In a long-term study of the blood vessels of the brain, 1-3 contrast media were used as
injection masses to demonstrate on roentgen film the course and cerebral relationship of
these vessels. One of these media was a water solution of lead (lead sulfamate*), which,
when injected into either the internal cerebral veins or the arteries coursing over the cerebral
cortex, filled a myriad of fine venous channels traversing the white matter of the cerebral
hemisphere. Interconnections between the superficial and the deep venous system of the …