  A quasi-periodicity has been identified in the strange emission shifts in
pulsar B1859+07 and possibly B0919+06. These events, first investigated by
Rankin, Rodriguez & Wright in 2006, originally appeared disordered or random,
but further mapping as well as Fourier analysis has revealed that they occur on
a fairly regular basis of approximately 150 rotation periods in B1859+07 and
perhaps some 700 in B0919+06. The events-which we now refer to as
"swooshes"-are not the result of any known type of mode-changing, but rather we
find that they are a uniquely different effect, produced by some mechanism
other than any known pulse-modulation phenomenon. Given that we have yet to
find another explanation for the swooshes, we have appealed to a last resort
for periodicities in astrophysics: orbital dynamics in a binary system. Such
putative "companions" would then have semi-major axes comparable to the light
cylinder radius for both pulsars. However, in order to resist tidal disruption
their densities must be at least some 10$^5$ grams/cm$^3$-therefore white-dwarf
cores or something even denser might be indicated.
