ORGANIC GROUPS AND SERIES. 35 



as shown in the group-tables to which I have already adverted, so 

 is every other primary monobasic acid, both of the fatty and 

 aromatic series, associated with a more or less complete set of 

 congeners, having to it the same relations of composition, pro- 

 perties, and mutual metamorphosis, that the various members of 

 the acetic, propionic, and butyric families have to the acetic, pro- 

 pionic, and butyric acids respectively. Here, for example, we 

 have tabulated the principal compounds which are associated in 

 this manner with benzoic acid : 



Benzole Group 



C 7 H 8 Benzoene 



C 7 H 8 Benzyl-alcohol 



C 7 H 8 O z Benzyl-glycol 



C 7 H 6 '0 Benz-aldehyd 



C 7 H 6 'o a Benzoic acid 



Cj H 6 3 Ampelic acid, &c. 



(34.) Conversely, we may select any set of compounds occu- 

 pying analogous positions in the different groups, and arrange 

 them in series corresponding to those of the monobasic acids. 

 Here, for instance, we have the series of aromatic hydrocarbons : 



Aromatic Hydrocarbon Series 

 C 6 H 6 Phenene 



C 7 H 8 Benzoene 



C 8 H IO Xylene 



C 9 H I2 Ketinene 



C IO H I4 Cymene 



Again, in the next table we have the two series of primary fatty 

 alcohols and of aldehydes resulting from their dehydrogenation : 



Fatty Alcohol Series Fatty Aldehyd Series 



C H 4 Methylie C a, O Chloroformic 



C a H 6 Ethylie C a H 4 O Acetic 



C 3 H 8 Propylic C s H 6 Propionic 



C 4 H I0 Butylic C 4 H 8 Butyric 



C 5 H IZ Amylic C 5 H I0 Valeric 



C 6 H I4 Caprylic C 6 H I3 Caproic 



C 7 H I6 Anthylic C 7 H I4 (Enanthic 

 &c. &c. 



D2 



