FIG. 1 is a perspective view of a cuvette showing my design;

FIG. 2 is a front elevational view, the rear elevational view being identical thereto;

FIG. 3 is a top plan view;

FIG. 4 is a side elevational view the opposite side elevational view being identical thereto;

FIG. 5 is a bottom plan view;

FIG. 6 is a longitudinal cross-section through plane VI--VI in FIGS. 3 and 7; and,

FIG. 7 is a longitudinal cross-section through plane VII--VII in FIG. 6.