 This study hopes to improve our understanding of how the immune system acts and how the skin responds to petrolatum. In order to reach this goal, normal volunteers, will be patch tested with petrolatum. Then, biopsies will be taken of the skin at the sites where petrolatum was. Also, small biopsies will be taken from an area that received a patch but no petrolatum and an area that did not receive a patch to serve as controls. The biopsied skin samples will then be studied in a laboratory by methods such as immunohistochemistry and RT-PCR analysis, which will help define the response of the immune system to petrolatum. The rationale for the study is to better define petrolatums effects in skin and how it is effective at preventing infections. 