and left.

"Seemed in a hurry," Rick commented.

The druggist nodded. "Seemed so. He usually stops to pass the time of
day. Had a terrible time yesterday with an infected hangnail. They can
be pretty painful. I tried to sell him a new analgesic ointment, but he
insisted on methyl chloride. He had an old refillable prescription from
some doctor over in Arlington. Said he got it because infected hangnails
bother him all the time. Lucky I had some. It used to be used all the
time for pain from superficial wounds, but it went out of style. He
bought a whole pint. Enough to last for fifty hangnails. Told him he
didn't need it, but he insisted."

Rick said thoughtfully, "His hands seemed to be all right today. No
bandages."

"All he had was a plastic-tape bandage around his thumb yesterday,
anyway. Guess the infection must have cleared up."

"What's methyl chloride?" Rick asked.

"A highly volatile chemical. It's not a painkiller in the usual sense,
like aspirin. You spray it on the area that hurts, and it evaporates in
seconds. You know what that does."

Rick did! And suddenly last night's events were perfectly, transparently
clear.

"Evaporation cools the surface," Rick said for Scotty's benefit. "The
faster the evaporation, the faster the cooling. This methyl chloride
must act pretty fast."

"It does," the druggist agreed. "That's how it kills pain, partly. It
chills the outer layer of skin almost instantly."

CHAPTER XV

The Missing Facts

Dr. Miller's conversation with Jethro Collins was something less than
satisfactory. He told the boys about it on the way home.

"I told him bluntly that I was suspicious about his offer because the
property he wants to buy has little value as farm land and contains no
timber or anything else of commercial value. I told him I wouldn't
consider an offer until I knew what the land was to be used for."

The scientist chuckled. "That was my way of putting him on a spot, of
course. But he refused to be cornered. He replied that his customer
wanted the land for reasons of his own, which it was not Collins' place
to divulge. He assured me the land would not be used for commercial
purposes, so my own property would be quite safe.

"I replied that I needed more assurances than his word, and demanded to
know the identity of his client. I pointed out that the name would
become known during the process of settlement anyway, unless his client
proposed to use a dummy of so