We all know the tale about the frog in the pot of water. If the water is boiling, it will leap out at once. If the water is cold, and gradually heated, the frog will stay in the pot and – eventually – die.
However, is the story true?
As part of advancing science, several experiments observing the reaction of frogs to slowly heated water took place in the 19th century. In 1869, while doing experiments searching for the location of the soul, German physiologist Friedrich Goltz demonstrated that a frog that has had its brain removed will remain in slowly heated water, but an intact frog attempted to escape the water when it reached 25 °C.
Other experiments showed that frogs did not attempt to escape gradually heated water. An 1872 experiment by Heinzmann demonstrated that a normal frog would not attempt to escape if the water was heated slowly enough, which was corroborated in 1875 by Fratscher.
Goltz raised the temperature of the water from 17.5 °C to 56 °C in about ten minutes, or 3.8 °C per minute, in his experiment which prompted normal frogs to attempt to escape, whereas Heinzmann heated the frogs over the course of 90 minutes from about 21 °C to 37.5 °C, a rate of less than 0.2 °C per minute. In “On the Variation of Reflex Excitability in the Frog induced by changes of Temperature” (1882) William Thompson Sedgwick writes: “in one experiment by Scripture the temperature was raised at a rate of 0.002°C per second, and the frog was found dead at the end of 2½ hours without having moved.”
In 1888 Sedgwick explained the apparent contradiction between the results of these experiments as a consequence of different heating rates used in the experiments: “The truth appears to be that if the heating be sufficiently gradual, no reflex movements will be produced even in the normal frog; if it be more rapid, yet take place at such a rate as to be fairly called ‘gradual’, it will not secure the response of the normal frog under any circumstances”.
Modern sources tend to dispute that the phenomenon is real. In 1995, Professor Douglas Melton, of the Harvard University Biology department, said, “If you put a frog in boiling water, it won’t jump out. It will die. If you put it in cold water, it will jump before it gets hot—they don’t sit still for you.” Dr. George R. Zug, curator of reptiles and amphibians at the National Museum of Natural History, also rejected the suggestion, saying that “If a frog had a means of getting out, it certainly would get out.”
In 2002 Dr. Victor H. Hutchison, Professor Emeritus of Zoology at the University of Oklahoma, with a research interest in thermal relations of amphibians, said that “The legend is entirely incorrect!”. He described how the critical thermal maximum for many frog species has been determined by contemporary research experiments: as the water is heated by about 2 °F, or 1.1 °C, per minute, the frog becomes increasingly active as it tries to escape, and eventually jumps out if the container allows it.
Notwithstanding its probable status as a myth, it’s a nice (in the strict sense) metaphor for what’s happening to the Federal coalition.
I wonder what the response would be if we asked them how the water was?
Meanwhile, I’ve reached the end of the first week of semester with the big second year course that I’m responsible for seemingly under control, while my first lecture in another subject was okay.
It’s wonderful to have the prospect of a couple of days of peace and quiet, though Melbourne is in for its longest spell of warm to hot weather for a couple of months. At least the forecast doesn’t have any appallingly hot days, so we should survive.
Jukebox time, I think . . .
I love Noni Hazlehurst, so I can’t resist adding this one: