428 
With a bacteriologic count as a guide it is comparatively easy to 
determine the cause of the trouble and to institute proper means to 
correct it. The enumeration of bacteria in milk is, therefore, one of the 
readiest and cheapest methods at the disposal of health officers to 
determine the general sanitary quality of the market milk supply. The 
laboratory results serve not only as a guide to direct the efforts of 
the health officer, but confirm the conclusions arrived at from an 
inspection of the dairies and dairy farms. 
While the bacteriological examination of milk has its uses, it also 
has distinct limitations. From a practical standpoint the long time 
required to obtain results is its greatest drawback. The qualitative 
determinations of the bacterial species in milk is too complex and 
difficult a method to adopt as a routine procedure. It is otherwise 
with quantitative counts. These determinations are comparatively 
easy and are of invaluable assistance to the progressive dairyman in 
controlling his methods and in discovering just ‘which cow, what 
person, or what part of the industry is at fault when things go wrong. 
It is comparatively easy to make bacterial counts of milk, and for 
practical purposes the method may soon be learned even by one not 
skilled in bacteriologic technique. Dairymen will find it to their 
advantage to make agar plates and roughly estimate the number of 
bacteria, not only of their finished product, but from individual cows 
and during various stages in the handling of the milk. 
In fact, a number of progressive dairymen are already using bacteri- 
ologic counts of their milk in order to improve the supply. In 
Boston, Jordan tells us that in 1906, six milk firms made over 27,000 
such examinations. 
In Rochester, Goler a has obtained a reduction in the average bac- 
terial count of the milk supply of that city from 837,000 per cubic 
centimeter in 1900 to 200,000 in 1903. In 1900, 26 per cent of the 
samples examined contained over 5,000,000 bacteria per cubic centi- 
meter; in 1903 only 4 per cent contained over 5,000,000. At the time 
the city milk supply contained an average of 235,000 bacteria per 
cubic centimeter, the milk that was procured under a process of cer- 
tification and education contained but 14,000 bacteria per cubic 
centimeter for the same period. 
In Washington the bacteriological examinations made in the 
Hygienic Laboratory and submitted to the dairies by the local health 
officer have stimulated the dairymen to use more ice, with the result 
that during the summer of 1907 the average temperature of 316 
samples of milk examined was 2.3° C. lower than during the correspond- 
a Goler, G. W.: The influence of the municipal milk supply upon the deaths of 
young children. N. Y. State Journ. Med., vol. 3, 1903, p. 493. 
