For defense of the nation, especially the safeguard of the seas, Parliament allotted the king for life, 3s. for every tun of wine imported and an additional 3s. for every tun of sweet wine imported. From about 1413, tunnage on wine and poundage on merchandise were duties on goods of merchants which were regularly granted by Parliament to the king for life for upkeep of the Navy. Before this time, such duties had been sporadic and temporary. The most common ailments were eye problems, aching teeth, festering ears, joint swelling and sudden paralysis of the bowels. Epidemics broke out occasionally in the towns in the summers. The plague swept London in 1467 and the nation in 1407, 1445, and 1471. Leprosy disappeared. Infirmaries were supported by a tax of the king levied on nearby counties. The walls, ditches, gutters, sewers, and bridges on waterways and the coast were kept in repair by laborers hired by commissions appointed by the Chancellor. Those who benefited from these waterways were taxed for the repairs in proportion to their use thereof. Alabaster was sculptured into tombs surmounted with a recumbent effigy of the deceased, and effigies of mourners on the sides. Few townsmen choose to face death alone and planned memorial masses to be sung to lift his soul beyond Purgatory. Chantries were built by wealthy men for this purpose. Chemical experimentation was still thought to be akin to sorcery, so was forbidden by King Henry IV in 1404. Gold was minted into coins: noble, half noble, and farthing.