With the famous violins, the internal structure is identical, but the measurements are slightly different and the shapes of the tops and backs vary a little. Here's an article that mentions the evolution in the shapes of Stradivari's own violins over time.

http://darntonhersh.com/a-viol.....tradivari/

With modern-day copies at the workshop level or higher, I would assume luthiers copy the dimensions and shapes. But that may not always be true with factory instruments; many factories may use a standard pattern and simply varnish the violins differently to match the appearance of the famous violin being copied.

Gordon Shumway said

Irv said
Perhaps the old wood was also infected with fungus.  Experiments were made about ten years ago with infecting spruce slabs with Physisporinus vitreus.  After several months of treatment, the gas biocide eto (commonly used on hospital linens) was used to fumigate the wood.  Violins made from the wood performed very well.  The process was commercialized under the trade name Mycowood.  

Just when you thought you'd conquered toxic mould!

It's a nice theory, but maybe it's a send the cat to eat the rat, send the dog to eat the cat situation. I'm thinking, what if your furniture gets infected. And will you need a face-mask?

AndrewH said
Joseph Nagyvary, who concludes that the sound of old Italian violins was merely a result of the way lumber was typically transported at the time: logs were tied into rafts and floated down rivers, spent a lot of time in water, and had minerals deposited in the wood. Nagyvary has had impressive results with wood salvaged from the bottom of Lake Michigan. His best violins sound remarkably like Guarneris -- they're even indistinguishable with FFT analysis.  

I assume there's more to his first-hand explanation than "minerals were deposited". I'd hope to see a chemist's analysis. What I mean is, wood is already full of "minerals", and a long soak in running fresh water will just swell the wood with distilled water by osmosis. The movement of mineral molecules too from the water into the wood is a different process and beyond my knowledge, but they'd have to be ones that were more plentiful in the water than those already in the wood, wouldn't they?

How old was the wood salvaged from the bottom of lake Michigan? Obviously here the mud will be more mineral rich than the streams in the Alps. Perhaps in the alps and Italy the geology is mostly limestone, leading to very hard water.

Earlier I was going to respond that it felt to me that there were a lot of good luthiers in Canada (if you include guitars), where presumably also you get good cheap spruce, but I didn't get around to it, and also I think someone else commented somewhere else that Canada had very few luthiers using some criteria.  

I don't know the answer to your questions about the chemistry, because I haven't seen the chemical analysis. I assume the mineral content of the water would be different from the wood. I also understand that the water in most of Italy is extremely hard. I've seen tourist guidebooks warn readers about it.

The wood from the bottom of Lake Michigan varies in age, with most of it between 100 and 200 years old.