PRODUCTION OF MILK OF LOW BACTERIAL CONTENT. 9 
TABLE 1.—Bacteria per cubic centimeter in dual samples of fresh milk produced 
under conditions. described in Haperiment No. 1. 
——— 
Sample) Open Small- Sample) Open Small- 
Date. No. pail. top pail. Date. No. pail. top pail. 
1915. 1915. 
dlive22 Deals so-so 1 T4SQ00 RE emese se INU Gp le Won se sooase 18 | 600,000 | 600,000 
Maly 23 as anes ee _- DF 170,000" (2 455000¥l| Aug ed: p. msnss es 19 | 650,000 | 550, 000 
Voly2235 ps Mee oss 3 | 125,000 GOR0008|| PATI eG Sips meee es: AQ AOS O00) aoocacsce 
dhuilly, 24. agile ts. = AN 2800007 150 O00R mA es /eralninl saat see 21 |} 300,000} 250,000 
duiliye265 0p, 12 5-5 - 5 | 600,000} 450,000 || Aug. 9,a.m-_..._.._-:- D2 alae ete ae 400, 000 
ABU PAs Cle 00s eS or Gia RAL esse Z0OFOO0D || Ate FON. dle erro oe 23 | 550,000 | 500,000 
dulys2/75)s Ms. We 2A0F O00) 1 30F000N | Ania tal O Mae make = ts DA lisse msepeeee 500, 000 
ianlye 28 amos e652 8 | 350,000 | 160,000 || Aug. 10, p.m-....-._.- 25 | 350,000 | 450,000 
Siliye2 Sepsis a ee 9 | 390,000 | 175,000 || Aug. 11,a.m..._.....- 26 | 400,000} 300,000 
dualiye29. arias sas6 22 °10} 320,000} 200,000 |} Aug. 11, p.m-...-..-... 27 | 900,000 | 450,000 
Duly 29 spe oS ae aes 11 | 500,000} 340,000 || Aug. 12,a.m...-...... 28 |1,200,000 | 500,000 
uly.30s acres 5 scr 12s 900X000) |e 75050007|| Anes 12ers =e 29 | 800,000} 400,000 
duilyed) -Aa Ma S25: 22. DBR etree = Oster SoORO00 7 PAIS 3 Vases yey als 30 | 600,000 | 450,000 
AgareS) a anes ee Ti | ese eee 750,000+|) Aug: 12; po m2. 2225. 31 | 450,000} 300,000 
aug. SADA Deere 8 15): 5503000) | Sasa 2 ess PAU CAR api eeeta rs ey 32 | 700,000 | 500,000 
WS. 45 A. Me Pe ee UG eee a Sere s 400, 000 - | 
ANTES 08 100 one aee oe I OOO; O0 ye secscnce INOUE Ses deoalleddouaes 497,653 | 368,214 
Perhaps the most interesting point brought out by the results was 
the relatively low bacterial count obtained in all samples. It is rea- 
sonable to suppose that milk produced under such extremely filthy 
conditions would contain millions of bacteria per cubic centimeter. 
The figures indicate very clearly, however, that large numbers of 
bacteria are not commonly found in fresh milk.. Even when ex- 
tremely high counts are obtained, they are probably attributable to 
some other factor, such as growth or subsequent infection during the 
various stages of handling. Throughout the experiments the milk 
was examined before cooling, as it was the intention to avoid the 
variable factor of contamination from unsterilized coolers. 
EXPERIMENT NO. 2 (COWS AND FLOOR DIRTY, MANURE REMOVED WEEKLY, 
j UTENSILS STERILIZED). 
Having determined the number of bacteria in fresh milk produced 
under extreme conditions of filth, where unsterilized utensils were 
used, the next step was to use one factor which was considered of 
utmost importance in preventing contamination, namely, sterilized 
utensils. Samples of milk were taken from September 14 to October 
7, 1915, under conditions as nearly identical as possible with those 
of the previous experiment, with the exception that the cans and 
pails were sterilized. 
By the use of sterilized utensils a remarkable decrease in the bac- 
terial content of the milk was found. From the results of 36 sam- 
ples shown in ‘Table 2 it will be seen that the average count of milk 
from open pails was 22,677 bacteria per cubic centimeter, compared 
with 17,027 from small-top pails. Comparison with the results shown 
in Table 1 is convincing proof of the value of sterilized utensils. It 
should be remembered that the figures represent samples taken under 
filthy conditions and that the only factor contributing to the differ- 
ence in the bacterial count was the use of sterilized utensils: 
The range in the bacterial content of samples taken from the open 
pail during the experiment was from 2,500 to 80,000, and in the sam- 
18989°—18—Bull, 642——2 
