The development of a theory:
Cancer is caused by absence in the human body of a serum which dissolves centres of infection. Therefore, extract this serum from animals and inject into humans.
But it is found necessary to repeat this treatment every few weeks, with the result that the patient's natural resistance is weakened.
It is then discovered that the serum which naturally prevents cancer is produced in a small gland in the neck, and that this gland becomes decreasingly active until, at 50, it often ceases to function. Therefore, stimulate this gland. But the...