What did toxicity mean in ancient times?

China has always been a big country in medicine. The ancient records of drug toxicity in China can be traced back to ancient times. Because Shennong has tasted all kinds of herbs in the world, there is a record of "seventy-two poisons a day". The Classic of Mountains and Seas also records the toxicity and function of Miscanthus chinensis, Wutiao and Wei Zi, and the pre-Qin medical prescription book Fifty-two Diseases unearthed from Mawangdui Han Tomb also records the poisons such as poisonous corydalis tuber, realgar, Darkmouth, Pinellia tuber and Lulu.

In ancient books and novels, there is often a scene in which the crane is red, and there is a scene in the court drama "Empress Entering the Palace" where a silver needle detects poison. Since ancient times, the "Dante" on the head of the red-crowned crane is often regarded as a highly toxic substance, called "Hedinghong" or "erysipelas". Once imported, people will die, and it is hopeless.

In fact, these statements are groundless! According to an article, Hemlock Red is red arsenic, which is a natural mineral of arsenic trioxide. After processing, it is arsenic, which is highly toxic. Perhaps because red arsenic sublimate is red, the name He Dinghong was used.

In ancient China, silver needle was widely used to test poison. Can arsenic trioxide really react with silver? In fact, the silver needle detects sulfur instead of arsenic.