A NEW ORGANIC BASE FROM COAL-TAR. 



135 



have here brought together in the form of a table, which does not pretend to any 

 scientific arrangement, its sole object being to point out the remarkable relations 

 of aniline and picoline to the group. 



Indigogene, . 

 Indigo, 

 Isatine, 



Anthranilic acid, 

 Salicylic acid, 

 Nitrosalicylic acid, . 

 Benzoic acid, 

 Nitrobenzoic acid, . 

 Chlorobenzoic acid, 

 Hydi'uret of benzoil, 

 Benzonitril, . 

 Stilbene, 

 Phenol, 

 Aniline, 

 Tribromaniline, 

 Benzin, 

 Nitrobenzid, . 



ChHsNO, 

 CifiH,NO, 

 C„H,NO, 



CuH.,(N04)0, 



Cl4 He O4 



ChH,(NO,)0^ 

 Ci4 H-, ClO^ 

 Ci4 Ho Oo 

 CuH,N 

 C14 Hfi 



C12 H; N 



Ci,H,BrsN 



Ci;h5(no,) 



Indine. 



?• 



Salicylous acid. 

 Nitrosalicylous acid. 

 Chlorosalicylous acid. 

 Benzoine. 

 Azotide of Benzoil. 



Picoline. 

 Tribromopicoline ? 



The facility with which aniUne can be obtained by the decomposition of dif- 

 ferent members of this group, renders it by no means impossible to anticipate the 

 artificial production of picoline also. 



As we can start fi'om benzoic acid, and convert it into benzin, benzin into 

 nitrobenzid, and that finally into aniline by the action of sulphuretted hydrogen, 

 it seems by no means improbable that salicylous acid, the isomeric of benzoic 

 acid, may be made to undergo a similar series of changes, the final result of 

 which would be the fonnation either of picoline, or of some other compound 

 isomeric with it and aniline. In order to subject this hypothesis to the test of 

 experiment, I mixed salicylous acid with equal weights of slaked lime and caustic 

 bai-yta, and distilled in the oil bath, with the view of obtaining a substance which 

 should be isomeric with benzin. The greater part of the salicylous acid, how- 

 ever, passed over unchanged ; but by agitating with solution of potass, there was 

 left undissolved an excessively minute quantity of a solid crystalline substance. 

 Finding this mode of operating unsuccessful, I passed salicylous acid over spongy 

 platinum heated to a very low red heat in a glass-tube. A dark viscid oily fluid 

 passed over into the recipient, of which the greater quantity dissolved in caustic 

 potass, but left behind a larger quantity of the solid substance than was yielded 

 by the first experiment. By distillation with water this substance passed into 

 the receiver in the form of oily drops, which solidified on cooling, and formed a 

 crystalline mass in which minute needles could be detected. It had a peculiar 

 pleasant smeU which resembled that of benzin ; but the quantity which I ob- 

 tained was much too minute to admit of its analysis, or of any attempt to con- 

 vert it into picoline. 



* Gerhabdt has observed (Precis de Chimie Organique, torn, ii., p. 21), that benzoic acid, when 

 fused with hydrate of potass, evolves hydrogen, and gives the potass salt of a new acid. This may pos- 

 sibly be isomeric with salicylic acid. 



VOL. XVI. PART II. 2 M 



