The doctor's instructions were quite clear.

If any sign of excitement or mental unrest manifested itself, the sleeping-draught contained in a small bottle on the mantelpiece was to be administered at once, or the consequences would be fatal.

But Thomas Oscard refused to take it.

He seemed determined to kill himself.

The son stood over him and tried threats, persuasion, prayers; and all the while there was in his heart the knowledge that, unless his father could be made to sleep, the reputed three thousand a year would be his before the morning.
It was worse than the actual physical struggle on the floor.