"We always sterilize our lips now before we kiss him--it's so much safer, you know." Aunt Hannah sat down limply, the baby still in her arms.
"Fiddlededee, Billy! What an absurd idea! What have you got in that bottle ?" "Why, Aunt Hannah, it's just a little simple listerine," bridled Billy, "and it isn't absurd at all.

It's very sensible.

My 'Hygienic Guide for Mothers' says--" "Well, I suppose I may kiss his hand," interposed Aunt Hannah, just a little curtly, "without subjecting myself to a City Hospital treatment!" Billy laughed shamefacedly, but she still held her ground.
"No, you can't--nor even his foot.

He might get them in his mouth.

Aunt Hannah, why does a baby think that everything, from his own toes to his father's watch fob and the plush balls on a caller's wrist-bag, is made to eat?
As if I could sterilize everything, and keep him from getting hold of germs somewhere!" "You'll have to have a germ-proof room for him," laughed Alice Greggory, playfully snapping her fingers at the baby in Aunt Hannah's lap.
Billy turned eagerly.
"Oh, did you read about that, too ?" she cried.