ohols comprising from 12 to 30 carbon atoms, in particular from 12 to 20 carbon atoms, and of sucrose or of glucose, in particular ethers of fatty alcohols comprising from 1.2 to 20 carbon atoms and of glucose, comprisin in particular' from 12 to 3 glycoside units, such .as the. compounds carrying the i C'I names CI2-18 alkylg-lucos'ide, CI 2-20 atky!gkeoside (tor example Montanov L from Seppic),