THE SURFACE OF ViRtlSES 143 



Fraction Remaining in Top Compartment 

 (From Lauffer and Miller, 19 44-) 



Boundary measurement Hemagglutination Infeetivity Nitrogen content 



100 

 45 

 35 

 34 

 25 

 15 

 



The effect of exposure to temperature on hemagglutination 

 was measured by Lauffer and Carnelly (1945). They found that 

 the inactivation follows a form such that, at any one tempera- 

 ture, the reciprocal of the square root of the agglutinating ac- 

 tivity is proportional to time. This corresponds to a reaction of 

 the three-halves order, which is hard to interpret literally. 

 Lauffer and Carnelly point out that there is probably some 

 kinetic process complication, as, for example, multiple sensitiv- 

 ity of agglutination receptors. In any event, it is possible to 

 characterize hemagglutination in this way even though it is 

 somewhat empirical. 



Using this basis of measurement, Lauffer and Scott (1946) 

 measured the rate constants at various temperatures and con- 

 cluded that, for the loss of hem agglutination, the value of 

 AH^, the energy of activation, is 110,000. The entropy of ac- 

 tivation cannot be calculated, as the reaction is not of simple 

 order. This value for AH^ is considerably higher than the energy 

 of activation for infeetivity loss, which is 34,000 calories. This 

 fits rather well with the behavior of serological affinity with 

 regard to thermal action, and fits a protein figure rather than 

 nucleoprotein inactivation kinetics. 



Studies of Newcastle disease hemagglutination have been 

 made by Woese (1953). The rates of loss of hemagglutinating 

 ability in both the wet and dry state were studied. In the wet 

 state, first-order kinetics were obeyed to a reasonable approxi- 

 mation. In the dry state, two reaction constants were clearly 



