It's been done -- after my mother passed away I found a letter indicating that she had, on her father's advice, slipped me a minute quantity of phenobarbitol before my first TATL trip. This was in the days of prop planes, which refueled three times between Cleveland and Le Bourget. "Worked like a charm" was the verdict.

But indeed it would be considered child abuse today. For the record, my mother was a wonderful woman, but those were different times...