"What a pity you were not here earlier," said Villebois, turning to Duval, "Delapine has been entertaining us with some experiments on feeding insectivorous plants in the conservatory, and began by showing us how remarkably susceptible they are to the faintest traces of certain drugs. By the way, professor, now that we are all here quietly, will you give us an exhibition of your thought-reading powers?"
"Certainly, my dear Villebois, with all the pleasure in the world," said Delapine; "but it is a pity that our amiable friend, Pierre, should have missed the experiments in the conservatory. Would you mind if we all went back there as I should like very much to let him see the effect of this coffee on one of the plants."
So saying he took up the cup, which had been filled for him, and moved towards the hothouse followed by his three companions. Edging up alongside Delapine, Pierre, with almost murderous thoughts surging in his breast, watched for an opportunity either to snatch, or even to risk all and dash the tell-tale cup from his rival's hand. Appearing, however, not to notice the agitated manner of the man walking so close to him, Delapine adroitly handed the cup to Riche while bending over to whisper something in his ear. Then turning towards Duval he quietly linked arms with him in the most natural and friendly manner in the world, without any apparent pressure, but at the same time so skilfully that it would have been very difficult for Pierre to have freed himself without arousing suspicion.
"My dear Duval," said Delapine, affectionately pressing the arm resting against his own, "you will be delighted with what I am going to show you, it's a most surprising experiment."
Once more in the conservatory, Riche at a sign from Delapine handed him a spoonful of the coffee, and Delapine gently let a few drops of the liquid fall on the tentacles of the Drosera.
As Delapine had previously remarked, the effect was surprising, but in a totally different manner from what he had meant at the time. Immediately the drops touched them the tentacles turned over and lost their colour, while the glands changed from a rich purple to a sickly pink.
"This is very strange, I cannot for the moment understand it," said Delapine. "Whoever would have thought that the coffee would have had such an effect?" Then after a minute of deep reflection he turned to Villebois—"Doctor, would you mind getting me a fresh cup of coffee, this result is so extraordinary that I must repeat the experiment."
So saying, Delapine calmly took the cup from Riche, and poured the remaining contents into an empty bottle, corked it, and then calmly put it in his pocket.
It was all done so quietly and naturally that Duval, although beside himself with suppressed rage, dared not put out a hand to prevent it, fearing to awaken the suspicions of the others.
Villebois, impressed with the calmness and with the queer look of determination and severity in Delapine's eyes, ran back to the summer-house, and brought a fresh cup of coffee.