Compressed Air Illness, or So-Called Caisson Disease

was to inflate the tunnel, as you would blow up a bladder, by corking up one end with a huge brick wall twelve feet thick and pumping in additional atmospheres. At the sea level the pressure of the atmosphere is well known to be about fifteen pounds per square inch ; but into this air-tight chamber the engineers pumped sometimes as much as an additional thirtyfive pounds to the square inch, so that the workers were supporting about half a hundredweight of air-pressure on every inch of their bodies. Dr. Snell has well utilised the almost unique opportunity of observing the nature of the strange illnesses to which men are liable when working under such abnormal conditions, and this volume gives us by far the most advanced monograph which has yet appeared on the subject. After an outline of the history of working in compressed air, the author gives a series of fifty cases, selected from a list of