The Dream Doctor
6. The Detectaphone
Far after midnight though it had been when we had at last turned in at our apartment,
Kennedy was up even earlier than usual in the morning. I found him engrossed in work at
"Just in time to see whether I'm right in my guess about the illness of Brixton," he
remarked, scarcely looking up at me.
He had taken a flask with a rubber stopper. Through one hole in it was fitted a long
funnel; through another ran a glass tube, connecting with a large U-shaped drying-tube
filled with calcium chloride, which in turn connected with a long open tube with an up-
Into the flask Craig dropped some pure granulated zinc coated with platinum. Then he
covered it with dilute sulphuric acid through the funnel tube. "That forms hydrogen gas,"
he explained, "which passes through the drying-tube and the ignition-tube. Wait a
moment until all the air is expelled from the tubes."
He lighted a match and touched it to the open upturned end. The hydrogen, now escaping
freely, was ignited with a pale-blue flame.
Next, he took the little piece of wall-paper I had seen him tear off in the den, scraped off
some powder from it, dissolved it, and poured it into the funnel-tube.
Almost immediately the pale, bluish flame turned to bluish white, and white fumes were
formed. In the ignition-tube a sort of metallic deposit appeared. Quickly he made one test
after another. I sniffed. There was an unmistakable smell of garlic in the air.
"Arseniureted hydrogen," commented Craig. "This is the Marsh test for arsenic. That
wall-paper in Brixton's den has been loaded down with arsenic, probably Paris green or
Schweinfurth green, which is aceto-arsenite of copper. Every minute he is there he is
breathing arseniureted hydrogen. Some one has contrived to introduce free hydrogen into
the intake of his ventilator. That acts on the arsenic compounds in the wall-paper and
hangings and sets free the gas. I thought I knew the smell the moment I got a whiff of it.
Besides, I could tell by the jaundiced look of his face that he was being poisoned. His
liver was out of order, and arsenic seems to accumulate in the liver."
"Slowly poisoned by minute quantities of gas," I repeated in amazement. "Some one in
that Red Brotherhood is a diabolical genius. Think of it--poisoned wall-paper!"
It was still early in the forenoon when Kennedy excused himself, and leaving me to my
own devices disappeared on one of his excursions into the underworld of the foreign
settlements on the East Side. About the middle of the afternoon he reappeared. As far as I
could learn all that he had found out was that the famous, or rather infamous, Professor