lice, and in combat he may don silk brocade when no other material can serve in its place. It is unlawful to wear a mixed fabric in which pure silk outweighs the other fibres; the converse is permissible, and—on the sounder view—so is a cloth in which the two are equal. A garment that is merely embroidered or trimmed with the customary amount of silk is likewise allowed. Outside prayer and similar acts of worship, one may wear a garment that is ritually impure, but not the hide of a dog or a pig—except out of dire necessity such as the sudden onset of fighting; the same ruling, on the stronger opinion, applies to the hide of an unslaughtered carcass. According to the prevailing view, it is also permissible to burn impure fat for lighting.