542 A CONTRIBUTION TO THE STUDY OP THE PRECIPITINS, 



dried egg-white. After 48 hours the superfluids were removed 



and a quantity of dried egg-white dissolved in saline solution 



added to each superfluid. No further precipitate formed in tube 



1, but precipitates formed in IIB, 12B, and 13B. Here again 



there is fair agreement in the amount from each 1 c.c. antiserum. 



When the amount of protein is insufficient to neutralise all 



the precipitin in a given quantity of antiserum, the amount of 



precipitate is diminished. An experiment showing the relation 



of the precipitate to the amounts of the interacting bodies may be 



now described. A rabbit was immunised by the injection of 



9-6 gm. dried egg-white in eight doses. The antiserum was 



employed fresh. A solution of egg-white was used for the 



homologous protein and the solid content determined by drying 



a fixed quantity. The quantities employed and the results are 



I'ecorded in Table xii. 



Table xii. 



It will be seen that the amount of antiserum was 3 c.c. in each 

 tube. This quantity yields only a small precipitate in the tubes 

 1 and 2, so that great stress cannot be placed on these figures. 

 The weights of the precipitates have been set in the graph 

 appended(fig. 1). The curve tends to be of a regular form. 

 The amount of antiserum obtained from a rabbit is not usually 

 more than 20 c.c, so that extended series cannot be carried out 

 with antisera from rabbits. It was not considered legitimate to 

 employ mixed antisera. Another series gave a graph of similar 

 form. At present the data are too few to discuss these results at 

 length, in order to determine the type of the interaction. 



