AN UNEMPLOYED factory worker has proved his immunity to snake venom by letting a deadly mamba bite his bare arm. Through a process of building up his immunity to poison by injecting diluted venom 45-year-old Tim Friede is able to not only survive a snake bite from a black mamba, which normally kills anyone bitten within just 20 minutes, but instead appears totally unaffected. This indifference by Tim is despite the bloody wound to his arm the lethal creature caused when Tim placed the mamba's jaws around his arm and the snake took a bite which injected poison into his arm. Tim hopes that by building up human immunity to snake poison he can contribute to the development of a new anti-venom, more efficient and affordable than the type produced from horses that is currently available. Where no anti-venom is available to people bitten by a black mamba the death rate is usually 100-percent..