Henry Slade and Johann Zollner

The first time that the idea of the 4th dimension began to circulate in the mind of the public was in 1877. 

Henry Slade, was a "psychic" who claimed to be able to summon spirits from the 4th dimension. He was arrested for fraud. However, many eminent physicists came to his defense, one of them being: Johann Zollner, who among others, proposed that Slade's feats were possible if one could manipulate objects in the 4th dimension. Zollner's defense of Slade was made public all throughout 19th century London and drove much controversy. 

In fact, Zollner's proposal was tested in 1877, that objects could be sent through the 4th dimension. Slade's skills as a medium were tested by Zollner in some controlled conditions. Of course today, we know that this kind of feat would require a miracle, or technology that supersedes our current capabilities. Most of the attempts were failed, however, Slade was able to fool Zollner in some...

At any rate, it is fascinating that the next dimension to be discovered was not one of space, as Zollner expected, however, one of time, as in Einstein's theories of relativity. This would not be known for several decades.