Misc: Who shot and killed himself while painting 'wheatfield with crows'?

Questions

In what year did Gail Borden invent condensed milk?

Who defined the contagion theory (infectious diseases caused by living agent transmitted from person to person) in 1546?

In what year did Girolamo Fracastoro define the contagion theory?

Who defined the continental drift theory in 1858?

In what year did Antonio Snider-Pellegrini define the continental drift theory?