Misc: what is a scallion?

Questions

sherlock holmes: he is the founder member of the 'diogenes club' in london?

sherlock holmes: he played prof moriarty in the 1976 movie 'the seven percent solution'?

sherlock holmes: holmes made his first appearance in 1887 in this novel?

sherlock holmes: name the team that holmes uses to do the legwork for him?

sherlock holmes: name the team that holmes uses to do the legwork for him?