30 BULLETIN 642, U. 8. DEPARTMENT OF AGRICULTURE. 
TapLte 11.—Total number of bacteria found in clean-washed but unsterilized 
utensils, 
Series No. Washed can. | Washed pail. |- Series No. Washed can. | Washed pail. 
1S See soo | 728, 000, 000 76, 400 | SE NSE ere aes 292, 090, 000 4, 200, 000 
2) tea eS ae 816, 000, 000 27000 7| ei Orataerces = ase i, 220, 000, 000 652, 000 
Sete see 860, 000, 000 ZrAQOA LO. 2 eae e eRe 1, 180, 000, 000 2, 200, 600 
7 i eee 5, 526, 000, 000 17, 600 | de ok sans eee 1, 640, 000, 000 10, 400, 000 
bu Rees eats 624, 000, 000 S008 || Sls pera ese | 116,800, 000, 000 1 700, 000, 000 
6) wae nea 870, 000, 000 12, 600, 000 | IES e eee 2-52) ela, 600}. 0008000 44, 000, 000 
1: ey ae 1, 580, 000, 000 1, 380, 000 | 
1 Held 8 hours before washing. 
During the work it was thought that one rinsing of a can with 
sterile water probably did not remove all the bacteria from the in- 
terior. To determine the point several tests were made, the results 
of which are shown in Table 12. In the first test the can was rinsed 
twice, with 400 cubic centimeters of sterile water each time. The 
first rinsing showed 860,000,000 bacteria and the second 478,800,000, 
or a total of 1,338,800,000 bacteria in the can. In a second test, in 
which the can was rinsed three times, each rinsing showed large 
numbers of bacteria, the count being lower after each rinsing. In a 
third test, in which four rinsings were made, the last one still re- 
moved a large number of bacteria. It follows from these results 
that one rinsing removes only a portion of the bacteria from the can, 
and therefore is not a true measure of the number of bacteria present. 
The highest total count per 5-gallon can in that test was 8,876,000,000 
bacteria. A simple calculation proves that if this can were filled 
with milk, 469,132 bacteria would be added to each cubic centimeter | 
through contamination from the can. This merely shows the possi- 
bility of great contamination from unsterilized utensils. 
TABLE 12.—Hffect of several rinsings in determining the number of bacteria 
i CANS, 
Number of bac- 
Number of rinsing. teria per 
; washed can. 
t Ls Sa ae oe ya Sn a, Sema N ee ates 860, 000, 000 
Dis SBS oe Ly ER RON ERE! SEER G ES” cee Ee 478, 800, 000 
UWe fe meet A eak Ae Aine 218 Sele | 1,338, 800, 000 
Wi SSIES CAS Ee, Peee | 5,520, 000, 000 
Die SRE I Snel Sry 38S CE eR ATS SA EE ms | 2,640, 000, 000 
AS Maes ae ar ie a aes a a 716, 000, 000 
Total Seo! cee ee eae | 8, 876, 000, 000 
Ne ne Fe ee AS es Cee ee 624, 000, 000 
De Le RAE Rap eae eke te Pee a OF arr ie 316, 000, 000 
Capen Mh Ee aoe me 5: | 109, 000, 000 
Bee esi Be Oe Cee 72, 000, COO 
Totaleoatee a ee eee ener | 1, 121, 000, 000 
\ 
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