Ron:
Ash has been found in home made brick used as a binder. Some adobe 
has had ash included in the formulas. None of these are fired brick 
that I know of. Used in naturally drying brick. Ash used is mostly from wood.
You will also find ash being used to make old farm soap from hog fat. 
In fact I truly believe the Marine Corps used it in the soap we used overseas.
Hope this doesn't confuse the issue.

DTP


At 08:03 PM 5/27/2007, you wrote:
>
>In a message dated 5/17/2007 9:49:43 A.M. Pacific Daylight Time,
>[log in to unmask] writes:
>
>What  kind of ash- coal ash or wood ash? Gurke, in his book Bricks  and
>Brickmaking (U. of Idaho Press 1987), mentions that ash is  sometimes
>mixed with clay to retard shrinkage and cracking while the bricks  are
>drying
>
>
>I cannot imagine organics surviving kiln firing of bricks. I have studied
>Mexican kilns in Baja California that created sandy bricks that trapped some
>organics in the core because oxygen hit the surfaces after the fuel 
>spent out,
>but I do not recall seeing ash or plant remains in the black carbon streak.
>Higher fired kilns with oxidizing temperatures would strip all organics from
>the  ceramics. What purpose would ash serve under these circumstances?
>
>Ron May
>Legacy 106, Inc.
>
>
>
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