he's given up the ganja, apparently, so has taken to smoking his finger as a substitute
Pho­to © karimsahai.com. Used with per­mis­sion.

Lee “Scratch” Per­ry and The Mad Pro­fes­sor per­formed At The Town Hall last night — Karim Sahai was there with cam­era in hand, and got some fan­tas­tic pix. Enjoy.