14 SCIENCE BULLETIN, No. 20. 



which produced acid in litmus milk but failed to coagulate it in three weeks, 

 while six streptococci readily produced both acid and clot. Two hundred 

 and eighty of the total bacteria in the water were inert or caused slight 

 alkalinity when inoculated into litmus milk. There were present two colonies 

 of pink yeast or torula, while the nine mould growths were species of dado 

 sporium, Phoma, Penicillium, and Mucor. 



Sample 01 General Service Water. The source- of this water, as in the 

 case of sample A r , was the head waters of a coastal river. The water was dis- 

 tributed from a conveniently positioned reservoir by means of the ordinary 

 system of mains and smaller pipes. The sample for plating was collected 

 into a sterile vessel from a tap on the cream-receiving platform, From 

 the counts, l^c.c. of water contained 2,409 micro-organisms. Of these 

 730 were classified as gelatin liquefiers and casein digesters. They 

 included Boot, mycoides, Bact. pyosyamous, Bad. fluorescens liquefaciens, 

 Bact. proleus vulgaris, and a large celled micrococcus. Of the undesirable 

 lactose fermenters five colonies of Bact. lactis cerogenes were counted. There 

 were 300 bacteria producing acid in litmus milk, while 100 of them were 

 also able to coagulate it ; 1,230 were determined as inert, causing no change, 

 or only slight alkalinity in litmus milk in three weeks. Forty-four colonies 

 of yeasts were -counted, and there were also present 100 mould growths, 

 comprising species of Penicillium Fusarium, Cladosporium, and Papulospora. 



As noted, both waters were from the same source of supply. The difference 

 in bacterial counts might be accounted for by the fact (a) that in still waters 

 as in the case of sample 7T (butter wash water), suspended matter and 

 bacteria having weight naturally gravitate to the bottom ; (6) that a low 

 temperature is injurious to many kinds of bacteria, even polluted waters 

 showing a marked decrease of intestinal organisms if the sample is kept cold. 



PLATE (A) DEMONSTRATING AIR INFECTION ARISING PROM SPRAY OF 

 POLLUTED WATER. 



A. Poured plates of ordinary agar, litmus lactose agar and acid agar 

 were placed on the edge of the cream-receiving vat; the lids were removed 

 for fifteen minutes. After four days incubation, counting of the colonies 

 was commenced. 



The total bacterial colonies appearing 011 the agar plate was 4,800. Pure 

 cultures were made of Proteus mirabilis, Bact. fluorescens liquefaciens, Bact. 

 lactis cerogenes, Oidium lactis, Bact. aurantiacus, and several chromogenic 

 micrococci. The colonies were too thick to enable the numbers of varieties 

 to be counted. 



The acid agar plate showed a total of 161 micro-organisms; fifty-four were 

 mould growths as follows: Cladosporium sp. 29; Fusarium sp. 8 ; Aspergillus 

 sp. 2 ; Penicillium sp. 8 ; Epicoccum sp. 4 ; Alternaria sp. 3. There were 

 also counted 102 colonies of yeast and 5 B. subtilis. 



It will be noted that in this case the cream-receiving vats were adjacent 

 to the condenser tower (about 25 feet distant), the water flowing over which 

 was pumped from a shallow stagnant lagoon adjacent to the factory 



