134 PROCEEDINGS OP THE AMERICAN ACADEMY. 



observed in all unpurified distillates. On this account very little impor- 

 tance has been attached to the composition of these oils as shown by 

 aualj'sis, except to demonstrate what slight weight can be given to those 

 results. Drying with sodium is indispensable, on account, as shown in 

 another connection, of the difficulty in removing water by other means. 



Determinations of carbon and hydrogen in the crude distillate 190°- 

 191° dried over sodium gave the following results : — 



0.1521 gram of the oil gave 0.4787 gram COo, and 0.1972 gram HoO. 



The specific gravity at 20° was found to be 0.7673. After thorough 

 agitation with sulphuric acid and wa&liiug with sodic hydrate and water, 

 the specific gravity was scarcely affected, 0.7662. 



A comparison of the composition and specific gravity of the crude 

 distillate 190°-191°, 730 ram., as shown above, with the results of War- 

 ren and of Pelouze and Cahours, in connection with what follows after 

 further purification, reveals the cause of the lack of uniformity in the 

 earlier work. The specific gravity of Warren's analyzed product, 0.7721 

 at 15°, which was only purified by boiling with sodium, is substantially 

 the same as that of Pelouze and Cahours, 0.7780 at 20°, which was puri- 

 fied with concentrated sulphuric acid and sodic carbonate, but appreciably 

 higher than the specific gravity of our crude distillate, only dried over 

 sodium. The percentage composition of these products purified in this 

 manner may be more clearly understood if the results of analysis are 

 brought together, as in the following table : — 



It is difficult to see how results so closely supporting the formula 

 C„H2«+2 ^s those of Pelouze and Cahours could be obtained in a 

 product still containing aromatic hydrocarbons, as shown by their method 



