This Vitagraph film from 1907 is a fairly good trick comedy for the era. A mad scientist figures out how to convert electricity to a liquid -- which reminds me of the Thurber story about his aunt who thought electricity was leaking from empty light sockets -- and he proceeds to spray it on slow moving people, whereupon they move like lightning. This simple gag is repeated four or five times.
The interesting point about this movie is that it shows signs of very careful cutting and possible back-screen projection, sometimes two or three layers of it, but done so carefully that it can only be inferred. The scientist sprays the electricity on a subject and the subject speeds up, but the scientist does not. The only way I could think of doing it was back-screen projection, but I'm not even sure it was invented at this time.