ion, the lungs of these men are free from pneumonicocci. On the
other hand there is a peculiar aspect of the tissues as though a very
powerful antiseptic solution had been applied to them."

"Hardly an antiseptic, Doctor; wouldn't you say, rather, a cauterizing
agent."

Dr. Bird bent again over the ultra-microscope.

"Are you familiar with the work done by Bancroft and Richter at
Cornell University last November and December?" he asked.

"No, I can't say that I am."

"They were working under a Heckscher Foundation grant studying just
how antiseptic solutions destroy bacteria. It has always been held
that some chemical change went on, but this theory they disproved. It
is a process of absorption. If enough of the chemical adheres to the
living bacterium, the living protoplasm thickens and irreversibly
coagulates. It resembles a boiling without heat. I have seen some of
their slides and the appearance is exactly what I see in this tissue."

Captain Murdock bent over the microscope with a new respect for Dr.
Bird in his face.

"I agree with you, Doctor," he said. "This tissue certainly looks as
though it had been boiled. It is certainly coagulated, as I can
plainly see now that you point it out to me. You believe, then, that
it is a simple case of gassing?"

"If so, it was done by no known gas. I have studied at Edgewood
Arsenal, and I am familiar with all of the work done by the Chemical
Warfare Service in gases. No known gas will produce exactly this
appearance. It is something new. Carnes, have those horses been
brought up yet?"

"I'll see, Doctor."

"If they are, bring one here."

* * * * *

In a few moments the body of a dead horse was dragged into the
operating room and Dr. Bird attacked it with a rib saw. He soon laid
the lungs open and dragged them from the body. He cut down the middle
of one of the organs and shaved off a thin slice which he placed under
the lens of a powerful binocular microscope.

"Hello, what the dickens is this?" he exclaimed.

With a scalpel and a delicate pair of tweezers he carefully separated
from the lung tissue a tiny speck of crystalline substance which
glittered under the red light in the operating room. He carefully
transferred it to a glass slide and put it under a microscope with a
higher magnification.

"Rhombohedral regular," he mused as he examined it. "Colorless,
friable, and cleaving in irregular planes. What in thunder can it