590 CONSIDERATION OF CARBON COMPOUNDS. 



Beta-amino-naphthalene, C 10 H 7 .NH 2 (Beta-naphthy famine), is easily obtained 

 by heating beta-naplitbol with the ammonia compound of zinc chloride to 210C. 

 It forms pearly scales, soluble in hot water, ordorless, and melting at 112C. It 

 does not give a colored compound with oxidizing agents. 



Naphthionic acid, C 10 H 6 (NH 2 )SO 3 H (1, 4, Naphthylamine-sulphonic add). A 

 number of sulphonic acids are formed when the naphthylarnines are treated with 

 sulphuric acid, some of which are valuable in the preparation of dyes. The 

 sodium salt of naphthionic acid is used in making congo red, which has the 



composition : 



C 6 H 4 .N 2 .C 10 H 5 (NH 2 )S0 3 Na. 



C 6 H 4 .N 2 .C 10 H 5 (NH 2 )S0 3 Na. 



Four mono-sulphonic acids are formed when beta-naphthylamine is treated 

 with sulphuric acid. 



Santonin, Santoninum, C 15 H 18 O 3 = 244.29, is an anhydride of 

 santonic acid, C 15 H 20 O 4 . As several reactions point to a relationship 

 between this acid and naphthalene, santonin is mentioned in this place. 



Santonin is the active principle of wormseed, the unexpanded 

 flowerheads of Artemisia, from which it is obtained by extraction 

 with alcohol and lime-water, and decomposition of the soluble com- 

 pound of lime and santonin by an acid. Santonin crystallizes in 

 colorless prisms, which turn yellow on exposure to light ; it is but 

 sparingly soluble in water, more soluble in alcohol and ether. 



Santonin taken internally confers upon the urine a dark color re- 

 sembling the color of urine containing bile; upon heating such urine 

 it turns cherry-red or crimson, the color disappearing on the addition 

 of an acid, and reappearing on neutralization. 



Analytical reactions : 



1. Santonin added to alcoholic solution of potassium hydroxide 

 produces a bright-red liquid which gradually becomes colorless. 



2. To 1 c.c. of sulphuric acid add a few drops of ferric chloride 

 solution and a crystal of santonin : on heating, a dark-red color is 

 produced, changing into violet-brown. 



Aromatic compounds containing- nitrogen in the cycle. 



Pyrrol, C 4 H 4 NH. During the destructive distillation of certain 

 nitrogenous matters (chiefly bones), a liquid known as bone-oil is ob- 

 tained, which contains a number of nitrogenous basic subtances, 

 among which pyridine and pyrrol are found. Pyrrol has but weak 

 basic properties, is insoluble in water, and has an odor like chloroform. 



