Tooth extraction was made in 82 cases, while 20 cases without extraction at random Mwere used as a control. About 4 cc of blood was taken from V. mediana within 15 minutes after extraction and examined bacteriologically. As the results obtained bacteria were positive in 17 among 82 cases : streptococcus in 8 cases, staphylococcus in 8 cases and hay bacillus in one case.
Then the relationships of bacteria-positivity to tooth diseases, such as pericoronitis, periodontoclasia, etc., to the number of extracted tooth, to localization of the tooth, and to difficulty of extraction were statistically considered and summarized.
No difference could be seen between positive and negative cases in appearance of Postexodontic troubles, such as chill, fever, and headache.