Describe the incident when Johnny was injured and what led up to it?

On Sunday, Johnny works to finish the basin as planned, even though Mr. Lapham forbid them to work on Sunday.  Dove, Dusty, and Mrs. Lapham all help him in the shop. Entrusted with this important task, Johnny becommes even more insufferable than usual. He bosses everyone around and even speaks rudely to Mrs. Lapham. To get revenge, Dove hands him a cracked crucible to melt the silver in. He thinks the silver will spill on the furnace and make Johnny look like a fool. This happens exactly as Dove plans. When Johnny sees the spill, he is so surprised he slips and his right hand lands on the furnace.

Johnny’s hand is horribly burned. Although the local midwife, Gran’ Hopper, does the best she can to treat it, she forgets to keep the hand flat and instead allows it to turn in on itself. Because of this, he loses the use of his thumb and is permanently crippled. Johnny will never be a silversmith.