This section is from the book "Alcohol, Its Production, Properties, Chemistry, And Industrial Applications", by Charles Simmonds. Also available from Amazon: Alcohol: Its Production, Properties, Chemistry, And Industrial Applications.
Owing to its fiscal as well as to its scientific importance, the Specific gravity of ethyl alcohol has been the subject of numerous investigations. In this country, the value obtained by Fownes,1 namely, 07938 at 15.6/15.6°, and the practically identical number found by Drinkwater,2 079381, have been largely used. In Germany, the value 07946 at 15.6°/15.6° was adopted by Tralles,3 and employed for many years, but has been replaced for fiscal purposes by data based on the work of Mendeleeff.4 This investigator, whose determinations are probably the most accurate of all, obtained the following results: -
At 0°/3.9°, 0.80625; „ 15°/3.9°, 0.79367; „ 30°/3.9°, 0.78096.
Referred to the temperature 15.6°, and compared with water at the same temperature, these values correspond with 0.79384 in vacuo, or to 0.79359 in air.
More recent workers (Young,5 1902; Klason and Norlin,6 1906) have found values somewhat higher than those of Fownes and Drinkwater - namely, 0.79395 and 0.79394 respectively. On the other hand, lower results even than Mendeleeff's have been published; thus Squibb7 found the specific gravity 07935. Since there is difficulty in eliminating the last traces of water, the lowest value ought to represent the purest alcohol, provided there is no other source of error. Squibb's result, however, has not been confirmed, and it has been suggested that perhaps the presence of a little ether may have caused the value obtained to be a little lower than the truth.
A careful review of the most trustworthy determinations indicates Mendeleeff's result, which corresponds with 079359 at 15.6°/15.6° (in air), as probably the most accurate value of the specific gravity of ethyl alcohol.