STING OF AN INSECT.--Apply a little hartshorn or spirits of camphor, or soda moistened with water, or a paste of clean earth and saliva. SULPHATE OF IRON (green vitriol).--Give syrup of ipecac, or mustard and warm water, or any convenient emetic; then magnesia and water. X. SELECTED READINGS TO ILLUSTRATE AND SUPPLEMENT THE TEXT. _Arranged in order of the subjects to which they refer_. "Read not to contradict and confute, nor to believe and take for granted, nor to find talk and discourse, but to weigh, and consider." LORD BACON. "He who learns the rules of wisdom without conforming to them in his life, is like a man who labored in his fields but did not sow." SAADI. SELECTED READINGS. _The figures indicate the pages in the text upon which the corresponding subjects will be found_. THE SKELETON. MAN, AS COMPARED WITH OTHER VERTEBRATE ANIMALS (p. 3).--Man, the lord of the animal kingdom, is constructed after the same type as the cat that purrs at his feet, the ox that he eats, the horse that bears his burden, the bird that sings in his cage, the snake that crawls across his pathway, the toad that hides in his garden, and the fish that swims in his aquarium. All these are but modifications of one creative thought, showing how the Almighty Worker delights in repeating the same chord, with infinite variations. There are marked physical peculiarities, however, which distinguish man from the other mammals. Thus, the position of the spinal opening in the middle third of the base of the skull, thereby balancing the head and admitting an upright posture; the sigmoid S-curve of the vertebral column; the ability of opposing the well-developed thumb to the fingers; the shortened foot, the sole resting flat on the ground; the size and position of the great toe; the length of the arms, reaching halfway from the hip to the knees; the relatively great development of the brain; the freedom of the anterior extremities from use in locomotion, and the consequent erect and biped position. In addition, man is the only mammal that truly walks; that is endowed with the power of speech; and that is cosmopolitan, readily adapting himself to extremes of heat and cold, and making his home in all parts of the globe.--STEELE'S _Popular Zoology_. FIG. 68. [Illustration: _Skeleton of Orang, Chimpanzee, and Man._] UNION OF FRACTURES (p. 8).--In the course of a week after a fracture, there is a soft yet firm substance, something between ligament and cartilage in consistence, which surrounds the broken extremities of the bone, and adheres to it above and below. The neighboring muscles and tendons are closely attached to its surface, and the fractured extremities of the bone lie, as it were, loose in a cavity in the center, with a small quantity of vascular albumen, resembling a semitransparent jelly.