This is a body slice of the chest of a male. The two darker sections are the lungs, and the thin valves of the heart can be seen in between them. The small white circle opposite the heart is the spinal cord. Colored wax has been used as a stain to highlight the different components. These body slices served as teaching tools for medical students in the 1930s and 1940s. They were provided by the Loyola University School of Medicine and the University of Illinois Department of Anatomy, and were refurbished by Michael Reese Hospital and Medical Center. The man and woman died of natural causes. Their bodies were frozen, cut into sections, and then preserved in glass containers filled with a formaldehyde solution.