PUS-PRODUCING MICROORGANISMS 85 



stain well by most methods, multiply best at 37 C. 

 (98 F.), but also at lower temperatures, and grow as 

 very delicate gray colonies. They have no effect upon 

 milk or gelatine. On media containing blood they 

 have the property of dissolving the red coloring 

 matter. 



They are killed in ten minutes when exposed to 

 52 C. (126 F.). When dried in blood or pus they 

 may live for a considerable time at room temperature, 

 but die quickly at body heat unless their food is 

 repeatedly renewed. They are killed by corrosive 

 sublimate, 1 to 1000; carbolic acid, 1 to 100; and 

 hydrogen peroxide, 1 to 100, in ten minutes if exposed 

 in water. Pus supplies a protective envelope, and the 

 germicide must be allowed to act longer. Streptococci 

 are very virulent for most lower animals and the same 

 lesions may be produced by artificial injection as arise 

 spontaneously in man. Streptococci produce a slight 

 amount of extracellular poison, but more arises from 

 the disintegration of the bacterial cells. Attempts at 

 producing some serum to neutralize either of these 

 toxins have met with little success. The vaccine 

 treatment is likewise not successful. 



To diagnosticate infections by the staphylococcus 

 or streptococcus we are obliged to make our technique 

 suit the individual case. If an abscess exist it is 

 sufficient to collect the pus. If a cellulitis or bone 

 disease is to be examined, it is necessary to go deeply 

 into the tissue and select the bloody material near 

 the healthier tissue. In septicemia or heart disease, 

 a blood culture is made. Both organisms grow with 

 ease upon ordinary culture media. 



