At the time of publication, this work is (and to some extent always remains) unique, being the only attempt at a comprehensive collection of every scientific and magical fact and theory of the time.
Many of the theories in Nature's Laws are later discredited or disproved, but the collation and fact-checking is meticulous (especially for its time). Nature's Laws is therefore not a representative magoscientific cross-section, missing as it does some of the more outlandish and obviously inaccurate philosophies of the age. One gets the feeling controversy is not an issue for Gery, as [Lenser's Reticule Invective]? is included, but he or she apparently yields to a not unreasonable fear of discredit in omitting the [Pixie-Powder fallacy]? and similar.
Some of Gery's notes and omitted entries are published much later and provide quite an illuminating insight, if readers will pardon the pun.