This determination is carried out in the same way as the bromine-decolorisation test for wood naphtha (p. 305). Instead of 50 c.c. of the standard bromide-bromate solution, however, only 5 c.c. are employed, and 1 c.c. of acid instead of 10 c.c. This quantity of the standard solution is equivalent to 0 05 gram of bromine, or to 0.02125 c.c. of unsaturated compounds calculated as allyl alcohol.