510 BIOLOGY OF PNEUMOCOCCUS 



the species. Neufeld and Schiemann 999 showed that trypaflavine and 

 different salts of 3-6 diamino-acridine were strongly bacteriostatic 

 in vitro. In vivo, the compounds when administered subcutaneously 

 rescued a certain percentage of mice infected intraperitoneally 

 with pneumococci. The dyes were also efficacious when applied in 

 the form of irrigations in wounds experimentally infected with 

 pneumococci in mice and guinea pigs (Neufeld and Reinhardt, 996 

 and Reinhardt 1184 ). From animal experiments, Schiemann, 1224 by 

 intraperitoneal or topical application, substantiated the observa- 

 tion on the favorable influence exerted by trypaflavine on pneumo- 

 coccal infection. Maeji 851 " 2 stated that trypaflavine was pneumo- 

 coccidal in a dilution of 1 to 100,000. To the list of pneumococco- 

 static agents Schiemann added the aurophosphine and trimethane 

 dyes, crystal violet and brilliant green. As for Mercurochrome, the 

 few references (Freeman and Hoppe, 481 and Phelps 1088 ), lacking 

 any laboratory tests, are not significant, whereas the somewhat 

 analogous substance, Metaphen, was reported by Kolmer and Bor- 

 row 742 to be less effective than optochin, a substance which will be 

 discussed later. From the few references in the literature it would 

 appear that such tinctorial substances derived from the nitroben- 

 zines as have been studied manifest no conspicuous pneumococcidal 

 properties when introduced into the animal body. 



METALS AND METALLIC SALTS 



Of metallic elements, gold in colloidal form has been tried in the 

 treatment of pneumococcal infection in man (Gautier 505 ), and as 

 a synergist with specific serum in the treatment of experimental 

 infection in rabbits (Gelarie and Sabin 510 ). In the latter case, the 

 survival ratio of the animals treated with serum and gold was 

 greater than that of those receiving subeffective doses of serum 

 alone. Schiemann and Feldt 1229 reported that gold in the form of 

 Sanocrysin had slight if any action in protecting mice infected 

 with pneumococci. Gautier mentioned iodine as a therapeutic agent 

 in the treatment of pneumonia but offered little information con- 



