ght me an ill
turn, but because of the malignancy they had in their hearts."[225]

It is almost certain that this removal of Cardan from his office of
teacher was part and parcel of a carefully-devised plot against him, and a
prelude to more serious trouble in the near future. Early in April 1570 he
had occasion to put into writing a certain medical opinion which was to be
sent to Cardinal Morone. He describes the episode: "It chanced that one of
the sheets of my manuscript fell from the table down upon the floor, and
then flew by itself up to the cornice of the room, where it hung, fixed to
the woodwork. Greatly amazed, I called for Rodolfo, and pointed out to him
this marvel. He did not indeed see it fly up, and at that time I was
ignorant as to what it might foretell, for I had no foreboding of the many
ills which were about to molest me. But now I see that the meaning of this
portent must have been that, after the approaching shipwreck of my
fortunes, my bark would be sped along with a more favouring breeze. It was
during the month following, unless I am mistaken, that, when I was once
more writing a letter to Cardinal Morone, I looked for a certain
powder-box which had been missing for some long time, and, when I lifted
up a sheet of paper in order to powder it with dust gathered up from the
floor of the room, there was the powder-box, hidden beneath the sheet. How
could it have come there on the level writing-desk? This sign confirmed
the hope I had already conceived of the Cardinal's wisdom and humanity;
that he would plead with the Pope, the best of men, in such wise that I
should find a prosperous end to my toilsome life."[226]

The blow thus foreshadowed fell on October 6, 1570, when he was suddenly
arrested and put under restraint. He speaks of a bond which he gave for
eighteen hundred gold crowns; and says that, while he was in hold, all his
estate was administered by the civil authorities. Rodolfo Sylvestro was
constantly with him during his incarceration, and on January 1, 1571, he
was released, just at nightfall, and allowed to return to his own house.
While he was in prison in the month of October some mysterious knockings
at the door supplied him with a fulfilment and explanation of the
portents lately chronicled. The knockings appeared furthermore to warn him
of approaching death, and he began to bewail his misery; but, having
gathered courage, he heartened himself to face his doom, which could be
noth