261 
The maximum number of organisms found was 151,200,000 per cubic centi- 
meter and the minimum was 50,000 per cubic centimeter. 
While the cleanliness of the manufactory does not, according to this inves- 
tigation, bear any constant relation to the presence of streptococci it does affect 
the cleanliness of the finished product as indicated by the total bacterial con- 
tent, a gradual rise being observed from the “ clean ” shops to the “ filthy ” ones. 
The latter were sometimes almost beyond description. For instance, sample 42 
was made in a shed adjoining both a dwelling and a stable for 8 or 10 horses. 
The workmen went from horses and stable cleaning to the ice cream shed with- 
out restraint, handling the utensils in the latter as necessity demanded, re- 
gardless of soiled clothes or hands. Ice cream cans and milk cans stood in a 
passageway common to both shop and ice cream manufactory, a part of which 
was bordered on each side by stalls for horses. The stench of this place finally 
caused complaint from the neighborhood and it was dealt with on the ground of 
a nuisance. On the other hand a large ice cream manufacturer had endeavored 
to preserve the strictest cleanliness possible. Employees engaged in ice cream 
making did no other work and each man had only certain duties or portions of 
the process assigned to him. He changed his clothing and took a bath when be- 
ginning the day’s work and clean lockers and plentiful showers were provided 
to enable the fulfillment of this regulation. The utensils were cleaned with 
soda and finally placed on a steam table for sterilization. Such precautions 
resulted in the counts given in samples 27 and 48 and 49, namely, 6,535,000, 
33,120,000, and 20,550,000. 
Through the courtesy and interest of the head of this ice cream firm a bacte- 
riological study of each step in the process was made possible. The cream in 
the supply tank was first sampled, a portion was then drawn off by the employee, 
mixed with the necessary sugar (cane) for sweetening, and a sample of this 
taken for examination. After adding the vanilla and transferring to the freez- 
ing cans it was again sampled, and then the frozen product was also examined. 
In the freezing the bulk a little more than doubled. Although frozen the ice 
cream was soft enough to measure in a wide-mouthed 10 cubic centimeter pi- 
pette, and it was plated, after appropriate dilution, at once. The results of the 
frozen cream, to be comparable with those of the preceding samples, should, 
therefore, be about doubled. The plates were of agar and were grown at 20° C. 
Organisms in ice cream at each step in the process of making. 
Articles. 
On agar at 
20° C., or- 
ganisms 
per cubic 
centimeter. 
Streptococci. 
Cream from tank 
Cream and sugar 
Cream, sugar and vanilla in freezer 
Frozen cream 
2.840.000 
7, 000, 000 
5. 750. 000 
a 2, 250, 000 
Present, about 25 per cent of all or- 
ganisms and in an active condition. 
a Multiplied by 2 equals 4,500,000. 
It is of interest to note in the examination of the above sample 
of ice cream that a careful pasteurization had been performed by 
the ice-cream maker immediately upon the receipt of the cream. 
The presence of streptococci in the ice cream on sale in the city of 
Philadelphia has been made the subject of special study in the article 
