130 PYRIDINE BASES. 



ammonia is heated to 90-100. Amorphous brown 

 mass, very much like acrolein-ammonia. Combines, 

 like the latter, with acids, yielding amorphous salts ; 

 and is resolved by heat into water and collidine. 



Pyridine bases, C n H 2n ~ 5 ]Sr. "When acrolein-ammo- 

 nia and cro tonal-ammonia are heated, there result liquid 

 bases, picoline and collidine, which belong to an homo- 

 logous series, the single members of which are formed 

 by the dry distillation of anthracite coal, peat, and 

 particularly of bones. They are extracted from the 

 distillation-products (coal-tar, bone-oil) by treating 

 with dilute sulphuric acid ; set free again by means of 

 alkalies ; and separated from each other by means of 

 fractional distillation. 



1. Pyridine, C 5 H 5 ISr. Colorless liquid, of a penetrat- 

 ing odor. Boiling point, 116.7 ; specific gravity, 0.986 

 at 0. Soluble in water. Strong base. The hydro- 

 chlorate C 5 H 5 ]NT.HC1 is deliquescent, and gives with pla- 

 tinum chloride a yellow double salt (C 5 H 5 KHCl) 2 PtCl 4 , 

 which is difficultly soluble in water. 



In the presence of metallic sodium, pyridine is 

 changed, gradually at the ordinary temperature, more 

 rapidly when heated, into a polymeric base, dipyridine 

 C 10 H 10 ^N" 2 , which crystallizes in colorless* needles, fuses 

 at 108, and sublimes without decomposition. 



2. Picoline, CflEFN. Is formed by the distillation- 

 of acrolein-ammonia and also when tribromhydrine is 

 heated for several days with alcoholic ammonia to 

 250. Colorless liquid, mixes with water; specific 

 gravity, 0.96 ; boiling point, 135. Strong base. Is 

 converted into a polymeric base by sodium, the same 

 as pyridine. 



3. Lutidine, C 7 H 9 N. Colorless liquid; specific 

 gravity, 0.946 ; boiling point, 155.5. More easily 

 soluble in cold water than in hot. 



