USE OF EXTRAVASATING DYE AS A MEASURE OF SKIN PERMEABILITY TO BACTERIAL INVASION

The subject of disinfection of the skin divides itself naturally into two categories: The first treats of the various chemical or physical means by which the skin is rendered sterile, in other words, the surgical disinfectants, and the second treats of the disinfective power of the skin itself. It is with the latter aspect that this study is concerned.

Colebrook and his co-workers¹ and Arnold² have conclusively shown that the epidermis not only acts as a mechanical barrier against invading organisms but maintains its own indigenous flora and prevents the percutaneous penetration of foreign bacteria. Arnold^2b demonstrated that exogenous bacteria and other antigenic substances penetrated into the stratum corneum, where by some unknown process they were either inactivated or destroyed. Tracing the fate of the vanished bacteria in the stratum corneum by the injection of scrapings of keratinized epithelium into animals, he was able to show the