4 BULLETIN 369, U. S. DEPARTMENT OF AGRICULTURE. 
were found to contain no B. coli in 10 ee quantities and very low 
total counts at both temperatures of incubation. The total counts 
very seldom were above 50 per cc, and often were less than 10 per cc. 
In certain instances legal actions have been brought against com- 
panies preparing and selling bottled waters when the waters examined 
have contained an excessive number of organisms, including B. coli. 
These companies having been thus impressed with the necessity of pro- 
ducing a clean co mm ercial product have responded by placing on the 
market later consignments from which no B. coli were isolated in 10 cc 
quantities from 12 or more bottles. Repeated examinations of water 
from many springs have failed to show any B. coli in 10 cc quantities. 
EXAMINATION OF COMMERCIAL BOTTLED WATERS. 
The methods employed in making these bacterial examinations 
were those prescribed from year to year by the committee on water 
analysis of the American Public Health Association. The high- 
temperature counts have always been made on plain agar after 
incnbation at 37 c C. : but the earlier low-temperature incubations 
were made on agar at 25 c C. instead of on gelatin at 20 3 C. as 
during the last two years. Dextrose broth, lactose bile, and lactose 
broth have been used at different times for the preliminary tests for 
B. coli: but in nearly every instance, when reported present, B. coli 
have been isolated. Many of these have been verified by testing 
special dextrose cultures with methyl red. as recommended by Clark 
and Lubs. 1 A summary of all these examinations follows: 
Of 110 domestic springs (see Table IV> — 
47 43 per cent contained no B. coli in 10 cc quantities. 
63 (57 per cent'; contained. B. coli in 10 cc quantities. 
61 (55 per cent contained B. coli in 5 cc quantities. 
59 53 per cent contained B. coli in 1 cc quantities. 2 
49 44 per cent) contained B. coli in 0.1 cc quantities. 
31 2S per cent ; contained B. coli in 0.01 cc quantities. 
10 (9 per cent) contained B. coli in 0.001 cc quantities. 3 
Sixty-nine (62 per cent) gave counts of less than 100 per cc on om 
or more bottles after incubation at 37 c C. for two days. 
Eighteen (16 per cent) gave average counts of less than 100 per cc 
on six or more bottles at 37 = C. 
Fourteen (12 per cent) gave no counts of less than 1 ; 000 per cc o 
six or more individual bottles. 
The highest average count on all samples from any one spr: 
was 191,238. 
1 Clark and Lubs, The differentiation of bacteria of the Colon-aerogenes family by the use of indicator 
Jour. Infect. Dis., v. 17, Xo. 1. 1915, p. 160. 
- Any potable water supply containing B. coli in 1 cc quantities is considered suspicious by healt 
departments and is at once investigated. 
3 Water containing B. coli in 0.001 cc quantities is too suggestive of dilute sewage to be accepted by 
