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Re: [at-l] Leave your soap behind?

Whoa, kids!  Some better scientist backfill for me on this and correct this 
resoundingly if t'ain't right but as I recall the active ingredient supplied 
by the wood ashes is good old burns-you-badly LYE.


>From: "David  F. Addleton" <dfa@wimlaw.com>
>To: "AT-L" <at-l@backcountry.net>
>Subject: [at-l] Leave your soap behind?
>Date: Sun, 8 Aug 1999 18:47:41 -0400
>How many folks take soap with them on the trail? (I still carry a tiny
>bottle of the stuff.) But I ran across this article at the BBC's website
>which could give new meaning to the LNT ethic!
>Friday, August 6, 1999 Published at 15:58 GMT 16:58 UK
>Clean and easy
>We take soap for granted
>By Pauline Newman of BBC Science
>You take the greasy animal fat from the bottom of a cooking pan. You add
>the grimy wood ash from the fire below. You mix them together and use the
>resulting goo to clean yourself.
>This is the essence of soap. OK, so modern soaps are a little more
>sophisticated, but this is essentially how our forebears would have made
>it. If you boil and cool the mixture, successively, over several days, it
>will eventually go quite hard.
>Chemist John Emsley from Cambridge University says it is quite easy to
>understand how soap might have been invented.
>"You can see how if someone was cooking something on a wood fire and it had
>fat in it and it boiled over and the fat dropped onto the wood-ash then the
>following morning, when they went to clean up the mess, they would find
>that when they put water on it that it would lather and it would clean very
>well. That was just a simple type of soap."
>The Pharaohs used soap nearly 3,000 years ago, and it worked for them in
>exactly the same way as it works for us today. The secret of its success
>lies in what are called amphiphilic molecules.
>"Soap molecules have a head and a tail," says John Emsley. "The head likes
>to attach itself to water; the tail likes to attach itself to grease. So
>when soap is put into water, it will find the grease, it will attach itself
>to the grease, and it will pull it into the water and then it can be washed
>Skin diseases
>But somehow, this miraculous property was forgotten, at least in some parts
>of the world. Instead, medical men from Ancient Greece and Arab countries
>used it as a skin balm, as did the Romans.
>"We know that the ancient Romans used soap because it's mentioned in
>several of their books," says Nina Hall. "But they didn't use it to wash
>their bodies, but instead used it as an ointment to treat skin diseases.
>And in fact, a soap making factory was discovered in the ruins of Ancient
>Roman Pompeii, which was destroyed by a volcano in AD 79."
>The Romans knew how to make soap
>The Romans did use soap to clean their clothes and they found it worked
>best when mixed with urine. In the city of Florence, the Emperor urged the
>townspeople to help.
>"There were great pots at the street corners where people could add their
>own contributions to this," says John Emsley. "The urine was left for
>several weeks until it actually decomposed and gave ammonia, and ammonia is
>a very good cleaning agent. It will remove grease and dirt from fabrics."
>After the Romans, soap making, as an industry, almost ceased to exist for
>hundreds of years. But there was an alternative to boiling up smelly fats
>and ashes.
>"One of the simplest ways that people around the world have found to get
>clean is to wash using a plant," says Pat Griggs of the Royal Botanic
>Gardens at Kew, near London. "Plants are absolutely amazing for this and
>there are many species around the world that contain a substance called a
>saponin which works in a similar way to a soap."
>Plant power
>Over 100 different types of plants make saponin and sometimes its found in
>the leaves of a plant, sometimes in the stem or roots and sometimes in the
>berries or other fruits.
>"What's happening when we use one of these plants is that the saponins make
>a foam when mixed with water, and this lifts off dirt and grease," says
>"It works just like an ordinary soap and it's often very good for washing
>your hair."
>In North America, native people sometimes used the root of the Yucca plant.
>In India, a shrub called the soap nut bush became very popular. The nuts
>are crushed and mixed with water to make the soap.
>The bars of soap we buy today contain lots of plant material, plant oil to
>make the soap itself and plant fragrance to scent it.
>We are not sure when commercial soap making began again after Roman times,
>but by 1200 AD, soap was being made in Bristol in England, and 200 years
>later the finest soap was being made and exported from Spain. This soap was
>based on olive oil.
>Revolting mixture
>"All kinds of oils and fats can be used to make soap," says John Emsley.
>"Mutton fat, tallow from cattle, palm kernel oil, coconut oil, olive oil,
>palm oil - any fish oil can be used to make soap.
>"If you want the soap to last a long time then you want to use a saturated
>fat. If you use an unsaturated fat then the soap will tend to go rancid
>after a certain length of time. Soaps made from saturated fats will last
>for years, they don't go bad."
>Coconut is a good source of saturated fat
>In times of hardship, when fat couldn't be spared to make soap, it has been
>made out bile. Bile is a natural soap, that helps animals digest the fats
>and oils they eat. During the First World War, the bile from slaughtered
>animals was used as a cleaning agent. This sounds revolting because bile is
>a vile green liquid but when it was processed it looked better and did a
>reasonably good job.
>Today's chemists boil the fat and oil, not with wood ash, but with sodium
>hydroxide, sometimes called caustic soda.
>"The general principle is to boil up fats with caustic soda," says Nina
>Hall. "Water is added and they're boiled for hours and hours until we get
>the soap forming. And as well as soap forming, you get glycerine and the
>two have to be separated. The soap curdles, a bit like milk curdling, and
>it gathers at the top of the big pans in which it's made and then the
>glycerine and salts and water settle at the bottom."
>Over eight million tonnes of soap are produced each year worldwide and the
>demand for soap is rising. 50 years ago, it would have all have been made
>from animal and plant fats, but in recent years, more and more synthetic
>soaps have been coming on the market, particularly for washing clothes.
>These are made from petrochemicals. Manufacturers like the synthetic soaps
>because the raw materials, the petrochemicals, are of consistent quality.
>Consumers like them because they work more efficiently and do not produce
>the scum sometimes seen in hard water.
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