DIBASIC AND TRIBASIC ORGANIC ACIDS. 287 



tained by dissolving the yellow mercuric oxide or veratriue in 

 oleic acid. 



QUESTIONS. 



411. What is the constitution of organic acids, which group of atoms 

 is found in all of them, and how does an alcohol radical differ from an 

 acid radical? 



412. Give some processes by which organic acids are formed in nature 

 or artificially ? 



413. Mention the general properties of organic acids. 



414. Which series of acids is known as fatty acids, and why has this 

 name been given to them ? 



415. Mention names, composition, and occurrence in nature of the 

 first five members of the series of fatty acids. 



416. By what processes may formic acid be obtained, and what are 

 its properties ? 



417. Describe the processes of manufacturing acetic acid from alcohol 

 and from wood. 



418. What is vinegar, and what is glacial acetic acid ? Give tests 

 for acetic acid and for acetates. 



419. Describe the processes for making the acetates of potassium, 

 zinc, iron, lead, and copper, and also of Goulard's extract and lead- 

 water ; state their composition and properties. 



420. Where and in what form of combination is oleic acid found in 

 nature, and what are its properties ? 



43. DIBASIC AND TRIBASIC ORGANIC ACIDS. 

 Dibasic acids of the general composition C,,H 2n - 2 4 . 



Oxalic acid, H 2 C 2 O 4 . 



Malonic acid, H 2 C 3 H.,O 4 . 



Succinic acid. H 2 C 4 H 4 O 4 . 



Pyrotartaric acid, H 2 C 5 H 6 O 4 . 



Adipic acid, H 2 C 6 H 8 O 4 . 

 etc. 



Of these acids, only the first member is of general interest. 



Oxalic acid, H 2 C 2 4 . This acid may be looked upon as a direct 

 combination of two carboxyl groups, C0 2 H CO 2 H, both atoms 

 of hydrogen being replaceable by metals. 



Oxalic acid is largely distributed in the vegetable kingdom in 



