The Jealous Mistress, vol. 1

From vol. 1, number 2 of The Jealous Mistress, a periodical briefly published starting in 1925 by the Colorado Bar Association.

The reference, of course, is to the phrase "the law is a jealous mistress," which is sometimes credited to Justice Joseph Story, in his speech at his inauguration as Dane Professor of Law at Harvard in 1829:

The student … should, at his first entrance upon the study, weigh well the difficulties of his task, not merely to guard himself against despondency on account of expectations too sanguinely indulged, but also to stimulate his zeal by a proper estimate of the value of perserverance. He who has learned to survey the labor without dismay, has achieved half the victory…. [The law] is a jealous mistress, and requires a long and constant courtship. It is not to be won by trifling favors, but by lavish homage.

To elaborate, from "Lex Concubina Invidia Est," 23 Case & Comment 28, 28 (1916):

She's jealous of the wine you drink;
She's jealous of the friends you keep;
She's jealous of your waking hours;
She's jealous of the time you sleep;

I've also seen it credited to Coke, who must have been writing two centuries earlier, but I couldn't find any reliable evidence of that. But even if Story was the first to say this about law, unsurprisingly others had said it before about other fields, such as painting (see this 1748 source).