£22 Dr. Anderson on the Products of the 



collidine, but as that substance did not appear likely to give 

 results of interest, I contented myself with this experiment as a 

 sufficient proof of its existence. 



The experiments described in the preceding pages sufficiently 

 establish the fact that picoline and its homologues must be con- 

 sidered as nitryle bases, that is to say, bases capable of taking 

 up only one additional atom of aethyle or any similar radical, by 

 doing which they are converted into fixed compounds, of the 

 class designated ammonium bases. If this be their constitution, 

 we must, according to the views at present entertained, assume 

 that these bases are formed from ammonia by the replacement 

 of its three atoms of hydrogen by as many different radicals. 

 Of the exact nature of these radicals, the experiments we at 

 present possess afford no data for drawing definite conclusions ; 

 but a moment's consideration suffices to show that they must be 

 substances remarkable for the simplicity of their constitution. If 

 we confine our attention to pyridine, as the fundamental member 

 of the series, it is obvious that the ten equivalents of carbon and 

 five of hydrogen which it contains must be distributed among 

 these three substances; and although we cannot, without further 

 researches, determine how they are distributed, it is at least 

 sufficiently obvious that the choice among different speculative 

 arrangements is by no means large. In fact, our knowledge of 

 the laws governing the constitution of organic compounds, 

 enables us to see that the total number of possible permutationst 

 of the elements of pyridine is only eight. They are as follows: — 



C 4 H 2 i C 4 H 3 i C 4 H-| C 4 H-| 



c 4 h 2 In c 4 h In c 4 h In c 4 h4n. 

 c 2 h j c 2 h j c 2 h 3 j c 2 h 2 j 



C 6 H 2 ] C 6 H 3 i C 6 H-| C 6 H~| 



c 2 h 2 Ln c 2 h In c 2 h In c 2 h 2 In. 



C 2 H J C 2 H J C 2 H 3 



^H 2 !>] 

 D 2 H 2 J 



Involving the existence of the following nine radicals, all, with 

 the exception of methyle, at present unknown : — 



C 6 H 3 C 4 H 3 C 2 H 3 



Q6 H 2 C 4 JJ2 C 2 H 2 



C 6 H C 4 H C 2 H 



Of these, two at least, C 6 H and C 4 H, are so extremely 



t I assume, with Gerhardt, that the number of atoms of carbon in any 

 radical must always be divisible by two. 



