Judy Seigel (jseigel@panix.com)
Sat, 17 Jul 1999 03:44:35 -0400 (EDT)
At 01:20 PM 7/15/99 -0400, Sil Horwitz wrote:
>Sorry, Dick, there might be some benzine in kerosene, but it would be an
>impurity. Benzine is a low molecular weight (meaning it's lighter and
> more volatile) aliphatic hydrocarbon that is the main constituent in
>the mixture we call gasoline (and the British call petrol). Kerosene is
> a mixture of higher molecular weight hydrocarbons, which makes it
> slightly viscous (oily). When the oil producers separate the ingredients
> in crude oil (if you can visualize ....
============CUT============================
>At 1999/07/15 09:40 AM -0600, Richard Sullivan wrote:
Sil,
Rats!
You always were smarter than me. My Merck said "See kerosene" so I thought
it was the same, now that I check it isn't. Sure thing, it isn't benzene.
========CUT =====================================================
Dear list,
While we're doing truth in chemistry, I have, finally, some authoritative
info on aqua regia. I hope the following quick summary will undo some of
the mischief perpetrated here last month when greatly exaggerated and/or
entirely mistaken claims were used to cast aspersions on Post-Factory's
fair name and credibility. Perhaps even some folks frightened into burying
their ancestor's gold tooth with the ancestor will be encouraged to
reconsider.
I omit chemical formulas here, although a document is in preparation to
make them available on request. Needless to say, I am not a chemist (nor
has the editor of the New York Times made the fennel-scented mussels in
rutabaga sauce cited in its recipe pages), but trust I convey the gist,
which is that calling the danger of aqua regia of a different order of
magnitude than that of other strong acids used in printing and photography
is, basically, a figment. As follows:
One mole of gold liberates 1 mole of NO gas, which becomes NO2 on contact
with air, ie., the "noxious" fumes at issue. Assuming you dissolve 10 g of
gold in an appropriate volume of aqua regia, the volume of NO gas would be
1.1 litres. There are 28 litres in a cubic foot, so the concentration of
NO2 in the atmosphere, using Sullivan's example of a room of 10,000 cubic
feet, would be ca 3 (three) p.p.m *WITH NO VENTILATION.* Sullivan quoted
the Merck Index "dangerous" level for that space as 100 ppm. In a SMALL
room, 1000 cu ft, the level would become 30 ppm, again with *NO
VENTILATION* -- and still below the cited danger level
However, we now have "safe level" figures from official sources: For
long-term exposure, *safe* level is 25 ppm. For brief exposure, 35 ppm. So
you could actually do the operation with no ventilation at all and still
be officially "safe." But of course no-one is suggesting it be done with
no ventilation. There's also the fact that, as Liam puts it, "The 1.1
litres of nitrogen dioxide would take several hours to accumulate. The gas
is unpleasant; it is inconceivable that anyone would be able to tolerate
high levels for any length of time." Which is to say, if you had for some
reason shut yourself up in a cupboard to do it, you'd at least open the
door. Of course out of doors this amount of gas would not be a problem.
Two other points: We now have several official formulas and scientific
sentences to demonstrate that aqua regia becomes more dilute with time --
supporting Lawless's observation that "it loses strength after a while."
The Handbook of Chemistry and Physics (Table D-131) recommends that "if
aqua regia is to be stored for any length of time, the formula should
include 1 volume of water..." Liam stores it straight, however, and says
it only makes a soft pop when he opens it. He also has repeatedly tossed
water onto these acids, together & separately, as didn't even raise a
fizzle. If, on the other hand, you are BOUND & DETERMINED to get an
explosion, you'll have to keep the mix in a closed vessel and heat it up
pretty good.
This is not the time or place to debunk in detail every one of the
suppositions hurled, but the process has now been tested by a couple of
real chemists who confirm Liam's observations about the relatively low
level of AR pressure, its limit of fizz, weakening with time, slow buildup
of the fumes, and that a "runaway reaction" may apply with palladium
sponge but not here. Details of these reactions will also be available
upon request.
Finally, I've heard from folks who declared that the Post-Factory gold
chloride article contains far more info (and warnings!) than anything else
in print on the topic. So take heart. Plus take every possible care of
course. And no smoking.
===================================================
OK ! That's it for the acid, now the SWEETS:
Judy's 20-minute (Heavenly) Peach Tutti Frutti
(Warning: Good ventilation may cause friends and neighbors to descend on
you: The aroma of this sauce cooking is one of the most exquisite in the
history of gastronomy.)
Conventional peach jam calls for unripe peaches because they have more
pectin, which makes them jell better. But to peel unripe peaches you dip
them in boiling water, which heats the kitchen and scalds the fingers. I
found that leaving the peel on adds (heavenly) flavor. I also accept the
runniness. Think of it as sauce or syrup -- sublime on yogurt, frozen
yogurt, blanc mange, fresh sliced fruit, ice cream, ice milk, vanilla
cookies, fried bread, shortbread, scones, sponge cake, or all of the
above, ESPECIALLY with a tablespoon of Kahlua on top. The ultimate best,
however, is directly out of the jar with a spoon at the kitchen counter at
3 AM.
When buying peaches, observe the stem ends -- pick those that look the
least green; they'll have the most flavor and ripen best. If soft at the
store they'll be rotten tomorrow, so buy peaches firm and let sit at room
temp a day or two, until just soft enough to split. Then run a knife
around the crease, and, grasping one hemisphere in each hand, twist to
separate halves from the pit. DO NOT PEEL. The old books say add a few
pits for extra flavor, or crack them open to get the interior kernel. I
add whole pits for atmosphere, but never did a variable test on whether
they actually add flavor or not.
INGREDIENTS: peaches, sugar, cinnamon sticks, navel orange, small lemon, 1
cup green seedless grapes optional, other fruit (eg. apricots) optional,
but not strawberries-- too overriding.
Slice orange and lemon VERY thin (so skins soften without overcooking the
peaches), halve, & put in a heavy 4-quart (4 litre) pot; add peach slices
until pot is three-quarters full. Pour 4 cups of sugar over the pile (5 if
you prefer) and insert maybe 5 broken up cinnamon sticks in the sugar.
Don't try to stir right away. Cover & let sit 12 to 24 hours at room temp
while the sugar draws the juice out of the peaches, stirring once or
twice, until you have peach slices swimming in syrup. If the volume is
much reduced, you might want to add a couple more peaches then-- or not.
Bring to boil and simmer, stirring occasionally, until peaches are
translucent, but still light in color (maybe 20 minutes).
Conventional jam calls for 3/4 as much sugar by volume as fruit. This
version, although much tastier and easier than "regular" jam, is quite a
bit less sweet, so probably won't keep under wax or in Ball jars at room
temperature. I hide some from maurauders for winter days by tucking in
dark corners of the refrigerator (or wrap in a B&H bag !). This year I
made extra and put in the freezer. Of course cold storage also avoids the
arduous boiling and sterilizing of jars.
Sweetly,
Judy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| Judy Seigel, Editor >
| World Journal of Post-Factory Photography > "HOW-TO and WHY"
| info@post-factory.org >
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