Patten i —Solutions of Hydrochloric Acid in Solvents. 343 
The sulphuric acid used was the ordinary c. p. concentrated 
acid and the phosphorus pentoxide was a sample from Bender 
& Hobein which had been standing sometime in a common stock 
bottle and was balled together in spots from having taken up 
moisture. Mr. Falk was unable to get a better sample and so 
used this one. The benzene had been shaken with concentrated 
acid till the thiophene was removed, as shown by the isatine 
test, washed with dilute aqueous caustic soda, then with water, 
then dried over calcium chloride. The benzene was then 
frozen, the residual liquid discarded and the crystals of ben¬ 
zene melted and allowed to stand over phosphorus pentoxide 
(commercial from Bender & Hobein) for at least four months. 
For this experiment a portion (about 600 cc) of the: above ben¬ 
zene stood over sodium chips till used; in addition, bright 
sodium chips were introduced a few hours before the experi¬ 
ment. The benzene was poured off through the air into the 
bottle (6 in Figure 1) still hot after being dried at 120° 0. in 
an air bath for an hour or more. The zinc was quickly intro- 
