IOWA ACADEMY OF SCIENCES. 89 



In the preparation of absolute ethyl alcohol precisely the 

 same method was used as is given above for methyl 

 alcohol, except that it was not found necessary to use the 

 return condenser during the action of the calcium carbide, 

 on accoinit of the higher boiling point of ethyl alcohol. 

 In one experiment where extra precautions w^ere not taken 

 against loss by evaporation, 700 grams of absolute alcohol 

 were obtained from 1,000 grams of an 89 per cent, alcohol. 



A specimen of Sargent's "95 per cent, alcohol," which 

 had a specific gravity of .8183 at 15.5 degrees C. (and which 

 was therefore a 92.7 percent, alcohol), when dehydrated, 

 had a specific gravity of .79357 on the average. This cor- 

 responds with the lowest figures obtained by Squibs and 

 Mendeleeff, and it would indicate that it was entirely 

 dehydrated. The fact that Yvon^i has also prepared abso- 

 lute ethyl alcohol by this method was overlooked until 

 after the above work was completed. The yield of alcohol 

 is very much diminished by decanting from the residual 

 calcium hydroxide, as he did, instead of distilling it off, 

 since fully one-third of the alcohol is held mechanically by 

 the bulky residue. 



Butyl Alcohol. The specimen of alcohol used was from 

 Merck & Company. It had a boiling point of 104 degrees 

 C. and a specific gravity of .8059. When treated with cal- 

 cium carbide it evolved acetylene when slightly warmed. 

 When the action was complete it had a specific gravity of 

 .8043 at 15.5 C. It was found NQvy unsatisfactory to com- 

 pare this result with the specific gravities given, as various 

 investigators have obtained results which differ widely. 

 Of the four specific gravities we find given for butyl alco- 

 hol, it is higher than one, but lower than three of them. 

 The burden of evidence is therefore in favor of its being 

 entirely dehydrated. 



Amyl Alcohol. A specimen of Dr. Theodore Schuchardt's 

 alcohol, that had a specific gravity of .8163 (which would 

 of itself indicate that it contained considerable water) 

 evolved acetylene rapidly when treated with calcium car- 

 bide and heated to 100 degrees C. When the action was 



irCompt. Rend. 1897, USl, nS2. 

 7 I AS 



