The History of Rebreathers Rebreather diving has a unique history. Despite common belief, it was used much earlier then regular scuba diving. The first recorded historical event started as early as 1680 when Giovanni Borelli had the idea that a closed breathing circuit could be obtained
by recuirulating air through a copper tube, cooled by sea water, which was assumed, would condense all impurities at the inside of the tube.

The first attempt of chemically scrubbing the exhaled air was done by Stephen Hale in 1726. He designed a flannel liner, soaked in sea salt and tarter, used in a helmet for mine disasters.

Henry Fleuss, a marine officer, began to develop an oxygen rebreather in
1878. He used a watertight rubber face mask and a breathing bag
connected to a copper oxygen tank. As an absorber for the carbon dioxide, he
used a rope yarn, which was soaked in a solution of caustic potash. First he
tested his new device by remaining in a watertank for about one hour. Later he
walked along a creek bed at a depth of 5,5m. This same system was used several
times to rescue mine workers in flooded tunnels. Further development leads to an apparatus, thats used for submarine escape 1905.

A special scrubber for rebreathers is patended by Khotinsky and Simon Lake, using a barium hydroxide as a chemical to remove CO².

In 1904 Siebe Gorman patents Oxylite, a potassium and sodium
peroxide mixture that liberates oxygen on contact with water.

In1912Draegerwerk in Germany demonstrates a submarine sled, using a closed circuit, equipped with oxygen for two hours.

In 1936 a descendant of the Fleuss Scuba, the Davis Lung, is used by the Italian Navy. Several rebreathers were developed and used during WW2. Making use of mixed gases was the big secret, allowing greater operational depths. One of the most used unites was the Lambertsen Amphibious Respiratory Unit (LARU), later replaced by the improved oxygen rebreather Emerson-Lambertsen
Oxygen Rebreather.