﻿Action of Dehydrating Agents on Organic Bodies. 21 



reaction has not thrown much light on the structure of the base 

 in question. The other sources of this body are the destructive 

 distillation of various nitrogenous matters. It is found in bone- 

 oil and in the distillate from peat, shale, &c, but in no case is 

 the rationale of its formation understood. 



In a paper read before the Chemical Society and published in 

 its Journal for August 1866, entitled " On the Production of 

 Acetic and Propionic Acids from Amylic Alcohol " (Chapman), 

 occurs this passage : — " Phosphoric acid attacks nitrates as well 

 as nitrites, though not so easily, and this may prove a method 

 of obtaining compounds of the same class as picoline. 



C 5 H 11 NO 3 might give us C 5 H 5 N + 3H 2 0. " 



Nitrate of arayle. Pyridine. 



This hypothetical equation has been realized exactly in the man- 

 ner indicated. 



If excess of dry nitrate of amyle be poured upon anhydrous 

 phosphoric acid, at first no reaction appears to take place; but 

 on long standing or on the application of gentle warmth, the 

 phosphoric acid is seen to shrink a little and to change in appear- 

 ance. This change generally commences at one side of the vessel, 

 and gradually creeps through the mass. Considerable heat 

 is produced, but no gas evolved. On treating the mixture 

 with water no further heat is generated; but the solid mass 

 in the vessel gradually dissolves, the excess of nitrate separates 

 and may be decanted off, and the last traces of it may be com- 

 pletely removed by a few minutes' boiling. On now adding 

 excess of potash to the liquid, the smell of pyridine is at once 

 produced. But though we operated on several ounces of anhy- 

 drous phosphoric acid, we could not in this manner obtain more 

 than the slightest traces of the base. A good deal of dark-brown 

 pitchy matter, possessing apparently feeble basic properties, is 

 the chief product of the reaction. This substance is probably 

 intermediate in composition between pyridine and nitrate of 

 amyle. Acting on this view, we determined to use excess of anhy- 

 drous phosphoric acid. We here, however, encountered another 

 difficulty, the reaction between anhydrous phosphoric acid and 

 nitrate of amyle being, under these circumstances, uncontrollably 

 violent, though it does not occur until some time after the sub- 

 stances have been placed in contact, or unless they have beei. 

 gently warmed. We found the only available method of opera- 

 ting was to take a very long-necked flask, and place in it between 

 two and three grammes of anhydrous phosphoric acid, together 

 with from one and a half to two grammes of nitrate of amyle. The 

 mixture was carefully spread out in a thin layer in the flask. 

 During this operation it is necessary to keep the flask cool by 



