RESEARCHES ON THE VOLATILE HYDUOCARI >< 



171 



That the difference may also be I s than 10° in sonic series receives confirmati 

 from the facts presented in the following tables. 



on 



6. Of the NUro-compowvh derived from the Hydrocarbons of the Btmok Series, 



Name of Substance. 



Formula, 



Boiling- 

 point. 



ElciDCMltAfy 



I >I it* 



IHfl of 



Nitro-benzole, 

 Nitro-toluole, 

 Nitro-xylole, 

 Nitro-isocumole, 



C l2 H 5 NO, 



C 14 1 1 7 \o, 



C 16 H 9 NO, 

 Q» H u NO, 



2 1 2. 1 \ 



225.9! 



C,H S 

 C 2 H 2 



C 2 H 2 







l.l.H 

 13.4 



7. Qf the Alkaloids derived from the Hydrocarbons of the Benzoic Series. 



Name of Substance. 



Aniline, 



Toluidine, 



Xylidine, 



Iso-curaidine, 



Formula. 



BolliDf- 



point. 





difference. 



Different* of 

 illng-iHiitili 



C 12 H 7 N 

 C„H 9 N 



C 16 Hn N 



C„II,«N 



18 "13 



184.6 

 201.7 



216.0 



C 2 II, 

 C 2 U, 



17.1 



In regard 



the 



presented 



tables, it may be remarked, first, 



of the difference shown in the table of nitro-compounds, viz. an average of 13 .6 



pti 



the discrepancy between this and the number 19°, being 5 D .6 

 no room for reasonable doubt that this is one of those exc< 

 the boiling-point difference is less than 19° for the element: 

 As this series does not appear to have been examined by Kopp, I have taken 



as accurate a determination of the difference as circumstances would a 



ch 



•y difference of C 2 If- 



to make as accurate a 



The boiling-points were corrected as 



for pressure and the upper 



umn 



The boiling-points which have already been published of these bodies, so far 



I have noticed, appear to have been given in the observed 



temp 



tures. The quantities of nitro-benzole 



d nitro-toluole which I operated upon 



fficiently large, and of a high degree of purity, presenting perfectly constant boiling 

 points. The quantity of nitro-xylole, however, was not so large as would have been 



desirable. 



those of nitro-benzole and nitro-toluole are more to be relied upon ; and omittin 



fraction, the number 14° may, I think, be safely taken as the true boiling-poi 



Although the boiling-point of this body is doubtless very nearly 



r 



lie 



this 



Secondly, that the less striking difference presented in the series of 

 alkaloids, being only 2° under the number 19°, cannot reasonably justify the assump- 



small discrepancy of 



bu table to impurity of 



* Not corrected. 



