PYOGENIC BACTERIA. 385 
to De Simone, a temperature of 39.5° to 41° C. maintained for two 
days is fatal to this micrococcus. 
Manfredi and Traversa have injected filtered cultures into frogs, 
guinea-pigs, and rabbits for the purpose of ascertaining if any solu- 
ble toxic substance is produced during the growth of Streptococcus 
pyogenes. They report that in some cases convulsions and in others 
paralysis resulted from these injections. 
Von: Lingelsheim has (1891) reported the following results 
obtained in an extended series of experiments made to determine 
the germicidal power of various chemical agents as tested upon 
this microérganism—time of exposure two hours : Hydrochloric acid 
1: 250, sulphuric acid 1: 250, caustic soda 1:130, ammonia 1 : 25, 
mercuric chloride 1 :2,500, sulphate of copper 1: 200, chloride of 
iron 1: 500, terchloride of iodine 1 : 750, peroxide of hydrogen 1 : 50, 
carbolic acid 1 : 300, cresol 1 : 250, lysol 1 : 300, creolin 1 : 130, naph- 
thylamin 1 : 125, malachite green 1.:3,000, pyoktanin 1 : 700. 
Fic. 84.—Section from margin of an erysipelatous inflammation, showing streptococci in 
lymph spaces. From a photograph by Koch. x 900. 
Pathogenesis.—When inoculated into the cornea of rabbits 
Streptococcus pyogenes gives rise to keratitis. Inoculations into the 
ear of the same animal usually give rise to a localized erysipelatous 
inflammation accompanied by an elevation of temperature in the in- 
oculated ear; at the end of thirty-six to forty-eight hours the in- 
flamed area, which has well-defined margins and a bright-red color, 
extends from the point of inoculation along the course of the veins to 
the root of the ear. This appearance passes away in the course of a 
few days and the animal recovers. Subcutaneous injections into mice 
or rabbits are usually without result, and the last-named animal also 
withstands injections of considerable quantities into the general cir- 
culation through a vein. When, however, the animal has previously 
been weakened by the injection of toxic substances the streptococcus 
may multiply in its body and cause its death (Fligge). 
Fehleisen has inoculated cultures, obtained in the first instance 
from the skin of patients with erysipelas, into patients in hospital 
suffering from lupus and carcinoma, and has obtained positive re- 
sults, a typical erysipelatous inflammation having developed 
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