Short story competition

Here goes my short story, perhaps a bit longer than planned...

The experiment that went wrong.

It was late at night and Jack was still working, surrounded by several strange bottles. He had been thinking about that matter for a long time and now it was time to try it.
Jack felt nervous because it had never been tried before and he feared the outcome the experiment could bring.
Now he had gained courage, took a jar and began to pour in it the liquids from some bottles he had carefully selected from the many stored on the shelves. The mixture aquired a strange colour and foams were forming on its surface. Then Jack offered it to Brian, his guinea pig, who had been eager and reluctant to drink the mixture. Once done, Brian began to feel dizzy and in a few seconds he fell to the floor and fainted.
Suddenly, a middle-aged man appeared and shout: "What have you done Jack?, are you crazy?, what in hell have you given to poor Brian?, he was already drunk!, Take him to the hospital urgently!, I hope your cocktail doesn´t kill him, or the Police will surely close my pub!!