180 PROTEIN POISONS 



warrant the flat declaration that the two phenomena result 

 from the same fundamental causes, there are enough data 

 at hand to justify the elaboration of a working hypothesis 

 that such is the case." The important question of the 

 relation between sensitization and immunity to infection 

 has been tested by Baldwin and Krause. Series of guinea- 

 pigs were sensitized to tuberculoprotein. The fact that 

 they were in full sensitization was demonstrated by testing 

 some of each set. Those that recovered from anaphylactic 

 shock and known as "refractory" were inoculated an hour 

 after the reinjection. Lot A had received a total of 25 c.c. 

 of the watery extract in seventeen doses over a period of 

 thirty-nine days. Lot B had received a total of 13 c.c. 

 of the watery extract in ten doses over a period of thirty- 

 nine days. Lot C had received a total of 8 c.c. of the watery 

 extract in six doses over a period of thirty-nine days. Lot 

 D had not been sensitized. The last sensitizing doses were 

 given June 14, 1910. All of these animals were inoculated 

 with the same amount of a virulent culture of the tubercle 

 bacillus July 1, 1910. Sixty-two days after inoculation 

 all the animals were killed and examined. A summary of 

 the findings is stated as follows: "The refractory animals 

 suffered most. The disease was pretty well disseminated 

 in all of them, and they exhibited far more tuberculosis 

 than any of the animals that had not been intoxicated, 

 and than any of the controls. . . . The animals that 

 were sensitized in various ways all became diseased. As 

 a general thing, we may say that the more protein the 

 animal received during preliminary treatment, the less was 

 the resultant infection. So far as one could tell from the 

 toxic symptoms of the test animals there was very little 

 difference in the average degree of sensitization in the 

 several sets of guinea-pigs. The results of inoculation 

 were, however, different. It is most likely that the differ- 

 ences were altogether independent of any degree of raised 

 or lowered resistance conferred by the sensitive state, but 

 that they w^ere due to the heightened immunity that followed 

 the protein injections." 



