Illustrative of nonionic surfactants are alkylpolyglycol ethers such as ethoxylation products of lauryl, oleyl, and stearyl alcohols or mixtures of such alcohols, such as coconut fatty alcohols; alkylphenol polyglycol ethers such as ethoxylation products of octyl- and nonylphenol, diisopropylphenol, triisopropylphenol and di-and tritertiarybutyl phenol, etc.