ABSTRACT
The experimental laws of mechanics worked out by Galileo and other early physicists, completed and summarized and built into a theoretical system by Newton have long been made the headstone of the corner of all Physics. There are no rules of course for substituting better for worse forms of laws; it is a matter that must be left to our native genius, supposing we have got any. A natural law as has been maintained is essentially a general correlation between classes; it is an orderly arrangement of classes. Many laws which are asserted with the utmost confidence are based upon a very minute number of observations. It is easy to think of constants of which the accepted value might be wrong or which might be variable without much upset of ordinary physical laws and which we nevertheless believe in confidently as the result of quite a few observations, as for instance the atomic weights of some of the rarer elements.
