Crying is a waste of perfectly good water. So why we do it? I have no idea, so I would like to hear your ideas. To get the ball rolling, here are eight hypotheses, each surely inadequate and probably false.

The Geneva Protocol was ratified the 17 June 1925, banned the use of biological weapons but Japan refused to approve the contract and the U.S. to ratify it.

Therefore in 1936 Shiro Ishii (1892 -1959) physician, microbiologist and general Japanese, guided the biological weapons program of the Empire of Japan, under the command of a military unit called Research Unit 731.