300 



PRKPARING BUTTER FOR MARKET 



created. It is essential, however, that we consider the cost of 

 printing tire butter and the loss in printing. Some httle waste of 

 butter accompanies the printing process. Butter to be printed 

 nicely should be firm but not hard, so that the print may assume 

 its proper shape. Butter should be worked to a point where it is 

 free from loose moisture; otherwise, the loss will be much heavier 

 in printing. 



Treatment of Tubs and Boxes. — Investigations were made by 

 Rogers ^ of the different treatments of tubs for the prevention 



Fig. 123. — Septic tank for creamery sewage disposaf (By Prof. J. Michels.) 

 The tank should be located in the ground with the top within a foot or 

 two of the surface. It may be constructed of planks. Brick, stone, or 

 concrete is preferable for durability. The tank should be built air-tight 

 except in two places, D and E. 



of contamination by mold. Comparison was made of the fol- 

 lowing methods: 



(i) Soaking the tubs overnight in cold water. 



(2) Boiling five minutes in a saturated brine solution and 

 leaving in the brine overnight. 



(3) Soaking overnight in a brine containing 9 per cent of 

 commercial formalin (which is a 40 per cent solution of formalde- 

 hyde) . 



(4) Coating the tubs on the inside with paraffin. 



(5) Immersing the tubs for a few seconds in paraffin at a 

 temperature of 250° to 260° F. 



Rogers comments upon the table giving results of his investi- 

 gations and makes some general observations, as follows: 



' Bulletin 8q, Bureau of Animal Husbandry, U. S. Dcpt. of Agriculture. 



