BACTERIA IN MILK OF LONDON 



123 



time of the bacterial examination. A chemical examination 

 (including detection of antiseptics) should always be adopted in 

 examining town milks. To prove the point in this particular case, 

 we therefore purchased twelve samples on twelve different occa- 

 sions during the next few days, to discover if this v-endor used 

 preservatives. The results obtained by Mr Kear Colwell, F.I.C., 

 showed that in eight samples out of \.\\e\\Q formalin was present, 

 approximately to the amount of i in 10,000 parts. In only three 

 cases was the milk normal and genuine. The returns are interest- 

 ing as showing the result of sampling a poor shop, consecutively, 

 and we append them as a note.^ 



Many similar investigations with very similar results might be 

 quoted, but the above will suffice to convey an impression of the 

 bacterial content of many milks. It is, of course, needless to add 

 that quantitative records, whether represented by high or low 

 figures, are in no sense an exact index as to the injurious nature 

 or othenvise of the milk in question, or as to its value for human 

 consumption. A knowledge of the exact quality of the milk — 

 of the kind of organisms and their role — is necessary before any 

 valid conclusions can be drawn. These matters we treat of 

 elsewhere. But it is desirable here to discuss the conditions 

 influencing both the quantity and quality of milk bacteria. Before 

 doing so, however, we may briefly summarise the answer to the 

 question concerning the practical standard of the number of 

 bacteria in milk. Bitter has suggested 50,000 organisms per c.c. 

 as a suitable standard. The Philadelphia and New York Milk 

 Commissions lay down 30,000 organisms as the standard for 



