234 
since the tubercle bacillus is destroyed under such 
conditions, and this is considered as a sanitary in- 
dex of efficient pasteurization. As the bacteriolog- 
ical standard they require that there should be a 
reduction of 99 per cent. of the bacteria after 
pasteurization as compared to the raw milk, but 
this is not strictly applied if the bacteria are less 
than 100,000 per ce. Koehler and Tonney have 
also shown the percentage of reduction during the 
various stages of pasteurization by the rapid 
method varying between 150° F. and 164° F., and 
by the slow method varying between 143° F. and 
150° F. The bacterial count even in the bottled 
milk at the end of both processes showed a hac- 
terial reduction of about 99.5 per cent., with the 
exception of the bottled milk in the rapid method, 
which only showed a reduction of 98.75 per cent. 
This article, then citing the work of the authors, 
shows an average reduction by pasteurization in 
Baltimore of 99.4 per cent. by the rapid method 
and 99.1 per cent. by the slow method. There 
were fewer counts made of the rapid method (96) 
than by the slow method (146), and the counts of 
the raw milk by the rapid method were much 
higher. 
The writers have also studied the percentage of 
cases in which the colon bacillus was present be- 
fore and after pasteurization in 1 e.c. or in 
1/10 ¢.e., and their results were as follows: 
PERCENTAGE OF CASES IN WHICH COLON BACILLI 
SCIENCE 
[N.S. Vou. XXXV. No. 893 
The conclusions are that the physical and bac- 
terial standards of Koehler and Tonney are rea- 
sonable, and that the question of an additional 
safeguard establishing a maximum amount in 
which colon bacilli can be present in pasteurized 
milk is still open for debate. 
Recent Developments in Pasteurization of Milk 
for a General Market: EDWIN HENRY SCHORER. 
Pasteurization is employed legitimately to de- 
stroy pathogenic organisms of diseases transmitted 
through milk and to preserve milk so that it may 
be transported when properly refrigerated to lo- 
calities where fresh milk is not obtainable. The 
process is used fraudulently to give low bacterial 
count to dirty milk, a redemption process, and to 
make milk keep in a manner similar to that of 
carefully obtained milk. In any event the process 
depends on heating milk to a temperature for a 
sufficient period of time to destroy the offending 
microorganisms. For fraudulent purposes it is 
only essential that a large percentage of bacteria 
be destroyed, while if milk is to be rendered free 
from possibility of causing infection, it is impera- 
tive that all pathogenic organisms be killed. 
. The entire process is based on scientific investi- 
gation, but unfortunately the results obtained in 
the laboratory are not obtained in the pasteuriza- 
tion of milk for the market. Pasteurization of 
WERE PRESENT BEFORE AND AFTER PASTEURIZATION 
Rapid Method 
Slow Method 
Number of | Colon Bacillus Pres- Colon Bacillus Pres- Number of Colon Bacillus Pres- Colon Bacillus Pres- 
Examina- | ent Before Pasteuriza- | ent After Pasteuriza- Examina- ent Before Pasteuriza- | ent After Pasteuriza- 
tions tion in 0.001 c.c. tion in 1 e.c. tions tion in 0.001 c.e. tion in1c.c. 
96 45 | 468% 48 | 50.0% 146 86 | 589% 87 | 50.5 % 
Number of | Colon Bacillus Pres- Colon Bacillus Pres- Number of Colon Bacillus Pres- Colon Bacillus Pres- 
Examina- | ent Before Pasteuriza- | ent After Pasteuriza- Examina- ent Before Pasteuriza- | ent After Pasteuriza- 
tions tion in 0.001 ¢.c. tion in 0.1 c.c. tions tion in 0.001 c.c. tion in 1 c.c. 
33 22 | 66.6 % 7 | 21.2 % 93 68 | 73.1% 42 | 45.1% 
The article then considers the recontamination 
of pasteurized milk, showing by the work of 
Koehler and Tonney that while the average count 
from a large number of freshly pasteurized milks 
was only 125,000, yet the average count from pas- 
teurized milk one day old was 602,000 bacteria 
per eubie centimeter. Some of this milk showed 
counts varying between 1,000,000 and 4,800,000 
per cubie centimeter. These authors think that 
this recontamination can best be obviated by a 
strict enforcement of a maximum standard for 
the temperature of milk of 50° C. 
market milk must either be done in the bulk before 
bottling and capping or else in sealed bottles. 
Bulk pasteurization does not prevent reinfection 
and pasteurization in the bottle is expensive and 
time consuming. 
While the primary object of the pasteurization 
of milk should be to destroy pathogenic bacteria,. 
determination of the accomplishment of this object 
is a relatively difficult and slow process. For this 
reason the reduction in numbers of bacteria in 
milk is taken as evidence of efficiency of pasteur- 
ization. It is generally claimed that pasteuriza- 
