A rapid reduced silver impregnation for arthropod central nervous systems is described. Material is fixed in Gregory's Dubosq-Brasil or in Carnoy's solution. Incubation of 2-3 $\mu $m sections in an urea-silver nitrate bath of the Ungewitter type is preceded by treatment with a dilute solution of mercuric chloride in 2% nitric acid in 70% ethanol in the presence of excess cobalt nitrate. Gold-toning follows conventional strategies. The method succeeds with a wide range of materials, and the results are comparable to those obtained with variants of the Bodian, Holmes and Bielschowsky routines.