Wien's method of impact excitation by employing a form of spark gap which quenches the primary discharge instantly and excites the free oscillations in the antenna by impact or shock.
Besides investigating other phenomena connected with a vacuum, he constructed an electrical machine which depended on the excitation of a rotating ball of sulphur; and he made successful researches in astronomy, predicting the periodicity of the return of comets.
The movements obtained by point-to-point excitation of the cortex are often evidently imperfect as compared with natural movements - that is, are only portions of complete normal movements.
If these spark balls are set at the right distance, then when the potential difference accumulates the antenna will be charged and at some stage suddenly discharged by the discharge leaping across the spark gap. This was Marconi's original method, and the plan is still used under the name of the direct method of excitation or the plain antenna.
In the marsupials it is more evident, and its excitation by electric currents evokes movements in the musculature of the crossed side of the body.
In this adjustment the lowest stage is taken by 'reflex action and instinct, where Spencer the change of the organs is purely automatic. As the external complexity increases, this automatic regularity fails; there is only an incipient excitation of the nerves.
According to Father Patrick Morrisroe, dean and professor of liturgy at Maynooth, the efficacy of benedictions is fourfold: (1) the excitation of pious emotions and affections of the heart, and by their means the remission of venial sins and of the temporal punishments due for these; (2) freedom from the power of evil spirits; (3) preservation and restoration of bodily health; (4) various other benefits, temporal and spiritual.
It is reasonable, therefore, to conclude that ornament is a stimulus to sexual selection, and this conclusion is enforced by the fact that among many comparatively nude peoples clothing is assumed at certain dances which have as their confessed object the excitation of the passions of the opposite sex.
Of the response of the nerve, it is found that unmistakable signs of fatigue appear even very soon after commencement of the excitation of the nerve, and the muscle ceases to give any contraction in response to stimuli applied indirectly to it through its nerve.
The muscular wall of the blood-vessels also exhibits tonic contraction, which, however, seems to be mainly traceable to a continual excitation of the muscle cells by nervous influence conveyed to them along their nerves, and originating in the great vaso motor centre in the bulb.