Page:The American Cyclopædia (1879) Volume IV.djvu/622

610 CIRCULATION CIRCUMCISION physiological congestion. Its capillary blood vessels enlarge in diameter, and admit a great- er quantity of blood than before. The rapidity of the capillary circulation is at the same time increased, so that a larger quantity of blood than usual passes in a given time through the vessels of the part. When the period of func- tional activity comes to an end, the capillary vessels return to their original diameter, admit a smaller quantity of blood, and the color of the organ resumes its ordinary pallid state. These variations in the capillary circulation are due to the action of the smaller arteries. The arteries generally, as we have already shown, are characterized mainly by their passive phys- ical property of elasticity. But the medium- sized and especially the smaller arteries are provided also with minute muscular fibres, running round them in a circular or transverse direction, and forming part of their middle coats. By the greater or less degree of con- traction of these muscular fibres, the calibre of the arterial twig is enlarged or diminished, and consequently the quantity of blood admitted by it to the capillary vessels varies in a corre- sponding degree. Thus, although the circula- tion everywhere is kept up by the central force of the heart's action, yet its influence on par- ticular parts is modified in degree by the con- tracted or relaxed condition of the smaller ar- teries. General rapidity of the circulation. The time required for the blood to traverse the entire round of the double circulation, that is, through the lungs and the general capillary system, returning again to the right side of the heart, has been found by experiment to be very much shorter than was formerly supposed. The observations of Hering, Poisseuille, Blake, and Matteucci on this subject were made, for the most part, by injecting into the jugular vein of one side upon the living animal some substance, like ferrocyanide of potassium, which could readily be recognized by its chem- ical reactions. Blood was at the same time drawn from the jugular vein of the opposite side ; and the interval which elapsed before the appearance of the foreign salt in the blood drawn from this second opening indicated the time required for the blood to pass from the point of injection through the vena cava to the heart, from the right side of the heart through the lungs to the left cavities, from the left ventricle through the carotid arteries and the capillary vessels of the head, and thence down- ward to the jugular vein on the opposite side. The average results obtained from these ex- periments were as follows : TIME REQUISITE FOR THE COMPLETE CIRCULA- TION OF THE BLOOD. In the horse 28 seconds. " dog 1ft " goat 18 " " fox 12tf " " rabbit 7 In man the complete double circulation prob- ably requires from 15 to 25 seconds. CIRCUHCELLIONES, fanatics who, about the year 317, in the war of the Donatists in Africa, occasioned by the election of the Carthaginian bishop Csecilianus, espoused the cause of the Numidians or Donatists, and went about as marauders to intimidate the Carthaginian par- ty, and to commit excesses in which the Do- natists rejoiced, but for which they were un- willing to be responsible. They had a strong desire for the honor of martyrdom, and sought it at the hands of the dominant party by vio- lence upon the prevalent social institutions and the civil rights of the citizens. Thus they threw themselves between the debtor and cred- itor, and demanded the discharge of the claim by the creditor on pain of death. Whenever they met a master and a slave, they manumit- ted the slave, and compelled the master to take his place. Constantine treated these excesses with forbearance ; but Constans, his successor, deprived the Donatists of their churches, and attempted to bring them to peace. This kin- dled the fanaticism of the Circumcelliones anew. Headed by Fasir and Axid, they committed new depredations, styling themselves Agonistici, and their leaders, " leaders of the sons of the Holy One." Their frenzy increased so furiously that they committed suicide in great numbers, and the Donatist bishops were obliged to apply to the civil power to restrain them. CIRCUMCISION (Lat. fircumrisw, a cutting around), a practice of eastern nations, consist- ing in cutting off the prepuce or foreskin in males and the internal labia in females. Among the Jews it is a strictly religious rite, and is used only on males. In ancient times it was not only obligatory on all males born of Jewish parents, but also on all proselytes, and on all the slaves of Jewish masters. The rite origi- nated, according to the book of Genesis, in the command of God to Abraham, and was na- tionalized by Moses. It was thenceforth prac- tised by the Jews, except during the journey through the wilderness. Circumcision among the Jews is performed on the eighth day after birth. From the fact that this rite was re- quired by religious ordinance, the term " un- circumcised " became a term of national re- proach, and is analogous to the word "hea- then " as used by Christian writers. The Egyp- tians, according to Herodotus, practised cir- cumcision. It is certain that at a later period in Egyptian history, under Persian and Greek influence, circumcision was confined to the priests and sages, but Herodotus makes no lim- itation in his statement. On the other hand, he states that the tonsure was confined to tlie priests. He also says that the Colchians (an Egyptian colony, as he believed) practised cir- cumcision. The same authority tells us that the Ethiopians practised it; and to this day the Coptic and Abyssinian Christian churches observe the custom. The Abyssinian church imposes the rite on both sexes. The Epistle of Barnabas testifies to the fact of Egyptian circumcision, and declares also that the cere-