Victor Meyer suggested a method for determining the types of alcohol i.e. (primary, secondary or tertiary). In this method the sample alcohol is treated with PI to get the iodoalkane which is again treated with AgNO to get the nitroalkane. The nitroalkane is then treated with nitrous acid which is obtained by NaNO and HCl. The resulting solution is treated with KOH and the colour is observed. The red, blue and no colour indicates the primary, secondary and tertiary alcohol respectively.