On the relation of precipitins to 

 precipitinogen 



by 



DR. J. COSTA CRU:^ 



The concomitant existence of preci- 

 pitins and precipitinogen circulating in 

 the blood of animals, vaccinated with sera 

 of distant species, is a fact which was 

 mentioned a long time ago and which 

 immediately attracted the attention of 

 nimierous authors, on account of it's ap- 

 parently conlractory signification. 



LINOSSIER and LEMOINE seem to 

 have been the firsts to verify this 

 phenomenon. EISENBERG studied it in 

 detail and tried to e.xpiain it as a sta- 

 te of chemical equilibrium following the 

 laws of mass action. 



VON DUNGERN, in 1V)04, demons- 

 trated by numerous experiments that the 

 reaction lay outside the dominion of that 

 law. A careful analysis of the phenome- 

 non led him to believe that in the anti- 

 genic sera there existed not one but 

 many precipitinogens which called into 

 existence, in the immunised animals, not 

 one but various precipitins, endowed 

 each one, with affinity for ils corres- 

 ponding antigen alone, so that tiie si- 



multaneous presence in the blood stream 

 of antigen and antibody, without preci- 

 pitalioïî could be readily understood. 



On the other hand the numerous 

 authors who occupied thenselves with de- 

 monstrating the specificity of precipi- 

 tins for certain proteins disagree con- 

 siderably in the results obtained 



LEBLANC, for instance, obtained, by 

 immunising rabbits with beef-serum al- 

 bumin (protein) and bullock serum pseu- 

 do-globulin, precipitins which would on- 

 ly precipitate with the antigens emplo- 

 yed in immunisation. OBERMAYER and 

 PICK, ROSTOSKL UMBER, LANDSTEI- 

 NER and CALVO believe, on the contra- 

 ry, that no such specificity is ascertai- 

 nable. In their experiments, OBER- 

 MAYER and PICK employed as antigen 

 different substances extracted from 

 white of egg: foin- chemically distinct 

 globulins, one crystallising and one im- 

 crystallising albumin. LANDSTEINER 

 and CAJ-.VO immunised animals with dit 

 fereiit fractious of horse-serum obtained 



