The meaning is as follows:
Eighteen evils and nineteen fears mean that some drugs should not be combined, and the consequences of combining them will produce various side effects. In ancient times, eighteen evils and nineteen fears generally referred to all kinds of drugs that could interact with each other, and they were summarized into formulas in the Jin and Yuan Dynasties.
eighteen proverbs:
Glycyrrhiza uralensis Fisch, Euphorbia Euphorbia, seaweed and Daphne genkwa; Radix Aconiti Fritillariae Cirrhosae, Fructus Trichosanthis, Rhizoma Pinelliae, Radix Ampelopsis and Rhizoma Bletillae; Veratrum nigrum, Radix Adenophorae, Radix Salviae Miltiorrhizae, Radix Scrophulariae, Herba Asari, and Radix Paeoniae.
herbal medicine clearly states the eighteen opposites
half-baked shellfish and clams attack Wu
algae and halberds attack the grass
all the ginseng, Xin Shao, rebel against Veratrum
Nineteen Fears Proverbs:
Sulfur fears mirabilite, mercury fears arsenic, and wolfsbane fears monks.
Sulfur is the essence of fire, and when you see it, you will argue with it.
Mercury is better than arsenic, and Wolf poison is most afraid of monks.
croton is the strongest, and it's against Petunia.
clove is not as good as turmeric, but saltpetre is hard to combine with Beijing Sparganium.
Aconitum kusnezoffii is not suitable for rhinoceros, and ginseng is most afraid of trogopterori.
Guan Gui is good at adjusting air conditioning, but he will bully others when it comes to stone grease.
in most cases, the harmony depends on the harmony, and the artillery is not dependent on the fire.
eighteen opposites and nineteen fears come from Shennong's Classic of Materia Medica. In the Preface of Shennong's Classic of Materia Medica, it is pointed out that "those who are evil and opposite should not be used", and "those who are afraid of each other and kill each other can be used if they are poisonous and appropriate to control, and they should not be used together". Some of the drugs of "Nineteen Fears" and "Eighteen Contradictions" are somewhat different from the actual application, and doctors in past dynasties have also talked about them, citing ancient prescriptions as evidence to prove that some drugs can still be used together. For example, croton and petunia in induction pills are used together; Gansui Banxia decoction is juxtaposed with Glycyrrhiza uralensis Fisch. Glycyrrhiza uralensis Fisch and Sargassum Yuhu Decoction are used together. The Ten Fragrant Soul-Returning Pill uses clove and turmeric together. Dahuoluo Danwu is used with rhinoceros horn and so on.
Reference: eighteen evils and nineteen fears _ Baidu Encyclopedia