in his experiement that air was necessary for spontaneous generation.
This accident seemed also to support the second objection, and Spallanzani did not answer it. The Fundamentals of Bacteriology Charles Bradfield Morrey From Spallanzani to Schultze, there were no further experiments to prove or disprove spontaneous generation. The Fundamentals of Bacteriology Charles Bradfield Morrey In the dispute, however, with which we are concerned Needham and Spallanzani defended opposite positions. Science and Morals and Other Essays Bertram Coghill Alan Windle Spallanzani knew nothing of these organisms; they were not discovered until many years after his death.