'I don't knowl' Hansen said, and his face was white with fear. Don was sorry he had asked. The man was doing his assigned job well enough, but he could not cope with the bigger problem.
'Then don't worry about it, well come up with something'
Easy words to say - but what could they do? Where could they get more oxygen in the depths of interplanetary space? Think! He cudgelled his tired brain but the results were a complete blank. Yet he had the gnawing feeling that the answer was right before his eyes.
The only thing before his eyes were the tiny plants in their watery environment. They were doing their best, he knew that, yet the answer was there. But where...?
Don laughed out loud.
'The answer was right in front of our eyes!' he said and clapped the astonished air tender on the back. 'Look in here - what do you see?'
'Why... the plankton, sir.'
'Anything else?'
'No, nothing. Just them in the water
'What was that last word?'
'Water.'
'And what is water made of?'
Sudden comprehension brightened Hansen's face. 'Hydrogen... and oxygen!'
'Absolutely correct. And we have all the power we need from the atomic generator. By feeding electricity into water, the two elements will be separated by the process of electrolysis...'
'We bleed the hydrogen off into space - and use the oxygen. But, Captain, we need the water too. The plankton are still necessary.'
'I wasn't thinking of depriving them. But I'm looking forward to more complaints from the passengers! All the ship's water is recycled - but we have far more than we need for survival. We'll determine the minimum amount needed and leave that much. The rest can be converted to oxygen. They may be dirty and a little thirsty - but at least they will be breathing!'
'What will we need for equipment?'
Don, feeling the drag of fatigue again, sat down wearily before he answered. He ticked off the points on his fingers.
'A container first, something like a bathtub. There's nothing complex about the reaction, and the container doesn't have to be sealed. We need direct current. A heavy cable from the generator will take care of that. Then we must have a weak solution of electrolyte to conduct the current. A simple salt or base dissolved in water.'
'Table salt?'
'That's what we don't want! That is sodium chloride - which means we will be getting some chlorine mixed in with our oxygen and we positively do not need a poison gas like that. We need an alkaline salt. Do you have anything like that among your plant nutrients?'
Hansen pulled out his supply list and ran down it. 'Will this do?' he asked. 'Magnesium is essential for the production of chlorophyll, so we have a store of magnesium sulphate...'
'Epsom salts! Couldn't be better. The only complication will be making some sort of container and piping for the cathode, the negative electrode in the solution. That's where the hydrogen will form. We'll draw that off and release it into space. The oxygen from the anode can just bubble off into the air.' He made a quick sketch of the details and passed it over to the air tender.
'This should work fine, sir,' Hansen said. 'We can use that glass-lined settling tank there for a vessel. I'll clean it out and mix a weak solution of electrolyte. But I'm not sure about the wiring, or pumping out the oxygen.'
'I'll get you some help. Chief Kurikka will know how to rig it, and if he doesn't he'll know who in the ship's crew will be able to do the job. Get him down here.'
Kurikka brought Sparks, then called in Acting-Chief Engineer Tyblewski. The cables from the now vanished frozen food lockers were located under the decks and torn out to bring in the necessary amount of current. While this was being done a glass dome, formerly a viewport in the observatory, was put over the cathode, and piping hooked from it to a valve that connected with the vacuum outside the ship. This could be adjusted so that the hydrogen was drawn off, but not the watery electrolyte.
'Ready,' Sparks announced finally.
'Well let her go,' Don said, so weary he could hardly sit up.
Kurikka threw the heavy-duty switch and Tyblewski slowly turned the handle on the rheostat. As current was fed to the electrode immersed in the bath, tiny bubbles began to form about it. Then, more and more, as the current was increased, large bubbles rose up and broke on the surface. Don leaned over and breathed deeply.
'Wonderful!' he said, as the pure oxygen cleared his head. 'It looks like our problems are over once and for all.'
He blinked, happily, in the oxygen-rich atmosphere so close above the tub, and was only vaguely aware of a phone ringing, and the handpiece being passed over to him.
'Speaking,' he said, then looked down to see the tiny image of Rama Kusum on the screen.
'Would you come to the sick bay sir. There are four more cases of fever, just like the first. And the first one, I do not know what to do about him. He is in a coma and his pulse is very slow and I cannot awaken him!'
Don had dismissed Rama, told him to get some sleep, because he wanted to be alone with this problem. The four new cases of fever were in the larger ward, but the first case, Preece, was in the isolation room. Don stood by his bed, listening to the man's heavy, slow breathing and looking at the battery of recording instruments that had been hooked up to the patients body. The situation was clear -but what did it mean?
Pulse, slow but steady. Heart, apparently normal. Temperature, 102 degrees and rising steadily despite the doses of antipyretics that were supposed to bring it down. The antibiotics, also, had apparently had no effect. What was the cause? A little earlier he had been priding himself that he could take care of any medical emergency that might arise. He wasn't doing too well with this one. And he was tired...
Stifling a yawn, he went out into his office and carefully washed his hands and arms, then put them into the ultrasonic sterilizer. Rama had left a thermos of hot coffee and he poured himself a cup. While he sipped at it he tried to fit the facts into a meaningful pattern.
What were the facts - other than that he had five patients hospitalized with a fever of unknown origin? The only specific symptom that Preece, the one with the most advanced case, presented was a peculiar twitching of his face and jaw. Very much like Colliver's symptom, though not as regular or strong. But this was not Colliver's symptom, which occurred only in the paralytic stage of poliomyelitis. There were no other polio symptoms and it could not possibly be that disease. Then what was it?
Like a dog worrying at an old bone, he kept returning to the thought that it was a disease that he had never heard of before. Which was certainly impossible. Diseases mutated or changed, or were very rare. But there were no new diseases. This must be one of the rare ones. He could waste days going through his library, so he had to narrow down the field a bit. Preece was his only lead. As the first victim there was a good chance that he was also the carrier. Don pulled the phone to him and dialled the pursers office.
'Joriquet, I need some information about a passenger.'
'What do you require, sir, my records are quite near?'
I have a passenger here named Preece. I want to know where he comes from, and where he went before he boarded this ship. Any information at all that you have on him.'
'One moment, sir. Will you hold on - or should I ring you back?'
'I'll be in my office, in the sick bay that is.'
He hung up as Rama Kusum came in with a covered tray. 'I had dinner, Captain, and the thought occurred to me that perhaps you had not dined lately. So I took the liberty...'
Don concentrated, but could not remember the last time he had eaten. But he was almost too tired to be hungry now.
'Thanks, but I doubt if I could eat. I saw some of those reconstituted dehydrated meals and I'm sure that they are nutritious. But they looked too much like damp sawdust. Not right now -'