6 BULLETTX 361, U. S. DEPAETMEXT OF AGEIGULTUEE. 



Table 6. — Comparison of bacterial count vdth Lorenz sediment test (jnilk filtered through 

 1-ply absorbent cotton and cheesecloth). 



Sample No. 



Bacteria 

 per cubic 

 centimeter. 



Character 

 of sediment. 



Sample Xo. 



Bacteria 



per cubic 



centimeter. 



Character 

 of sediment. 



1 



760, 000 

 67,000 

 31,400 

 42,000 

 61, 300 



Good. 

 Do. 

 Do. 

 Do. 

 Do. 



6 



57,000 

 362, 000 

 471,000 



4S, 000 

 191,000 



Good. 



2 



7 



Do. 



3 . ... 



8 



Do. 



4 



9 



Do. 



5 



10 



Do. 









In every instance in which the milk was filtered through any sub- 

 stances to remove visible dirt the disks were classed as good. 



It would seem from the results shown in the last three tables that 

 if milk is strained before applying the sediment test the latter is of 

 little, if any, value in estimating visible dirt. 



CONCLUSIONS. 



1. The writer considers the Lorenz apparatus the most convenient 

 and practical for demonstrating dirt in milk. 



2. The quantity of sediment or visible dirt present on the disk is no 

 criterion as to the kind or number of bacteria contained in the milk. 



3. The various sediment tests are applicable only in roughly esti- 

 mating the quantity of sediment in unstrained mUk, and can not be 

 used solely as a means of determining the hygenic conditions under 

 which it was produced. 



4. If milk is strained through the substances mentioned, the sedi- 

 ment testers are of little value in estimating the degree of contami- 

 nation. 



REFERENCES TO LITERATURE. 



New and Improved Tests of Dairy Products. S. M. Babcockand E. H. Farrington, 



Wisconsin Station Bulletin No. 195, pp. 3-13. 

 The Milk Sediment Test and Its Application. A. 0. Baer, Wisconsin Agricultural 



Experiment Station, Circular of Information No. 41. 

 Experiment with Fliegel's Apparatus for Determining Dirt in Milk. J. Klein, 



Milchw. Centbl. 1. (1905), No. 7, pp. 305-307. 

 Comparison of Bacteria in Strained and Unstrained Samples of Milk. H. W. Conn 



and W. A. Stocking, Storrs Agricultural Exj^eriment Station Bulletin, 1903-1905. 



