Realgar Wine

In ancient times, people believed that realgar wine could drive away evil spirits and toxins in the body. It was a popular drink during the Dragon Boat Festival. 

In fact, the realgar wine contains highly poisonous ingredients -- arsenic sulphide, that can be extracted into arsenic, which is harmful to the body if consumed for a long period of time, and that's why we are told not to drink this kind of wine nowadays.