The possibility of obtaining greater optimization of spectrochemical techniques by selectively isolating radiation from the analytical spark gap is discussed. Instrumental factors required to achieve positional stability of the spark necessary for these techniques are discussed in terms of the chemical reactions controlling spark formation. Using simple optical systems capable of viewing the spark differentially, emission profiles of several metallic and sparking-gas species have been recorded. The heterogeneous spatial and temporal structure in these profiles has been employed to group the spectral lines into classes according to when and where they appear in the discharge. Suggestions are made as to how the spark may be viewed to isolate lines of one class from those of other classes, thereby reducing background and line interferences and enhancing signal-to-noise ratios.