388 Scientific Proceedings, Royal Dublin Society. 



27. Methyl Alcohol} — The specimen was prepared by the action of ammonia 

 on re-crystallized methyl oxalate. The distillate was rectified, and was 

 re-distilled, first over quicklime, and then over barium oxide. It was finally 

 distilled six times over small quantities of sodium. As tlie boiling-point was 

 not quite constant, the alcohol was fractionated. The boiling-point was 64-7° 

 under normal pressure ; the specific gravity was only determined at 22-94°, 

 and was found to be 0-78909. 



It has since been observed^ that the last traces of water can best be 

 removed from methyl alcohol by distillation through a very efficient still- 

 liead. Purified in this way a specimen of the alcohol boiled at 64-7° under 

 normal pressure ; its specific gravity at 074° was 0-81000. 



Ethyl Alcohol.'^ — Absolute alcoliol was frequently distilled over lime, and 

 finally over a little sodium. The boiling-point was quite constant. The 

 specific gravity was not determined, but the value 0-80633 was adopted. 



Ethyl and propyl alcohol can best be dehydrated by distillation with 

 benzene through a very efficient still-head.* A specimen of ethyl alcohol, 

 purified in this way, had the specific gravity 0-80634 at 074°. By subse- 

 quent distillation with normal hexane, the specific gravity fell to 0-80627, 

 owing probably to the removal of a trace of benzene. This value agrees 

 very well with that of Mendeleeff, 0-80625. 



Boiling-point under normal pressure, 78-3°. 



Propyl Alcohol.^ — The specimen was procured from Kahlbaum. It was 

 purified by fractional distillation, potassium carbonate being added to the 

 lowest fractions each time to remove part of the water from the mixture of 

 minimum boiling-point. 



Specific gravity at 074°, . . 0-81929 



Boiling-point under normal pressure, . 97-4° 



At a later date" a fresh quantity of propyl alcohol was obtained from 

 Kahlbaum, and, after being purified by fractional distillation, was distilled 

 with benzene through a very efficient still-head to remove the last traces of 

 water. The specific gravity of this specimen at 074° was 0-81923, and the 

 boiling-point under normal pressure, 97-20°. 



Acetic Acid.'' — The specimen employed for all the determinations had 



1 Kamsay andToung, Trans. Koy. Soc, olxxviii., p 313, 1887. 



* Fortey and Young, Trans. Chem. Soc, Ixxxi., p. 717, 1902. 



3 Ramsay and Young, Trans. Eoy. Soc, clxxvii., pt. i., p. 123, 1886. 



* Young, Trans. Chem. Soc.,lxxxi., p. 707, 1902 ; Fortey and Young, ibid., Ixxxi., p. 739, 1902. 

 5 Eamsay and Young, Trans. Roy. Soc, olxxx., p. 137, 1889. 



^ Fortey and Young, loo. cit. 



' Ramsay and Young, Trans. Roy. Soc, olxxv., p. 461, 1884; Trans. Chem, Soc, xlix., p. 790, 

 86 ; Young, ibid., lix., p. 903, 1891. 



