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Bruce Tai

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    Stradivari violins, hi-fi audio, music collection

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  1. Dear friends, My wife Wenjie and I wrote new article discussing the role of alchemy in Cremonese violin making has appeared in the December issue of The Strad: https://www.thestrad.com/current-issue/wood-treatment-the-magic-touch/13907.article It discusses our new findings on chemical treatments in Cremonese spruce plates, published this summer in Angewandte Chemie. Moreover, we described our views on the influence of alchemy in violin making, based on the analytical results of varnish and wood accumulated over the years. Alchemy seems so arcane and mysterious at first. Modern chemists pay basically zero attention to what alchemists have written. I would like to thank Joseph Nagyvary, Andres Preuss, and Jose Maria Lozano who have discussed alchemical issues with me over the years. I learned a lot from them. However misguided the old alchemical beliefs were, there has always been practical industrial chemistry throughout human civilization. So I try to link practical alchemy to what Cremonese masters have done. Spiritual alchemy, on the other hand, could have provided some theoretical inspirations for the old masters. In the end, we failed to uncover a direct link between alchemy and Cremonese makers in historical records. But I learned that Monteverdi, the son of a Cremonese druggist, was also an alchemist and famously so, even being called a "grand chemistry professor." Monteverdi recommended Cremonese masterworks (presumably Amati) over Brescian violins in response to Galileo's inquiries in 1637 (Hills, p 241). We are a glad to report that a 1619 Amati viola already incorporated chemically treated spruce and maple. From Wenjie's perspective, there may have been a creative ecosystem that allowed Cremonese makers to absorb scientific knowledge from experts in other areas. So Cremonese masterpieces were not simply born out of luck, personal genius, accident, or constant tinkering. There was an creative, intellectual atmosphere that allowed them to be created. The best fruits always grew out of the fertile ground. At least that's our theory.
  2. Ars Technica had mistakenly mentioned varnish in the title, I have contacted them to have it corrected. Study confirms superior sound of Stradivari is due to how wood was treated https://arstechnica.com/science/2021/09/study-confirms-superior-sound-of-a-stradivari-is-due-to-the-varnish/ We will have a Strad article in December to explain our finding and its relation to alchemy. Before we conducted this study, no one could predict what we will find in Amati, Stradivari, and Guarneri spruces. I believed that we will find some chemical additives. But the results are still surprising for us. Each family had different recipes. Strad and DG did not really use untreated wood to build violins. Sometimes they used heavily treated woods. That is worth knowing, if you care about what old masters did. We made all our research results openly available for all. The Excel table in the Supplementary Information has the elemental compositions of every wood sample we tested, easy to download, read and analyze. Next, we plan to analyze old violins from other cities, even 19th-century France. But it will take years and sufficient resources to complete.
  3. That's good to know. Is this a recent CT measurement?
  4. The reason I say alum and potash is because they are fuzzy terms but historically accurate terms. Renaissance alchemists named chemicals that way for practical reasons and limitations. Potash (pot ash) can be made from burning wood or grass. Depending on the temperature, it can be K2CO3 and KOH in different ratios. A lot of CaO may be present, but they can be removed by some means. A purer kind of potash can be made from burning potassium tartrate (tartar, wine stone) or burning potassium bitartrate (cream of tartar). The product is called burnt tartar or Alumen faecis, high-purity K2CO3. Alum has many names in medieval texts but dyer's alum is almost always KAl(SO4)2. Ancients knew how to make highly pure synthetic KAl(SO4)2 by recrystallization. They also prepared NH3Al(SO4)2 similarly, also called alum. Natural alum may be KAl(SO4)2 or Al2(SO4)3. Al2(SO4)3 was chemically produced in large quantities in the 19th century for industrial use. I think an entire book may be written about alum's history. I am just giving a very brief summary.
  5. https://www.bormanviolins.com/pdfs/VSAPBormanandStoel.pdf This paper has different measurements for the Titian Strad Density: spruce 0.368; maple 0.579 Weight: top 61.7g (no bass bar); back 93.6g
  6. I can imagine that CT density may be a few percent off. But 48.1 and 66.6 is night and day difference. I have never done violin CT. I wonder how reliable it is. So what is the lightest Strad top out there? Joseph curtin reported 54 and 55.5 grams without bass bar in a Strad magazine article if I remember correctly.
  7. Assuming 550 cm^2 (includes arching), 2.3 mm thick, 0.35 density, that's 44.3 g. Bass bar 4 g -> 48.3 g. Very close to the Titian measurements. Am I more correct this time?
  8. As you can see from our published photos that have been color-calibrated, the answer is no.
  9. So David, what is the area of the violin plate? Is it 500 square centimeter? I am trying to calculate average thickness based on the area. But the area number is difficult to find on the net. What is the average thickness of the Titian top?
  10. Thanks a lot. I have read this thesis before but missed the data. The top is 48.1 g with bass bar with wood density of 0.35. So the average thickness may be 0.24-0.25 mm. That's a very thin top made of low density spruce. And yet it survived well and sounds great. And yet Joseph Curtin thought a 54 g top without bass bar (for a Strad) is already very light.
  11. In a nutshell, the relevant ones are: Minor additives (tens of ppm): copper sulfate, iron sulfate Major additives (thousands of ppm): 1. Stradivari: table salt, potash 2. Del Gesu: alum, lime We don't know the order and application conditions. We don't know about washing or potential baking/boiling steps.
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