ある種の毒は、適当に使えば役に立つ。の英語

Certain poisons, properly used, are useful.

Properly used, certain poisons will prove beneficial.

the state or quality of looking really poisonous

Diamond cuts diamond.

We've got to fight fire with fire!

It soon proves to have toxic effects.

to neutralize poison with poison 【イディオム・格言的には：】“Like cures like”

“Like-cures like.”【イディオム・格言的】

She's been poisoned.

Poison enters into the system.

All overs are ill.

Whether it is really toxic is a matter of controversy [a moot point].

There is controversy as to whether it is really toxic.

something that protects against poison

to be able to poison a person

the condition of something looking as though it is poisonous

in a virulent manner

of or relating to or caused by a toxin or poison

If it is wrongly used, the medicine will be a poison.

That has the possibility of becoming an addiction.

That has the possibility of becoming a poison.

having the qualities or effects of a poison

this poison is a thousand-fold more toxic

The system works out the virus.

That will not mend or mar matters.

the degree to which something looks really poisonous

The poison has pervade his whole system.

The poison has pervaded his whole system.

The poison spread through his whole body.

That also has an effective as protection from food poisoning.