Topic started by honey (@ is4.publib.saskatoon.sk.ca) on Mon Oct 2 21:33:19 .
All times in EST +10:30 for IST.
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Does any one how to make a silver varaq. For those of who are wondering what the heck it is, it is the silver decoration on sweets. Is it even possible to make it at home. |
Responses:
- Old responses
- From: Ravi Sundaram (@ 192.149.1.187)
on: Wed Dec 20 10:59:26 EST 2000
JB! sorry I forgot I made a posting here.
Yes you are right about the difference between
tin and lead.
But they DO make vessels out of lead. real soft
lead, what would be called kaariiyam. It usually
comes with a coating of lead tin inside. But I dont think it protects all that much. I am sure
I am talking about the correct lead here. The vessels are quite soft, they easily deform
if I press them, they melt very quickly. We have lost a few to fire. If the water boils off, it would melt in less than a minute. People
from Madras or TN can walk into a paaththira kadai and buy real lead cooking utensils. It is quite
expensive though.
My sister-in-law is very health conscious and is practically obsessive about her children's health. But she grew up in Hubli and knew only spoken tamil. She never
made the connection that lead and iiyam (ok, kaariiyam for you JB ;-)) are one and the same.
Oh! She was dismayed to learn the fact and retired the lead vessels immediately. My parents-in-law lost their beloved iiya sombu rasam thanks to
their pudhu maappiLLai :-)
- From: ravi sundaram (@ 192.149.1.187)
on: Thu Jan 18 08:41:39 EST 2001
Today I was listening to National Public Radio (USA). There was a piece about the new president George W Bush, and how some restaraunts in Washington DC are trying to get his favourite foods on their menu etc.
They asked the owners of Jeffry's (a restaraunt in Austin TX) what GWB's favourite dessert was. It was "chocolate intemperance". It is a chocoloate fudge brownie, topped with a chocolate goulash, with a chocolate glaze and berries and GOLD DUST!
Edible Gold Dust! So the westerners too are sprinkling heavy metals on their desserts! I never knew there was something called Edible Gold Dust. I actually dont know if it is really gold or if it is dried apricot powdered and dyed gold.
- From: Susmitha (@ 203.199.64.142)
on: Sat Jan 20 05:33:15
I am confused now. Earlier it was mentioned that 'Iyam' used in vessels is not lead, it is only Tin. But Ravi, you are saying that "iyam' is lead, which in turn in poisonous.
Pl clarify this, as I make Rasam everyday in 'Iya Chombu' and I do not want to poison my kid everyday.
- From: Ravi Sundaram (@ pa-bethelpark2a-530.pit.adelphia.net)
on: Sat Jan 20 17:30:09
Susmitha,
I think lead is iiyam. I have drunk iiya sombu rasam for years and many of my relatives still do.
But Dr JB knows a lot and when he says it is tin not lead, and makes the distinction between "kaariiyam" and "veLLiiyam" I start doubting myself. I told all my relatives categorically that
iiyam is lead and some of them, like my sister in law, stopped using these vessels. Needless to say I have not used the iiya sombu that came as my wedding "seeru" even once.
So maybe we should ask Dr JB to really clarify if
iiya sombu is made of lead or tin.
Here is the table of Young's Modulus of various
materials:
Aluminium 70 kN/mm^2
Lead 16
Tin 47
Steel 240
Copper 124
CastIron 115
It shows tin is three times as strong as lead
and Aluminium is about 4.5 times stronger than lead. Thus if the vessel has unusually thick walls and despite that if it deforms easily or dents easily it is more likely to be lead than tin.
I'll see if I can search the net for more info.
- From: ravi sundaram (@ pa-bethelpark2a-530.pit.adelphia.net)
on: Sat Jan 20 21:41:16
Sorry for the mangled editing:
It should read "When he says iiyam is tin ...".
So hope Dr JB gets time to read it and clarify the issue.
- From: JayBee (@ 203.106.194.234)
on: Sun Jan 21 02:57:47
I made a search in the various dictionaries also.
I will compile them and post in a while.
Somebody living in India could ask a brass-seller(vengglak-kadai) and get more details. That will be the most accurate fact.
One of Malaysia's chief product is Tin.
We call it as 'Iiyam'. The tin-market is known as 'Iiyachchandhai'.
I'll try to clarify as much as possible. I would also like to correct myself if I made any mistake.
- From: A Bear of Very Little Brain (@ access-isdn2-8.oz.psu.edu)
on: Sun Jan 21 21:27:48
Ya know, you may want to design cooking vessels based on melting temperature of the metal, as well as its Young's modulus.
As a reformed metallurgist, I'd suggest you compare the melting temperatures of lead and tin as well as the Young's moduli..
Nyuk nyuk!
- From: Sundar (@ access-isdn2-8.oz.psu.edu)
on: Sun Jan 21 22:00:21
Just to put this on a scientific basis .. so to speak.
Tin, (Sn) a chemical element belonging to the carbon family, Group IVa of the periodic table. It is a soft, silvery-white metal with a bluish tinge, known to the ancients in bronze, an alloy with copper. Tin is widely used for plating steel cans used as food containers, in metals used for bearings, and in solder. Tin is nontoxic, ductile, malleable, and adapted to all kinds of cold-working, such as rolling, spinning, and extrusion. The colour of pure tin is retained during exposure because a thin, invisible, protective film of tin(IV) oxide is formed spontaneously by reaction with the oxygen of the air. The low melting point of tin and its firm adhesion to clean surfaces of iron, steel, copper, and copper alloys facilitate its use as an oxidation-resistant coating material. Tin exists in two different forms, or allotropes: the familiar form, white (or beta) tin, and gray (or alpha) tin, which is powdery and of little use. The gray form changes to the white above 13.2º C (55.8º F), rapidly at temperatures above 100º C (212º F); the reverse transformation, called tin pest, occurs at low temperatures but is prevented by small amounts of antimony, bismuth, copper, lead, silver, or gold normally present in commercial grades of tin. atomic number 50 atomic weight 118.69 melting point 231.97º C (449.54º F) boiling point 2,270º C (4,100º F) density (white) 7.28 (gray.
Lead: metals used in the ancient world (the others are gold, silver, copper, iron, tin, and mercury). Its low melting point of 327º C (621º F), coupled with its easy castability and softness and malleability, make lead and lead alloys especially suitable for a wide range of cast products, including battery grids and terminals, counterweights, plumbing components, and type metal. With a specific gravity of about 11.35 grams per cubic centimetre, lead is the densest of the common metals, except for gold; this makes it a good shield against X rays and gamma radiation. Its combination of density and softness make it an excellent barrier to sound. Compared with other metals, lead is a poor conductor of heat and electricity, although it has excellent corrosion resistance when it can form an insoluble protective coating on its surface. The metal has a face-centred cubic crystal lattice structure.
So, you got two low-melting metals, one a poor consuctor of electricity and heat. Which one would you make cookware out of ? =)
Let me throw in a couple of spanners. You need a good knowlesde of tin metallurgy to make bronze. Also, tin extraction is mentioned as early as Nagarjuna's "rasaratnakara" (~950 CE).
Spanner 2: Bidri ware dating back at least to the 15th/16th century CE, employs zinc, as does brass.
So, Zinc (Zn), chemical element, low-melting metal of Group IIb (zinc group) of the periodic table, essential to life, and one of the most widely used metals. Zinc was known in Roman times only in combination with copper as the alloy brass. The metallurgists of India seem to have isolated the individual metal as early as the 13th century, and those of China had achieved large-scale production of zinc by the 16th century. Freshly cast zinc has a bluish silver surface but slowly oxidizes in air to form a grayish protective oxide film. Highly pure zinc (99.99 percent) is ductile; the so-called prime western grade (99.8 percent pure) is brittle when cold but above 100º C (212º F) can be rolled into sheets that remain flexible.
Just to mak ethis interesting, anyone think eeyam = zinc? *grin!*
- From: ravi sundaram (@ 192.149.1.187)
on: Mon Jan 22 07:48:43
Sundar,
zinc is thuththanaagam. It is not iiyam. But mayil thuththam the well known poison is copper sulphate.
A Bear of Bery Little Brain:
There is a reason why I mentioned Young's Modulus and not the melting point. We have a mother with a vessel and wants to find out if it is made of tin or lead. The simplest (non destructive) test to distinguish between these two metals would be by their "relative strengths". Just squeeze the circular mouth slowly and try to deform it to a oval. Then find another vessel of known material with equally thick walls, do the same. One should get a pretty good idea of the "strength" of the unknown material and guess if it is lead or tin.
Since the iiya sombu usually has very thick walls,
the only other cooking utensil with equally thick walls would be castiron or Hindalium kaRaai. (also known as iluppa satti, bondli, etc), or Aluminium or stainless steel pressure cookers. So it would be a difficult task to guess the strength of iiya sombu in the kitchen. So I did not post the rather elaborate experiments I was suggesting to Susmitha.
I have not brought my iiya sombu to the U.S. I would not mind doing destructive tests on it. I think one can scratch the outer surface with sandpaper to get a powdery sample and use high school chemistry sets to determine the metal.
JB: I was very sure about lead being tin. Upto my XI std I studied in tamil medium. I recollect after your posting that tin was called kaariiyam in the books.
But it is very unlikely that I am the only one who read about the lead poisoning of the Romans and the printing press type setters and made the connection between lead and iiya sombu. So if it is really true that iiya sombu is actually lead sombu, I am sure the many other tamils, especially
doctors would have brought it to the public attention. Our X Std science text book did talk about the inner coatings given to brass vessels and how food will react with brass and generate poison without this coating. So I am sure the text books would have warned about lead vessels too.
I am very confused now. But since I live by the motto, "thaan petra inbam peruka iv vaiyam" :-) I am dishing it out to the whole world and am confusing everyone ;-) Let me see what else I can turn up in the net search. So far keywords: "india cooking vessel utensil lead tin warning" etc have not turned up any warnings about lead vessels. I found that pewter is actually an alloy of tin and lead, used in drinking cups.
- From: ravi sundaram (@ 192.149.1.187)
on: Mon Jan 22 08:44:22
Found one report of lead poisoning due to rasam.
http://www.leadpoison.net/environment/empirical.html
Relevant passage:
Case Series in Vellore
Dr. A. M. Cherian
A few cases highlighting some unusual sources of clinical lead poisoning in Vellore, India are presented herewith.
Case 1: A forty-five year old lady was brought to emergency with seizures; she had a history of generalized seizures of 5
years duration and diminished vision of 2 years duration. She was previously seen in ophthalmology and neurology where
a diagnosis of optic atrophy was made and was continued on anti convulsant drug. She was also given treatment by her
local doctor for hypertension and episodes of abdominal pain and vomiting.
On examination, she was semiconscious, responding to pain only. There was pallor and
her BP was 180/100 mmHg. Fundus examination revealed optic atrophy with a visual acuity of 6/60 in both eyes.
Investigation showed anemia with PCV of 28%,and 24 hrs lead level of 173 mg (Normal-45-120mg).Serum lead level was
135 ægm%. EEG showed bilateral slow wave dysfunction.
Bone marrow exam showed ring conderblast. All other investigation including CT brain and lumber puncture were normal.
Diagnosis was lead poisoning and she was treated with penicillamine and improved gradually. The source of poisoning was
the cooking utensil used for Rasam, which was kept in it for long periods for fortification of taste.
Family screening - Husband 50 years, staying with patient had slight tremor of bands and investigations showed lead
poisoning, and he was treated with penicillamine.
Will report if I find more.
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