130 BACTERIA IN DAILY LIFE 



hours after milking, a little over 9,000 bacteria in 

 a cubic centimetre. The sample was divided into 

 three portions, which were kept at different tem- 

 peratures, and after definite intervals of time they 

 were examined. The following table shows at a 

 glance the results obtained : 



NUMBER OF BACTERIA IN ABOUT TWENTY DROPS OF MILK. 



Thus, after being kept in the laboratory for 

 three hours the original 9,000 bacteria had in one 

 case doubled, and in another more than trebled 

 themselves. It will be seen that the temperature 

 most favourable to the multiplication of these 

 bacteria was 25 degrees Centigrade. 



If a sample of milk containing originally such 

 a comparatively small number of bacteria for a 

 figure under 10,000 per cubic centimetre sinks into 

 utter insignificance when we read of samples con- 

 taining 2,500,000 if such relatively bacterially 

 pure samples may support such prodigious numbers 



