Do you think there is a scientific basis for testing whether food is poisonous with silver needles in costume dramas?

I believe many people have seen such scenes in costume dramas. Before the emperor began to eat, the eunuch in charge of eating would take out a silver needle and insert it into the rice to find out. If the color of the silver needle has not changed, then the imperial meal can be presented to the emperor. If the inserted silver needle turns black, it means that the food is highly toxic and must not be eaten. Until now, people are convinced of the silver needle drug test.

The poison mentioned by the ancients mainly refers to "arsenic", and its chemical name is arsenic trioxide.

Due to the backward production technology in ancient times, arsenic always contains a small amount of sulfur or sulfide. When sulfur comes into contact with silver, there will be a chemical reaction to produce black silver sulfide. Modern, refining technology has been greatly improved. There is no sulfur and sulfide in arsenic, and silver needles can't be tested! ! !

This method of drug testing is too limited!

In fact, egg yolk also contains sulfur. When silver needles are inserted into egg yolk, it will turn black, but egg yolk is a non-toxic food!

Song Ci, a famous forensic scientist in Song Dynasty, also mentioned the use of silver needles for autopsy in Injustice Collection.

If the corpse has rotted, no matter whether the deceased was poisoned before his death, corrosive gas containing hydrogen sulfide will be produced, and the silver needle will turn black.

If it is because of toxic substances such as potassium cyanide and sodium cyanide poisoning, because it does not contain sulfur, fresh corpses cannot be detected with silver needles.

Poison test: silver needle is really useless.