A German chemistry journal is not the first place one would expect to find an article on violins, but Angewandte Chemie has published an article on the secrets of the 17th-century Italian luthiers.
The sound of the stringed instruments that came from the workshops in Cremona by masters such as Antonio Stradivari and Andrea Guarneri have rarely been matched, but now scientists believe that they have identified the chemical treatments that gave the instruments their characteristic rich tone.
In the 1950s, Joseph Nagyvary, a Hungarian chemist and violin maker, now 87, took lessons on a violin once owned by Albert Einstein. Einstein himself – who once said, “Life without playing music is inconceivable for me.” – had long been fascinated by the construction of violins and why their sounds varied so much. From 1983, at Texas A&M University, Nagyvary devoted his research to the study of recreating the famous Cremona sound.
He and an international team of researchers took tiny wood shavings from Stradivari and Guarneri instruments taken during restoration procedures. Nine different chemical and structural analysis tests were performed on these samples.
Apothecaries in Cremona supplied chemicals to the instrument makers that were applied to the wood as preservatives. Although both Stradivari and Guarneri used borax and metal sulphates as fungicides, each had his own secret recipe: Stradivari used table salt to dry the wood and potash to make the fibres denser, while Guarneri used alum and lime. Interestingly, centuries earlier, Chinese zither-making manuals recommended similar techniques by using alkaline potash and lime. A scan carried out by the team of scientists suggests that this process changed the microscopic structure of the soundboards.
On the Texas A&M University site, Nagyvary says,
Borax has a long history as a preservative, going back to the ancient Egyptians, who used it in mummification and later as an insecticide. The presence of these chemicals all points to collaboration between the violin makers and the local drugstore and druggist at the time. Both Stradivari and Guarneri would have wanted to treat their violins to prevent worms from eating away the wood because worm infestations were very widespread at that time.
This new study reveals that Stradivari and Guarneri had their own individual proprietary method of wood processing, to which they could have attributed a considerable significance. They could have come to realize that the special salts they used for impregnation of the wood also imparted to it some beneficial mechanical strength and acoustical advantages. These methods were kept secret. There were no patents in those times. How the wood was manipulated with chemicals was impossible to guess by the visual inspection of the finished product.
Varnish recipes were not secret because varnish is not a critical factor of tone quality. However, the treatment of fresh spruce planks is critical for the final sound.
Nagyvary says that further research is needed to clarify other details of how the chemicals and wood produced pristine tonal quality.
First, one needs several dozens of samples from not only Stradivari and Guarneri, but also from other makers of the Golden Period (1660-1750) of Cremona, Italy. There will have to be better cooperation between the master restorers of antique musical instruments, the best makers of our time, and the scientists who are performing the experiments often pro bono in their free time.
Hwan-Ching Tai is an associate professor of chemical biology at National Taiwan University and one of the study’s authors.
The finest Strads are brilliant and sweet; the finest Guarneris are dark and sonorous. I like the Guarneri even better. According to our research, the chemical treatments applied by Stradivari and Guarneri were quite aggressive.
Such procedures carried the risk of damaging the wood, also involving extra time and cost . . . So the benefit must have been more than just preservation. We believe strongly that the benefit they were pursuing was acoustic improvement.
It is not yet possible to reproduce such an instrument:
Even in the 1800s some violin makers were already experimenting with chemically treated woods, but the results were usually terrible because they lacked good guidance. Our paper provides many new clues on how Stradivari and Guarneri may have done it – but not the exact recipes and protocols. Many violin makers will at look our data and carry out experiments on their own.
A few of them may eventually surpass Stradivari, but we won’t know until 100 years from now, after their instruments have properly aged.