1.
The entropy of the universe tends to a maximum.
Rudolf Clausius
2.
The energy of the universe is constant.
Rudolf Clausius
3.
The total energy of the universe is constant; the total entropy is continually increasing.
Rudolf Clausius
4.
The algebraic sum of all the transformations occurring in a cyclical process can only be positive, or, as an extreme case, equal to nothing. Statement of the second law of thermodynamics, 1862
Rudolf Clausius
5.
Heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time.
Rudolf Clausius
6.
The fundamental laws of the universe which correspond to the two fundamental theorems of the mechanical theory of heat.
1. The energy of the universe is constant.
2. The entropy of the universe tends to a maximum.
Rudolf Clausius
7.
The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.
Rudolf Clausius
8.
In all cases where work is produced by heat, a quantity of heat proportional to the work done is expended; and inversely, by the expenditure of a like quantity of work, the same amount of heat may be produced.
Rudolf Clausius