Mithridate

The drug was administered in a drink of water given at the start of each day's exercise.
Twenty-five minutes later, the first effects of the drug became apparent: the men began to relax, and to giggle.
This man was more seriously affected, and had to be removed from the exercise.
After 35 minutes, one of the radio operators had become incapable of using his set, and the efficiency of the rocket-launcher team was also very impaired.
Ten minutes later, the attacking section had lost all sense of urgency: notice the bunching and indecision as they enter the wood occupied by the enemies.
Almost immediately, the section commander tried to use a map to find the location of troop headquarters, as the prisoner's escort had to have the way pointed out, though it was in plain sight 700 yards away over open country.
Fifty minutes after taking the drug, radio communication had become difficult, if not impossible, but the men are still capable of sustained physical effort.
However constructive action was still attempted by those retaining a sense of responsibility, despite the physical symptoms.
But one hour and ten minutes after taking the drug, with one man climbing a tree to meet the birds, the troop commander gave up, admitting that he could no longer control himself, or his men.
He himself then relapsed into laughter.