The lead powder that settled after the fire is toxic to humans, making researchers take careful precautions when working in the cathedral.

火灾后沉淀的铅粉对人体有毒，因此研究人员在大教堂工作时要小心谨慎。

Leonardo is thought to have melted lead oxide powder, which has an orange color, in linseed or walnut oil to make it thicker and dry faster.

人们认为，莱昂纳多在亚麻籽或核桃油中熔化了橙色的氧化铅粉，以使其变得更稠，干燥更快。