Submarine medicine is a distinct medical specialty, requiring not only selection of specially qualified and competent Medical and Hospital Corps personnel, but also requiring additional specialized training. The primary duty of these Medical and Hospital Corps members is the same as for any other type of Navy duty, that is, the care of the sick and injured. They also share with the other units of the Fleet and shore stations the routine duties, - such as inspections, preparation of reports, etc. that pertain to their jobs. However, in addition to these more or less well defined duties, there are many special duties required of both the Medical and Hospital Corps personnel in the Submarine Service. They must become specialists in submarine construction and operation to the extent at least, that they will be able to under stand the problems of maintaining a satisfactory environment for submarine personnel, and understand the problems of submarine safety and salvage. This requires a knowledge of such things as the operation of rescue apparatus, such as the rescue "Bell''; the use of the submarine escape appliance, the "lung," and methods of escape from a disabled submarine; the treatment of casualties that may develop during escape training; the normally required concentrations of oxygen and carbon dioxide, and methods for determining these percentages aboard a submarine; the special angles to the problems of food: and nutrition, water supply and sewage disposal peculiar to submarines. In addition to this, the submarine medical officer must be proficient in the field of personnel selection, and should be able to properly evaluate early signs of fatigue and war neurosis, so as to take men off the boats for proper rest and treatment before any breaks actually develop. The submarine pharmacist's mate, the only medical representative normally aboard the submarine during war patrol, has additional duties as a member of the crew. He may be assigned such special duties as sonar operator or day or night lookout. He is usually the librarian, and is regularly assigned the cleaning detail for the after-battery compartment. The original text and artwork have been used in this publication; occasionally there may be instances of imperfections with these old texts (i.e., blurred or missing pages, poor image quality)."