  The anomalous propagation of longitudinal ultrasound with the frequencies of
70 and 150 MHz in the high pure Gallium single crystal at the weak external
magnetic field (the magnetic field H perpendicular to the wave vector k) at the
low temperature of 0.4 K was researched experimentally. The delayed ultrasonic
signal, comparing to the main ultrasonic signal, is detected. The research on
the new magneto-acoustic effects made it possible to find the temperature
dependence of the frequency of collisions between the electrons and the thermal
phonons in the high pure Gallium single crystal. It is found that the anomalous
oscillations of propagation velocity of ultrasonic signal pulses and the
signals, propagating by the way of the electron transport in the high pure type
I superconductor, can be detected at the directions of the magnetic field H
close to the magnetic field H parallel to the wave vector k.
