776 EXPERIMENT STATION RECORD. [Vol.40 



tween 1 and 50 per cent, 7 between 51 and KM) per cent. 6 between 101 and i. r v> 

 percent, 3 between 151 and 200 per cent, while 'J increased I s " and Ti',7 per cent, 

 respectively. The average change was an Increase of G8 per cent. 



In 9 samples containing originally from 100,000 t<» 500,000 bacteria there was 

 a decrease dp to 55 per cent in 7 cases and '_' Increases, 1 of 27 per cent and one 

 of 44 per cent. The average change was a decrease of 7 per cent. In :<•_' samples 

 with a count of over 500,000 bacteria there was a decrease ap to :<i per cent in 

 17 cases and an Increase up to •"ii per cent In 15 cases, The average change was 

 a decrease of 1 per cent. 



In (;.". comparisons of the tissue-cell contenl of clarified and unclaimed milk, 

 clarification caused a decrease of from ii to 7s per cent, the average being 41. 

 The average cell content of the nnclarifled milk was 808,778 and thai of the 

 clarified 177,635 per cubic centimeter. No relationship was noticed between the 

 percentage of cells thrown out and the original cell content, the percentage of 

 fat, or the temperature of the milk. 



fourteen samples of clarifier slime were studied as to the numbers of bacteria 

 and cells contained. The bacterial content varied from 7,800,000 to 5,210,000,000 

 per gram and the cell content from 57,000,000 to 058,000,000 per gram. Slime 

 with a high bacterial content generally came from milk with a high bacterial 

 content. 



Clarified pasteurized milk gave a higher bacterial content than anclarlfied 

 pasteurized milk in II of 20 comparisons. In four it gave a lower bacterial 

 content, while in two cases there was no difference. 



Clarified and nnclarifled milk showed the same acidity after holding in three 

 of 26 comparisons. In 13 the clarified milk showed the higher acidity, while in 

 10 the clarified milk showed the lower addltj . 



Clarification slightly reduced the creaming ability, as determined In tubes held 

 in ice water, of both raw and pasteurized milk. The Influence was loo small 

 to be of practical Importance in milk allowed to cream in bottles. 



Differences in the results of Clarification by the Sharpies and by the I' Lava] 

 methods are attributed to differences in milk samples used. 



Clarification is held to be a legitimate practice " While clarification can not 

 be expected to improve the keeping quality of milk or to make it safe as far as 

 possible pathogens are concerned, it can give ii a much more pieasinu' appearance 

 and thus result in an increased consumption. The elimination of body cells also 

 is desirable from an esthetic viewpoint, although within certain limits the) are 

 normal constituents of milk, and it would be extremely difficult to prove them 

 harmful." 



Studies on the uniformity of heating- in the final package method of pas- 

 teurization, B, \Y. IIammhi and A. J. II.u siu (Jour. Dairy 8ci., i (1918), \ 

 6, pp. 462-474). — This paper reports experiments at the Iowa Experiment Sta- 

 tion Involving a comparison between a type of anal package pasteurizer in which 

 the bottles are Immersed in a \at of water and a type in which they are not 

 Immersed. In (he latter verj ureal variations in bacterial count and depth of 

 cream line of different bottles of the same run were found, in the Immersion 

 type only slight variations were found, too small to be of practical significance. 



All the experiments showed fairly close agreement betwe the effect of heat 

 on the bacterial count of a bottle and on its cream line. It is BUggested that by 



determining the a unl of cream thrown up by a number of bottles pasteurised 



In a given run a good index of the degree of uniformity in heating could be 

 secured. 



Data on bacteria and cream line are published for 63 bottles from 7 runs with 

 tin- nonimniersion type and 111 bottles from 29 runs with the luuuerslOl 

 apparatus. 



