386 Scientific Proceedings, Royal Dublin Society. 



1 4. Carbon tetraclilorklc} — A specimen which was obtained from Kahlbaum 

 was fractionated, and a product of perfectly constant boiling-point was 

 obtained. 



Specific gravity at 074°, .... 1-63255 

 New specimen and new tube, . . . 1-63267 

 Boiling-point under normal pressure, . 76-75° 



15. Stannic Chloride.'^ — A very pure specimen was obtained from 

 Kahlbaum ; the first portions of the distillate contained a little hydrate, after 

 the removal of which the liquid boiled quite constantly. The receivers in 

 which this very hygroscopic substance was collected were placed in a 

 cliamber containing phosphoric anhydride in order to prevent absorption of 

 moisture by the distillate. This dry chamber was also used for many of tlie 

 other substances investigated. The chamber resembled an ordinary balance- 

 case ; a hole about an inch and a half in diameter, rather above the centre of 

 one side of the case, was closed by a piece of sheet indiarubber ; and the 

 delivery-tube from the still-head or distillation-bulb passed througli a per- 

 foration in the indiarubber. The receiver could be inserted or removed by 

 lifting the front side of the case. 



In all the experiments with stannic chloride the greatest care was taken 

 to prevent access of moisture. 



Specific gravity at O"/!", . . . 2-27875 (Thorpe^) 



Boiling-point under normal pressure, . 114-1° 



16. Ethyl Ether.* — The ether was prepared by heating absolute alcohol witli 

 sulphuric acid in the usual manner. The distillate was shaken with caustic 

 soda to remove any sulphurous acid, and was re-distilled. It was then left in 

 contact with calcium chloride for some time to remove most of the alcohol. 

 After re-distillation it was shaken repeatedly with small quantities of water ; 

 it was then dried with calcium chloride and distilled again. Metallic sodium 

 was then added from time to time until all evolution of gas ceased, and the 

 ether was distilled from the sodium. It was afterwards left in contact with 

 sodium until required, and was always re-distilled over sodium before being 

 used. The specific gravity was not determined ; but the mean of the values 

 given by Kopp, Pierre, MendeleefE, and Perkin, -0-7362, was adopted. 



Boiling-point under normal pressure, 34-6°. 

 17-26. Ten Esters — Methyl Formate to Methyl Isobulyrate.^— DeteTmrnations 

 were made in each case with two different specimens. The one was obtained 



1 Trans. Chem. Soc. lix., p. 911, 1S91. 'Ibid. ^ Ibid., xxxvii., p. 89, 1880. 



* Ramsay and Young, Trans. Roy. Soc, clxxviii., p. 57, 1887. 

 5 Thomas and Young, Trans. Cliem. Soo., Ixiii., p. 1191, 1893. 



