282 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS TABLE I*--EFFECT OF 5% POLYOL ON A 2% G-3720 SOLUTION Atspergillus Pseudomonas Bacillus Polyol niger aeruginosa subtilis Dipropylene glycol G G G 1,4-Butanediol G G G 1,3-Butanediol G G G Hexanetriol-1,2,6 G G G Pentanediol-l,5 G G G G = growth -- = no growth TABLE •2--E•'FECT OF 5% POLYOL PLUS 0.2% METHYL p-HYDROXYBENZOATE ON A 2% G-3720 SOLUTION zfspergillus Pseudomonas Bacillus Polyol niger aeruginosa subtilis Dipropylene glycol -- G G 1,4-Butanediol -- G G 1,3-Butanediol - G G HexanetrioL1,2,6 - G G Pentanediol-l,5 -- - -- TABLE 3--EFFECT OF 10% POLYOL ON A 2% G-3720 SOLUTIOIq dspergillus Pseudomonas Bacillus Polyol niger aeruginosa subtilis Dipropylene glycol . G G G 1,4-Butanediol G - G 1,3-Butanediol -- -- -- Hexanetriol-l,2,6 G G G Pentanediol-l,5 -- -- -- TABLE 4--EF}'ECT OF 10% POLYOL PLUS 0.2% METHYL p-HYDROXYBENZOATE ON A 2% G-3720 SOLUTION zf spergillus P seudomonas Bacillus Polyol niger aeruginosa subtilis Dipropylene glycol - G G 1,4-Butanediol -- -- -- 1,3-Butanediol -- -- -- Hexanetriol-l,2,6 -- -- -- Pentanediol-l,5 - - -- TABLE 5--EFFECT OF 5% ALCOHOL ON A 2% SOLUTION OF G-3720 ß /lspergillus ?seudomonas Bacillus Alcohol niger aeruginosa subtilis Methyl G G G Ethyl - G G n-Propyl - G G Isopropyl - - G n-Butyl -- -- -- sec-Butyl -- G G

THE INTERFERENCE OF NONIONIC EMULSIFIERS 283 TABLE 6--EFFECT Or 5% ALCOHOL PLUS 0.2% METHYL p-HYDROXYBEI'/ZOATE ON A 2% SOLUTIO•r Or G-3720 dspergillus P seudomonas Bacillus Alcohol niger aeruginosa subtills Methyl - G G Ethyl - - - n-Propyl - - - Isopropyl - - - n-Butyl -- -- -- sec-Butyl -- G G TAI•LE 7--EFFv CT or 10% ALCOHOL O• • 2% G-3720 SOLUTION' ztspergillus Pseudomonas Bacillus Alcohol niger aeruginosa subtills Methyl - -- - Ethyl - - - n-Propyl - - - lsopropyl - - - n-Butyl - - -- sec-Butyl - -- G T^BLE 8--ErrEe'r or 10% ALCOHOL PLUS 0.2% METHYL p-HYDKOXYBENZOATE ON' A 2% G-3720 SOLUTION' zt spergi llus P seudomonas Bacillus Alcohol niger aeruginosa subtills Methyl Ethyl n-Propyl Isopropyl n-Butyl sec Butyl *The results reported in Tables 1-8 reflect the effect of various additions to nutrient or Czapek DoT media as described under "Experimental" herein. ALCOHOLS Simple aliphatic alcohols were thought to be possibly better preserva- tives than the polyols because the introduction of more than one hydroxyl group into a compound to form a polyol, results in a decrease of physiologi- cal activity. The bactericidal action of the normal primary alcohols in- creases with an increase in length of carbon chain to about six carbon atoms. This study takes in alcohols methyl through sec-butyl, because amyl alco- hol is only slightly soluble in aqueous solution, and alcohols higher than amyl are still less soluble. Tables 5 and 6 record the results of the effect of 5 per cent alcohol on a 2 per cent nonionic solution with and without methyl p-hydroxybenzoate. Examination of Table 5 reveals that the bactericidal action of the lower all phatic alcohols does, indeed, increase with increase in molecular weight, ex- cept in the case of sec-butyl alcohol, which is as effective as ethyl alcohol.