Series  III 
59^ 
Date 
FL.ysK  ‘A,’  without  larvae 
Flask  ‘  B,’  with  larvae 
Date 
Bacteria  per  c.c. 
Bacteria  per  c.c. 
5.Z.IO 
7.2.10 
8.2.10 
9.2.10 
27 
19.1 
1,760 
3,920 
56 
149,000 
168,000 
5.2.10 
7.2.10 
8.2. 10 
9.2.10 
Series  IV 
Date 
Flask  ‘  A,’  water  to  which 
typhoid  bacilli  were  added, 
but  no  larvae 
!l 
;j  Flask  ‘  B,’  same  water  with 
'  larvae  added 
Oatc 
No.  of  B.  typhosus  present 
per  c.c. 
|i  No.  of  R.  typhosus  present 
i  per  c.c. 
Ii- 
5.12.09 
12 
\ 
.  ’3 
5.12.09 
*5' I --09  i'"'  Large  increase  of  B.  typbnsHS  6. 1 2.09 
and  other  bacteria 
7.12.09 
S.12.09 
6 
3 
31 
n 
.10 
7.12.09 
8.12.09 
9.12.09 
— 
7 
9.12.09 
11.12.09 
— 
6 
1  I.I2.O9 
12.12.09 
— 
0 
12.12.09 
il 
Series  V. — 'i'o  ascertain  the  effect  on  drinking  water  of  the  Water  Cyclops. 
Date 
Flask  ‘  A,’  without  Cyclops 
Flask  ‘  B,’  with  Cyclops 
Bacteria  per  c.c. 
Bacteria  per  c.c. 
-{  JJatc 
1 
28.1.10 
25 
1,060 
1,460 
28.1.10 
30.1.10 
109 
29.1. 10 
31. 1. 10 
599 
i  '4,200 
30.1. 10 
1.2. 10 
3,090 
48,600 
69,000 
31.1.10 
1.2.10 
i  173,000 
i 
3.2. 10 
Rcsul/  : 
From  these  experiments,  it  will  be  seen  that  in  clean  drinkinp- 
water  drawn  from  the  tap  and  exposed  to  the  air,  there  is  a  sliglit 
multiplication  of  the  number  of  bacteria  for  a  few  days,  and  that  then 
the  liacteria  rapidly  decrease,  in  all  probability  owing  to  the  want  of 
food  material. 
