;;; Procedure:
;;;   compound-field-index
;;; Parameters:
;;;   field, a symbol
;;; Purpose:
;;;   Given the name of a field, determine its index in the
;;;   vector.
;;; Produces:
;;;   index, an integer
;;; Preconditions:
;;;   field must be one of 'boiling-point, 'color, 'formula, 'melting-point
;;;     'molecular-weight, or 'name. [Unverified]
;;; Postconditions:
;;;   index is the index associated with field.
(define compound-field-index
  (let ((name 1)
        (formula 2)
        (molecular-weight 3)
        (melting-point 4)
        (boiling-point 5)
        (color 6))
    (lambda (field)
      (eval field))))