// Update is called once per frame
    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            RaycastHit hit;

            if (Physics.Raycast(GetComponent <Camera>().ScreenPointToRay(Input.mousePosition), out hit, 50))
            {
                Ingredient i = hit.transform.GetComponent <Ingredient>();
                Book       b = hit.transform.GetComponent <Book>();

                if (i != null)  //Clicked on an ingredient
                {
                    foreach (Ingredient.effect effect in i.effects)
                    {
                        cauldron.addProperty(effect.symptom, effect.value);
                    }
                    Debug.Log(cauldron.ToString()); //DEBUG STRING OUTPUT
                }
                else if (b != null)                 //clicked the book
                {
                    book.toggle();
                    if (book.bookOpen())
                    {
                        shelf.turnOffColliders();
                    }
                    else
                    {
                        shelf.turnOnColliders();
                    }
                }
                else if (hit.transform.tag == "Right-arrow")  //clicked a right arrow
                {
                    book.nextPage();
                }
                else if (hit.transform.tag == "Left-arrow")  //clocked a left arrow
                {
                    book.previousPage();
                }
            }
        }
    }