282 



CONSIDERATION OF CARBON COMPOUNDS. 



Fusiny-point. Boiling-point. 

 254 

 270 



Occurs in : 



Leaves of geranium. 

 Butter. 



> Cocoanut oil. 



Palm oil, butter. 

 (Obtained artificially.) 

 Most solid animal fats. 



] 



j- Oils of certain plants. 



Beeswax. 



The name fatty acids has been given to these acids on account 

 of their frequent occurrence in fats, and also in allusion to 

 the somewhat fatty appearance of the higher members of the 

 series. 



The gradual change of properties which the members of a 

 homologous series show, is well marked in the series of fatty 

 acids, thus: 



First member 



Is liquid. 

 Volatilized at 100. 



Strongly acid. 

 Strongly odoriferous. 

 Easily soluble in water. 

 Produces no grease spot. 

 Forms salts easily soluble with- 

 out decomposition. 



Last member . 



Is solid. 



Not volatilized without decom- 

 position. 



Scarcely acid. 



Odorless. 



Insoluble in water. 



Produces a grease-spot. 



Forms salts which are insoluble or 

 decomposed by water. 



The intermediate members of the series show intermediate 

 properties, and this change in properties is in proportion to the 

 gradual change in molecular weight. 



Formic acid, H.CH0 2 or CHO.HO. This acid is found in the red 

 ant and in other insects, which eject it when irritated. It is also 

 contained in some plants, as, for instance, in the leaves of the 

 stinging-nettle. 



It is formed by the oxidation of methyl alcohol : 



CH 3 + 2 = CH 2 2 



Methyl Formic 



H 2 0, 



alcohol. 



acid. 



