The Mystery of the Fifteen Sounds

by Van Powell

  Chapter 23 THE ACID TEST

  "Oh, no you don't," Grover spoke for the first time during theinterview, "there is a matter of a vanished scientific student of thestars, 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 besurprised--yes, there they are."

  The police car, sent by the Chief of Police, brought two patrolmen andas a frightened clerk ushered them in, the lama shrugged.

  Captor became prisoner, and with his pair of native aides, the lama wastaken to the laboratory by the interested officers.

  There, as Grover's car discharged its crowd of former captives, Rogerwas able to reward the taximan who had faithfully read his signal andwho was waiting with a patrolman to be assured that all was well therebefore going to the address the taximan had noted.

  "I knew this joint was lucky," the taximan chuckled, pocketing apleasing 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 whichhad been set off during the exciting developments, Roger was busyassembling the ingredients for an experiment which Grover meant toconduct, in order to learn which of the people there had held the pistolthat might have harmed old Astrovox--that had certainly been fired inthe office.

  To their surprise as they brought together the necessary chemicals andRoger got out plaster-of-Paris from his stock-room, with highly refinedparaffin, the star electrician, Ellison, arrived.

  "What brings you here at five in the morning?" Grover stared at him witha degree of suspicion.

  "I have been working out theories about our queer situation," declaredthe electrical specialist, "I could not sleep, because Clark had told meall about his experiences with Roger in Tibet, and I was of the opinionthat Roger might be in danger."

  "I told him how they had captured you," Clark said, as Roger recalledthat they had worked together in India on power-construction, so thatthere was nothing to fix suspicion on them in thus having a reunionafter Clark's return.

  "I went to your home," he told Grover. "Roger's room was open, his auntwas 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 somepolice departments have tried, and it will interest you."

  Roger assembled on the interviewing desk his heater for a great lot ofthe wax, held in a crucible over the electric stove. In a large glasscontainer he mixed, according to a formula dictated by Grover, nitricacid and other chemicals, which discretion suggests should not bementioned 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 thesimplest way to narrow down investigation. Once we know our culprit, hemust reveal where Astrovox is, what happened."

  The very modern experiment, the police saw, was based on the fact thatthe 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 ourtest is made within five days after such an occurrence, the test willreveal it.

  "I will be first. Roger will take the wax, properly softened, and at atemperature around one hundred and fifteen degrees, Fahrenheit, not hotenough 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 holdits shape, is taken off."

  This, also, Roger carried out carefully, securing a sort of cast withthe 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 thepeculiar gases of powder combustion on it, within the past five days,the acid and solution will bring up the stains as bluish discolorationson the wax."

  No such spots appeared.

  Although a tedious operation to carry out for the Tibetan trio, andthen, by their own insistence, for Doctor Ryder, Clark, Tip and Roger,the results in each case held them in suspense until there was clearexoneration of all.

  "But Ellison hasn't submitted yet," said Tip, suddenly.

  "Because I have handled chemicals in my work that may come out in thereaction," Ellison frowned.

  Nevertheless, though he declared that his work had brought out thestains that showed as small blue spots and smears within his mould,everybody felt that he ought to know what he declared he did not--wherewas the star-scientist?