BENZENE SERIES. AROMATIC COMPOUNDS. 369 



CH 3 OH OH 



H \ /<L H H L OIL H C vX X OH 



\J/ vQ/ ^C ^C ^C 



(I /C\ .Cv /C v .Cv /C. 



TTX \.r\ / / TT TT^ Nf^-x ^OH H ^C^^ 



H H CO 2 H 



Toluene, methyl-benzene, Pyrogallol, C 6 H 3 (HO) 3 . GaHic acid, C 6 H 2 .CO 2 H.(OH) 3 . 

 C 6 H 5 .CH 3 . 



CH 3 OH OH 



/i r^TT TT C* r^TT TT I 1 (Ti TT 



"v^vx ^v-'-tlfi ^1\ >VA\ x^-^s **\ /^<X / V ^ W 2 J:I - 



\C X ^C X 



H ^ ^ ^ o J 



vV v /,^- / \ x^ \ X>>^\ v ^ \ /s~* * 



H 



Xylene, di-methyl-benzene, Cresol, C 6 H 4 .CH 3 .OH. Salicylic acid, 



C 6 H 5 .(CH3) 2 . 



CH 3 CH 3 COH 



cj d ' A 



X C X \H H x \C X ^OH H x \C^ ^H 



C 3 H 7 C 3 H r H 



Cymene, methyl-propyl benzene, Thymol, C 6 H 3 CH 3 .C 8 H 7 .OH. Benzaldehyde, oil of bitter 

 C 6 H 4 .CH 3 .C 3 H 7 . almond, C 6 H 5 .COH. 



The preceding graphic formulas show in the first column (besides 

 nitro-benzene) a number of hydrocarbons, in the second column alco- 

 hols (or phenols), obtained by introducing hydroxyl into the hydro- 

 carbon molecule, and in the third column chiefly aromatic acids, 

 formed by introducing carboxyl, CO 2 H, or carboxyl and hydroxyl. 



Phenols. While the term phenol is generally used for carbolic 

 acid, it also belongs to that class of substances which we may call 

 aromatic alcohols. According to the number of hydrogen atoms re- 

 placed by hydroxyl, we find mon-atomic, di- atomic, and tri-atomic 

 phenols, corresponding to the similarly constituted alcohols. Phenols 

 differ from common alcohols in not yielding aldehydes or acids by 

 oxidation. 



Carbolic acid, Acidum carbolicum, C 6 H 5 OH = 94 (Phenol, 

 Phenyl hydrate, Phenyl alcohol). Crude carbolic acid is a liquid 

 obtained during the distillation of coal-tar between the temperatures 

 of 170-190 C. (338-374 F.), and containing chiefly phenol, be- 



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