Research was started in 1969 to develop near infrared (NIR) technology for measuring the chemical composition of tobaccos and tobacco products. This program led to the design of the COMP/SPEC a computerized spectrophotometer complete with software for collecting and analyzing NIR spectra over the range from 900-2600 nanometers. Work with the COMP/SPEC has shown that many constituents can be measured from a single NIR scan of a tobacco sample. Wavelength information gained from these studies has been incorporated in many of the commercially available NIR instruments. Standard errors of prediction of sugars, nicotine, nitrogen, water-soluble nitrogen, calcium and potassium have been determined to be +- 0.99%, +- 0.178%, +- 0.14%, +- 0.14%, +- 0.19% and +- 0.16% respectively. Most recent work based on Fourier analysis of NIR spectra shows that a simplified interferometer can be used to obtain Fourier coefficients directly. These coefficients can be used to estimate che mistry. This instrumentation is especially suited for on-line monitoring of chemistry.