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
Italian submarine Malachite both miss. "Malachite" was forced to dive and undergo lengthy depth charge attack. From 10 to 18 April 1941 she was posted northeast of the Gulf of Sollum. At 23:37 on April 14 "Malachite" sighted a large convoy but was prevented from attacking it due to preemptive action by the escorts. On May 20, 1941 "Malachite" together with numerous other submarines was deployed to an area between Crete, Alexandria and Sollum, to support the German invasion of Crete (Operation Merkur). "Malachite"'s area operation was south of the island of Gaidaro. On the night of June 19, 1941 while patrolling off