In its basic form, gin is vodka that has been redistilled with herbs and botanicals. Gin-makers use citrus peels, coriander, ginger, rose petals, nutmeg, and cassia bark, but the most prominent is the juniper berry. Dr. Sylvius, a Dutch professor and physician, is credited with making gin as a cure-all tonic in the 1650s. Today, many alcohol historians debate this claim, because the juniper berry was quite plentiful in Italy, which leads them to believe that Italian monks were the first to make gin.