At some point, it became more profitable to gamble, than to continue being a dentist. It wasn't a hard decision to make; card-playing allowed him to drink near-constantly, hang out in dens of ill-repute (the best kinds of dens, really) and to never be up and about before noon. And he liked gambling. He was good at it. The whiskey calmed the consumptive cough in his chest and his earnings were enough to supply his vices. And no sane person wanted a dentist who hacked up blood to have hands in his mouth, extracting a rotted tooth.