SPOROGENES TEST. 



13 



Table 4. — The sporogenes test tvith milk produced under clean and under dirty 



conditions. 



CERTIFIED MILK. 



Sample 

 No. 



Sporogenes test in sets of 10 tubes , with 20 c. c. of milk. 



Posi- 

 tive 



tests. 



Bacterial 

 count. 



1 



2 



3 



4 



5 . 



6 



7 



8 



9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18 

 19 

 20 



21 



22 

 23 

 24 



+ 

 + 



+ 



+ 

 + 

 + 

 + 

 + 

 + 



+ 



+ 



+ 

 + 



+ 



+ 

 + 



+ 



+ 



+ 















2 

 2 

 



1 

 

 

 

 



1 



4 

 2 

 1 

 1 

 1 

 

 2 

 

 1 

 

 

 

 

 1 

 2 



3,900 

 4,400 

 4,600 

 6,500 

 8,200 

 8,600 

 8,100 

 9,900 

 10, 300 

 10, 500 

 10, 500 

 11,000 

 12, 200 

 12, 600 

 12, 700 

 16, 700 

 . 18, 000 

 20,700 

 28, 400 

 31, 500 

 31,800 

 36,600 

 40, 700 

 45, 000 



MILK PRODUCED UNDER DIRTY CONDITIONS; COWS DIRTY; UTENSILS NOT 



STERILIZED. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 

 11 

 12 

 13 

 14 

 15 



16 



17 

 18 



+ 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 



+ 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 

 + 



+ 

 + 



+ 

 + 

 + 

 + 

 + 



+ 

 + 

 + 

 + 

 + 

 + 

 + 

 + 



+ 

 + 

 + 



+ 

 + 



+ 



+ 



+ 



+ 

 + 

 + 

 + 

 + 

 + 



+ 

 + 

 + 



+ 

 + 

 + 



+ 



+ 

 + 

 + 

 + 

 + 

 + 



+ 



+ 

 + 



+ 



+ 



+ 



+ 

 + 

 + 

 + 

 + 

 + 



+ 

 + 



+ 

 + 



+ 



+ 

 + 



+ 

 + 



+ 



+ 

 + 



+ 



+ 



+ 



+ 



+ 



+ 



+ 

 + 



+ 



9 

 7 

 6 

 2 

 9 

 5 

 9 

 3 

 4 



10 

 4 

 3 



10 

 7 

 6 

 7 



10 

 6 



33, 000 



46, 000 



101, 000 



106, 000 



107, 000 



112, 000 



118, 000 



129, 000 



245, 000 



320, 000 



750, 000 



1,340,000 



1,810,000 



2,900,000 



11,600,000 



22,500,000 



25,000,000 



61,000,000 



An examination of the results obtained from milk produced under 

 extremely dirty conditions shows that in general the number of posi- 

 tive tubes was considerably higher than in the case of the certified 

 milk. It is true that there were some samples which showed only two 

 or three positive results. Such samples would be difficult to place by 

 this test. The general picture presented by the results, however, is 

 such that a marked difference is shown in the results obtained by the 

 sporogenes test when milk is examined which has been produced under 

 these extreme conditions. It is evident that these results determine 

 the limitations of the test. The number of positive reactions in a set 

 of 10 tubes using 20 c. c. quantities of milk, therefore, must fall either 

 within the range of the results shown in Table 4, which represent the 

 examination of good and bad milk, or somewhere between these fig- 



