the Constitution of Carbon Compounds. 



97 



Methyl amine . 

 Ethylamine . 

 Propylamine . 

 Ainylamine . 

 Dimethylamine 

 Diethylarnine 

 Trimethylamine 

 Triethylamine 



2 



46760 



92530 

 135560 , 

 226290 i 4 



877401 9 

 179940 J * 



45770 

 44400 



44882 



, 46100 



1286901 

 268300 J 



3 . 46537 



Primary amines may be regarded as formed by the with- 

 drawal of a molecule of hydrogen from a molecule of ammonia 

 plus a molecule of the corresponding hydrocarbon, and 

 secondary as formed in like manner from primary, and ter- 

 tiary from secondary amines : — 



C a H 6 + NH 3 = a H^i.NH 2 +H 2; &c. 



The heat-disturbance in such reactions may be deduced from 

 the heats of formation of the three compounds, that of am- 

 monia at constant volume being 11310 units (Table IX.). 



Table IX. 



CaHfi. 



P. 



CaH&-i.NH 2 . 



p.. 



P'-(P-fll310). 



Methane 



21170 



Methylamine ... 



8380 



-24100 



Ethane 



27400 



Ethylamine 



15770 



-22940 



\ Propane 



33370 



Propylamine ... 



20420 



-24260 



Pentane 



44950 



Amylamine 



35080 



-21180 



Benzene 



-13670 



Aniline 



-19190 



-16830 



Propylene ... 



2060 



Allylamine 



- 2880 



-16250 



0-H in 



29100 



Piperidine* 



Isobutylamine . 



24090 



— 16320 



Isobutane ... 



40130 



35560 



-15880 



On inspection of the last column of the table, it will be 

 seen that the primary amines form two groups ; the difference 

 is too great and too constant within each group to be the 

 result of accident. Hence Thorn sen is of opinion that the 

 amines of the two groups differ materially in constitution. 

 The numbers for secondary and tertiary amines (Table X.) 

 closely resemble those afforded by the members of the second 

 group of primary amines, which may be regarded as indicative 

 of similarity in constitution. 



It is commonly held that the amines are formed by the 

 displacement of the three hydrogen atoms in ammonia one by 



* Thomsen regards piperidine as a primary amine. 



