X-Message-Number: 3121 Date: 12 Sep 94 13:45:52 EDT From: yvan Bozzonetti <> Subject: SCI.CRYONICS Darwin/Ettinger's water problem There has been an exchange between M. Darwin and R. Ettinger about the water quality used in perfusion (+ some more problems). I have encountered a similar question with silvering astronomical mirrors. I have some large mirrors mounted on glass foam, a product very hard to outgas in a conventional aluminizing bell. So, I was constrained to use an open air silvering process for these mirrors. The main problem to get a good reflecting surface is to wash out any dust or chemical impurity. The laboratory selling the basic chemicals for the process recommends the use of distilled water; In a first trial with commercial "distilled water", there was many traces spotted on the surface, even at the naked eye inspection level. I don't know the situation in the U.S. but in France "distilled water" is not a deposited norm. Here, if the word milk is printed on a bottle, it cannot contains anything else than pure milk, without additive. The same holds for apple juice and so on. On the contrairy, distilled water can be anything and is indeed anything. It is simply tape water passed on deionising system just able to remove Ca++ ions. There is anything in this water, from minerals, disolved gas to trace hydrocarbures and dust. My solution is to put this water at the bottom of a clean fridge fitted with bands of hydrophyl cotoon dripping in the batch. Evaporation gives a frost of truly distilled water recovered in the defrost cycle. The water is boilled in a micro wave hoven before use to remove any gas in solution. There are neverthless some defects in the silvering, everything would be conduced under a plastic bell to suppress dust and there would be two fridges for a two steps process. I don't know how this cheap water compares with a medical grade product, but it is far better than the supermarket one. I find sad to think amateur astronomers are better served than cryonics patients, even if this is a minor problem in the face of some others. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3121