He frequently discussed with his mother his lessons.

She was not well posted in the knowledge derived from books, and sometimes she mildly resented this newer learning which he brought into the home and seemed to intrude on her old-established ideas.

For instance, when the cold winter nights came, and Dorian kept open his bedroom window, the mother protested that he would "catch his death of cold." Night air and drafts are very dangerous, especially if let into one's bedroom, she held.
"But, mother, I must have air to breathe," said Dorian, "and what other kind of air can I have at night?
I might store a little day-air in my room, but I would soon exhaust its life-giving qualities at night.
You know, mother," he went on in the assurance of his newly acquired knowledge, "I guess the Lord knew what He was about when He enveloped the earth with air which presses down nearly fifteen pounds to the square inch so that it might permeate every possible nook and corner of the globe." Then he went on to explain the wonderful process of blood purification in the lungs, and demonstrated to her that the breath is continually throwing off foul matter.

He did this by breathing into a fruit jar, screwing on the lid for a little while, and then having the nose make the test.
"Some bed rooms I've gone into smell just like that," he said.
"Here, mother is a clipping from a magazine.

Listen: "'Of all the marvels of God's workmanship, none is more wondrous than the air.