How marijuana affects the mind. Marijuana reaches the same pleasure centers in the brain that are targeted by heroin, cocaine and alcohol. Depending on the quantity, quality and method of consumption, marijuana can produce a feeling of euphoria â or high â by stimulating brain cells to release the chemical dopamine.
History of Penicillin. Originally noticed by a French medical student, Ernest Duchesne, in 1896. Penicillin was re-discovered by bacteriologist Alexander Fleming working at St. Mary's Hospital in London in 1928. He observed that a plate culture of Staphylococcus had been contaminated by a blue-green mold and that colonies of bacteria adjacent to the mold were being dissolved.
Penicillin is one of the earliest discovered and widely used antibiotic agents, derived from the Penicillium mold. Antibiotics are natural substances that are released by bacteria and fungi into the their environment, as a means of inhibiting other organisms - it is chemical warfare on a microscopic scale.