Malachite green metabolized into LMG. Only the cation MG is deeply colored, whereas the leuco and alcohol derivatives are not. This difference arises because only the cationic form has extended pi-delocalization, which allows the molecule to absorb visible light. The leuco form of malachite green was first prepared by Hermann Fischer in 1877 by condensing benzaldehyde and dimethylaniline in the molecular ratio 1:2 in the presence of sulfuric acid. Malachite green is traditionally used as a dye. Kilotonnes of MG and related triarylmethane dyes are produced annually for this purpose. MG is active against the oomycete "Saprolegnia", which infects fish eggs in
Ruby, Gold and Malachite Ruby, Gold and Malachite Ruby, Gold and Malachite is an oil-on-canvas painting by Henry Scott Tuke. It depicts six young men in and around a boat, bathing in the sea. It was painted near Falmouth and exhibited at the Royal Academy summer exhibition in 1902, along with two other works by Tuke, "The Run Home" and "Portrait of Alfred de Pass". It was one of his greatest successes. The painting measures by . It was acquired by the City of London Corporation and is displayed at the Guildhall Art Gallery. Tuke was born in York in 1858, but his family