  Three-body distribution functions in classical fluids have been theoretically
investigated many times, but have never been measured directly. We present
experimental three-point correlation functions that are computed from particle
configurations measured by means of video-microscopy in two types of
quasi-two-dimensional colloidal model fluids: a system of charged colloidal
particles and a system of paramagnetic colloids. In the first system the
particles interact via a Yukawa potential, in the second via a potential
$\Gamma/r^{3}$. We find for both systems very similar results: on increasing
the coupling between the particles one observes the gradual formation of a
crystal-like local order due to triplet correlations, even though the system is
still deep inside the fluid phase. These are mainly packing effects as is
evident from the close resemblance between the results for the two systems
having completely different pair-interaction potentials.
