3Q 



Irst series: 0,5 serum nr. 1 (2nd 



bleed¡ng)-|-0,5 1/2 etc. serum nr. 1 of 

 lhe Irst bleeding: 0. 



2nd series: 0,5 serum nr. 1 (2nd 



bleeding)-f-0,5 1/2 etc. serum nr. 2 of 

 the 2nd bleeding: 0. 



3rd series: 0,5 serum nr. 2 (2nd 



bleeding)4-0,5 1/2 etc. serum nr. 1 of 

 the Irst bleeding: 1/16. 



4th series: 0,5 serum nr. 2 (2nd 



b]eeding)+0,5 1/2 etc. serum nr. 2 of 

 the Irst bleeding: 1/8. 



From these results one might draw 

 tlie following conclusions: 



On the 21rst day the precipitinogen 

 has not remained in circulation in the 

 rabbit in appreciable quantities when 

 one injects 15 cc. horse serum. 



When a vaccinated animal is bled 

 twice, with a regular space of time be- 

 tween, altho igh the precipitin titre should 

 pot have augmented, the serum of later 

 (iate acquires the property of demonstra- 

 ting tlie precipilinogen of the one 

 of the first bleedi ig. If, on the other 

 l:and, the amouut of blood taken at the 

 first bleeding is sufficiently large, the 

 senun of this animal not only shows a 

 very noticeable reduction in its titre, 

 Lut also does not acquirer the property 

 of precipitating the seriun of earlier da- 

 U': It appears, therefore, that in this ca- 

 se the bleeding not only removes 

 for the greater part the precipitins al- 

 ii'ady in circulation, but also the precipi- 

 linogen circulating in the blood; this 

 circulating precipitinogen must therefo- 

 I e be considered as being indispensable 

 for the formation of the precipitins which 

 precipitate the precipitinogen of the 

 First bleeding. Everything occurs, in the 

 process of vaccination, as if the diffe- 

 rent serum fractions were removed from 

 the circulation, as the antibodies which 

 precipitate them make their appearance 

 in the blood, antibodies these that sum 

 quantitatively up to the twenty first 

 4^iirst) day, or perhaps even later. 



One more fact might guide in this 

 study. It is known that many antibodies; 

 function, if not directly as precipitino- 

 gens, at any rate as substances very 

 nearly related to these bodies (KRAUS 

 and PRIBRAM). DEHNE and HAMBUR- 

 GER announced in 1904 that anti-horse 

 rabbit sera were able to produce a fall, 

 together with the precipitate, the teta- 

 nus antitoxin of horses actively immu- 

 nised against this toxin. 



That this reaction was absolutely 

 specific and was not to be accounted 

 for as a physical phenomenon was most 

 convincingly proved by the work; nof 

 only of these authors but oí KRAUS and 

 PRIBRAM and of V. EISLER andTSURU. 



■We began by ascertaining up to 

 what space of time tetanus toxin could 

 be found circulating in rabbits inocula- 

 ted with sufficient quantities, and the 

 results we obtained resemble those obtai- 

 ned by the authors who studied this 

 point (DENNE and HAMBURGER, TIZ- 

 ZONI etc.). 



Three rabbits of medium size were 

 inoculated at intervals of five days= with 

 3, 5, 7 cc. of antitetanus serum represen- 

 ting a total of 15.000 A. U. As we care- 

 fully ascertained, the rabbit senun 

 had previously shows itself indifferent 

 with regard to the antitoxin. 



13 days after the last inoculation 

 we had still two animals which were 

 bled and furnished serum for examina- 

 tion. 



Reaction of precipitins present) 



irst Guinea-pig— 1/2000 antiser.— 2 

 cc. physio!, salt sol.—Cont. dosis: Died of 

 tet. on 5th day. 



2nd Guinea-pig — 1/1000 antiser. — 2 

 cc. physio!, salt sol.— Conl. dosis; Survi- 

 ved. 



3rd Guinea-pig - 1/2000 antiser. ~ 3 

 cc. serum of rabbit sol. no 1.— Cont. do- 

 sis: Died tet. 8lh day. 



4tb Guinea-pig — 1/1000 antiser. — 1 



