84 REportT OF DEPARTMENT OF BACTERIOLOGY OF THE 
rubber parts were kept in brine and the filter cups were care- 
fully filled with cotton before each milking. The results are 
given in Table VII. 
TABLE VII.—GERM CONTENT OF THE B—L—K MACHINE USING AN EFFICIENT 
SucTION FILTER, AND KEEPING THE RUBBER PARTS IN BRINE. 

Vacuum broken threugh 
Vacuum broken through ( 
stanchion hose. 
teat cups. 
Machine Machine 
1908. No. 2716. No. 2437. 
Machine Machine 
. 1908. No. 2716. No. 2437. 



Filter | Other | Filter | Other 
side. | side. | side. | side. 
Filter | Other | Filter | Other 
side. | side. | side. | side. 








Germs per cc. in milk. Germs per cc. in milk. 
Tate ocean 3,410) 6,740): 2,070)75,630)\\Jan. 30..2..) 3, 660 520] 1,080) 2,050 
Heb; wie sella 00 610) 1,350 750 4 SLs ite 5; 080| Share 2,970; 1,070 
. 6....;21,400} 1,650} 1,340 S9Ql|\Feb.. - 3.2...2. 1-4, 100) "1 5610) eee 
x LS Bitad ele hee ee el] Gores ee 2,820] 2,050 be 5 1,980 850} 1,620) 7,390 
. HS YP en RPS eel dacs Ato eee 2,780 520 ‘. 7 4,840} 6,560 810 890 
: geet ee Ma al Bt eh 1,060) 1,660 4 4a Ae ale eae 2,790} 1,520 
: 1S) tere ey ke aie Kol et ume cian 1,680 440 - LS. ai othe Rese oe eee 990} 1,290 
Average....| 9,600} 3,000} 1,870} 1,710 3,930) 2,380) 1, 710) n22 200 







* Plates lost by contamination. 
These results indicate that the larger suction filter is capable 
of removing the germs from the air which rushes in at the 
time the stanchion hose is removed from the stanchion cock, 
since the germ contents of the two sides of the pail when the 
air is admitted in this way are practically equal. 
The average germ content in this experiment is actually 
lower when the air is admitted in this manner than when the 
vacuum is broken through the teat cups but since this differ- 
ence is mainly due to the high numbers obtained at a single 
milking (February 6) little stress should be laid upon this 
fact. 
While the difference in time and accompanying possibility 
of change in the barn conditions precludes a close comparison, 
it is significant that while the average germ content obtained 
with the original small filters was from 7,000 to 10,000 per ce. 
