VEENBOER ON BORAX AND BORIC ACID IN MILK. 89 



Tliis test may be applied direetlA' to the milk by placiug one 

 cubic centimeter of it in a large tube-test, adding one-half 

 cubic centimeter of strong hydrochloric acid and ten cubic centi- 

 meters of methyl alcohol. This mixture is rapidly- boiled down 

 nearly to dryness when it may be ignited and the green flame olttained. 

 The methyl borate which is formed nuiy be taken up on a platinum 

 loop and the flame obtained b}- ignition with a Bunsen burner. By 

 another method, the milk can be evaporated to dryness over a water- 

 bath, and the itowdered residue rubbed ujt with anhydrous sodium 

 sulphate in order to extract the water. The boric acid is now abstracted 

 from this mass with absolute metlivl alcohol and the filtered extract is 

 distilled into a concentrated soda solution, which is evaporated and 

 tested by the flame. 



The flame tests are not as delicate as those with turmeric and the color 

 of the flame is easily masked by sodium, potassium, copper, and some 

 other substances. 

 12 



