Half an hour later he straightened up and examined the tube of the gas analysis apparatus with which he was working. The level of the gas showed it to be of the original volume but the liquid under the argon was stained a light brown.
"It's impossible, Davis," cried the doctor, "but nevertheless, it's true. Expose some of those crystals to strong sunlight and see what happens."
The crystals rapidly disappeared as the light from a sun-ray arc fell on them.
"It's true, Davis," cried the doctor, positive awe in his voice. "Keep this strictly under your hat for the present. Now that you know what we're up against, fix up a couple of masks and air-collecting apparatus. That stuff will show up again in the swamp to-night and I am going down there to collect some samples. I'll telephone the hospital now."
As Dr. Bird emerged from the dark room, Carnes hurried up with a worried expression.
"The devil's to pay, Doctor," was his greeting.
"All right, stall him off for a minute while I telephone the hospital. I think I can save some of those poor fellows up there."
Carnes paced the floor in anxiety while Dr. Bird got Captain Murdock on the telephone.
"Bird talking, Murdock," he said crisply. "How much deep therapy X-ray apparatus have you got up there?... Too bad.... Well, at least you can give every patient a four-minute dose of maximum intensity and repeat in an hour or so. Keep them under sun-ray arcs as much as you can. Be ready for a fresh attack of the same epidemic to-night. As fast as the patients come in, give them a five-minute dose of X-rays and then sun-rays. Do you understand?... All right, then."