West Bengal Chief Minister Mamata Banerjee on Thursday called on her ailing predecessor Buddhadeb Bhattacharjee at his south Kolkata home to enquire about his health.Asked about the purpose of her visit, Banerjee said: "...I asked about his health and we talked about books as he love books."Banerjee went to the 73-year-old communist leader's tiny two-room apartment on Palm Avenue.Bhattacharjee is suffering from a respiratory problem chronic obstructive pulmonary disease (COPD).