s been very well described by Gray
who says that the French authors had their attention directed to the
subject by the descriptions of two American authors--those of Beard
upon "The Jumpers of Maine," published in 1880, and that of Hammond
upon "Miryachit," a similar disease of the far Orient. Beard found that
the jumpers of Maine did unhesitatingly whatever they were told to do.
Thus, one who was sitting in a chair was told to throw a knife that he
had in his hand, and he obeyed so quickly that the weapon stuck in a
house opposite; at the same time he repeated the command given him,
with a cry of alarm not unlike that of hysteria or epilepsy. When he
was suddenly clapped upon the shoulder he threw away his pipe, which he
had been filling with tobacco. The first parts of Virgil's aeneid and
Homer's Iliad were recited to one of these illiterate jumpers, and he
repeated the words as they came to him in a sharp voice, at the same
time jumping or throwing whatever he had in his hand, or raising his
shoulder, or making some other violent motion. It is related by
O'Brien, an Irishman serving on an English naval vessel, that an
elderly and respectable Malay woman, with whom he was conversing in an
entirely unsuspecting manner, suddenly began to undress herself, and
showed a most ominous and determined intention of stripping herself
completely, and all because a by-standing friend had suddenly taken off
his coat; at the same time she manifested the most violent anger at
what she deemed this outrage to her sex, calling the astonished friend
an abandoned hog, and begging O'Brien to kill him. O'Brien,
furthermore, tells of a cook who was carrying his child in his arms
over the bridge of a river, while at the same time a sailor carried a
log of wood in like manner; the sailor threw his log of wood on an
awning, amusing himself by causing it to roll over the cloth, and
finally letting it fall to the bridge; the cook repeated every motion
with his little boy, and killed him on the spot. This miryachit was
observed in Malaysia, Bengal, among the Sikhs and the Nubians, and in
Siberia, whilst Beard has observed it in Michigan as well as in Maine.
Crichton speaks of a leaping ague in Angusshire, Scotland.

Gray has seen only one case of acute palmus, and records it as follows:
"It was in a boy of six, whose heredity, so far as I could ascertain
from the statements of his mother, was not neurotic. He had had trouble
some six months before