Prepare a glass plate (preferably of the thin variety commonly used for lantern- 

 slide covers) as follows : First, thoroughly clean and polish, and coat on one side by 

 carefully dipping while hot in a mixture of equal parts of Carnaiiba wax and paraffin. 

 Near the middle of the plate make a small cross or other distinctive mark through 

 the wax with a sharp instrument, such as a pointed piece of wood or ivory, which 

 will remove the wax and expose the glass without scratching the latter. Add a few 

 drops of concentrated sulphuric acid to the residue in the crucible and cover the cru- 

 cible with the waxed plate, having the mark nearly over the center and making sure 

 that the crucible is firmly embedded in the wax. Place in close contact with the top 

 or un waxed surface of the plate a cooling device consisting of a glass tube covered 

 tightly with a thin sheet of pure rubber. A constant stream of cold water is passed 

 continually through the tube. The whole arrangement is lowered so that the cruci- 

 ble rests upon a heated electric stove, where it remains for an hour. 



Remove the glass plate and indicate the location of the distinguishing mark on the 

 unwaxed surface of the plate by means of gummed strips of paper, and melt off the 

 wax by heat or a jet of steam and thoroughly clean the glass with a soft cloth. A 

 distinct etching will be apparent on the glass where it was exposed if a fluorid be 

 present. 



ANALYTICAL RESULTS. 



The accompanying tables give the results obtained by the different 

 analysts on the two samples sent out. The various factors determined 

 are reported in full. 



TABLE 1. Analytical results obtained by cooperating chemists on referee's sample of beer 



No. 1. 



[Results calculated to grams per 100 cc except where otherwise stated.] 



[Cir. 33] 



