1907.] Phenomena exhibited by Precipitin Antisera. 



471 



deposit was taken up into solution, but by far the greater portion was so 

 taken up, only a small trace being left in marked contrast to the original 

 deposit, and in marked contrast also to the full deposit which reappeared 

 when a precipitate was shaken up with any heated antiserum other than 

 that strictly homologous. It seems legitimate to draw the conclusion that 

 the capacity for dissolving precipitate is a specific property of inhibitory 

 antisera. 



This conclusion is reinforced by the results of testing the solubilities of 

 the precipitates obtained in " crossed " interactions, as indicated in Table II, 

 and by comparison of these results with the " crossed " inhibitions shown in 

 Table I. 



Table II. 



No. 



Homologous protein, 



Active antiserum, 



Precipitate 



after 

 24 hours. 



Heated anti- 

 serum, 0'1 c.c, 



Result 



0-005 c.c. 



0-1 c.c. 



added to 



to precipitate. 











precipitate. 











mm. 







1 



Hen-egg white 



Hen-egg 



2-0 



Hen-egg 



Dissolved 



2 



Ostrich-egg white 



Ostrich-egg 



3-0 



»j 



Unaffected 



3 



Horse serum 



Horse 



15 



s> 



j» 



4 



Hen-egg white 



Ostrich-egg 



0-5 



JJ 



Dissolved 



5 



Ostrich -egg white 



Hen-egg 



0-5 



„ 



}> 



6 



jj >j 



Ostrich-egg 



3-0 



Ostrich-egg 



?» 



7 



Hen-egg white 



Hen-egg 



2-0 



jj 



Unaffected 



8 



Horse serum 



Horse 



1-5 



}? 



}j 



9 



Ostrich -egg white 



Hen-egg 



0-5 



>j 



Dissolved 



10 



Hen-egg white 



Ostrich-egg 



0-5 



» 



5) 



These results suggest that the precipitum given by hen-egg antiserum 

 and ostrich or any egg albumin, other than hen-egg albumin, may be 

 regarded as similar to that produced by ostrich-egg antiserum and any egg 

 albumin other than ostrich-egg albumin. We may assume this precipitum 

 to result from the general avian character, or component, of the proteins 

 used in the immunisation, while the greatly increased precipitum produced 

 by hen-egg antiserum and hen-egg albumin, or by ostrich-egg antiserum 

 and ostrich-egg albumin, we may assume to be due to the specific hen or 

 ostrich character, or component, of the protein used for injection. A heated- 

 egg antiserum would thus inhibit and dissolve the general avian precipitum 

 plus its own strictly homologous precipitum, but would neither inhibit nor 

 dissolve the non-homologous component of any precipitum, however closely 

 related. This principle is probably of general application, and might be of 

 value in the practical differentiation of closely related proteins. 



The phenomena above described emphasise the close relationship that 



