IOWA ACADEMY OP SCIENCES. IIB 



added and the water will be free from ammonia and suit- 

 able for Nesslerizing purposes." 



Id our experiments we have found that the water pre- 

 pared by this method has been unsatisfactory, and prob- 

 ably due to the addition of potassium iodide. The presence 

 of the iodide apparently destroys the sensitiveness of the 

 Nessler reagent. While this method may be satisfactory 

 under certain conditions, it has been found without value 

 for work in this laboratory. The following method is sug- 

 gested for the preparation of water free from ammonia and 

 nitrogen as nitrates and nitrites. 



Sodium peroxide is added to the water in an ordinary 

 round bottom flask, in the proportion of one dram to each 

 liter of water. P'lasks of five or six liters in capacity are 

 found to be very satisfactory. The contents of the flask is 

 boiled for thirty minutes or longer, until it is estimated 

 that the water is free from ammonia. The time for boil- 

 ing and the amount of sodium peroxide will vary according 

 to the amount of ammonia which may be present in the 

 water. If it is desired to prepare water that is free from 

 ammonia and nitrogen as nitrates and nitrites in order that 

 one supply may serve for making standards for the deter- 

 mination of ammonia, nitrites and nitrates, the contents of 

 the flask are transferred to a copper distilling vessel and 

 distilled. The flrst portion of the distillate is rejected and 

 the remainder kept in bottles in the usual manner. 



THE PREPARATION OF PHENYL ETHER. 



BY ALFRED N. COOK. 



While ethyl ether, the common ether of the modern 

 drug store, has been known for three and a half cen- 

 turies, and has been used as an anesthetic for over 

 fifty years, phenyl ether is of more recent origin. It has 

 never been put upon the market and has never been put to 



