ce, am subject to
the most unexpected attacks of neuritis. But, of course, I am under the
influence of the rays fifty or sixty times a day, while she had only a
few treatments at intervals of many days."

"Now, on the other hand," resumed Craig, "I know you, Gregory, very
well. Only the other day, before any of this came out, you told me the
whole story with your fears as to the outcome. I know that that lawyer
of Close's has been keeping this thing hanging over your head for a
long time. And I also know that you are one of the most careful X-ray
operators in the city. If this suit goes against you, one of the most
brilliant men of science in America will be ruined. Now, having said
this much, let me ask you to describe just exactly what treatments you
gave Mrs. Close."

The doctor led us into his X-ray room adjoining. A number of X-ray tubes
were neatly put away in a great glass case, and at one end of the room
was an operating-table with an X-ray apparatus suspended over it. A
glance at the room showed that Kennedy's praise was not exaggerated.

"How many treatments did you give Mrs. Close?" asked Kennedy.

"Not over a dozen, I should say;" replied Gregory. "I have a record of
them and the dates, which I will give you presently. Certainly they were
not numerous enough or frequent enough to have caused a dermatitis such
as she has. Besides, look here. I have an apparatus which, for safety
to the patient, has few equals in the country. This big lead-glass bowl,
which is placed over my X-ray tube when in use, cuts off the rays at
every point except exactly where they are needed."

He switched on the electric current, and the apparatus began to sputter.
The pungent odour of ozone from the electric discharge filled the room.
Through the lead-glass bowl I could see the X-ray tube inside suffused
with its peculiar, yellowish-green light, divided into two hemispheres
of different shades. That, I knew, was the cathode ray, not the X-ray,
for the X-ray itself, which streams outside the tube, is invisible to
the human eye. The doctor placed in our hands a couple of fluoroscopes,
an apparatus by which X-rays can be detected. It consists simply of a
closed box with an opening to which the eyes are placed. The opposite
end of the box is a piece of board coated with a salt such as
platino-barium cyanide. When the X-ray strikes this salt it makes it
glow, or fluoresce, and objects held between the X-ray tube and the
fluoroscope