Kirchner — Bacteriological Examination of River Water. 281 
TABLE VI. 
SUMMARY OF RESULTS OF COMPARATIVE TESTS. 
; Average per cent. increase or decrease of 
Medium Lots Compared. | ~"New Medium over Older. 
Old and 
‘ 
1 
ae 
se 3 
6é 4 
8 +1 % 
és 6 
e 7 
sé 8 
of 9 
“el : —T % 
« 12 —5% 
13 3 —17% 
De OON MD OF Oo De 
— 
no 
S 
— 
o 
o 
2 
3 
AVERAGE PERCENTAGES 
_ 
S 
5 Gir Fe ee Oia es ae 
MEDIA LOT NUMBERS. 
Fig. 2. 
