Page:The American Cyclopædia (1879) Volume VI.djvu/694

 EPIDEMIC DISEASES EPILEPSY and temples dedicated to other divinities. Pil- grimages were made to this temple by the sick, and every four years a festival was celebrated here. It was plundered by the Romans. Some of its foundations are still traced, and the the- atre is one of the best preserved of all the old Greek edifices. The modern Epidavro is a small village, noted as the place of assembly of the first Greek congress in 1821, which promulgated the constitution called after the place. EPIDEMIC DISEASES (Gr. &rf, upon, and <%*of, people) are those which attack at the same time a great number of persons in a given locality, depending on some temporary, acci- dental, and generally inappreciable cause ; dif- fering in this respect from endemic diseases, or those developed under the influence of some constant or periodic cause. Many diseases, ordinarily sporadic, may become epidemic un- der certain ill-understood conditions ; or some new disease, introduced by contagion or other favorable circumstances, may spread epidem- ically. Having ascertained the cause, or the epidemic tendency of the season, the treatment must depend on the nature of the disease and the constitution of the patient; even when remedial measures seem powerless, the phy- sician can do much to check an epidemic by in- spiring confidence and moral courage, and by withdrawing the attention of a community from the continual consideration of any sup- posed causes. The human constitution may become acclimated to epidemic diseases in ma- larious climates, as is shown by the greater mortality among new comers. In the white races there is no acclimation against endemics of intermittent and bilious fevers and other marsh diseases, as the experience of our south- ern states and the Pontine marshes of Italy fully proves. Negroes to a certain extent be- come insusceptible to the effluvia of the rice fields, but not so much so to the causes of dis- ease on the cotton plantation; they suffer more than whites from cholera, typhoid dis- eases, plague, and smallpox, but are much less liable to intermittents, and the smallest admix- ture of negro blood is a great protection against yellow fever. (See ACCLIMATION.) EPIDERMIS, or Cntlele, the thin semi-trans- parent pellicle which covers the surface of the dermis or true skin. It is composed of layers of tessellated or pavement epithelium cells, of a flattened oval or polygonal shape, and about T^-JJ- of an inch in diameter ; each cell contains a nucleus with several distinct paler granules. The cells are developed from germs supplied by the basement membrane, nourished by the sub- jacent vessels, and cast off externally from time to time, to be succeeded by others ; when first formed they are spherical, gradually becoming dry and flattened ; the deeper layers are more distinctly cellular, while the outer ones are scale-like. The epidermis has no vessels nor nerves, but is pierced by the ducts of the seba- ceous and sweat glands, and by the shafts of the hair or feathers. The rete mucosum seems to be composed of the same microscopic ele- ments as the overlying epidermis, being the principal seat of the pigment cells which give the color to the skin. The epidermis covers the whole exterior of the body, even the front of the eye, and is continuous with the epithe- lium of the internal mucous membrane ; it is thickest in those parts most subjected to fric- tion, as on the heel and the palms of the hands, where it becomes almost as hard as horn. Its use is to protect the sensitive true skin from mechanical injury or the contact of air ; in the living body, when abraded, it is speedily re- placed; but when it is removed after death, the cutis underneath soon becomes brown and dry. The chemical composition of the thick epidermis of the heel has been found to be very nearly the same as that of the corneous matter of nails, hoofs, horns, and hair. The epidermis is familiarly seen in the occurrence of blisters, constituting the raised portion un- der which the fluid is effused. The epidermis prevents not only evaporation from the dermis, but also absorption of fluids from without ; it is well known to the physician that in intro- ducing medicinal agents into the system by the endermic method, the process is rendered very much more rapid and effectual by previously removing the epidermis by a blister. EPIGOM ' (Gr. fafywoi, descendants), the seven sons of the seven Argive heroes who, under command of Adrastus, made an unsuc- cessful expedition against Thebes, in which all but the leader lost their lives. At the sugges- tion of Adrastus, the sons made war on Thebes ten years later, to avenge the death of their fathers. Their names are not the same in all the accounts, but as usually given they are Alcma3on, ./Egialeus, Diomedes, Promachus, Sthenelus, Thersander, and Euryalus. Under command of Alcmseon, the Argive forces at- tacked and defeated the Thebans, who lost their leader, Laodamas ; while of the Epigoni, ^Egialeus, the son of Adrastus, was slain. The Thebans then abandoned their city and sued for peace, but the Argives razed it to the ground. This war of the Epigoni was cele- brated in verse, and statues of the seven heroes were erected at Delphi. EPILEPSY (Gr. eirtfurfia, from tKikafifiavuv, to seize upon), a disease characterized by sud- den and temporary seizures of unconsciousness, accompanied by convulsions. This is one of the most horrible diseases that afflict mankind, and it is not surprising that in ignorant ages, in Rome, in Egypt, and elsewhere, epileptics were considered as having excited the anger of the gods, or were worshipped as possessing supernatural powers. This was due to the violence and extraordinary force developed by the muscles in epileptic convulsions; the screaming, the changes in color, the contor- tions of the face, and the biting of the tongue, followed by a comatose state and afterward by a degree of mental alienation. There are so