  We experimentally determine the force exerted by a bath of active particles
onto a passive probe as a function of its distance to a wall and compare it to
the measured averaged density distribution of active particles around the
probe. Within the framework of an active stress, we demonstrate that both
quantities are - up to a factor - directly related to each other. Our results
are in excellent agreement with a minimal numerical model and confirm a general
and system-independent relationship between the microstructure of active
particles and transmitted forces.
