Liquid electricity is a fictional liquid substance that often appeared in comedy short films of the silent film era. It is the "distilled essence of electricity" in liquid form, a (usually) glowing substance easily stored in bottles. It provides fantastic energy and super-speed when used as a fuel for automobiles, aircraft, and machines of all sorts. One variant of liquid electricity could be drunk by humans, who often did so for humorous effect in silent film comedies.
The use of "liquid electricity" as a comedic plot device was often used by filmmakers as a way to present "speeded-up motion" and demonstrate the use of this special effect in film. The motion picture industry was in its infancy in the early 20th century, and the use of slow motion and fast motion effects were a new novelty to movie-going audiences. In 1987's Spaceballs, a similar substance called "Liquid Schwartz" is used to power a spaceship in the same manner as liquid electricity. Comcast's commercials for its "high-speed Internet" service portrayed a similar substance (a mercury-like substance that could be rubbed onto machines, shoes, or even drunk) that was used, again, for a comedy punchline.
The use of liquid electricity is seen as an early form of science fiction in film, and a number of the early short films that used this substance (most of which have been lost) are classified as "science fiction" films.