A 48 year old man working as glass bangle maker presented with tremors of his hands. In which of the following heavy metal poisoning 'Hatter's shakes' are seen?

Danbury tremors are seen with chronic mercury poisoning (hydrargyrism). It occur first in the hands, then progress to lips and tongue and finally involves arms and legs. The advanced condition is called Hatter's shakes or glass-blower's shakes, because they are common in persons working in glass-blowing and hat industries. The most severe form is known as concussio mercuralis, in which no activity is possible. Ref: The Essentials of Forensic Medicine and Toxicology, 27th edition, Page 477.