294 PROCEEDINGS OF THE AMERICAN ACADEMY. 



vacuo under 13 mm. ; it came together for the most part at 150°-] 55°. 

 The specific gravity of the monochloride was 0.9748 |jo ; at Do 0.9730 ; at 

 50°, 0.9661 ; and at ^o, 0.9579. The mean coefficient of expansion, 

 within 20°-40°, from these results, is 0.00078. 



A determination of chlorine gave a value required for the mono- 

 chloride : — 



0.1559 grm. of the oil gave 0.0989 grm. AgCl. 



Calculated for Ci4H27Cl. Found. 



CI 15.39 ' 15.80 



As mentioned above, the decreasing proportion of chlorine in these 

 derivatives with the increasing molecular weight, and the consequent 

 larger volumes of gases, beyond the strength of the ordinary Carius 

 tubes, gives a smaller weight of silver chloride than could be desired, 

 but the accuracy of the method permits of sufficiently reliable results, 

 even with the small weights. 



The molecular weight of the chloride was determined at the freezing 

 point of benzol : — 



0.8923 grm. of the oil and 17.76 grms. benzol gave a depression of 1°.094. 



Calculated for CiiHjjCl. Found. 



230.5 225 



The index of refraction was found to be, 1.493, and the molecular 

 refraction 68.67 ; calculated for C14H27CI, 69.37. 



The boiling point of this chloride cannot be accurately determined 

 under atmospheric pressure because it is rapidly decomposed at the 

 higher temperature and in presence of air, although it may be distilled 

 indefinitely in vacuo. Probably the boiling point under atmospheric 

 pressure is not far from 275°. 



Pentadekanaphtene Chloride, C15H29CI. 



This chloride was prepared from pentadekanaphtene, which had been 

 well fractioned in vacuo. These higher chlorides are formed as readily 

 as the lower ones. After washing and fractional distillation under 

 14 mm. this monochloride came together for the most part at 170°-175° 

 without decomposition. Its boiling point under atmospheric pressure is 

 probably near 300°. Its specific gravity at ^o was 0.9771 ; at |]o 0.9753 ; 

 and at 550, 0.9714; and at ^o, 0.9643. The coefficient of expansion calcu- 



