DETERMINATION OF THE WATER 49 



EXERCISE Xni 



Determination of the Water Content of 

 Butter 



Irish Moisture Test 



Read carefully the following explanations and test 

 samples of butter according to directions. 



Weigh 10 grams of butter into an aluminium cup 

 upon a sensitive scale. Evaporate the water by 

 holding the cup and contents over the flame of an 

 alcohol lamp. Place a mirror over the cup to catch 

 and condense the escaping steam. When no more 

 steam condenses on the- mirror the sample has been 

 boiled long enough. Cool and weigh again, the per- 

 centage of loss being calculated and considered as 

 water.^ 



Gray's Method 



A number of schemes have been tried, some giving 

 results more or less satisfactory, but one only, that 

 of Prof. C. E. Gray of the Dairy Division of the 

 Department of Agriculture, Washington, D. C, has 

 been perfected to such an extent as to give results 

 which seem wholly satisfactory. With this method 

 (requiring apparatus costing only a few dollars) 

 any one of average intelhgence, after a few trials, 

 may make moisture determinations with comparative 



' The weights added to indicate the loss in weight by re- 

 moval of moisture are so marked that, by adding the figures 

 upon them, the percentage of water can be determined direct. 



