This principle is applicable not only to heat, the most general and most widely
diffused form of motion, but to other forms as well. in every case, it is always just
the one term in the chain of the three interchangeable motions, the character of the
molecular work, that is changed. Work of disgregation and mechanical work can be
done, e.g., by electricity as well as by heat. There are, therefore, various kinds of
molecular work; but there is in the last resort only one ...