THE EXCRETORY AND TUBERCULAR 
CONTAMINATION OF MILK 
By RUBERT BOYCE 
As the result of analysis which have been made in the Laboratory during the 
last eighteen months, namely of 1,020 samples of milk, and 733 samples of water, 
it will be seen at a glance, that, as compared with water, milk is a highly contaminated 
substance. 
The average number of bacteria in the water in Liverpool is 28 in 733 
samples. The B. coli was found only seven times, and a gas forming anaerobe* in 
none of the samples. This water from its source to its supply to the consumer is 
under the strictest possible control. Inspectors are on the watershed, and are 
stationed along the pipe line ; the filtration beds and reservoirs are under strict 
supervision and bacteriological investigations are made daily. The result is a pure 
supply, and no fear of infection by means of it. 
The contrast between milk and water is very remarkable, and unmistakably 
shows that the milk supply of the country constitutes a very strong element ot 
danger. For example, leaving out the total number of bacteria per c.c. which is so 
great that it is not to be compared with water, it will be seen in the Tables appended 
that B. coli is present 205 times in 1,026 samples or 19*09 per cent., and that a gas 
forming anaerobe is present 113 times. This means that owing to the crude 
methods of collecting and dealing with milk that excretory contamination is liable to 
occur to the extent ot 19*09 per cent. If water contained such an average percentage 
its use would be immediately forbidden. How this extraordinary degree of 
contamination can take place is only too well known to those who have entered into 
the question of milk production. The significance of the contamination is obvious. 
If B. coli is present, so may pathogenic organisms, such as the B. typhosus. The 
B. coli not only indicates dirt and intestinal contamination, but it also may become 
harmful in itself and give rise to intestinal inflammations. It shows that it such 
neglect of the rules of cleanliness can take place in the shippon, in all probability the 
health of the animal giving the milk is equally neglected. And what do we find ? 
Of the 1,026 samples 27 are tubercular, giving a percentage of 2 - 6 per cent. 
In the majority of these cases the udder was obviously diseased, and yet the 
milk of the animal was consumed. If neglect such as this can occur in the case of 
tuberculosis of the udder, it is quite certain that there are animals suffering from 
* Obtained by heating the milk at 8o"C for fifteen minutes, anil incubating anaerobically. As in all cases an inoculation into 
the guinea pig has not been made we cannot say that the organism is the B. enteritidis sporogene.3. 
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