882 



EXPERIMENT STATION RECORD. 



lot. The butter was left until another da}- and worked onoc or twice 

 until the water content appeared normal. The results were variable, 

 but the average water content of the third portion averaged slightly 

 higher. 



The results also indicate that butter worked moderately when hard 

 tends to hold on to its water content. To the old rule that soft butter 

 should not be worked might be added that hard butter should not be 

 workinl until it Ix'comes soft as it will become too poor in water. 



The chemical action of molds on butter, J. Haxus and A. Stocky 

 {Ztschr. Untemuch. JVahr. u. Genmmxtl., 3 {1900), xYr>. 9, -pp- ^06- 

 61Jf). — In preliminary experiments Mucor racetnoms was found to 

 grow best on butter, and this was used in subsequent experiments. 

 In the latter it was found that the principal change was a cleavage 

 of the glycerids. resulting in an increased iicidity of the butter. From 

 the fact that enzyms have been found in many molds the theory is sug- 

 gested that the mold grows first on the nutrients it linds in the butter, 

 /. <?., the carbohydrates and proteids, and when these are exhausted, 

 elaborates the enzyms in large quantity which are capaljle of cleaving- 

 butter fat, and then feeds upon the glycerin liberated. The fungi 

 appeared to be able to assimilate only such of the fatty acids liberated 

 as are of low molecular weight. 



Cream testing, C. H. Pickles {loim Sfa. BuL 62^ pp. Sl-Jf.^). — The 

 author discusses testing cream by the Babcock method, reporting- 

 several investigations in this connection and giving suggestions for 

 avoiding common sources of error. 



The influence of the thickness of sweet and sour creauj upon the 

 amount adhering to the pipette in measuring was tested. Cream was 

 measured with a IT.t^ cc. pipette when sweet and again after i^-t hours. 

 In one measurement in each case the pipette was l)lown out as in test- 

 ing milk, and in one the adhering cream was rinsed out and added to 

 the measured (juantity. The results are given in the following table: 



Comparison of two nietJiods of measuring cream for the Babcock test. 



Pipette , Pipette 



blown rinsed 



out. out. 



Per cent. 



Fresh from separator 19. 6 



Sour, acidity O.7.! por cent ]9. 6 



Fresh from st^parator 29.8 



Sour, acidity II. ill per cent 29.5 



Fresli friiiii separator 41.5 



Sour, acidity 0..>1 per cent 41 



Per crnt. 

 20 

 20. 5 

 80.4 

 30.9 

 42.5 

 43.5 



Gain by 

 rinsing. 



Per cent. 

 0.4 

 .9 

 .6 

 1.4 

 1 

 2.1 



"From thene figures it it? evident no change in amount measured could be made to 

 remove thi.s varying error. This error can be removcil easily ami completely by 

 rinsing out the pipette witli about one-third of its volume of Avarm water and adding 

 this to the measured cream. ' ' 



