The only way to test this thing was by doing it on humans.

"Perhaps the same process may work again, on other humans."

Since then the techniques had been used on other humans.

This movie shows the possibility of such a similar thing on humans.

If I have, it doesn't seem to work on humans.

If all goes well, trials of the technology on humans will begin soon.

They were able to start experiments on humans in 1941.

There seems to be no negative effects on humans or the environment.

You can hardly try them on humans, that the the of these, I mean.