110 MANUALuXIE^GENERAL AGRICULTURE. 



(c) Formalin (optional). 



To 10 c.c. of milk in an evaporating dish add an equal 

 volume of hydrochloric acid. Add one drop of ferric 

 chlorid solution, heat gently, stirring until contents are 

 nearly boiling. The formaldehyde turns the casein of the 

 milk violet. If no formalin is present the liquid turns 

 brown only. 



83. DETERMINATION OF MOISTURE IN BUTTER. 



Materials : 300 c.c. aluminum cup, butter to be tested, 

 ring stand, spatula or spoon, fine wire or thread, scales, 

 alcohol lamp. 



Anyone who is familiar with testing of butter for 

 moisture is well aware of the fact that an accurate test is 

 not possible unless the sample taken for testing is a repre- 

 sentative one. In view of the heavy penalties imposed be- 

 cause of excessive moisture, no buttermaker can afford to 

 do the work ignorantly or carelessly. The matter of 

 proper ways of taking samples and of testing is as yet 

 more or less unsettled, but the following suggestions are 

 generally recognized as being worthy of attention. 



In taking a sample from the churn, remove a portion 

 of the surface of the butter at vairous places of the churn, 

 and by means of a spatula or spoon take out small pieces. 

 Butter in the churn contains many water pockets and 

 these must be avoided, as they are worked out in packing. 



In taking a sample from the print use a fine wire or 

 thread as butter can be easily cut in this way. Several 

 small slices from different parts of the print are sufficient. 

 As fast as the slices are made, place them in an ordinary 

 pint fruit jar and after they are all in it, screw the cap 

 down air-tight. 



Samples taken as above are approximate representa- 

 tives only, so that in order that the parts taken may be- 

 come a uniform mixture, it is necessary that they be 

 melted at as low a temperature as possible (not above 

 120 F.) in order that none of the volatile substances pass 

 off as vapor. This may be done by placing the sealed sam- 

 ple in a pail of water as hot as the hand will bear and 



