What is the name of the treaty that is designed to limit the spread of nuclear weapons and that  has been  signed by 190 countries?

What does the quote describe? “the closeness of the place, and the heat of the climate, added to the number in the ship, which was so crowded that each had scarcely room to turn himself, almost suffocated us….the shrieks of the women, and the groans of the dying, rendered the whole a scene of horror almost inconceivable.”