434 MILK AND MILK PRODUCTS 
that there were not enough pus cells in the milk which he examined to 
cause suspicion. The following sums up his opinion: 
The presence, in reasonable number of the bacteria commonly found in fresh 
milk—Bacillus coli, streptococci, a few staphylococci, and B. enteritidis sporo- 
genes—is comparatively unobjectionable. A large proportion of the bacteria of 
milk seem to be destroyed in the process of condensation. It was found that con- 
densed milk was almost a differential medium for staphylococci. From his work 
it would seem that if a few Staphylococcus pyogenes aureus were present in the 
milk after condensation many more might be found when the can was opened. 
Efficient pasteurization before condensation should greatly reduce the pos- 
sibility of the staphylococci getting into the final product. 
Park et al. (1915) found that evaporated milk contained fewer 
bacteria than condensed milk. This may have been due vo the higher 
temperature at which it is prepared. Kossowicz (1908) found that 
condensed milk was not bacteria free. He found Bacillus fluorescens 
liquefaciens, Bacillus prodigiosus and Bacillus sinapwagus to be present. 
Savage (1914) reports several investigations in England, the data from 
which do not differ materially from those secured in this country. The 
very interesting experiment of Delepine with regard to the effect of the 
condensation processes on Bacterium tuberculosis is mentioned. The 
tubercle bacillus, even though heavily seeded into milks, was killed 
and could not be demonstrated in the final condensed milk. 
Delepine (1915) has studied the effect of preserving and drying milk 
on the virulence of the tubercle bacillus. In the manufacture of sweet- 
ened milk, the mixed raw milk had a bacterial content of 38,000,000 
which was reduced by the treatment to less than fifty in one case. The 
finished sweetened product failed to produce lesions when inoculated 
into and fed to rabbits and guinea pigs. 
Ick CREAM 
The term is a general one and covers many types of similar sub- 
stances. Those interested in the history of this food should look up 
the paper by Washburn (1910). 
The bacteriology of ice cream has, of late, received much attention 
since it became necessary to establish some bacterial standards. Wiley 
(1912) and his co-workers studied the ice cream manufactured in the 
District of Columbia and found rather large numbers of bacteria. 
Many of them contained streptococci. Esten and Mason (1915) 
studied the effect of storage on the number and kinds of bacteria. The 
