xii MILK AND THE PUBLIC HEALTH 



FACE 



Estima,tion of the number of B. coK and allied organisms : pro- 

 cedure, composition of media to use, dilutions to examine, pro- 

 cedure to isolate, comparison of methods, identification tests to use, 

 comparative value of the different identification tests — Determina- 

 tion of the number of streptococci : procedure, isolation, differentia- 

 tion tests, preparation of media — Estimation of the number of B. 

 enteritidis sporocjenes spores ; methods, dilutions to use, patho- 

 genicity tests. 



CHAPTER XI 



The Cellular and Sediment Examination of Milk . . 191 



Methods for estimating the cellular contents — Comparative value of 

 the different methods — Examination of the stained centrifugalised 

 deposit — Comparative count of the different cellular elements — 

 Methods for estimating the sediment in milk — Value of the 

 oytological estiniation — Value of the sediment estimation. 



CHAPTER Xn 



Chemical Tests to estimate the Purity and Freshness of 

 Milk. The Examination of Cream and Special 

 Forms op Milk . • . 202 



Acidity determinations : variations, value, method of estimation — 

 The determination of the formalin-methylene blue reduction time — 

 The detection of heated milk — The detection of preservatives. 



Condensed milk : method of examination, bacterial content — 

 — Dried milk — Examination of cream. 



CHAPTER Xni 



The Detection of Pathogenic Bacteria in Milk . 214, 



B. tuberculosis : microscopic method of detection, inoculation 

 methods, reliability of the methods — Differentiation of tubercle 

 bacilli of human and bovine origin — Detection of tubercle bacilli in 

 butter — Detection and isolation of diphtheria bacilli — Isolation 

 of the typhoid bacillus — Isolation of other pathogenic bacilli. 



CHAPTER XIV 



Interpretation of Results and Bacteriological Standards 

 for Milk ..... 



The three groups of contamination— Comparative value of the total 

 bacteria estimation as a measure of general contamination — Value 

 of the B. coli estimation . for byre milk, for vended milk, coli 



228 



