Dip them in milk, then in flour, and sauté them slowly in butter in a frying pan over medium heat until golden brown all over — six to eight minutes. Remove to hot serving dish, salt and pepper lightly, and sprinkle with lemon juice and finely chopped parsley. Over all, pour what remains of the browned butter in the frying pan and garnish with a slice of lemon.
From French Cooking in Old Detroit Since 1701 by Lucy and Sydney Corbett.
"In 1910 Detroit produced, shipped, and consumed 12 tons of frog legs, 6 million pairs of legs (called 'saddles')," writes Bill Loomis in the article "When Frogs Were King" for Hour Detroit.