In Ch. 19, Mrs. Dashwood is being her charming self and trying to cheer a nearly despondent Edward up. They have this exchange:

"...a young man of eighteen is not in general so earnestly bent on being busy as to resist the solicitations of his friends to do nothing. I was therefore entered at Oxford and have been properly idle ever since."

"The consequence of which, I suppose, will be," said Mrs. Dashwood, "since leisure has not promoted your own happiness, that your sons will be brought up to as many pursuits, employments, professions, and trades as Columella's."

Those of you who have the Broadview edition have seen the note about this literary reference. Paraphrasing a little, it refers to Columella or the Distressed Annchoret, a 1779 novel by Richard Graves. It is a satire on the idea of retiring to the seclusion and peace of the country.

The title character retired at a young age to live a life of inactivity in the country and fell into "an incurable melancholy". Hoping to avoid a similar fate for his sons, he arranges for them to go into professions when the eldest boy is only 10 years old. They are to become a solicitor, a tradesman and an apprentice to a man who is an 'apothecary, surgeon, midwife, bone-setter, tooh-drawer, hop-dealer and brandy-merchant'!

In this way, Columella hoped his sons would be spared living the 'tedium and disgust' he felt with his life because of 'indolence and activity'.

The page I have linked below has quite a long and interesting note on the novel as well, because one of the things Columella did to fill his time was to make improvements to his grounds (Does this sound like John Dashwood?)

In the novel, Columella also has a neighbour who is not a member of the landed gentry, but who instead has made a lot of money in business. He has the financial means to take part in the pastimes of the gentry, He, too, tries to improve his own grounds and gardens, but has overfilled it with 'fashionable' garden trappings and not a whole lot of good taste.

A final note I took from a French website suggests that the novel incorporates several of the great themes from the end of the 18th century: what is happiness, esthetic debates, and the opposition of city life and country life.