THE EFFECT OF HIGH PRESSURES ON HEMAGGLUTINATING ANTIBODIES.

It was found that exposure of hemagglutinating sera to pressures of the order of 3,000 to 4,000 atmospheres destroyed their agglutinating power, but did not convert them to inhibiting ("blocking") antibodies. Higher pressures (4,500 to 5,500 atmospheres) were required to destroy inhibiting anti-Rh(0) antibodies in a "blocking" serum. This conforms with ideas already held that the "blocking" antibodies are significantly more stable than the agglutinating antibodies.