We consider the question of whether observers in the 17th century left historical records on the monitoring of the plasma tails of comets, which would allow us to judge the physical parameters of the solar wind. The magnitude of the deviation angle of the comet tail from the prolonged radius-vector of a comet defines the type of the comet tail: plasma or dust. We consider Bessel's and Bredikhin's calculations of trajectories of 10 comets during the Maunder minimum (1645-1715). For these comets the value of the angle between the tail axis and the prolonged radius-vector on the average exceeds 10 degrees that is typical of dust tails. Also note that visual observations of the ion tails of comets are very difficult due to the spectral composition of their radiation. This confirms our conclusion that the comet tails observed in the 17th century are not suitable for discussion about the physical parameters of the solar wind in the past.