The prescription was for a preparation of arsenic, which Matilde had formerly taken for some time.
The chemist would not make any difficulty about preparing twenty doses of it for the Countess Macomer, though the whole quantity of arsenic contained in so many would probably be sufficient to kill one not accustomed to the medicine, if taken all at once.
But though Matilde was so anxious to have the stuff before luncheon, she had a number of doses of it put away in a drawer, which she took out and counted, after Elettra had gone.

She opened one of the little folded papers and looked at the fine white powder it contained, took a little on the end of her finger and tasted it.

Then, from the same drawer, she took a package done up in coarser paper, and opened it likewise, looked at it, smelt it, and touched it with the tip of her tongue very cautiously indeed.

It was white, too, but coarser than the medicine.
She was very careful in tasting it, and she immediately rinsed her mouth with water, before she tied up the package again, shut the drawer, and put the key into her pocket.
By and by Elettra came back and brought her the jet and the medicine, returning her the change without any remark.

Matilde thanked her, and laid the package of twenty doses upon her dressing-table, before the mirror.
At luncheon, she persuaded Veronica to go out with her for a drive in the afternoon.