Just like cigarette.

Look," and he inhaled some of the vapour and blew it out through his nostrils, after which his face seemed to change to me, though what the change was I could not define.
I hesitated till Scroope said: "Come, Allan, don't shirk this Central African adventure.

I'll try if you like." "No," said Harut brusquely, "_you_ no good." Then curiosity and perhaps the fear of being laughed at overcame me.

I took the bowl and held it under my nose, while Harut threw over my head the antimacassar which he had used in the mango trick, to keep in the fumes I suppose.
At first these fumes were unpleasant, but just as I was about to drop the bowl they seemed to become agreeable and to penetrate to the inmost recesses of my being.

The general affect of them was not unlike that of the laughing gas which dentists give, with this difference, that whereas the gas produces insensibility, these fumes seemed to set the mind on fire and to burn away all limitations of time and distance.