"Leave all that to me," his companion answered confidently; and taking the bust, he carefully unscrewed its malachite base, revealing a cavity wherein rested a small square receptacle, oblong and deep, something of the shape of a large-sized snuff-box. It was secured in its place by two springs, which, when released, allowed the box to fall out. Taking it up and opening it, he said to his companion-- "Here you are. Fill it up, while I arrange the tube." Then, while the Doctor carefully filled the box with some greyish-white powder from a tiny green glass bottle on the table, Nenci took up a tube of thin glass about an inch long, one of the two or three which Malvano had just filled with acid and hermetically sealed by the aid of his spirit-lamp and blow-pipe. This he carefully inserted in the opening, afterwards replacing the closed box of grey compound, securing it deeply in its place by the two little steel springs. Again he placed it upon the table, and, retreating a few steps, stood admiring it. "The reproductions are all absolutely perfect," he observed. "We've only now to prove that our calculations are correct. Come, let's go. If anybody meets us, they'll think you've been called out to some urgent case. Therefore we're safe enough." "Very well," the Doctor agreed; and both put on their coats and went out, Nenci with the bust covered carefully beneath the long ulster he assumed in the hall. Noiselessly they let themselves out by the servants' entrance, crossed the large paved yard to the stables, and, finding a spade, the Doctor hid it beneath his overcoat. Then, crossing the lawn, they passed through a gap in the boundary fence, and was soon skirting a high hedge-row, proceeding towards the open country, crossing field after field until about twenty minutes later they paused at a lonely spot. The place where they halted was so dark that they could scarcely see one another, but the mossy, marshy ground was soft beneath their feet; therefore the Doctor, knowing the country well, suggested that this was the spot where the experiment should take place. His companion at once acquiesced, and the Doctor, speaking in a low undertone, drove his spade deep into the earth, and worked away digging a hole, although he could scarce see anything in that pitch darkness. Presently Nenci, placing the bust upon the ground, boldly struck a match, and by its fickle light ascertained the depth of the hole. Malvano was still working away, fearful lest they should be discovered, the perspiration dropping from his brow in great beads.