go 
SURFACE.—22-9-II. RAIN. 
a TE 














| | | | 
Glucose.} Lactose. id | 2 |x slant 2] Name 
8 |S |S iS le lors] or 
I 20 { 3 |Nal-1tNill IsiSidial ./Ylo Number. 
2 IO} 2|Nialq 2 | Nal| 2 1 |e pms [> | fe 
3 5 | 3 | Natt 3 | Nat | 
2 I 3 | Nil 3 | Nil I l+|—| +] +|—|-—|Lactis xrogenes. 
3 i ad ge os Na) 2) Fe | 
3 "05 3 | Nil 3 |Niu| 3 |+!—-|+}—|+]|-|-| Lactis zrogenes. 
3 03 | 3 | Nal} 3 | Na} 4 |+|-|+\-]+]/-|- Do. 
3 OE) 5) BEE SN els te fl Do. 
3 O95, | 113) |'NaP 3 | Wal | 8 ae Do. 
3 003 | 3|Nal 3 | Nil 7 |\+;—|+)-|—|-|—| Gasiformans. 
3 ‘OO! 2°) Os ee hcl bee feet boo [oma foal a 
SAO “003 9 | +l—) +)/—|- ae Gasiformans. 
Pollution complete. RO Ne fied rt oe ee 
immediately after pollution by the rain. It will be observed 
that this pollution did not add any coli communis or 
susceptible organisms. Consequently, it is impossible to 
discuss the rapidity of disappearance of this particular 
organism. Unfortunately, also on account of the short time 
available, the final analysis did not demonstrate any great 
prevalence of either bacillus cloace, vesiculosus or the 
Grunthal group. But the point that is strikingly demon- 
strated by this series is that during 10 days after pollution 
there is a most extracrdinary prevalence of bacillus lactis 
eerogenes. This point will not be discussed at great length 
here, but it bears out the result given in the previous portion 
of this chapter, namely, that after pollution lactis z#rogenes 
usually becomes prevalent fora certain length of time. A few 
typical analyses from these results are given in Table VIII (c) 
these demonstrate this point ; it should be remembered that 
this organism was not present prior to the shower of rain. 
TABLE VIII (c) 
SURFACE.—26-9-ITI. 











: | . = 
Glucose. | Lactose. 43 r| d| | .| | Name 
[SiHlsis | ey or 
I 20( 1 |Niu{Nil| 1 | Q}2| O}5|8 a % Number. 
z licens | S|5\ sl Ele! Sls 
3 5 3 | Nui Nia) 3 | i ae ac at oe 
3 I | Nil fe kt ee Be 2 | | 
3 L | Nadi 3 i Nad) 3 | 2 | 
3 OR tas || Sak Nel. BM 4 | 
. OS INGE) “SNe <3 3 re! / 
3 ‘or | Nil| 34Nil| 3 | G could not be isolated. 
3 005 | Nil; 3 4Niw| 3 | 7 | 
3 003 | Nil| 34 Nil} 3 8 | 
3 “OOI | Nil| 3 4Nil' 3 9 | 
5 60 10 | } 
Note.—Great purity of water 5 days after pollution. 
