MALT LIQUORS. 



313 



to dryness and burned to ash. The alkalinity of the ash was then as- 

 certained, with the following results : 



From these results it will be seen that the alkalinity of the ash shows 

 very plainly the addition of considerable quantities of bicarbonate, but 

 small additions would not be detected in this way. Again, the books 

 state that the addition of bicarbonate of soda can be recognized by the 

 strong effervescence of the ash with an acid. This statement is based 

 eniirely upon theoretical grounds, which have been shown by later in- 

 vestigations to be fallacious. When the acidity of normal beer was sup- 

 posed to be due chiefly to lactic acid, the formation of lactate of soda, 

 which would be converted into a carbonate on ignition, would, theoret- 

 ically, make an ash which would effervesce strongly with acid. But now 

 that it is known that the acidity is due to acid phosphates, it is easily 

 seen that the addition of bicarbonate would only tend to the produc- 

 tion of neutral or alkaline phosphates, which would give no effervescence 

 with acid. This is shown by experiments I made with the sample of 

 normal beer. Several portions of lOOcc. each were taken, and different 

 quantities of bicarbonate of soda added, and when solution had been 

 effected the beer evaporated, and the residue carefully incinerated. 

 The test for the presence of carbonate was made very carefully, by pour- 

 ing a few drops of water on the ash, and turning the whole into a test- 

 tube containing dilute acid. 



It will be seen from the above that there was no carbonate in the ash 

 until sufficient bicarbonate was added to the beer to neutralize all its 

 acidity, leaving an excess of bicarbonate in the beer. In Nos, 4 and 5 

 the beer reacted alkaline before evaporation. 



