Full Idea
Not all laws are causal 'experimentalist' laws, such as those for falling bodies, or the Gas Law, or Ohm's Law. Some are more like conceptual principles, giving a frame of reference, such as inertia, or conservation of energy, or the law of entropy.
Gist of Idea
Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy)
Source
G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §9)
Book Reference
'Causation', ed/tr. Sosa,E. /Tooley,M. [OUP 1993], p.121
A Reaction
An interesting and important distinction, whenever one is exploring the links between theories of causation and of laws of nature. If one wished to attack the whole concept of 'laws of nature', this might be a good place to start.