The severest penalty inflicted by the Druids was the interdiction of the sacrifice to those who had offended them. Woe to the unhappy wretch on whom the awful sentence fell! He ceased to be considered a human being. Like the beast of the forest, his life was at the mercy of any one who chose to take it. He lost all civil rights, and could neither inherit land nor sue for the recovery of debts; every one was at liberty to spoil his property; even his nearest kindred fled from him in horror. They were also accustomed to sacrifice human victims on their altars, or burnt them as offerings to the gods, in wicker baskets.
It is now time to give some account of the dogmas of this extinct religion, once the general faith of Britain. Like the monks of the Middle Ages, the Druids of the higher orders lived in community in the remote depths of the vast gloomy forests, where they celebrated their rites. In these retreats they initiated the youthful aspirants for the priesthood, who frequently passed a novitiate of twenty years before being admitted. Disciples of all ranks flocked to them, despite the severity of the probation, tempted, no doubt, by the honours and great privileges attached to the order, amongst which exemption from taxation and servitude was not the least. The mistletoe is said by Pliny to have been a peculiarly sacred plant in their rites.
The Druids taught the immortality of the soul, and its transmigration from one body to another, till, by some extraordinary act of virtue or courage, it merited to be received into the assembly of the gods. Cæsar, in his "Commentaries," also informs us that they instructed their pupils in the movements of the heavenly bodies, and the grandeur of the universe. Their knowledge of mathematics must have been considerable, since we find it applied to the measurement of the earth and stars. In mechanics they were equally advanced, judging from the monuments which remain to us. Of these, the most remarkable in England are Stonehenge, consisting of 139 enormous stones, ranged in a circle; and that of Avebury, in Wiltshire, which covers a space of twenty-eight acres of land. But the largest of all the Druid temples is situated at Carnac, in the department of Morbihan, in France. It is formed of 400 stones, varying from five to twenty-seven feet in height, and ranged in eleven concentric lines. It should be mentioned, however, that some authorities consider these erections to belong to a period anterior to the arrival of the Celts in Europe, though they were probably utilised by them.