Mosquito tobacco is used in China for protection from what is to us a great summer pest. The ingredients are pine and juniper sawings, wormwood leaves, and tobacco leaves reduced to powder, a small portion otun-wang and arsenic. The quantity of the latter is exceedingly small, and can hardly be injurious to health, as this tobacco is used by probably one hundred million human beings. The odor is not at all disagreeable. It is no luxury to the mosquitos, for in two or three minutes after it is ignited, not a bug or mosquito is to be seen.