"What is this thing?" asked Aux Cayes, as Collette drew back, and he caught her by the arm.
For the moment Kennedy said nothing, but opened a carefully sealed door and slid the pallet out, unhinging it, while I saw Castine trembling and actually turning ashen about the lips.
"This," Kennedy replied at length, "is what is known as a respiration calorimeter, which I have had constructed after the ideas of Professors Atwater and Benedict of Wesleyan, with some improvements of my own. It is used, as you may know, in studying food values, both by the government and by other investigators. A man could live in that room for ten or twelve days. My idea, however, was to make use of it for other things than that for which it was intended."
He took a few steps over to the complicated apparatus which had so mystified me, now at rest, as he turned a switch on opening the carefully sealed door.
"It is what is known as a closed circuit calorimeter," he went on. "For instance, through this tube air leaves the chamber. Here is a blower. At this point, the water in the air is absorbed by sulphuric acid. Next the carbon dioxide is absorbed by soda lime. Here a little oxygen is introduced to keep the composition normal and at this point the air is returned to the chamber."
He traced the circuit as he spoke, then paused and remarked, "Thus, you see, it is possible to measure the carbon dioxide and the other respiration products. As for heat, the walls are constructed so that the gain or loss of heat in the chamber is prevented. Heat cannot escape in any other way than that provided for carrying it off and measuring it. Any heat is collected by this stream of water which keeps the temperature constant and in that way we can measure any energy that is given off. The walls are of concentric shells of copper and zinc with two of wood, between which is 'dead air,' an effective heat insulator. In other words," he concluded, "it is like a huge thermos bottle."
It was all very weird and fascinating. But what he could have been doing with a dead body, I could not imagine. Was there some subtle, unknown poison which had hitherto baffled science, but which now he was about to reveal to us?
He seemed to be in no hurry to overcome the psychological effect his words had on his auditors, for as he picked up and glanced at a number of sheets of figures, he went on: "In the case of live persons, there is a food aperture here, a little window with air locks arranged for the passage of food and drink. That large window through which you looked admits light. There is also a telephone. Everything is arranged so that all that enters, no matter how minute, is weighed and measured. The same is true of all that leaves. Nothing is too small to take into account."
