A novel approach to measuring the overall and layer-by-layer thickness of in vivo skin tissue based on near infrared absorbance spectra is described. The support structure may include a support pole. Moreover, an outer periphery coating material constituting the outer peripheral wall of the honeycomb structure 1 has a porosity of 10 to 60%. A socket service program 84-1 receives audio data from the audio-data processing program 83 under the control of a first process. There is provided a treatment solution for forming of a black trivalent chromium chemical coating on zinc or zinc alloy, comprising trivalent chromium ions, a chelating agent capable of forming a water-soluble complex with trivalent chromium, zinc ions, a sulfur compound and phosphite ions. Liquid crystals with little or no toxicity to cell lines may be added to cell culture media or added to components used in cell culture media.