400 STATE BOARD OF AGRICULTURE. 



that react at a dilution of 1-50,000 are potent. Here we have a serum 

 produced in a peculiar manner with a high agglutinative power, but 

 with little or no potency. 



Table IV give the results of the test for potency of the serum from 

 Expt. pig 315 on small pigs. The serum was tested against a very 

 virulent uufiltered hog cholera virus. We found no indication of any 

 protective power in this serum. Perhaps larger doses might have revealed 

 the presence of protective substances. 



We next attempted to eliminate B. cholerae suis from the process of 

 hyperimniunization. Our object was to hyperimmunize a ])ig with virus 

 blood free from any cultivable organisms. It proved to be a herculean 

 task on account of the slow filtration and frequent presence of cloudi- 

 ness in our filtrates and especially on account of our mistake in select- 

 ing a large pig for the experiment. Wo planned to dilute with equal 

 })arts of sterile .85 per cent NaCl solution the clear serum from de- 

 hbrinated hog cholera virus blood and filter through both Berkefeld and 

 Chamberland filters. We were then to inject 20 c.c. of this filtrate for 

 each pound of live weight of the pig. It was soon discovered that our 

 facilities for filtering the vli'us blood could not keep pace with the in- 

 crease in weight of the pig. 



Expt. pig 387, Yorkshire, weight IG lbs. 



Feb. 7, 1910, injected 20 c.c. mixed serum 53 and 1 c.c. virus 125. 



June 24, weighed 81 lbs. 



August 27, injected 250 c.c. virus Expt. 434 and 250 c.c. virus 205. 

 Both lots were clear blood serum diluted with equal parts of sterile .85 

 per cent NaCl solution and filtered through Berkefeld, then through 

 Chamberland filters. 



Two Berkefeld filters were used for virus Expt. 434 and one new 

 Chamberland candle at air pressure of about 3 Kg. per square centi- 

 meter. Incubated 3 days, no growth. Virus 205 put through 3 Berke- 

 feld filters and one Chamberland at 2 to 3 Kg. pressure. Incubated 4 

 days, no growth. 



Sept. 1, injected 75 c.c. virus 208, 125 c.c. virus 209, and 50 c.c. virus 

 211 diluted and filtered as above. Virus 208 put through one Berke- 

 feld and two Chamberland filters at 3 to 4 Kg. pressure. Incubated 2 

 days, no growth. Virus 209 put through 3 Berkefeld filters and one Cham- 

 berland very slowly. Incubated 5 days, no growth. 



Sept. 7, injected 25 c.c. virus 208 and 225 c.c. virus 210. Diluted 

 and filtered as above. Virus 210 put through one Berkefeld and one 

 Chamberland filter at 3 to 4 Kg. pressure. Incubated 7 days, no growth. 



Sept. 14, injected 75 c.c. virus 211 and 125 c.c. virus 207. Prepared 

 as above. Virus 211 filtered through 2 Berkefeld and one Chamber- 

 land filter very slowly. Virus 207 put through one Berkefeld and one 

 Cluimberland filter. Incubated (5 days, no growth. 



Sept. 20, injected 100 c.c. virus 207, a portion of above Berkefeld fil- 

 trate passed through one Chamberland filter 9-13-'10. Incubated 7 days, 

 no growth. The pig weighed 138 lbs. on this date. 



Sept. 28, injected 400 c.c. virus 223. Prepared as above. Filtered 

 through one Berkefeld and one Chamberland. Incubated 6 days, no 

 growth. 



Oct. 5, injected 500 c.c. of a mixture of virus Expt. 455 to 459. Pre- 

 pared as above. Filtered through 3 Berkefeld filters and 5 Chamber- 



