In the North they also have a strange custom, called chewing gum. This gum is the exudation from certain trees, and is manufactured into plates and sold in an attractive form, merely to chew like tobacco, and young and old may be seen chewing with great velocity. The children forget themselves and chew with great force, their jaws working like those of a cow chewing her cud, only more rapidly; and to see a party of three or four chewing frantically is one of the "sights" in America, which astonishes the Heathen Chinee and convinces him that, in the slang of the country, "_there are others_" who are peculiar. There are many manufactories of this stuff, which is harmless, though such constant chewing can but affect the size of the muscles of the jaw if the theory of evolution is to be believed; at least there will be no atrophy of these parts. In New England, the northeastern portion of the country, this habit appeared to be more prevalent, and I asked several scientific persons if they had made any attempt to trace the history of the habit or to find anything to attribute it to. One learned man told me that he had made a special study of the habit, and believed that it was merely the modern expression in human beings of the cud chewing of ruminating mammals, as cows, goats, etc. In a word, the gum-chewing Americans are trying to chew their cud as did their ancestors. Any habit like this is seized upon by manufacturers for their personal profit, and every expedient is employed to induce people to chew. The gum is mixed with perfumes, and sold as a breath purifier; others mix it with pepsin, to aid the digestion; some with something else, which is sold on ships and excursion-boats as a cure or preventive for seasickness, all of which finds a large sale among the credulous Americans, who by a clever leader can be made to take up any fad or habit.