In the published scientific literature, various articles have described the process of "photobiostimulation". This process involves the irradiation of tissue with infrared light sources resulting in the improvement in such conditions as wounds and arthritis. Some authors have described the improved healing of wounds and arthritis not only at the irradiated sight but also on contralateral limbs. These findings suggest the presence of a humoral substance which may be formed as the result of tissue irradiation by infrared light. This experiment will use an animal model to identify the presence of such a humoral substance. At baseline a blood mass spectography will be measured then subjects will be irradiated with infrared light and repeat mass spectographic measurements will be taken and compared to baseline. Several different infrared wavelengths and power densities will be compared. Bilateral wounds will be created on each subject and on control group. Comparison will be made on wound healing times between the groups and between the contralateral wounds. Also, the presence of wound infection will be noted, if it occurs, and compared between groups. The identification of the formation of a substance with tissue healing effects due to the application of infrared light is a groundbreaking discovery. The further elucidation of the substance could have profound therapeutic benefits in a wide variety of potential applications such as wounds, burns, degenerative musculoskeletal disorders and cancer. In burn injuries for instance, light therapy (or the substance) may prove far superior to conventional treatments and skin grafting. Also, in a military setting combat personnel in the field could possibly benefit from the immediate application of light therapy to wounds or burn injuries. This equipment could be designed to be portable, lightweight and capable of withstanding the rigors of the operational environment.