College boys sometimes procure from the chemical laboratories of their institutions materials which are used with telling effect on the social functions of higher or lower classes; in one instance a banquet was cleared of guests by the conscienceless introduction of chemicals just before the festivities were to have begun. Efforts to introduce powerful gases as weapons in war have failed because the effect is not confined to the enemy. Gases which are offensive are not always positively harmful, but as a rule those which offend the nose are to be avoided. Some deadly gases do not affect the sense of smell at all, as in the case of earth damp which stupefies and kills men in mines and wells without warning. But the nose is a great detector of bad air, especially that of a noxious character, and sewer gas as well as other poisonous airs which bring on the worst types of fever are offensive to one who is not living all the time within their range. But a small part of the mucous membrane of the nose is the seat of this important sense. The olfactory cells are not as easily examined and traced in their connections as are the end organs of the sense of taste. Yet the anatomist finds in the structure of the noses of the flesh-eating animals sufficient indications of their superiority over man in the exercise of the sense of smell. The peculiar development of the membrane and the complicated structure of the nasal cavities in the region occupied by the cells which are supposed to connect with the extreme divisions of the olfactory nerve are all that one would expect from the differences in endowment. Aside from peculiar powers of smell there are other endowments of noses which are remarkable. The common hog has a snout that is easily moved and has great strength. He can take down a rail fence with it quite as skillfully as a boy would do it. He can turn a furrow in the soil in search of eatable roots, and when the ground is frozen to a considerable degree of hardness he pursues his occupation with unabated zeal and no evident embarrassment. The fresh-water sturgeon has a large gristle in his nose which boys sometimes convert into a substitute for a rubber ball. His nose is a useful instrument in securing food from the mud in the river bottom. The rhinoceros has a fierce horny protuberance rising from his nose which is valuable to him in war. Indeed some are equipped with two horns, one behind the other. The female rhinoceros with one horn guides her calf with it, causing him to move ahead of her, but the female of the kind with two horns does not use them upon her offspring at all except in anger, and her calf is content to follow her in feeding.