21 



LECTUEE II. 



Proximate animal and vegetable principles included in the class of organic 

 compounds, together with various bodies resulting from their natural 

 and artificial metamorphoses Carbon the characteristic element of 

 organic compounds Number, variety, and complexity of its combina- 

 tions with hydrogen and oxygen Highly complex organic bodies built 

 up of less complex molecules Salicin formed of saligenin and glucose ; 

 populin of benzoic acid, saligenin, and glucose Occurrence of con- 

 stituent molecules in an incomplete state Doctrine of residues Exist- 

 ence of minute residues of acetic acid and ammonia in aceto-nitrile, and 

 of oxalic acid and ammonia in cyanogen Eesidues of constituent 

 molecules ever ready to regenerate complete and separate molecules by 

 an absorption of water Aplone molecules either possessed of simple 

 constitution, or associated with bodies of simple constitution as members 

 of the same family Distribution of aplone molecules into series of 

 similarly constituted compounds Also into groups of dissimilarly con- 

 stituted compounds susceptible of mutual metamorphosis Series of 

 primary fatty acids Propionic and butyric groups Relations of alcohols 

 and glycols to mono- and di-basic acids Nature of homologous series 

 Differences and resemblances between the fatty acids Series of 

 aromatic acids and hydrocarbons Other groups and series Every aplone 

 molecule referrible to a definite position in some homologous series and 

 heterologous grouping Hippuric acid formed of three constituent resi- 

 dues, convertible into complete molecules by an absorption of water 

 Assignment of these molecules to appropriate positions in groups and 

 series Possibility of obtaining any two residues in combination, by 

 destruction or removal of third Assumed pre-existence of benzamide, 

 benzoglycolic acid, and glycocine in hippuric acid Probable internal 

 arrangement of the acid Illustrative animal products formed of two 

 constituent residues Urea, glycocine, leucine Analogy of spermaceti 

 and myricin to acetic ether The true fats Illustrative animal products 

 formed of more than two residues Taurine, sarcosine, alloxan, and the 

 biliary acids Scheme of the constitution of kreatine. 



