Regarding cigarette smoking.I hold never smoked but can a smoker explain to me the following facts:?

A friend of mine smokes more when he is emotional roughly something so does this mean that smoking calm one's nerves? And is this because it prevents oxygen getting to the brain, therefore the brain go a bit sleepy? He smokes 30 a day but if he know he has to jump somewhere the next hours of daylight where he is excluded to smoke, he will smoke 60 the day since to make up the quota he allows himself. When he does that, at the finishing of the day his tongue feel hard, approaching a block of pencil eraser rubber. But after a few days back to 30 a light of day, his tongue goes subsidise to normal. He have a snow white raised spot come up on the finale of his tongue, the size of about partly the diameter of the average cigarette. It matches the rest of his tongue contained by texture, but not in colour. Has anyone have knowledge of something approaching that before? He would never run to a doctor. Smoking is injurious to health and it is showing on your friend.
Smoking is desperate 4 your health man.