  Since the temperature of a typical Schwarzschild black hole is very low, some
doubts are raised about whether the fluctuations of the black hole can be
treated thermodynamically. It is shown that this is not the case: the
thermodynamic fluctuations of a black hole are considerably larger than the
corresponding quantum fluctuations. Moreover the ratio of the mean square
thermodynamic fluctuation to the corresponding quantum fluctuation can be
interpreted as a number of the effective constituents of a black hole.
