644 SCIENTIFIC EECORD FOR 1885. 



greatly increased. Chlorocyanogen and dicyanogen, for example, are 

 more volatile than hydrocyanic acid : 



H-CN boils at +26° 

 Cl-OX boils at +15o 

 NC-CN boils at -21^ 

 and cyanethyl boils at 96°, higher than cyanacetyl, which boils at 93^ C. 

 The chloronitrils exhibit similar peculiarities. These and similar facts 

 prompted the author to examine the influence on the boiling j)oint 

 of introducing atomic groups in the place of the chlorine in those bodies 

 in which the chlorine itself produces no change or marked change in the 

 volatility. To this end the author prepared the four nitrils named 

 below ; their formula, and boiling points compared with trichloraceto- 

 nitril. are given in the table : 



Name. Formula. B. P. Differ- 



° ence. 



Trichloracetonitril CCI3— CN 84 



-64 

 Dichlormethoxylacetonitril OH3O— COI2-ON 148 



-13 

 Dichlorethoxylacetonitril CaHgO-CClz-CI^ 161 



-21 

 Dichlorpropoxylacetonitril ... C3H7O-CCI2-CN 182 



—14 

 Dichlormonoisobutoxylacetonitril ..C4H9O— CGI2— ON 196 



Whence it appears that the replacement of chlorine by methoxyl 

 raises the boiling point 64°, and beyond this the boiling point increases 

 with each addition of the carbon group in about the same rat«o as in 

 homologous compounds of like character. 



In the compounds cited below, an unusual elevation of the boiling 

 point occurs when oxymethyl enters. 



In some cases the boiling point rises regularly 20° for each CH2 in- 

 troduced into the compound. 



Name. Formula. B. P. 



o 



Dichlorpropoxylacetonitril CCl2(OC3H7)CI»r 183 



Monochlordipropoxylacetonitril . CCl(OC3H7)2CN 200 



Tripropoxylacetonitril C(OC3H7)3CN 218 



Dichlorisobutoxylacetonitril ^ COl2(OC4H9)CN 195 



