When they came into a hot climate the fire of the sacrifices and domestic cookery was removed out of the house; but the dead were probably still for a while buried in or near it, and the tulsi was planted over their graves, at once for the salubrious fragrance it diffuses and to represent the burning of incense on the altar of the family Lar.
If the latter be insoluble, the gas diffuses into the solution and, when this becomes saturated, escapes into the air.
The quantity of substance which diffuses through unit area in one second may be taken as proportional to the difference in concentration between the fluids at that area and at another parallel area indefinitely near it.
At the same time, carbon dioxide diffuses from the venous blood into the alveolar sacs.
The unity of procedure consists in the fact that every sacrifice involves putting the divine in communication with the profane by an intermediary - the victim - which may be piacular or honorific, a messenger or a means of divination, a means of alimenting the eternal life of the species or a source of magical energy which the rite diffuses over objects in its neighbourhood.