7(1 



The 23 coiDpouiids of lliis homologous series studied here are: 



Methyl-, Diinethi/l-, and Trbiiethylaniine ; Ethyl-, Diethyl-, and 

 Triethylamine ; norm, Propyl-, Dipjvpyl-, and Tripropylninine ; Ino- 

 propylnmlne ; AUyhimine; norm. Butyhuiiine; Isohntyl-, Dlisohutyl-, 

 and Triisobutylamine ; tertiary Rutylamine, norm. Amylamine; Isoantyl-, 

 and Diisoamyhimine \ tertiary Amylamine; norm. Hexyl-, &nd l.sohexyl- 

 amine; norm. Heptylamine; while for the purpose of comparison 

 the measurements of Formamide are reproduced here also. 



The pure amines were first dried by means of metallic sodium or 

 potassiumhydroxide, then fractionated in vacuo over KOH ; because 

 of the inevitable bumping of the liquid, the thermometer-readings 

 oscillated within limits of about 2". 



The specific gravity must be determinated with most of these 

 substances by means of a volumeter, because of their volatility and 

 their tendency to attract carbondioxide and water-vapour from the 

 atmosphere. Especially in the case of the lower-boiling amines these 

 experiments appeared to be highly cumbersome and demanded much 

 time ; however we think the obtained results to be exact within 

 about 0.1 7o, which must be quite sufficient for the use here made 

 of them. 



Molecular Surface-Energy 

 fji in Erg pro cm-. 



9fO 

 950 

 920 

 890 



mo 



830 

 800 

 770 



7W 

 710 



650 

 6:10 

 690 

 560 

 530 

 500 

 U70 

 IW 

 i/0 

 380 

 350 

 320 

 290 

 260 



'SO'M'W'5(rw'-30'-20'/0' o' Ml' :v\w' itrvi/^'/k^' 7)rdv»r/(in'//nwm/it^VM/6e'r;<^^ Temperature 



Fig. 1. Primary Amines. 



