DiscussionFrom the graphs presented it is obvious that it is possible to measure the blue color developed with antimony trichloride with accuracy, even though the rate of change in the intensity of color is rapid.An attempt was made to slow down the rate of fading of the blue color through addition of acids, dehydrating agents, or phenols ( 7 ) . Of the materials tried phosphoric acid seemed the most efficient, but its effect was only apparent, since a slight cloudiness developed in the solution that tended to compensate for the fading of the blue color.Fading continued progressively beyond the readings given, although a t a slower rate, but on the more dilute solution was complete in from 5 to 10 minutes.