Cities in Flight by James Blish Read Free Book Online Page A

isoniazid viomycin, and so on, right up to Bloch's isolation of the TB toxins and the development of the metabolic blocking agents.
    "Then came the broad-spectrum antibiotics, like tarramycin, which attacked some virus diseases, protozoan diseases, even worm diseases; that gave us a huge clue to a whole set of tough problems. The last major infectious disease-bilharzia, or schistosomiasis-was reduced to the status of a nuisance by 1966."
    "But we still have infectious diseases," Paige objected. "Of course we do," the girl said, the little atomic points in her brooch picking up the candle-light as she leaned forward. "No drug ever wipes out a disease, because it's impossible to kill all the dangerous organisms in the world just by treating the patients they invade. But you can reduce the danger. In the 1950's, for instance, malaria was the world's greatest killer. Now it's as rare as diphtheria. We still, have both diseases with us-but how long has it been since you heard of a case of either?"
    "You're asking the wrong man-germ diseases aren't common on space vessels. We bump any crewman who shows up with as much as a head-cold. But you win the point, all the same. Go on. What happened then?"
    "Something kind of ominous. Life insurance companies, and other people who kept records, began to be alarmed at the way the degenerative diseases were coming to the fore. Those are such ailments as hardening of the arteries, coronary heart disease, embolisms, and almost all the many forms of cancer-diseases where one or another body mechanism suddenly goes haywire, without any visible cause."
    "Isn't old age the cause?"
    "No," the girl said forcefully. "Old age is just the age; it's not a thing in itself, it's just the time of life when most degenerative diseases strike. Some of them prefer children-leukemia or cancer of the bone marrow, for instance. When the actuaries first began to notice that the degenerative diseases were on the rise, they thought that it was just a sort of side-effect of the decline of the infectious diseases. They thought that cancer was increasing because more people were living long enough to come down with it. Also, the reporting of the degenerative diseases was improving, and so part of the rise in incidence really was an illusion-it just meant that more cases than before were being detected.
    "But that wasn't all there was to it. Lung cancer and stomach cancer in particular continued to creep up the statistical tables, far beyond the point which could have been accounted for by better reporting, or by the increase in the average life-span, either. Then the same thing took place in malignant hypertension, in Parkinsonism and other failures of the central nervous system, in muscular dystrophy, and so on, and so on. It began to look very much as though we'd exchanged a devil we knew for a devil we didn't.
    "So there was quite a long search for a possible infectious origin for each of the degenerative diseases. Because some animal tumors, like poultry sarcoma, are caused by viruses, a lot of people set to work hunting like mad for all kinds of cancer viruses. There was a concerted attempt to implicate a group called the pleuropneumonia-like organisms as the cause of the arthritic diseases. The vascular diseases, like hypertension and thrombosis, got blamed on everything from your diet to your grandmother.
    "And it all came to very little. Oh, we did find that some viruses did cause some types of cancer, leukemia among them. The PPLO group does cause a type of arthritis, too, but only the type associated with a venereal disease called essential urethritis. And we found that the commonest of the three types of lung cancer was being caused by the radio-potassium content of tobacco smoke; it was the lip and mouth cancers that were caused by the tars. But for the most part, we found out just what we had known before-that the degenerative diseases weren't infectious. We'd already been down that dead end.
    "About there