NotesThis desalting kit was a specially prepared outfit issued to the United States Naval and Air Force Personnel. The kit was used to provide the facilities to make fresh drinking water from sea water in the event of an emergency. It consists of a tin container, desalting bag, 6 packets of salt removing chemical, and one roll of patching material.
The following was written on an old Museum label that accompanied this kit:
"In 1935 two English chemists, Adams and Holmes, discovered that certain synthetic resins could remove all the solid substances dissolved in water. The substances usually found are sulphates and carbonates of calcium and magnesium; some waters contain common salt and bicarbonate of soda. By merely passing the water through a container holding one of the resins it was found practicable to remove the calcium, magnesium, sodium, and similar metallic ions.
The water, after passage through this resin, was found to be acid, and so it was passed through a further container of another synthetic resin. This removed all the acidic ions, i.e. the sulphates, chlorides, ect.
The water issuing from the last container was neutral and pure. By this means a sterile water, produced without heat, was obtained, equal in quality to the best distilled water.
This classical investigation laid the basis of modern water purification. The method has been applied commercially in Germany, the United States of America, and the United Kingdom, and has made very rapid strides during the past few years. Newer and more efficient synthetic resins have recently been prepared.
There were obvious difficulties in applying the method economically to small scale operations, such as lifeboat equipment and for general household purposes. The war, however, has stimulated research into methods for demineralising or desalting seawater, so that the worst terror of shipwreck, THIRST, which also faces airmen forced into the sea, would be overcome.
The great firm of Permutit Co. Ltd. Has succeeded in preparing the two synthetic resins in a small compact cake, so that they can be applied on a small scale for the use of naval and air force personnel.
It is now practicable to remove the salt dissolved in sea water, and thus make available a supply of fresh drinking water for the benefit of airmen forced down into the sea."
The desalting bag was accompanied by a label reading "This bag is made of vinylite plastics and fitted with a filter pad, suction tube, and screw plug. To make water-tight when filled, the top opening of bag is rolled over and secured with strap and buckle. A lanyard is attached to prevent loss of bag. When filled to the blue line the bag holds about 1 pint of water."
The synthetic resin compound was accompanied by a label reading "made up in waterproof packets and secured together with tape as a safety measure. Contents of one packet are required to remove salt from one pint of seawater. Not all the salt is removed, a little is left to compensate for perspiration losses."
Museum label, H4656 Desalting kit, Blue File H4656
Penfold, A. R., 'Plastics and Synthetic Fibres', A.H. Pettifer, Government Printer, Sydney, 1956