THE ACID TEST
"Oh, no you don't," Grover spoke for the first time during the
interview, "there is a matter of a vanished scientific student of the
stars, a shot prior to his disappearance, and other things."
The lama turned toward his aides.
Grover, as Roger and Potts sidled close, smiled.
"An hour and ten minutes has elapsed since I arrived," he remarked,
pleasantly, cool and slightly triumphant, "I would not be
surprised--yes, there they are."
The police car, sent by the Chief of Police, brought two patrolmen and
as a frightened clerk ushered them in, the lama shrugged.
Captor became prisoner, and with his pair of native aides, the lama was
taken to the laboratory by the interested officers.
There, as Grover's car discharged its crowd of former captives, Roger
was able to reward the taximan who had faithfully read his signal and
who was waiting with a patrolman to be assured that all was well there
before going to the address the taximan had noted.
"I knew this joint was lucky," the taximan chuckled, pocketing a
pleasing tip, "Hope all stays well--but if it doesn't--I'll be handy."
While Tip was sent to develop camera films from various devices which
had been set off during the exciting developments, Roger was busy
assembling the ingredients for an experiment which Grover meant to
conduct, in order to learn which of the people there had held the pistol
that might have harmed old Astrovox--that had certainly been fired in
the office.
To their surprise as they brought together the necessary chemicals and
Roger got out plaster-of-Paris from his stock-room, with highly refined
paraffin, the star electrician, Ellison, arrived.
"What brings you here at five in the morning?" Grover stared at him with
a degree of suspicion.
"I have been working out theories about our queer situation," declared
the electrical specialist, "I could not sleep, because Clark had told me
all about his experiences with Roger in Tibet, and I was of the opinion
that Roger might be in danger."
"I told him how they had captured you," Clark said, as Roger recalled
that they had worked together in India on power-construction, so that
there was nothing to fix suspicion on them in thus having a reunion
after Clark's return.
"I went to your home," he told Grover. "Roger's room was open, his aunt
was greatly disturbed because you were also absent."
Naturally, he had come to the laboratory.
While he softened the paraffin, Roger told him their adventures.
"Now," Grover told the absorbed patrolmen, and a detective who had come,
by Police Chief's order, from Headquarters, "here is a dodge that some
police departments have tried, and it will interest you."
Roger assembled on the interviewing desk his heater for a great lot of
the wax, held in a crucible over the electric stove. In a large glass
container he mixed, according to a formula dictated by Grover, nitric
acid and other chemicals, which discretion suggests should not be
mentioned here.
"The purpose of this experiment," Grover said, "is to learn which hand,
if any among us, held, and discharged the weapon. That seems to be the
simplest way to narrow down investigation. Once we know our culprit, he
must reveal where Astrovox is, what happened."
The very modern experiment, the police saw, was based on the fact that
the charges used in modern pistol projectiles form, during combustion,
gases which leave marks on any hand discharging the bullet.
Grover explained his procedure.
"The gases blow back sufficiently to mark the hand," he stated. "If our
test is made within five days after such an occurrence, the test will
reveal it.
"I will be first. Roger will take the wax, properly softened, and at a
temperature around one hundred and fifteen degrees, Fahrenheit, not hot
enough to scald, will pour it over and will mould it around my hand."
Roger carried out the action as it was described.
"The paraffin, now cooling, at a point where it is hard enough to hold
its shape, is taken off."
This, also, Roger carried out carefully, securing a sort of cast with
the shape of the hand moulded inside it.
This, as Grover talked, Roger carefully placed in the chemical solution,
and they all watched in absorbed attentiveness.
"If my hand has discharged any weapon or in any other way has gotten the
peculiar gases of powder combustion on it, within the past five days,
the acid and solution will bring up the stains as bluish discolorations
on the wax."
No such spots appeared.
Although a tedious operation to carry out for the Tibetan trio, and
then, by their own insistence, for Doctor Ryder, Clark, Tip and Roger,
the results in each case held them in suspense until there was clear
exoneration of all.
"But Ellison hasn't submitted yet," said Tip, suddenly.
"Because I have handled chemicals in my work that may come out in the
reaction," Ellison frowned.
Nevertheless, though he declared that his work had brought out the
stains that showed as small blue spots and smears within his mould,
everybody felt that he ought to know what he declared he did not--where
was the star-scientist?