A spectrophotometer cuvet is described which is emptied by suction without removal from the instrument. The use of this cuvet saves time and minimizes the chance of breakage. Data from C " measurements and absorbances of a dye solution show minimal retention error from successive specimens. expended in determining the absonbances of a large series of individual samples in a spectrophotometer ca...

HE PRINCIPAL SUBJECT MATTER of this paper is the description of a thod of obtaining a calibration curve relating apparent absorbancy 81) and concentration (x). It is frequently observed that the orbancy index decreases with increasing concentration in cases in ich one would expect Beer’s law, A = log(10/I) = KX, to hold. For ample, with our instrument, the absorbancy index at 273.5 m of a lutio...