“I must obey you, madame, for I also was left for dead.  Who carried me away from the middle of the corpses with which that room was filled?—­You.  Who cured me of my wounds?—­You.  Who concealed me?—­You always.  Order, then, and I will obey, provided that you do not order me to leave you.”

“So be it, Remy; you are right; nothing ought to separate us more.”

Remy pointed to the portrait.

“Now, madame,” said he, “he was killed by treason—­it is by treason that he must be revenged.  Ah! you do not know one thing—­the hand of God is with us, for to-night I have found the secret of the ‘Aqua tofana,’ that poison of the Medicis and of Rene the Florentine.”

“Really?”

“Come and see, madame.”

“But where is Grandchamp?”

“The poor old man has come sixty leagues on horseback; he is tired out, and has fallen asleep on my bed.”

“Come, then,” said Diana; and she followed Remy.

CHAPTER LX.

The laboratory.

Remy led the lady into a neighboring room; and pushing a spring which was hidden under a board in the floor, and which, opening, disclosed a straight dark staircase, gave his hand to Diana to help her to descend.  Twenty steps of this staircase, or rather ladder, led into a dark and circular cave, whose only furniture was a stove with an immense hearth, a square table, two rush chairs, and a quantity of phials and iron boxes.  In the stove a dying fire still gleamed, while a thick black smoke escaped through a pipe fastened into the wall.  From a still placed on the hearth a few drops of a liquid, yellow as gold, was dropping into a thick white phial.  Diana looked round her without astonishment or terror; the ordinary feelings of life seemed to be unknown to her who lived only in the tomb.  Remy lighted a lamp, and then approached a well hollowed out in the cave, attached a bucket to a long cord, let it down into the well, and then drew it up full of a water as cold as ice and as clear as crystal.

“Approach, madame,” said he.

Diana drew near.  In the bucket he let fall a single drop of the liquid contained in the phial, and the entire mass of the water became instantaneously yellow; then the color evaporated, and the water in ten minutes became as clear as before.

Remy looked at her.

“Well?” said she.

“Well, madame,” said he, “now dip in that water, which has neither smell nor color, a glove or a handkerchief; soak it in scented soap, pour some of it into the basin where you are about to wash your hands or face, and you will see, as was seen at the court of Charles IX., the flower kill by its perfume, the glove poison by its contact, the soap kill by its introduction into the pores of the skin.  Pour a single drop of this pure oil on the wick of a lamp or candle, and for an hour the candle or lamp will exhale death, and burn at the same time like any other.”