The work described in this article was undertaken following the observation in a neighboring hospital that B. pyocyaneus was found, in several contemporary cases, growing in dressings of mercurochrome220 soluble after the first twenty-four hours' applications to a wound. The questions arising for solution concerned the unusual frequency of infections by B. pyocyaneus—Pseudomonas aeruginosa (Schroeter)—usually an infrequent invader, and the specific value of mercurochrome as an antiseptic in infections with this microbe.
Pus was chosen as a medium for growth in an endeavor to imitate to some degree the conditions in the body, especially in infected surgical incisions. The pus used was sterile, having been drawn from a shoulder bursitis and having failed to produce any growth on blood agar plates or in dextrose broth. It was thick and creamy and on microscopic examination showed countless pus cells and ropey, mucus-like shreds, but no bacteria.
The cultures of B.