Change the comma after time machine to a period and capitalize However.
Did you spot the typo? Change turnign to turning.
I suggest changing have managed to create to just have created.
Scientists have created the world’s first time machine. However, it can only send messages to itself in the past. Within seconds of the machine being turned on, messages of warning begin to flood in from the future.
(Ah, quantum entanglement… This scenario is plausible, you know.)
If you’re going to add extra letters to so and stretch it out (do this only in dialogue/first-person narration, imitating how the character says it), add a sufficient number of them that it won’t be confused with a different word: sooo, for example.
Change the comma after move to a period.
You we’re? As in, a contraction of You we are? *shakes head* Get rid to the apostrophe and make that were.
“It sooo was a move. You were trying to hit on me!”
First, we don’t capitalize the second word in a scientific name (binomial nomenclature). Second, we do italicize such scientific names.
We don’t capitalize the common names, though.
Add a comma after Arum maculatum, get rid of the comma after also known, and add an apostrophe to adder’s tongue. Add a comma after adder’s tongue.
Don’t use an ampersand (&) in normal prose except for where it appears in a proper name. (It is correct to write, “My kid sister plays Dungeons & Dragons,” because that’s how the title of that game is written, but it is not correct to write, “I like peanut butter & jelly sandwiches.”)
Add it is to the introductory adverbial phrase (betcha didn’t know if is an adverb, did you?) If ingested to make it say If it is ingested, because otherwise the sentence says the symptoms are what may be ingested, and that’s just weird.
Arum maculatum, also known as adder’s tongue, is one of the most toxic wild plants. It smells of rotten meat. If it is ingested, symptoms include irritation of the mouth and tongue, swelling of the throat, difficulty breathing, burning pain, upset stomach, and intense convulsions followed by death. Medicinal purposes include treating sore throats and rheumatic pain, and removing freckles and blemishes.
Today’s second glitch:
Add a comma after the introductory adverbial phrase After years of stress.
Don’t capitalize hero; it’s a common noun, not a proper name.
In the second sentence, change to the eyes to in the eyes.
Unless you mean that the person who comes to save the city never suspected this, either, change suspecting to expected.
There’s a typo in the second sentence, too: comea should be comes.
Change the period after city to a colon, and don’t capitalize the or villain.
After years of stress, the hero snaps and goes crazy, destroying everything in his path. Unbelievably in the eyes of the citizens, the least expected person comes to save the city: the villain.