430 STATE BOARD OF AGRICULTURE. 



niaximum reaction at 1-500. In another case after an injection of 

 4.50 cc. of bouillon cultures 15 to 20 hours old mixed with 915 cc. nor- 

 mal pig blood an agglutination reaction was secured at a maximum 

 of 1-25,000. In this case we probably introduced approximately 225 

 billions of living B. cholerae suis or about 7,500 times as many as in- 

 jected into any of the seven cases, (in Tables IV to XXIII) that re- 

 acted at 1-50,000. 



It is our belief that the number of B. cholerae suis increases greatly 

 locally in the tissues of the injected pig, thus furnishing the agglutin- 

 ogen in great amount. This belief is strengthened by the almost 

 constant presence of the so-called B. cholerae suis abscesses in serum 

 hogs treated intramuscularly. 



AGGLUTINATION REACTIONS WITH MIXED SERA. 



The term "mixed serum" in this paper is applied to a mixture of 

 all the bleedings from one serum hog. Table XXIII shows the agglutina- 

 tion reactions with 51 samples of mixed sera. These tests were made 

 at a variable length of time after drawing the blood and mixing it. 

 Table XXIV shows retests with 25 of these samples and with a mix- 

 ture of several others (m. s. 56). 



Excepting the mixed sera and the four samples in Table IV, all the 

 tests have been made with fresh serum separated from the corpuscles 

 in defibrinated blood, without the addition of a preservative. All the 

 samples in Tables XXIII and XXIV were defibrinated blood preserved 

 in .5 per cent, phenol (10 cc. 5 per cent, phenol to 90 cc. defibrinated 

 blood) except mixed serum 54a which was preseiwed by the addition 

 of .5 cc. trikresol to 99.5 cc. defibrinated blood. The mixed sera were 

 kept in cold storage at 6°-15° O. 



Table XXIII shows that out of 51 mixed sera tested, 



3 or 5.88 per cent did not agglutinate at 1 — 400. 

 3 or 5.88 per cent agglutinated at 1 — 400. 



3 or 5.88 per cent agglutinated at 1 — 800. 



2 or 3.92 per cent agglutinated at 1—1,000. 



10 or 19.60 per cent agglutinated at 1—2,000. 



12 or 23.52 per cent agglutinated at 1—4,000. 



1 or 1.96 i>er cent agglutinated at 1 — 5,000. 



4 or 7.84 per cent agglutinated at 1 — 8,000. 



6 or 11.76 per cent agglutinated at 1—12,000. 



7 or 13.72 per cent agglutinated at 1—50,000. 



The object in the retests was to determine to what extent diminu- 

 tion in agglutinins or agglutinative power takes place with age. It was 

 thought that perhaps we might be able to throw some light upon the 

 subject of diminution or weakening of antibodies in general, including 

 the protective substances against hog cholera. We do not possess the 

 records of any extensive biological tests that show how long the Dor- 

 set- Niles serum retains its potency. 



