+199+. Where water cannot be had, usage in Islam and in some forms of Christianity permits the substitution of sand or dust--both thought to have cleansing power. Similar power is ascribed to urine and dung of domestic animals.[369] Such usages may originate in a belief in the physical cleansing efficacy of those substances (the Toda women employ dried buffalo's dung in household cleaning), or they may be supposed to derive their efficacy from the sacredness of the animals. The Todas also make much use of a certain bark for purification.[370] The origin of these customs is obscure; they go back to times and conditions for a knowledge of which data are lacking--possibly to the early conception of the sacredness of all natural objects.[371] It is less difficult to explain the belief in the purifying power of fire. Its splendor and utility caused it to be regarded as a god in India and Persia, and if it was also destructive, it often consumed hurtful things. It was sacred, and might, therefore, be a remover of impurity. Its employment for this purpose is, however, not frequent;[372] it is oftener used to consume corpses and other unclean things. +200+. In the more developed religious rituals, sacrifice is a common accompaniment of purifying ceremonies, the object being to procure the forgiveness of the deity for the offense held to be involved in the impurity; the conception of sin in such cases is sometimes physical, sometimes moral, and the ceremony is always nearly allied to one of atonement. In the Hebrew ritual a human bodily impurity and the apparatus of the temple alike require a sin-offering.[373] In India the bath of purification stood in close relation with a sacrifice.[374] In Greece the two were associated in the cults of Apollo and Dionysos and in ordinary worship in general.[375] Thus, men and gods take part in the process of freeing the worshiper from the impure elements of life: the man obeys the law of the ritual, and the god receives him into association with the divine. +201+. Ancient examples of the purification of a whole community are the Hebrew ceremony on the annual day of atonement[376] (which is called in the text a purification), and the Roman Lupercalia.[377] An elaborate festival of this sort was observed every year by the Creeks;[378] it lasted eight days, included various cathartic observances, and ended in a physical and moral reconstruction of the nation. Among the Todas a similar ceremony for the purification of a village exists.[379]