I then told him all my mishaps in Sorombo, as well as of the "blue-devil" frights that had seized all my men.
blue devil n.
A blue capsule or tablet containing barbiturate amobarbital or its sodium derivative.
A feeling of depression; despondency.
A capsule of Amytal2, a type of barbiturate
[1950s+ Narcotics; perhaps fr a 1920s popular song ''My Blue Heaven'']