Col legno (Italian for with the wood) is a method of playing bowed string instruments (particularly the violin, viola, cello and double bass) whereby the strings are struck with the wood of the bow rather having the hair pulled across them.
... die Bearbeitung derselben durch Vera (1868)
Erläuterungen zu Hegels Encyklopädie der philosophischen Wissenschaften (1871).
Two other of his works on Hegel are ...