One of Spike Walker's most notable accomplishments in the field of polarized light microscopy is his ability to control the crystallization of vitamin C from evaporated aqueous solutions. The photomicrograph presented above is from a supersaturated solution placed on a microscope slide that was scratched into approximately 1.5-millimeter squares with a fine needle to provide 'windows' in which crystallization could proceed independently. The preparation was breathed on at 60-second intervals to alter the rate of crystal growth fronts. Illumination was provided by a 12-volt, 100-watt tungsten halide lamp with crossed polarizers. The microscope was a Zeiss Ultraphot III equipped with an automatic 35-millimeter photohead. The film was Fujichrome Velvia. (10x)