Making beaver hats, 1750. Although called beaver, little or no beaver fur was used. According to quality, nap on felt fabric was made of mixtures of beaver, musquash or rabbit fur, and cotton wool, and was bowed into condition by man at right. Felt base was softened in the 'kettle' and the nap then applied. Mercury was used during manufacture and the fumes inhaled by the men round steaming 'kettle'. Many hatters suffered from the uncontrollable shaking typical of mercury poisoning which damaged the central nervous system. The Mad Hatter in Alice in Wonderland exhibited these symptoms. From The Universal Magazine, (London, 1750). Engraving.