she became his wife, would lend colour to his story that she had
gone off with a former lover, taking with her the money which Derues
had paid her for Buisson-Souef. He would then produce the necessary
documents proving the payment of the purchase-money, and Buisson-Souef
would be his for good and all.

The prime necessity to the success of this plan was the disappearance,
willing or unwilling, of Mme. de Lamotte and her son. The former had
settled down quite comfortably beneath the hospitable roof of the
Derues, and under the soothing influence of her host showed little
vigour in pressing him for the money due to herself and her husband. She
had already spent a month in quietly enjoying Paris and the society of
her friends when, towards the end of January, 1770, her health and that
of her son began to fail. Mme. de Lamotte was seized with sickness and
internal trouble. Though Derues wrote to her husband that his wife was
well and their business was on the point of conclusion, by the 30th of
January Mme. de Lamotte had taken to her bed, nursed and physicked by
the ready Derues. On the 31st the servant at the Rue Beaubourg was
told that she could go to her home at Montrouge, whither Derues had
previously sent his two children. Mme. Derues, who was in an interesting
condition, was sent out for an hour by her husband to do some shopping.
Derues was alone with his patient.

In the evening a friend, one Bertin, came to dine with Derues. Bertin
was a short, hustling, credulous, breathless gentleman, always in a
hurry, with a great belief in the abilities of M. Derues. He found the
little man in excellent spirits. Bertin asked if he could see Mme. de
Lamotte. Mme. Derues said that that was impossible, but that her husband
had given her some medicine which was working splendidly. The young de
Lamotte called to see his mother. Derues took him into her room; in the
dim light the boy saw her sleeping, and crept out quietly for fear of
disturbing her. The Derues and their friends sat down to dinner. Derues
kept jumping up and running into the sick room, from which a horrible
smell began to pervade the house. But Derues was radiant at the success
of his medicine. "Was there ever such a nurse as I am?" he exclaimed.
Bertin remarked that he thought it was a woman's and not a man's place
to nurse a lady under such distressing circumstances. Derues protested
that it was an occupation he had always liked. Next day, February 1, the
serva