How do you get the ingredients on Vampire's curse island?

Answer 1

The garlic and the wolfsbane are in the laboratory. The mandrake root is outside the castle, on the wall (to the right of the moat). Take the crossbow outside the castle, go right from the moat, and you will find a wall. Shoot arrows into it and climb up to find the mandrake root.

In the library, roll the loose cannonball to the fireplace. When it is hot, use the fireplace Poker (rod) to shove it left into the dumbwaiter (throw the handle with the red knob). Go back to the laboratory and throw the lever there, and the hot cannonball will wilt the wolfsbane.

Get the garlic from the shelf and you have all three ingredients. Look through the microscope and click the dropper to pick up drops of each: 1 mandrake, 3 wolfsbane, 3 garlic. Add to the cells and you have the anti-vampirism serum.