156 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1945 



the water was better than sea water, the combination of induced alka- 

 losis and dehydration condemned the method. 



6. Aquamax method (5). — This relatively simple ion exchange 

 chemical method was limited by the fact that the weight and volume 

 ratio of water produced to chemical employed was too low for con- 

 sideration. Chemical analysis of the water produced permitted its 

 recommendation as drinking water, but no physiologic studies were 

 made. Development of a field kit would have lowered the ratio still 

 further. 



7. Red Jacket (6). — This method was similar in principle to the 

 Aquamax method. The factor that limited its use was the low weight 

 and volume ratio. A field kit was developed which had much to rec- 

 ommend it for simplicity, but the added weight of the kit resulted in a 

 much lower water ratio. 



8. British Permutit (7) and American Permutit (2), (8), (9). — 

 These methods were very similar and were in fact originally exactly 

 alike. A silver and barium zeolite was employed, which upon inter- 

 action with the salts of sea water caused the precipitation of silver 

 chloride and barium sulfate and sodium and magnesium zeolites. The 

 chemical was loosely packaged into a small cartridge, and a number 

 of the cartridges were packaged into a bakelite processing container. 

 The container, shaped in the form of a cylinder, had two removable 

 lids. On one end a filter was placed over a screwed-down cap with a 

 protruding teat. At the other end a screw cap with a rubber vent 

 allowed the formed gas, but not the water, to escape. Sea water was 

 scooped into the container to an inscribed mark, and the contents of a 

 cartridge were added. The top lid was screwed on and the contents 

 shaken for 20 minutes. The processed water was removed by sucking 

 on the teat at the bottom. 



Although the original Permutit methods produced excellent water, 

 the ratio of water produced to chemical employed was almost as poor 

 as those of the previously mentioned methods. They had, further- 

 more, not been considered practical for life-raft use for a number of 

 reasons. First, it was less trouble and expense to package canned 

 water. Second, the method of processing was complicated ; the parts 

 at times required mechanical tools for disassembling, especially the 

 screw caps. Third, the method of removing the drinking water was 

 much too difficult. Fourth, the resistance in the filtering system was 

 frequently too great for a man to suck out the water. 



9. Naval Medical Research Institute method (2), (10), (11). — Dur- 

 ing the last part of 1942 a new chemical method for the preparation 

 of drinking water from sea water was discovered by Spealman (12). 

 Basically, the method consisted of adding silver oxide to sea water 

 and filtering off the precipitated silver chloride and magnesium hy- 



