Medicine: One Number for All Types

On an average day, New York City patients get a thousand blood transfusions, but even the biggest hospitals cannot hope to have all types on hand all the time. So now the New York Blood Center has set up the world's biggest computerized inventory for human blood, which will be available to all.

When a hospital needs blood of a certain type, a phone call to a single number will get the request checked against an inventory to show the nearest supply. The charge for locating the blood is $3 (nothing for the blood itself); for delivery in radio-equipped cars, $4....