Not a day passed on which Rosa did not come to have her chat with Cornelius.

The tulips, concerning whose cultivation Rosa was taught all the mysteries of the art, formed the principal topic of the conversation; but, interesting as the subject was, people cannot always talk about tulips.

They therefore began to chat also about other things, and the tulip-fancier found out to his great astonishment what a vast range of subjects a conversation may comprise.

Only Rosa had made it a habit to keep her pretty face invariably six inches distant from the grating, having perhaps become distrustful of herself.

There was one thing especially which gave Cornelius almost as much anxiety as his bulbs -- a subject to which he always returned -- the dependence of Rosa on her father.

Indeed, Van Baerle's happiness depended on the whim of this man. He might one day find Loewestein dull, or the air of the place unhealthy, or the gin bad, and leave the fortress, and take his daughter with him, when Cornelius and Rosa would again be separated.

"Of what use would the carrier pigeons then be?" said Cornelius to Rosa, "as you, my dear girl, would not be able to read what I should write to you, nor to write to me your thoughts in return."

"Well," answered Rosa, who in her heart was as much afraid of a separation as Cornelius himself, "we have one hour every evening, let us make good use of it."

"I don't think we make such a bad use of it as it is."

"Let us employ it even better," said Rosa, smiling. "Teach me to read and write. I shall make the best of your lessons, believe me; and, in this way, we shall never be separated any more, except by our own will."

"Oh, then, we have an eternity before us," said Cornelius.

Rosa smiled, and quietly shrugged her shoulders.

"Will you remain for ever in prison?" she said, "and after having granted you your life, will not his Highness also grant you your liberty? And will you not then recover your fortune, and be a rich man, and then, when you are driving in your own coach, riding your own horse, will you still look at poor Rosa, the daughter of a jailer, scarcely better than a hangman?"

Cornelius tried to contradict her, and certainly he would have done so with all his heart, and with all the sincerity of a soul full of love.

She, however, smilingly interrupted him, saying, "How is your tulip going on?"

To speak to Cornelius of his tulip was an expedient resorted to by her to make him forget everything, even Rosa herself.

"Very well, indeed," he said, "the coat is growing black, the sprouting has commenced, the veins of the bulb are swelling, in eight days hence, and perhaps sooner, we may distinguish the first buds of the leaves protruding. And yours Rosa?"

"Oh, I have done things on a large scale, and according to your directions."

"Now, let me hear, Rosa, what you have done," said Cornelius, with as tender an anxiety as he had lately shown to herself.

"Well," she said, smiling, for in her own heart she could not help studying this double love of the prisoner for herself and for the black tulip, "I have done things on a large scale; I have prepared a bed as you described it to me, on a clear spot, far from trees and walls, in a soil slightly mixed with sand, rather moist than dry without a fragment of stone or pebble."