Powder some borax finely, and mix it in a porcelain basin with a few c.c. of the alcoholic liquid, which for this test should be free from acid, and strong enough to burn. Allow the mixture to stand for a minute or two and then ignite the vapour. A green coloration is imparted to the flame if methyl alcohol is present in sufficient quantity, whereas ethyl alcohol gives the coloration only after sulphuric acid is added. About 5 per cent. of methyl alcohol in ethyl alcohol can be thus detected (E. Pieszczek).1